PSL300 EXAM

Seminiferous tubules

Sperm is produced within the ________________ of the testes - these are masses of coiled tubes clustered into 250-300 compartments within the testes

Ampullary

Sperm meets an ovulated oocyte in the ___________ of the fallopian tube

False (Optimal at 2-3˚C below body temperature)

Sperm production is optimal at 2-3˚C below room temperature (True/False)

46

Spermatogonia have ____ chromosomes per cell

a single, many

Schwann cells can wrap around _______(a single/two/many) axon(s) and oligodendrocytes can wrap around _______(a single/two/many) axon(s) to form a myelin sheath

Extended

Cardiac muscles sustain contractions for a(n) ____________(shorter/extended) period of time in comparison to skeletal muscles

False (Convergence is the greatest in the peripheral retina and least in the fovea where some photoreceptors project 1:1 to bipolar cells [i.e. no convergence])

Convergence is greatest in the fovea where the receptors most efficiently transmit information into the ganglion cells (True/False)

True (Enhances sensitivity and discards spatial information)

Convergence of olfactory receptor cells on each olfactory bulb neuron enhances sensitivity (True/False)

lower, higher

Epinephrine has a higher affinity for Beta receptors at _______ (lower/higher) concentrations and a higher affinity for alpha 1 receptors at ________ (lower/higher) concentrations

Cerebellum

Equilibrium pathways mainly project to this segment of the brain upon stimulation

True (Estrogen and progesterone are needed for the development of mammary glands but inhibit milk production)

Estrogen and progesterone inhibit milk secretion (True/False)

Follicular Phase

Estrogen is dominant during which phase(s) of the ovarian cycle?

True

Flexion withdrawal reflexes involve a multi-synaptic pathway to neurons (True/False)

False

Hair cells can be regenerated in mammals (True/False)

Cholesterol

Steroid hormones are all derivatives of this molecule

False (Steroid hormones are lipophilic and are synthesized as needed since they easily diffuse through membranes)

Steroid hormones are stored in vesicles within a cell (True/False)

Long (Not soluble in plasma and bind to carrier proteins for transportation [Binding protects hormone from enzymatic degradation])

Steroid hormones have a _______ (short/long) half life

Lipophilic

Steroids are ___________ (lipophilic/lipophobic)

True (Cornea is responsible for 2/3 of the eye's refraction and the lens for just 1/3)

The cornea is responsible for more of the refraction of light through the eye then the lens is (True/False)

False (The corpus luteum is sustained for roughly seven weeks - by then the placenta has taken over progesterone production, and the corpus luteum is no longer needed, by which point it is degraded)

The corpus luteum is retained for the duration of pregnancy in order to prevent menses and the degeneration of the endometrial lining in the uterus (True/False)

True (Progesterone is the major hormone of the luteal phase, but estrogen levels also increase slightly)

The corpus luteum under influence of LH and FSH releases progesterone, inhibin and estrogen (True/False)

False (ATP hydrolysis)

The crossbridge cycle of muscle contraction relies on GTP hydrolysis (True/False)

False (Typically 0.4λ away)

The distances of the synapses on a dendritic tree to the trigger zone is typically one length constant (λ) away (True/False)

Spatial location -- where an object is

The dorsal visual stream projects to the dorsal premotor cortex -- what is it responsible for?

False (The fovea contains almost exclusively cones and almost no rods)

The fovea contains the highest concentration of both rods and cones (True/False)

True

The muscle fibres of a motor neuron all contract together (True/False)

True

The muscle fibres of a motor unit are all of the same type (True/False)

False (Myosin heads are attached to a hinge region that allows limited free movement)

The myosin heads are locked in place and cannot move at all (True/False)

Acclimatization

The natural adaptation of physiological processes to a given set of environmental conditions

Leydig cells

These cells are found in the interstitial tissue outside seminiferous tubules and function to secrete testosterone - They first become active in the fetus, when testosterone is needed to direct development of male characteristics, but after birth, the cells inactivate; at puberty they resume testosterone production

Blue-yellow opponent channel

These are ganglion cells that are excited by blue light and inhibited by red and green lights (yellow light) OR excited by red and green lights (yellow light) and inhibited by blue light

Red-green opponent channel

These are ganglion cells that are excited by green light and inhibited by red light OR excited by red light and inhibited by green light

R+G cells (Yellow channel)

These are ganglion cells that are excited by red light and by green light

Natriuretic peptides (ANP, BNP, CNP)

These are hormones released in response to a stretch of the heart (Atria and ventricles) - in response they dilate blood vessels and decrease blood volume by increasing the renal excretion of fluids

Inhibin

These are hormones which inhibit FSH secretion

Transient receptor potentials Channels (TRP channels)

These are ion channels commonly found in nociceptors and thermoreceptors that can give a response to damaging heat and to chemicals

Optic Nerves

These are known as Cranial Nerves II and recieve information from the million ganglion cells in each retina

Agonist

These are ligands that bind to a receptor and activate it's function

Antagonist

These are ligands that bind to a receptor to block it's function

Photoreceptors

These are light-sensitive neurons in the retina which display phototransduction

Tropomyosin (Associated with troponins)

These are long structures found on thin myofilaments which bind onto roughly 7 actin monomers -- associated with the calcium binding proteins of thin myofilaments

Cranial nerve

These are nerves that directly enter or leave the brain other than the spinal cord

Neuromodulator

These are neurocrines that acts slowly as a paracrine/autocrine signal

Neurohormone

These are neurocrines that are released into the bloodstream for distribution

Neurotransmitter

These are neurocrines that diffuse out of the neuron through a narrow extracellular space and contribute to a rapid effect

Retrograde transmitter

These are neurotransmitters that travel to the presynaptic terminal during long-term potentiation to increase vesicle release probability (Eg. Nitric Oxide)

Pacinian corpuscles

These are onion-shaped receptor cells located deep within the dermis

Utricle and Saccule

These are parts of the vestibular apparatus and contain hair cells that are activated when the head tilts relative to gravity

Pore loop

These are segments of protein channels which have specific physical properties to allow selectivity when transporting molecules

Propriospinal tracts (Reminder: tract refers to white matter)

These are spinal tracts which remain in the spinal cord

Astrocyte

These are star-shaped glial cells in the nervous system that connects blood vessels to neurons and plaster the walls of capillaries with their feet

Osmoreceptors

These are stretch sensitive neurons that increase their firing rate as osmolarity increases -- Vasopressin release is controlled by receptors of this kind found on the hypothalamus

Hypothalamus, pons, medulla

These are the autonomic control centres for maintaining homeostasis within the body (3)

Spermatid

These are the cells which spermatogonia differentiate into before gaining a tail (4 produced from one spermatogonia) and they remain on the apical side of the seminiferous tubule until they've completely matured

Bouton

These are the ends of axons and contain neurotransmitter vesicles

Fimbriae

These are the flared open ended sections of the fallopian tubes held close to the adjacent ovaries by connective tissues -- helps ensure that eggs released from the surface of the ovary will be swept into the tube rather than float into the abdominal cavity

Sulci

These are the folds of a brain

Nodes of Ranvier

These are the gaps found between myelin-forming cells

Spermatogonium

These are the immature sperm cells that are mostly formed prenatally - found near the basal lamina of seminiferous tubules

Connexin

These are the membrane spanning proteins that make up the individual segments of the gap junction

Myosin heads

These are the parts of myosin that cause contractions

Nicotinic cholinergic receptors

These are the receptors found on the of muscle cells which bind to acetylcholine

Gyri

These are the ridges of a brain

Stereocilia

These are the stiff 'hairs' found on hair cells

Dorsal columns

These are the tracts which large fibers take to travel up the spinal column

Spinothalamic tracts

These are the tracts which small fibers take to travel up the spinal column

Taste buds

These are where our main taste receptor cells are clustered

RANKL

This is a ligand which sits outside the osteoblast - it attaches to a corresponding receptor found on osteoclast precursors which differentiates those cells into functioning osteoclasts

Axon

This is a long extension of the cell body (like a wire) on a neuron that carries an action potential away to some other location

Myofibril (AKA Sarcomere)

This is a repeating sequence of myosin and actin in muscle cells and run the length of the muscle cell -- composed of a thick myofilament (myosins) and thin myofilament (actins)

Merkel disks (Merkel cells)

This is a saucer shaped cell found at the bottom of the epidermis and very sensitive to deformation of the skin

Antiporter

This is a secondary active transporter which cotransports molecules down their concentration gradient in the opposite direction of the molecule moving up it's concentration gradient

Symporter

This is a secondary active transporter which cotransports molecules down their concentration gradient in the same direction of the molecule moving up it's concentration gradient

M line

This is a segment of myosin to which Z disks are pulled towards (Found directly between two Z disks)

Choroid plexus (In ventricles)

This is a segment of the brain found in the ventricles which produces cerebrospinal fluid - it consists of capillaries and ependymal cells which pumps sodium and other solutes from the blood plasma into the ventricles (Water follows osmotic gradient)

Nephron

This is the functional unit of a kidney - consisting of a glomerulus and its associated tubule, through which the glomerular filtrate passes before emerging as urine

Neuron

This is the functional unit of the nervous system

Somatostatin (SS)

This is the growth hormone inhibiting hormone which is stimulated by the release of IGF-1 and produced in the hypothalamus

Presbyopia

This is the hindrance of accommodation of the lens and is usually caused by aging leading to stiffening of the lens

Growth Hormone Releasing Hormone (GHRH)

This is the hormone released by the hypothalamus to stimulate release of somatotropin

Thyrotopin Releasing Hormone (TRH)

This is the hormone that is released from the hypothalamus to stimulate the anterior pituitary gland in secreting TSH

Trigger zone

This is the initial segment of the axon (at axon hillock) and the closest excitable membrane to the cell body

Trabecular bone

This is the inner layer of spongy bone material

Endometrium (Middle layer = myometrium)

This is the inner layer of the uterus which is responsible for responding to hormones

Adrenal medulla

This is the inner portion of the adrenal gland which is made up of modified sympathetic ganglia (nervous tissue) - functions to secrete catecholamines (Eg. Epinephrine) in mediating rapid responses in flight-or-flight situations

Titin

This is the largest protein in the body and as contraction of the muscle cells occur, this protein shortens up -- once myosin releases contraction, this protein causes myosin to spring back to it's original position and keep myosin in place

Zona glomerulosa

This is the layer of the adrenal cortex responsible for the production of aldosterone

Zona fasciculata

This is the layer of the adrenal cortex responsible for the production of glucocorticoids

Zona reticularis

This is the layer of the adrenal cortex responsible for the production of sex hormones

Rhodopsin

This is the light-sensitive pigment molecule found in the disks of rods

Homeostasis

This is the maintenance of a stable, internal body environment

Progesterone

This is the major hormone of the luteal phase and is responsible for pregnancy preparation in the endometrial cells, cervical mucus thickening (this acts as a cervical 'plug' which acts as a septic barrier from sperm and bacteria for a possible pregnancy), and smooth muscle relaxation (helps moves embryo from fallopian tube to uterus) - a decrease in this hormone will contract blood vessels in the endometrium layer causing surface cells to die (lack of oxygen); this leads to menstruation

First messenger

This is the messenger that brings information to a target cell

Red-green color blindness (Aka Daltonism)

This is the most common type of color-blindness

Complex/Volitional movement

This is the motor output that is planned and refined by the motor cortex, basal ganglia and cerebellum

Bipotential primordium

This is the organ in the fetus which develops into either male testis or female ovarian tissues

Adrenal cortex

This is the outer portion of the adrenal gland and functions to secrete steroid hormones

Sclera (White of the eye)

This is the outer wall of the eyeball

Luteal phase

This is the phase of the ovarian cycle following ovulation and is characterized by the hormone secretions from the corpus luteum

Organ of Corti

This is the portion of the cochlear duct which contains the receptor cells for hearing

Lateral geniculate nuclei (LGN)

This is the portion of the thalamus to which the optic tracts project to and contains ~2 million neurons, roughly the same as the number of ganglion cells in the two retinas

Bone resorption

This is the process when osteoclasts act to break down tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood

Saltatory Conduction

This is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials

Absolute refractory period

This is the refractory period in which no stimulus can trigger another action potential

Relative refractory period (Only a few voltage-gated sodium channels are reset to their original configuration, so a larger stimulus is required -- usually around 2-5ms duration before all channels are back to their original configuration)

This is the refractory period in which only a larger than normal stimulus can trigger another action potential

Ovulation

This occurs between the follicular phase and the luteal phase and is characterized by the ovum's release of the 'ripened' oocytes into the fallopian tubes

Smooth Endoplasmic Reticulum

This organelle is responsible for producing steroid hormones

Vestibular apparatus

This part of the cochlea extends outwards and is responsible for sensing head positions and motions

Nicotinic Receptor (EPSP)

This postsynaptic membrane receptor binds to acetylcholine which opens the cation channel and results in depolarization of the membrane potential (If these receptors are blocked, muscle paralysis can occur -- Botox)

All-or-None principle

This principle states that whether a membrane is depolarized to threshold or greater, the amplitude of the resulting AP is the same; if the membrane is not depolarized to threshold, no AP occurs

Angiotensin II

This protein created through the RAAS (Renin-Angiotensin Aldosterone system) pathway increases blood pressure both indirectly and directly: 1. It increases vasopressin secretion (through receptors in the hypothalamus) 2. Stimulates thirst 3. Acts as a very potent vasoconstrictor (Increases blood pressure without change in blood volume) 4. Receptors in the cardiovascular control center increases sympathetic output to the heart and blood vessels 5. Indirectly increases proximal tube Na+ absorption (through aldosterone synthesis in adrenal glands)

β-adrenoreceptor (Increases cAMP via GPCR mechanism which then activates kinases that phosphorylate membrane Ca2+ channels -- leads to increase in Ca2+ influx)

This receptor is a metabotropic receptor for noradrenaline

Ganglia

This refers to a cluster of neurons arranged in bundles outside the central nervous system

Precentral gyrus

This region is also known as the primary motor region and similar to the somatosensory cortex, it displays somatotopic mapping

Vitreous chamber

This region is found behind the lens and is filled with the vitreous body, a clear jelly that helps maintain the eyeball's shape

Anterior chamber

This region is found in front of the lens and is filled with aqueous humour, a plasma-like fluid

Z disks

This region of a myofibril is found next to the titin proteins and is visually seen as the striations in muscle cells

Supplementary Motor Area

This region of the brain is found on the medial wall of each hemisphere and similar to the motor cortex, represents the body with a somatotopic map (but with less detail than motor cortex)

Hippocampus

This region of the brain is important for long-term memory storage and used in memories of spatial environments

Sensorimotor association areas

This region of the brain recognizes environmental cues and forwards the signals to the frontal lobe (prefrontal & premotor cortex) in order to trigger motor reactions

Paraventricular Nucleus (Paraventricular nucleus > CRH release > ACTH release > Adrenal cortex)

This region of the hypothalamus regulates CRH release from the hypothalamus (green in picture)

True (Contrastingly Catecholamines are not lipid-soluble and are stored in vesicles)

Thyroid hormones are lipid soluble (True/False)

True

Though there are 4 types of pigments in rods and cones collectively, only one type of pigment can ever be found in a single photoreceptor (True/False)

1. By controlling the rates of enzymatic reactions 2. By controlling the transport of ions or molecules across cell membranes 3. By controlling gene expression and the synthesis of proteins

Three basic ways Hormones act on their target cells

Steroid, Peptide, Amine

Three types of hormones

90 (This is known as an *ultradian rhythm* [Rhythm that is less than 24hrs but more than 1hr])

We cycle through the stages of sleep with a period of about _____ minutes

False (We have more cold receptors than warm)

We have more warm receptors than cold (True/False)

*Inner segment* Nucleus and organelles required for protein synthesis *Basal layer* Synapse which releases glutamate

What is found in the inner segment and the basal layer of cones and rods?

All the intracellular activity that needs to happen (Eg. Calcium moving back to sarcoplasmic reticulum, titin relaxing myofibril, etc.)

What is the latent period of a muscle fibre action potential caused by?

Chloride (Cl-)

What is the major anion in the extracellular fluid outside of cells?

Sodium (Na+)

What is the major cation found in the extracellular space of cells?

Potassium (K+)

What is the major cation found within cells?

Greater (Everything we see becomes more in focus)

When the pupil is tightly constricted we have a _________(greater/shallow) depth of field

False (When the stereocilia of a hair cell bend toward it's LONGEST cilia, the hair cell excites it's neuron)

When the stereocilia of a hair cell bends toward it's shortest cilium, the hair cell excites it's neuron (True/False)

Troponin holds tropomyosin over the myosin binding sites on actin (Actin can't bind to myosin and no contraction can occur)

When there is no calcium, why is muscle relaxed?

G protein-coupled receptors

When these proteins are activated they can either open ion channels in the membrane or alter enzyme activity on the cytoplasmic side of the membrane - important for hormone signalling

Red (G-R cells are active when looking at green and fatigue after overstimulation - after looking away the fatigued cells are less active and the R-G cells are more active, so they visualize red instead)

When you stare at something that is green for a long time, then look away, what color would you expect to see?

The fluid will slosh leftward activating hair cells that notify the brain that your head moved to the right

When your head turns rightward, what happens in the semicircular canals of the vestibular apparatus?

Spinal cord and brain stem

Where are CPGs principally located?

On the cell body halfway between the EPSPs and the trigger zone (This means that IPSP's can shunt depolarizing EPSP currents out of the cell before reaching the trigger zone)

Where are IPSPs usually found on neurons?

Adrenal Cortices, Gonads, Placenta (In women)

Where are steroid hormones produced in the body?

- On top of tongue (Mainly) - Soft palate - Epiglottis - Upper esophagus

Where are tastebuds found? (4)

Cell bodies are located in the dorsal root ganglia (thick portion of dorsal root)

Where are the cell bodies of receptors for somatic sensation below the chin located?

Cell bodies are located in the brain

Where are the cell bodies of receptors for somatic sensation of the head located?

Red and green cone visual pigments - X-chromsome Blue cone visual pigments - chromsome 7

Where are the genes for red, green, and blue cone visual pigments located?

Olfactory epithelium

Where are the olfactory receptors located?

Preganglionic neuron *cell bodies* are located in the CNS, either in the brainstem or spinal cord

Where are the preganglionic neuron cell bodies of the autonomic nervous system located?

CSF exits via an opening in the fourth ventricle

Where does CSF exit the ventricular system and enter the subarachnoid space?

Arachnoid Villi (Fingerlike projections of the arachnoid membrane)

Where does CSF get reabsorbed into the general bloodstream?

Olfactory cortex (Bypasses thalamus)

Where does the olfactory bulb project to?

Brainstem or sacral spinal cord (Above and below preganglionic sympathetic neurons)

Where in the spinal cord do preganglionic parasympathetic neurons orginate from?

Proliferative phase

(Phase in uterine cycle) This is the latter part of the ovary's follicular phase, during which the endometrium adds a new layer of cells in anticipation of pregnancy -- Endometrium develops in response to estrogen; the endometrial lining thickens as the blood supply to the tissue is re-established and cells proliferate

Menses

(Phase in the uterine cycle) This is the beginning of the follicular phase in the ovary and corresponds to menstrual bleeding from the uterus -- Blood vessels supplying the endometrium undergo constriction which causes shedding of the endometrial lining because of declining levels of progesterone and estrogen

Secretory phase

(Phase in uterine cycle) After ovulation, hormones from the corpus luteum convert the thickened endometrium into a secretory structure -- meaning the luteal phase of the ovarian cycle corresponds to this phase of the uterine cycle -- If no pregnancy occurs, the superficial layers of the secretory endometrium are lost during menstruation and the uterine cycle begins again Glands in endometrium secrete more viscous fluid, endometrial cells deposit lipid and glycogen in cytoplasm under the influence of progesterone and estrogen

Arcuate nucleus

This nucleus found within the hypothalamus regulates feeding

- Physical protection - buoyancy reduces brain weight > less pressure on nerves and blood vessels - Waste removal - Regulation of the ECF environment for neurons

0What are the functions of CSF? (3)

Higher

A ______(higher/lower) length constant (λ) leads to improved signal conduction

Osteoclast

A bone cell responsible for breaking down cells via acid and enzymes

Osteoblast

A bone cell responsible for forming cells - typically found on the outside of bones

Trophic Hormone

A hormone that controls the secretion of another hormone

Hormone

A chemical secreted by a cell or group of cells into the blood for transport to a distant target, where it exerts its effect at very low concentrations

Stimulus

A component of the response loop described as the disturbance or change that sets the pathway in motion

Input (afferent) Signal

A component of the response loop sent by the sensor to the integrating centre

Output (efferent) Signal

A component of the response loop that acts as an electrical and/or chemical signal that travels to the target

Integrating centre

A component of the response loop that compares the input signal with the setpoint, or desired value of the variable

Sensor

A component of the response loop that continuously monitors its environment for a particular variable

Target (Aka Effector)

A component of the response loop which is described as the cell or tissue that carries out the appropriate response to bring the variable back within normal limits

Growth Factor

A large group of substances that influence cell growth and division

L3 to L5 (spinal cord stops at around L2)

A lumbar puncture is done between these vertebrates to reduce spinal cord damage risk

Intravenous injection (IV)

A medical procedure by which fluids can be quickly and directly added into the plasma

False (This is unlikely due to the different synergy of muscles that would be required to control a precision grip vs. a power grip -- a different set of neurons at a different loci of the motor cortex would be responsible for the power grip)

A motor neuron responsible for controlling precise grips would also be responsible for controlling power grips (True/False)

Organotherapy

A physical practice done by physicians where the patients are injected with extracts of many different endocrine organs

Antagonistic control

A physiology-associated control system where antagonistic pathways that have opposing effects can be changed to maintain homeostasis

Tonic control

A physiology-associated control system where the response is always present but can be increased or decreased depending on the state of the internal environment

False (Without calcium, a low affinity binding may be made between myosin and actin, however a powerstroke cannot be made)

A power stroke can still be made my myosin without a calcium signal (True/False)

Feedforward Control

A reflexive response that has evolved to enable the body to predict that a change is about to occur and start the response loop in anticipation of the change (Eg. Salivation in expectation of eating food)

True (Olfactory epithelium is pigmented and the richness of its colour correlates with olfactory sensitivity [In humans, the pigmentation is a pale yellow])

A region of olfactory receptors that is a more rich yellow than it's surrounding regions would have a greater sensitivity (True/False)

Hypothalamus

A region of the brain that controls many homeostatic functions

Closer (A rounder lens bends light more)

A rounder lens (in the eye) will have a __________(closer/further) focal point

False (There is a set of CPGs for each leg)

A single CPG controls the step cycle for both legs (True/False)

False (A motor neuron can innervate numerous myofibrils [myofibril is an actin-myosin complex])

A single motor neuron can only innervate a single muscle fibre, hence there is a motor neuron for ever muscle fibre in the body (True/False)

Hypothalamic Hypophyseal Portal System

A special set of blood vessels where hypothalamic neurohormones that regulate the release of the anterior pituitary hormones can pass from the hypothalamic tissue into the anterior pituitary gland

Local communication

A type of cell to cell communication that involves gap junctions, contact dependent signals, and chemicals that diffuse through the extracellular fluid to act on cells close by

Long distance communication

A type of cell to cell communication that involves the use of electrical signalling in nerve cells and the transfer of molecules in the blood stream

False (A typical taste bud contains at least five kinds of receptor cells)

A typical taste bud contains several of a single receptor cell (True/False)

False (A zygote that inherits only a Y chromosome will die because the larger X chromosome contains essential genes that are missing from the Y chromosome)

A zygote that inherits only a Y chromosome (YO) [No X chromosome] will be a phenotypically male (True/False)

True

A zygote that inherits only an X chromosome (XO) [No Y chromosome] will be phenotypically female

False (ANP's respond to HIGH blood pressure [stretches of the cardiac muscles and ventricles] by decreasing water and sodium reabsorption which will also increase potassium reabsorption [opposite of aldosterone])

ANP's increase water and sodium reabsorption and decrease potassium reabsorption (similar to aldosterone) in order to combat low blood pressure detected in the heart (True/False)

*Shorten* H zone I band *Remain constant* A band (myosin doesn't change shape)

Amongst the H zone, I band, and A band, when the muscle is contracted, which bands shorten/extend?

True (Without insulin their GLUT4 receptors are withdrawn from the membrane and stored in cytoplasmic vesicles)

Adipose tissue and resting skeletal muscle require insulin for glucose uptake (True/False)

Asymmetric (1 nueronal progenitor cell gives rise to 1 progenitor cell and 1 neuronal cell [migrates to neocortex])

After 6 weeks of embryonic development, neuronal progenitors experience _____________(symmetric/asymmetric) division

False (After *two* Ach molecules bind to nicotinic cholinergic receptor of the sarcolema [on skeletal muscles], the channel opens and a net sodium influx depolarizes the muscle fibre )

After a single acetylcholine molecule binds to a nicotinic cholinergic receptor of the sarcolema (on skeletal muscles), the channel opens and a net sodium influx depolarizes the muscle fibre (True/False)

False (During capacitation, albumin, enzymes, and lipoproteins bind to sperm [that are produced in the uterus] as well as the removal of the glycoprotein coat and intracellular changes that develop strong whip-like motions -- high levels of estrogen changes the cervical mucosa to make it thinner)

After entering the vagina, the cervical mucous becomes thicker and only allows spermatazoa which are the strongest and those that are able to pass though the ability to fertilize an egg (True/False)

12-24 hours

After ovulation, how long is an oocyte viable for?

False (The developing embryo cannot secrete testosterone until after the gonads differentiate into testes -- Testosterone is also not required for testicular development)

After proteins such as SOX9 begin the development of the testis, the developing embryo will secrete testosterone which will help in it's own development in a positive feedback loop until they are fully formed (True/False)

28 days (Average)

After puberty, one primary ooctye completes meiosis I and enters meiosis II to become a secondary oocyte every _________

False (After puberty, primary oocytes undergo meiosis up until the separation of sister chromatids [metaphase II] - from here meiosis stops and the egg will be ovulated; if fertilized after ovulation the egg will complete meiosis, if not, the egg will disintegrate)

After puberty, primary oocytes undergo meiosis and release one haploid cell (one cell disintegrates after meiosis I and another cell disintegrates after meiosis II) from the ovary before being fertilized by a sperm (True/False)

4-6 days

After sperm is ejaculated into the female reproductive tract, how long is it viable for?

True (This is staple of all living cells)

All cell membranes have sodium potassium pumps (True/False)

False (All cells in the body have a resting membrane potential, but only neurons have a resting membrane potential of -70mV)

All cells in the body have a resting membrane potential of around -70mV (True/False)

True (Because inactivation occurs early in development, before cell division is complete, all cells *of a given tissue* will usually have the same active X chromosome)

All cells of a given tissue will usually have the same active X chromosome, either maternal or paternal (I.e. The barr body's of each cell will be the same) (True/False)

Acetylcholine

All motor neurons release this NT

False (Only parts of neurons that tranduce somatic sensations [touch, pressure, etc.] transudce electrical signals in their nerve endings) (CHECK THIS, UNSURE -- TWEED_7_SLIDE6)

All neurons transduce electrical signals in their nerve endings (at the tips of their fibres) (True/False)

False (Receptor potentials may use vesicles when depolarized to transmit a signal contrary to hyperpolarization following an action potential leading to the release of neurotransmitters)

All receptor potentials use an action potential to transmit a signal (True/False)

False (The sound waves may go straight through the cochlear duct and bypass the pathway which would go around the entire cochlea [though some sound waves do traverse the entire cochlea])

All sound waves must pass through the helicotrema after entering the cochlea (True/False)

False (Amplitude is the pressure difference between peak and trough)

Amplitude is the time difference between peak and trough (True/False)

False (Exercising muscles don't require insulin to get glucose into the cell)

An exercising muscle still requires insulin to get glucose into the cell just as much as a non-exercising muscle does (True/False)

False (Increase in GLUTAMATE will increase prostaglandin release at astrocytes that triggers vasodilation of blood vessels)

An increase in GABA at synapses can increase vasodilation of blood vessels (True/False)

Ligand

An ion or molecule attached to a metal atom by coordinate bonding

True (Only estrogen can cause a negative/positive feedback on GnRH release)

Androgens always maintain negative feedback on gonadotropin release (True/False)

True

Angiotensinogen is constantly being produced by the liver (True/False)

Cytokine

Any of a number of cell signalling molecules, such as interferon, interleukin, and growth factors, that are secreted by certain regulatory peptides and have an effect on other cells - These control cell development, cell differentiation, and the immune response Specifically cells of the immune system

Nasal (Inner side)

At the chiasm, the fibres from the ___________(nasal/temporal) half of each retina cross

Increases, increases, decreases

At the level of the kidneys, PTH _________ (increases/decreases) calcium reabsorption in the distal tube, _________ (increases/decreases) calcitriol synthesis, and _________ (increases/decreases) phosphate reabsorption in the proximal tube

True (As luteal cells degenerate, production of estrogen and progesterone decrease, which stops the negative feedback to the pituitary glands and allows synthesis of FSH and LH)

As luteal cells degenerate, FSH and LH levels increase (True/False)

False (Myosin is stationary and doesn't contract/extend)

As myosin pulls actin filaments closer together during contraction, it contracts itself (True/False)

Between T1 and L2

Between which vertebrae do preganglionic sympathetic neurons orginate from? (In thoracolumbar spinal cord)

False (The activation gate is closed below the threshold potential [-55mV] and the inactivation gate is open)

At -68mV, the inactivation gate on a voltage-gated sodium channel is closed (True/False)

False (Even though the inactivation gate is triggered by depolarization above -55mV, it has a delay of 0.5ms which translates to a membrane potential around 30mV before it can close)

At 10mV (immediately following activation gate opening), the inactivation gate on a voltage-gated sodium channel is closed (True/False)

Cerebrum (Cerebrum surface is still smooth [lissencephalic] at this point)

At 11 weeks, the growth of the __________ is noticeably more rapid than the other segments of the brain

Inside

At equilibrium, there is a net cation accumulation ________ (inside/outside) the membrane

Closed (Opened only when cell depolarization occurs)

At normal resting membrane potential, voltage-gated sodium channels are ______ (open/closed)

False (Spermatogonia may either continue to undergo mitosis [as in the embryo] or begin a meiotic cycle)

At puberty, all the spermatogonia begin to undergo meiosis and differentiate into mature sperm cells (True/False)

True (K+ diffuses out of the cell via membrane leak channels)

At rest, a neuron is most permeable to K+ ions (True/False)

False (At the peaks of sound waves, the molecules are crowded together at high pressure -- at the troughs of sound waves, the molecules are far apart at low pressure)

At the troughs of sound waves, the molecules are crowded together and the pressure is high (True/False)

1000-3000 Hz

At what range is acuity the highest for humans sound perception?

>45˚C

At what temperature do pain receptors become activated?

Around 2 AM

At what time of the day is melatonin secretion the highest from the pineal body?

Late follicular phase (This is because ovarian estrogen secretion peaks at the end of the follicular phase - this somehow triggers a positive feedback loop in the pituitary gland to secrete more LH and FSH which will further increase the production of estrogen)

At which phase of the ovarian cycle does estrogen secretion peak?

False (Auditory signals from both sides [left and right] are passed on to both the left and right sides of the brain)

Auditory signals from the left side travel to the right side of the brain and auditory signals from the right side travel to the left side of the brain (True/False)

Myelinated, 70

Aβ fibres are _____________(myelinated/unmyelinated) and conduct spikes at up to ____ m/s

10000, 5000

Babies have around _______ taste buds while adults have around _______ taste buds

False (Before differentiation, both the Müllerian and Woffian ducts are present - the presence of testosterone and/or anti-Müllerian hormone will determine which duct is degraded)

Before differentiation only Müllerian ducts are present in the bipotential embryo - Wolffian ducts will develop in the presence of the SRY gene (True/False)

1. Somatic motor neurons release ACh at NMJs 2. A net entry of Na+ through ACh channels initiates a muscle action potential 3. The action potential travels down the T-tubules and triggers a conformational change in the DHP receptors 4. DHP receptors open RyR Ca2+ release channels found on the sarcoplasmic reticulum and Ca2+ enters the cytoplasm 5. Ca2+ binds to troponin and allows actin-myosin binding (Tropomyosin is moved away from actin-myosin binding sites) 6. Myosin heads execute power strokes to slide the actin filaments towards the centre of the sarcomeres (myofibrils) 7. *Sarcoplasmic Ca2+ ATPase* pumps Ca2+ back into the sarcoplasmic reticulum 8. Decrease in free Ca2+ causes troponin to bind back onto tropomyosin and inhibit actin-myosin binding 9. Titin proteins cause the thin filaments of myofibrils to go back to their relaxed states

Beginning from a signal by a motor neuron, describe how a skeletal muscle myofibril can contract (9)

False (Cones and rods don't fire action potentials -- respond to stimuli with graded membrane potentials)

Both cones and rods have similar structures which allow them to fire an action potential upon the stimulus of light (True/False)

False (Only small fibres in the somatosensory neural system encodes for reflex responses)

Both large fibres and small fibres in the somatosensory neural system encode for reflex responses (True/False)

*Pre*ganglionic neurons release *Ach* onto *Nicotinic receptors*

Both sympathetic and parasympathetic ____(pre/post)ganglionic neurons release ______(Ach/Norepinephrine/GABA/Glutamate) onto their receptors

True

Bouton vesicles are already docked in preparation of exocytosis before Ca2+ ions can trigger their release (True/False)

Beta (This is why an epipen can raise blood pressure [epinephrine works on alpha receptors at high conc.] without constricting the arteries in the lungs)

Bronchioles only have _____ receptors that allow the dilation/constriction (depends on answer) of blood vessels

unmyelinated, 2 myelinated, 30

C fibres are _____________(myelinated/unmyelinated) and conduct spikes at up to ____ m/s; Aδ fibres are _____________(myelinated/unmyelinated) and conduct spikes at up to ____ m/s

False (Aδ fibres are thicker than C fibres, hence why Aδ fibres transmit signals at faster velocities [additionally due to myelin sheaths])

C fibres are thicker than Aδ fibres since C fibres have to conduct signals without myelin sheaths

True

CPGs are important for behavioural responses, locomotion, and motor control (True/False)

False (CPGs in the CERVICAL cord program the motion of the arms during walking)

CPGs in the thoracic cord program the motion of the arms during walking (True/False)

True (Corticotropin-releasing hormone (CRH) secreted by the placenta is the signal to begin labor - (CRH is also a hypothalamic releasing factor that controls release of ACTH from the anterior pituitary) - In the weeks prior to delivery, maternal blood CRH levels increase rapidly - women with elevated CRH levels as early as 15 weeks of gestation are more likely to go into premature labor)

CRH is secreted by the placenta (True/False)

True (The turnover is roughly 3.7 times per day)

CSF production is 550 ml/day (True/False)

False (Calcitonin is produced in the thyroid gland)

Calcitonin is produced in the parathyroid glands (True/False)

True

Calcitriol binds to the vitamin D nuclear receptor which increases the expression of calcium channels/binding proteins/transporters in the kidneys and intestine and also increases expression of RANKL and OPG in osteoblasts (True/False)

True

Calcitriol is a non-polar metabolite that acts similar to a steroid hormone by binding to nuclear receptors and directly increasing the expression of certain proteins (True/False)

Myosin light chain kinase (MLCK)

Calcium-calmodulin complexes activate these proteins

Same Na+ Reduced K+, Ca2+, Mg2+ Increased H+

Cerebrospinal fluid has the same osmolarity and _______ as the blood, greatly reduced _______, _______, and _______, and increased _______ (Blanks represent ions)

False (Pain can be gated by Aβ activity)

Pain can be gated by Aδ activity (True/False)

True (They eventually go to a normal [antigravity] pattern)

Children display the babinski pattern (True/False)

30˚C, 45˚C

Cold receptors respond maximally at roughly _____˚C and warm receptors at roughly _____˚C

True (Cold receptors respond briefly to temperatures >45˚C causing a paradoxical cold where a hot object touched briefly may feel cold)

Cold receptors respond to temperatures >45˚C (True/False)

True (Color-opponent ganglion cells exist in LGN, visual cortex, and retina)

Color-opponent ganglion cells exist in the LGN and visual cortex (True/False)

False (Long-term use of cortisol analogs can result in inhibition of ACTH secretion and atrophy of cortisol-secreting cells)

Cortisol drugs can be taken daily with no health risks associated if required (Eg. To inhibit inflammatory responses, asthma, allergies...) (True/False)

False (Cortisol has a negative effect on growth and is the cause for a condition known as 'failure to thrive' where constant stress leads to stunted growth)

Cortisol has a positive effect on growth (True/False)

True (A synergistic effect occurs that exponentially increases blood glucose levels)

Cortisol is required for the full activity of glucagon and epinephrine (True/False)

True (Actin-myosin complexes are what allows the contractility of muscle cells)

Cytoskeleton takes up most of the space within a muscle cell (True/False)

1. Glutamate (released as NT) binds to AMPA and NMDA receptors 2. A net Na+ entry through AMPA receptors depolarizes the cell 3. Mg2+ ions are released from the NMDA receptors (due to depolarization of cell - repelled away) and allow Ca2+ ions to enter through NMDA channel 4. Ca2+ stimulates second messenger pathways 5. Cell becomes more sensitive to glutamate due to second messenger pathways and paracrine signals are released to the former neuron's presynaptic cleft to enhance glutamate release

Describe a method of long-term potentiation (method of enhancing connection between neurons) with the use of glutamate, AMPA receptors, and NMDA receptors

1. Action potential enters from a pacemaker neuron 2. Voltage gated DHP receptor channels open to allow Ca2+ into the cell 3. Ca2+ induces RyR channels to open and release Ca2+ from the SR 4. Summed Ca2+ sparks (release from SR) create a Ca2+ signal that can bind to troponin and initiate a contraction 5. Ca2+ unbinds from troponin and the myofibrils relax 6. Ca2+ is pumped back into the SR through Sarcoplasmic Ca2+ ATPases 7. Ca2+ is exchanged with Na+ in the ECF through NCX antiporters on the plasma membrane 8. Na+ gradient is maintained through Na+ K+ ATPases

Describe how cardiac muscles contract (8)

1. Intracellular [Ca2+] increases when Ca2+ is released from the SR or enters from the ECF (this is different from skeletal muscles) 2. Ca2+ binds to calmodulin and this complex activates myosin light chain kinase (MLCK) 3. MLCK phosphorylates light chains in myosin heads to increase myosin ATPase activity 4. Active myosin crossbridges form and slide actin filaments to create muscle tension 5. [Ca2+] decreases in the cell when it is pumped back into the SR or into the ECF 6. Ca2+ unbinds from calmodulin and MLCK activity decreases -- this leads to MLCP activity dominating 7. MLCP removes phosphate from myosin light chains and thus decreases myosin ATPase activity 8. Less myosin ATPase activity leads to decreased muscle tension

Describe how smooth muscle cells contract (8)

The load will activate a *muscle spindle* in the bicep which sends signals to the CNS - The CNS will activate a *motor neuron* that contracts the same muscle that was stretched Note: In this way the muscle spindle has a direct connection with the motorneuron that causes contraction

Describe how the bicep stretch reflex would respond to an addition of a load to the hand?

1. Calcium levels increase in the cytosol 2. Calcium binds to troponin on the thin filaments of myofibrils 3. Troponin-Calcium complexes pull tropomyosin away from actin's myosin binding site 4. myosin binds strongly to actin and completes a *power stroke* 5. The actin filament moves

Describe the crossbridge cycle in terms of what happens to the actin filament [Not the myosin] (5)

1. ATP binds to myosin and myosin *releases the actin filament crossbridge* 2. Myosin hydrolyzes ATP and uses this energy to rotate the myosin head to the 'cocked' position where it can *weakly bind* actin 3. *After a calcium signal* moves tropomyosin off the binding site, a power stroke can be made where the head actin-binding head of myosin swivels and moves actin towards the M line 4. ADP and Pi are released at the end of the power stroke and *the cross bridge is still in place* (Cross bridge only released upon ATP binding)

Describe the crossbridge cycle in terms of what happens to the myosin [Not the actin filament] (4)

If the flexor burst generator is on, the extensor burst generator is inhibited - an inhibitory neuron within the flexor burst generator inhibits the flexor burst generator's functioning and eventually releases the inhibition on the extensor burst generator

Describe the inhibition characteristics between the flexor burst generator and the extensor burst generator

1. Tap the patellar tendon to stretch the quadricep muscles 2. Muslce spindle stretches and fires towards spinal cord 3. A *monosynaptic stretch reflex* is activated that contracts the quadriceps - At the same time, an interneuron inhibits the somatic motor neuron of the hamstrings allowing the hamstrings to remain relaxed and allow extension of the leg

Describe the patellar tendon reflex (3)

Overexertion of the muscle will lead to an activation of the golgi tendon reflex - the golgi tendon reflex will *activate inhibitory interneurons* in the CNS that *reduce activity of motor neurons* - this will inhibit/reduce tension in the muscles

Describe the pathway of a golgi tendon reflex upon stimulation

*Stretch reflex* As you move the cup up, you contract your biceps and stretch your triceps -- this leads to the stretch reflex activating and attempting to counter the stretch of the triceps by contracting them *Golgi tendon reflex* As you move the cup up, you contract your biceps -- This activates the golgi tendon reflex which will attempt to counter the contraction by reducing the contraction of the biceps

Describe what happens in terms of stretch reflexes and golgi tendon reflexes when you lift a cup towards your mouth to drink from

In daylight, rods are 'bleached out' -- their visual pigment, rhodopsin, is broken down so they become light-insensitive -- When the lights go dim, the rods dark adapt as they rebuild their stores of rhodopsin (~30 min)

Describe why rods only operate in low light

Central fatigue Peripheral fatigue

Despite a continuous stimulus, if the muscle is unable to maintain a prolonged contraction, it will experience *fatigue* - what are the two types of fatigues?

Peptide hormones are composed of 3+ amino acids; amines are composed of single amino acids

Difference between amine and peptide hormones?

True (Though receptor cells of all five kinds are all over the top of the tongue)

Different areas of the tongue vary slightly in their thresholds for different flavours (True/False)

high, low

Dopamine at ______ (low/high) concentrations primarily works on Alpha 1 receptors causing vasoconstriction, at medium concentrations it works on B1 receptors causing inotropy/chronotropy (myocardial contractility) and at _______ (low/high) concentrations primarily on D1 receptors causing vasodilation

True (ALTHOUGH there is no body movement, only rapid eye movement [REM])

During REM sleep, large corticospinal and reticulospinal tracts are very active (True/False)

False (Myosin heads undergo conformational changes that result in swivelling back and forth between a high energy form [high affinity for actin -- strong crossbridge] and a low energy form [low affinity for actin -- weak crossbridge])

During the crossbridge cycle of muscle contraction, myosin heads constitutively exist in a high-energy form until calcium is released by troponins (True/False)

True (FSH and LH levels decrease through negative feedback from the estrogen released by the granulosa cells [this ensures that FSH and LH don't increase production of additional follicles in the same cycle], however estrogen stimulates additional estrogen production on the granulosa cells [positive feedback] which maintains a high estrogen level without the need of FSH and LH)

During the early follicular phase of the ovarian cycle FSH and LH levels slowly decrease (True/False)

True

During the onset of puberty, the GPR54-kisspeptin system is thought to trigger the increased frequency in the release of GnRH (True/False)

False (Single motor nuclei (muscles) are represented in columns at many loci of the motor cortex depending on how many synergies they are involved in -- muscles which participate in the most synergies have the biggest representation)

Each muscle is only represented once in the precentral gyrus (motor cortex) (True/False)

False (Covers 1-1.5mm of axon)

Each myelin forming cell covers 2-3mm of axon (True/False)

False (Each olfactory receptor cell has a single dendrite that extend into the olfactory epithelium - each dendrite branches into multiple nonmotile cilia that increase the surface area of the cell giving it a greater chance of catching odourant molecules)

Each olfactory receptor cell has multiple dendrites that extend into the olfactory epithelium (True/False)

False (Each olfactory receptor cell has several copies of A SINGLE odourant molecules on its membrane -- each receptor cell can only detect one odour)

Each olfactory receptor cell has several copies of different odourant molecules on its membrane (True/False)

Bottom, top

Earliest migrated neurons reside at the _________(top/bottom) of the neocortex, while later migrated neurons reside at the _________(top/bottom) [Note: Top refers to the Pia zone and bottom refers to the ventricular zone]

Because of the relatively short distance to cross, the long basal process of the cell extends to the outer surface and the nucleus can move up through cytoplasm

Early in neocortex development, how do neuronal cells migrate from the ventricles to the pial surface?

Ventral (Since efferent signals are carried by the ventral root)

Efferent nuclei are in the __________ horn of the spinal cord

False (Both endocytosis and exocytosis require energy in the form of ATP to function)

Exocytosis and endocytosis are not always ATP-mediated (True/False)

(A.K.A Kiss and Run method) 1. The secretory vesicles dock and fuse with the plasma membrane at specific locations called 'fusion pores' 2. Vesicle can connect and disconnect several times before contents are emptied (Since only part of the contents are emptied in one 'Kiss', the process can be repeated several times before the vesicle is depleted) Note: Generally only part of vesicle contents diffuse into the interstitial fluid, used for low rate of signalling

Explain Exocytosis 1

(Full exocytosis) This is the complete fusion of an excretory vesicle with the cell membrane, leading to the total release of cell contents at once -- Necessary for delivery of membrane proteins and high levels of signalling and must be counterbalanced by endocytosis to inhibit cell volume increase

Explain Exocytosis 2

Transmitter molecules are released by the presynaptic axon terminal into the synaptic cleft -- the postsynaptic dendrite contains specialized receptors that can bind specific transmitter molecules which can then elicit a response from the target neuron

Explain chemical synapses and how they function

Electrical synapses are formed by two neurons linked together by gap junctions - the electrical signal (depolarization from ions) can directly pass through the gap junctions and the AP can be trasmitted without the release of neurotransmitters

Explain electrical synapses and how they function

False (Extracellular fluid resistance is not adjustable and is relatively low compared to internal resistance)

Extracellular fluid resistance is an important factor when considering the length constant (True/False)

Follicle-stimulating Hormone (FSH)

FSH; This hormone is trophic in the gonads

False (Facilitated diffusion is an ATP-independent process of diffusion, where molecules diffuse across with their conc. gradient, with the assistance of a carrier protein)

Facilitated diffusion is the process where ATP is used up to move ions and particulates with their concentration gradients (True/False)

False (Don't require myoglobin)

Fast-twitch glycolytic muscles require myoglobin (True/False)

False (Fast-twitch oxidative-glycolytic muscles are usually glycolytic, but can be trained to become oxidative)

Fast-twitch oxidative-glycolytic muscles are usually oxidative, but can be trained to be glycolytic (True/False)

False (Follicular cells use active transport through sodium-iodine symporters [NIS] to concentrate iodine into the cells)

Follicular cells use passive transport to bring iodide ions into the cell in order to create thyroid hormones (True/False)

3, out, 2, into

For each molecule of ATP consumed in the Na+/K+ pump ___ Na+ ions are pumped ____ (out/into) the cell and ___ K+ are pumped ____ (out/into) the cell

Pitch

Frequency is the number of wave peaks per second - how is this represented in terms of sound?

7

G protein coupled receptors are membrane spanning proteins that cross the phospholipid bilayer _____ times

True

GH causes a decreased insulin sensitivity in the muscles (True/False)

Ligand

GPCR's are ______-gated channels

Nucleus (Steroid-receptor complexes are transcription factors that activate/repress one or more genes)

Generally the ultimate destination of steroid-receptor complexes is the ___________

These physically block the receptors and can cause paralysis in muscle cells Eg. Curare

Give an example of a nicotinic receptor blocker and describe what it does

Acetylcholine builds up in the synapse and continually excites the post-synaptic membrane (Causes dilation of eyes, foaming of the mouth, tearing of the eyes, etc. through immediate effects [since Ach is present at other neurons in the body too])

Give an example of an Acetylcholinesterase inhibitors and describe what it does

These block exocytosis from occurring in the presynaptic bouton Eg. Botox

Give an example of an exocytosis blocker of skeletal muscle NMJs and describe what it does

1. Sunlight peaks at 400-700nm 2. Earth's atmosphere is most transparent to those wavelengths 3. Sea water is most transparent at <500nm where eyes first evolved

Give three explanations as to why evolution preferred the visual spectrum at 400-700nm

~3 ms

Given a sustained, constant stimulus, a nerve ending's membrane depolarizes - how long before it will return to baseline

False (GnRH is released in pulses (Roughly every 2-3 hours)[Pulse freq./amplitude change during development])

GnRH is continually released from the neuroendocrine cells of the hypothalamus (True/False)

False (Gonadotropin secretion, which is suppressed by luteal inhibin production and negative feedback from estrogen and progesterone, remains shut down throughout most of the luteal phase)

Gonadotropin secretion is maintained at high levels during the luteal phase (True/False)

False (Granulosa cells secrete inhibin and progesterone in addition to estrogen - this will dramatically increase levels of LH and slightly inhibit levels of FSH [inhibin will only inhibit release of FSH])

Granulosa cells secrete inhibin and progesterone in addition to estrogen - this will dramatically increase levels of FSH and slightly inhibit levels of LH (True/False)

False (Growth hormone is a PEPTIDE hormone that binds to growth hormone binding protein in the blood which protects plasma GH from being filtered into the urine and extends its half-life in the plasma)

Growth hormone is a steroid hormone that binds to growth hormone binding protein in the blood which protects plasma GH from being filtered into the urine and extends its half-life in the plasma (True/False)

False (Glia are about as numerous as neurons)

The amount of glial cells surpasses the number of neurons (True/False)

Give the patient ADH - if the urine continues to remain dilute, then the patient has Peripheral Diabetes Insipidus

How do you tell apart peripheral diabetes insipidus and central diabetes insipidus?

GLP-1 also inhibits glucagon secretion (Both increase insulin production and decrease gastric acid)

How does GLP-1 (Glucagon-like peptide 1) differ from GIP (Gastric inhibitory peptide)?

False (High frequency waves are HIGH pitched, while low frequency waves are LOW pitched )

High frequency waves are low pitched, while low frequency waves are high pitched (True/False)

When the stereocilia bend of a hair cell bends toward it's shortest cilium, the hair cell experiences hyperpolarization (less transmitter released)

How does a hair cell hyperpolarize?

Constricted (Small pupil ensures each point on the retina receives light from just one direction in space)

If the pupil is ______________(constricted/dilated), light will be focussed better on the retina

Local control

Homeostatic signalling restricted to the region where the change takes place

Reflex control

Homeostatic signalling which involves a long-distance pathway that uses the nervous system, endocrine system, or both

Gonadotropins

Hormones trophic to the gonads

Loudness (Larger the amplitude, the louder a sound is)

How are the amplitudes of sound waves percieved by our minds?

Detection of salt and sour involves ion channels (NOT G proteins)

How are type I and type III taste receptor cells triggered to excite neuronal pathways?

1. Stimulatory molecule binds to a G protein called gustducin 2. Signal pathway which increases intracellular [Ca]2+ is activated 3. ATP is released

How are type II cells triggered to release ATP? (3 steps)

Note: Aβ fibres are activated in response to merkel cell/encapsulated mechanoreceptor activity which responds to touch -- additionally in the dorsal horn C fibres contact secondary neurons which can be influenced by Aβ fibres via interneurons 1. Slow pain signals are sent through the C fibres 2. Upon rubbing of the affected area, merkel/encapsulated mechanoreceptor cells are activated which activate Aβ fibres 3. Aβ fibres dampen/block pain signals from the C fibres through interneurons connected to C fibre secondary neurons in the spinal cord

How can pain be gated by Aβ activity?

Vigorous stroking of the sole of the foot can stimulate the extensor thrust reflex in the toes

How can you elicit the extensor thrust reflex manually?

Block the cell from repolarizing (By blocking the repolarization of the cell, the gated sodium channels will be permanently inactivated [by the inactivation gate] and another action potential will not be produced) This can be done by raising the extracellular potassium ion levels so a concentration gradient is not apparent between the intracellular and extracellular spaces (hence, potassium will not leave the cell to repolarize it)

How could you completely block the membrane from producing an action potential?

Vigorous stroking of the sole of the foot -- Normal extensor thrust reflex in the toes would show flexion of the toes away from the body -- Damage would show withdrawal of the toes towards the body (Babinski pattern)

How could you detect for a damage in the corticospinal tract by looking at a person's extensor thrust reflex?

(Astrocytes are connected with neurons at their synapses) 1. When the astrocytes detect increased glutamate at the synapses it triggers Ca2+ release within the astrocytes 2. Ca2+ wave travels down astrocyte body and triggers prostaglandin (PGE2) release at their end-foots (connected to blood vessels) 3. PGE2 causes vasodilation/increased blood flow

How do astrocytes control local blood flow?

1. Astrocytes pick up glucose from the blood stream 2. Within the astrocyte cell body, glucose is metabolized into lactate (through glycolysis) 3. Lactate is delivered to neurons which use it to efficiently make ATP

How do astrocytes provide energy to neurons?

Gap junction communication

How do cardiac muscle cells maintain a synchronous beat?

Opioids decrease transmitter release from primary sensory neurons and postsynaptically inhibit secondary sensory neurons

How do opioids (Eg. Morphine, codeine) function to relieve pain?

Release ATP (also acts on type III taste receptor cells)

How do type II taste receptor cells activate gustatory neurons?

During ovulation (Around day 14 of the menstrual cycle) a mature follicle secretes collagenase (enzyme that dissolves collagen in the connective tissue holding the follicular cells together) - the breakdown products of collagen create an inflammatory reaction, attracting leukocytes that secrete prostaglandins into the follicle which may cause smooth muscle cells in the outer theca to contract, rupturing the follicle wall at its weakest point - Antral fluid then spurts out along with the egg, which is surrounded by two to three layers of granulosa cells - The egg is then swept into the fallopian tube and carried away to be fertilized or die

How does a mature (teritiary) follicle escape the ovum during ovulation (in-depth)

ASA inhibits prostaglandins and inflammation and slows transmission of pain signals

How does acetylsalicylic acid (aspirin) function to relieve pain?

1. Specific receptor proteins bind to a specific odorant 2. This activates a coupled G-protein which activates adenyl cyclase leading to the production of cAMP 3. cAMP directly binds to ion channels which allow cations (Na+ and Ca++) to go through and depolarize the membrane

How does the olfactory receptor function? (3)

Communicates via a channel called the *"Aqueduct of Sylvius"*

How does the third ventricle of the brain communicate to the fourth ventricle?

Firing frequency (Louder sounds make auditory sensory neurons fire at a faster rate)

How is loudness conveyed (in terms of action potential) in auditory sensory neurons?

hCG is secreted by the chorionic villi and the developing placenta which will sustain the corpus luteum - the corpus luteum synthesizes estrogen, progesterone, and inhibin so suppression of the pituitary continues throughout pregnancy - eventually the placenta will be able to produce it's own progesterone to inhibit follicular cell development and the corpus luteum can be degraded

How is ovulation suppressed after a blastocyst has implanted itself into the uterus?

Pre-synaptic inhibition is regulated by an inhibitory neuron: 1. The inhibitory neuron releases GABA into the axo-axonal (NOT axo-dendritic) synapse 2. The GABA ligands bind to receptors on the target axon's bouton which stimulates an influx of Cl- into the axon terminus 3. The influx of Cl- restores the membrane potential of the neuron and inhibits voltage gated Ca2+ channels to open 4. Exocytosis is inhibited

How is pre-synaptic inhibition regulated in neurons? (4 steps)

Amount of hormone released

How is the stimulus intensity regulated in the endocrine system?

Astrocytes regulate tight junction formation by paracrine stimuli

How is tight junction formation in CNS endothelial blood vessel cells regulated?

30-40ms (This is how long the neurotransmitter is typically binded to the receptor for)

How long do EPSP's typically last for?

4-5 days

How long does it take for a dividing embryo to move from the fallopian tubes to the uterine cavity?

14 days

How long does the luteal phase generally last?

12 days (It takes 2 days for the cell to die, so 14 days in total)

How long is the intrinsic lifespan of a corpus luteum cell (without pregnancy)?

~10 days

How long is the lifetime of a taste bud?

46

How many chromosomes are there in a human zygote?

23

How many chromsomes are there in a human gamete?

~400 different receptor cells

How many different kinds of olfactory receptor cells do we have?

1000 genes (Roughly 3-5% of the genome)

How many genes control the olfactory receptor cells in vertebrates?

The neocortex forms an orderly 6 layer structure

How many layers are involved in the neuronal migration to form the neocortex?

100-600 million neurons

How many neurons does the enteric nervous system have?

10 million

How many olfactory receptor cells are there in total?

~100 receptor cells

How many receptor cells does a taste bud have?

50-100 stereocilia per hair cell

How many stereocilia are found on a hair cell?

4 Ventricles in total 1/2. Lateral ventricles - one located in each hemisphere 3. Third Ventricle - Found under the cerebral hemisphere 4. Fourth Ventricle - Ventricle closest to the spine

How many ventricles of the brain are there and what are they called?

Give the patient a steady supply of GnRH agonists (a steady supply will briefly increase the androgen and estrogen levels, but steady high levels of GnRH cause down-regulation of the GnRH receptors on gonadotropin cells, making the pituitary unable to respond to GnRH)

How would you treat a patient with prostate or breast cancer stimulated by androgens or estrogens?

Ectopic pregnancy (Where fertilized egg implants on the fallopian tube wall and embryo develops there)

If the zona pelliiculada breaks in the fallopian tube after fertilization, what possibly fatal incidence can occur?

Inhibit (Ib interneurons are the neurons used by the golgi tendon reflex to inhibit α-motoneurons)

Ib-interneurons __________(inhibit/activate) α-motoneurons of same muscle

Inhibit ionotropic receptors (Ionotropic receptors have quick membrane potential responses -- metabotropic receptors don't necessarily control ion channels and have a slow effect if they do)

If a lab wanted to inhibit quick synaptic responses between neurons, what should it do?

Thioamides (Thioamides inhibit the function of Thyroid peroxidase, hence no T3 and T4 synthesis) or more thyroid hormones (Assuming no tumour, negative feedback will suppress thyroid hormone secretion)

If a patient has hyperthyroidism, what can be given to try to alleviate their condition?

-Deletion of the SRY gene (Male differentiation is avoided completely) -Defective gene for 5 alpha-reductase (No external male organ development) - Complete androgen insensitivity (androgen receptors not functional - so testosterone and DHT are non-functional, produces an infertile phenotypic female)

If an XY genotypic fetus is phenotypically a female, what could be a possible cause? (3)

Focus falls behind the retina (As object moves closer, angle of incidence increases so angle of refraction is smaller and the image will be found further from the original focal point [behind retina])

If an object were to move closer to your eye, but the lens didn't change it's shape to accommodate, where would the focus now lie?

Relaxation (This protects the muscle)

If excessive load is placed on a muscle, the Golgi tendon reflex causes _____________(contraction/relaxation)

*Parasympathetic* reflexes *via cranial nerve III* are triggered to constrict circular pupillary iris muscles

If it's too bright, how does the pupillary light reflex respond?

*Sympathetic* reflexes *via the thoracic cord* are triggered to constrict radial pupillary iris muscles

If it's too dark, how does the pupillary light reflex respond?

False (The action potential would increase until it reaches an equilibrium potential of around 60mV -- the equilibrium potential of sodium)

If the inactivation gate on a voltage-gated sodium channel was non-functional, the action potential would increase indefinitely due to a surge in sodium ions (True/False)

Radial (NOT ring shaped)

What shape are the muscles found in the iris which are responsible for dilating the pupil?

The sound will vibrate through the midline of the patient's forehead and make it seem as if sound is coming from both ears -- however, the good ear will have environmental sounds competing with this sound which will reduce it's loudness, while the bad ear will only seem to hear the sound of the tuning fork

In a Weber test, why is the sound louder through a patient with conductive hearing loss' bad ear?

Cortex

In a nephron, this general region contains dilute interstitial fluid

Medulla

In a nephron, this general region contains highly concentrated interstitial fluid

True (Completely open once the membrane potential reaches 30mV and the voltage-gated sodium channels have closed)

In an action potential, voltage-gated potassium channels begin to open once a membrane potential of -55mV is reached (True/False)

False (In an extensor thrust reflex, Aβ (BETA) receptor cells fire to intermediate zone interneurons in the spinal cord which project to extensor motoneurons in the calf)

In an extensor thrust reflex, Aδ and C cells fire to intermediate zone interneurons in the spinal cord which project to extensor motoneurons in the calf (True/False)

LH

In both males and females, a high-frequency pusatile release of GnRH will stimulate the release of _______

FSH

In both males and females, a low-frequency pusatile release of GnRH will stimulate the release of _______

parasympathetic, contract

In bright light ______________ signals from the brain ____________(contract/dilate) the pupillary constrictor muscles, shrinking the pupil

constrict, dilate (Can dilate to ~20 times the size)

In bright light, the pupils __________(constrict/dilate) and in the dark they __________(constrict/dilate)

True (But we do still respond to airborne chemical signals)

In humans the vomeronasal organ disappears during fetal development (True/False)

LH

In males, this hormone stimulates leydig cells to secrete testosterone

FSH

In males, this hormone stimulates paracrine molecules needed for spermatogonia mitosis and spermatogenesis - also indirectly secretes inhibin (hormone that inhibits FSH release) and Androgen-binding protein [ABP] (Helps to concentrate androgens in testis)

False (In *multi-unit smooth muscle cells* each muscle cell is separated and each smooth muscle cell can be recruited to respond individually [leads to find movement])

In single-unit smooth muscle cells, each muscle cell is separated and each smooth muscle cell can be recruited to respond individually (leads to fine movement) (True/False)

Ryanodine receptor-channel (RyR)

In skeletal muscles this receptor is bound to DHP receptors and found on the sarcoplasmic reticulum -- upon depolarization, the DHP receptor undergoes conformational changes that opens this receptor to allow calcium to be released into the cytoplasm

Calmodulin

In smooth muscle cells, calcium binds to this molecule instead of directly binding to actin (Since smooth muscle cells don't have troponin)

The lens of the eye isn't bending the light rays enough -- Can be treated with an additional convex lens which can bend light rays even more before entering the eye

In terms of the lens, what causes hyperopia and how can it be fixed?

The lens of the eye is bending the light rays too much -- can be treated with a concave lens which can diverge light rays slightly before entering the eye

In terms of the lens, what causes myopia and how can it be fixed?

Neural plate

In the 20-day embryo this migrates towards the midline and is composed of neuro-ectodermal stem cells which will give rise to the CNS

good, bad

In the Weber test, if a patient has sensorineural hearing loss, the sound will be louder through their _______(good/bad) ear; if a patient has conductive hearing loss, the sound will be louder through their _______(good/bad) ear

True

In the absence of a functional SRY gene, the cortex of the bipotential gonads will develop into ovarian tissue (True/False)

True

In the absence of vasopressin, the collecting ducts are completely impermeable to water absorption (True/False)

False (In the ascending portion, only solutes are reabsorbed into the interstitial fluid)

In the ascending portion of the Loop of Henle, only water is reabsorbed into the interstitial fluid (True/False)

Bones (Bones - 99%, ICF - 0.9%, ECF - 0.1%)

In the body calcium is most abundant in the _________

One spike per 6 seconds

In the cortex, what is the average rate of action potentials produced per cell per second?

sympathetic, contract

In the dark ______________ signals from the brain ____________(contract/dilate) the pupillary dilator muscles, shrinking the pupil

True

In the descending portion of the Loop of Henle, only water is reabsorbed into the interstitial fluid (True/False)

insensitive, good (At the fovea, each ganglion cell gets input from a few photoreceptors -- mostly cones [insensitive to light], but each gets input from a few densely packed cones [good spatial acuity])

In the fovea, though each ganglion cell is _________(sensitive/insensitive) to light, they are ________(good/poor) at reporting spatial detail

sensitive, poor (In peripheral vision, each ganglion cell gets input from many photoreceptors [sensitive to light], but blends information over all these receptors [poor spatial acuity])

In the peripheral vision, though each ganglion cell is _________(sensitive/insensitive) to light, they are ________(good/poor) at reporting spatial detail

False (In the presence of a functional SRY gene, the MEDULLA of the bipotential gonads will develop into testis)

In the presence of a functional SRY gene, the cortex of the bipotential gonads will develop into testis (True/False)

True (Action potentials which don't reach 30mV can be made -- amplitude increases from a given stimulus as relative refractory period duration increases [Eg. amplitude from stimulus given at 1ms after beginning of relative refractory period is smaller than stimulus given at 1.5ms])

In the relative refractory period, smaller amplitude action potentials can be made (True/False)

Extensor burst generator

In the step cycle, this drives extensor motor nuclei and allows the leg to extend and stand

Flexor burst generator

In the step cycle, this drives flexor motor nuclei and allows the leg to flex

S4, 4

In voltage-gated channels, the voltage-sensing domain is the ____ segment which constitutes the ____th transmembrane domain

False (A grey block may be visualized as BLUE -- if the block were actually blue then it wouldn't be reflecting any light and would appear grey to our eyes, so the brain might infer it's colour based on the surroundings to be blue)

In yellow light, a grey block may be visualized as red (True/False)

Parasympathetic (Sympathetic decreases gastrointestinal activities)

Increased gastrointestinal activities indicates activity from the ___________(parasympathetic/sympathetic) nervous system

160 ms

Inference of the identification of objects is unconscious and fast - we can usually identify things visually in _______ ms without conscious effort

glycolysis, glycogenesis, glycogen

Insulin activates enzymes for glucose utilization (__________), and for glycogen synthesis (____________) - If more glucose has been ingested than is needed for energy and synthesis, the excess is made into ____________ or fatty acids

Tyrosine kinase (This type of receptor transfers a phosphate group from ATP onto a protein)

Insulin binds to this receptor in non-hepatocyte cells

False (Insulin INDIRECTLY increases the glucose uptake by the liver - The presence of insulin will allow it's binding onto hexokinase on hepatocytes [liver cell] which then phosphorylates glucose to glucose-6-phosphate - this tricks the cell into thinking the glucose concentration is low in the cell and more glucose diffuses into the cell through GLUT2 facilitated diffusion transporters)

Insulin directly increases the glucose uptake by the liver (True/False)

False (Insulin is the dominant hormone of the fed state and decreases blood glucose, promotes the formation of glycogen, fat, and protein)

Insulin increases blood glucose and breaks down glycogen, fat, and protein (True/False)

False (Insulin is a peptide hormone)

Insulin is a steroid hormone (True/False)

hyper, hypo

Insulin prevents (hyper/hypo)_________glycemia and glucagon prevents (hyper/hypo)_________glycemia

True (Intermediate filaments help with contraction by increasing the tension during contraction since the myosin spindles are bound together at different angles *[unlike skeletal muscle cells]*)

Intermediate filaments help with contraction of smooth muscle cells (True/False)

Luteinizing Hormone(LH)

LH; This hormone is trophic in the gonads

False (Large fibres enter the spinal column and run ipsilaterally (same side of the body) up to the medulla oblongata where they synapse on cells whose axons *cross the midline* [so left hemisphere receives right side somatosensory information and vice versa])

Large fibres of the somatosensory neural system enter the spinal column and run ipsilaterally (same side of the body) up to the medulla oblongata where they synapse on cells which run ipsilaterally to the brain (True/False)

Late in neocortex development, neurons have a long distance to cross, so radial glial guides (neuronal progenitor cells) extend processes to connect the ventricular zone with the plial surface - support migration of many neurons

Late in neocortex development, how do neuronal cells migrate from the ventricles to the pial surface?

False (Lateral inhibition is in the visual system to enhance edges and in somatosensory system to enhance edges formed by touch, temperature, etc. [Eg. Water surface is the most uncomfortable upon entering a pool])

Lateral inhibition is only exhibited in the somatosensory fibres (True/False)

Receptor Channel

Ligand binding opens or closes these channels and alters the ion flow across the membrane

Receptor-enzymes

Ligand binding to this enzyme activates an intracellular enzyme; has two regions: a receptor region on the extracellular side and an enzyme region (with an active binding site that phosphorylates or amplifies proteins) on the cytoplasmic side (may or may not be separate proteins)

Integrin Receptors

Ligands that bind to this receptor alters enzymes or the cytoskeleton

True

Lipophilic signals are generally gene modulators and directs the nucleus to make mRNA (True/False)

• Stretch reflex • Golgi tendon reflex • Flexion withdrawal reflex • Patellar tendon reflex • Cross extension reflex • Extensor thrust reflex • Vestibulo-spinal reflex

List 7 examples of reflexes

- Temperature regulation - Regulation of feeding - Plasma osmolality - Sexual response - Stress response

List five functions of the hypothalamus

1. Baroreceptors in the heart send afferent signals to the nucleus solitary tract (NTS) located in the medulla 2. The NTS sends signals to the ventrolateral medulla (VLM) 3. Rostral and caudal VLM excitation levels will dictate the response of the sympathetic efferent output to the heart

List the pathway for a baroreflex (3)

NMDA receptor

Long-term potentiation is mediated by these receptors - when the cell is depolarized it allows an influx of calcium into the cell which triggers ionotropic EPSP enhancement, upregulation, etc.

False (MLCP activity is constitutive in smooth muscle cells -- during relaxation calcium is sequestered back into the ECF or SR which reduces MLCK activity so the MLCP activity dominates [leading to decrease in muscle tension])

MLCP activity is increased after a power stroke in smooth muscle tissues (True/False)

True

Majority of axons are unmyelinated (True/False)

False (Fetus' with non-functional androgen receptors lack external male genitalia, internal male organs, and internal female organs -- however they have testes since this is coded by the SRY gene and is testosterone independent)

Male fetus' with non-functional androgen receptors lack testes, external male genitalia, internal male organs, and internal female organs (True/False)

False (Each corpuscle is made up of many looping endings)

Meissner corpuscles are made up of several linear endings and detect sideways shearing (True/False)

Nicotinic receptors (This is why smokers have low hunger and can be susceptible to malnourishment)

Melanocortin receptors (of the arcuate nucleus) contain these receptors which activate the satiety network (stimulation of these receptors on melanocortin will reduce hunger)

Suprachiasmatic nucleus

Melanopsin ganglion cells are photoreceptors and send signals to this region of the brain which is a center for circadian rhythms

1. Suprachiasmatic nucleus (Region of hypothalamus) 2. Pretectal area → sympathetic efferents → superior cervical ganglion → pineal body

Melanopsin signals project to these two areas

False (Melatonin is a *neurohormone* involved in sleep induction)

Melatonin is a neurotransmitter involved in sleep induction (True/False)

True

Membrane resistance is an important factor when considering the length constant (True/False)

Rapid, nongenomic

Membrane steroid receptors produce _________ (rapid/slow) ____________ (genomic/nongenomic) responses

False (Often coupled to GTPases that can influence intracellular activity -- namely G-proteins)

Metabotropic receptors are usually coupled to ATPases that can influence intracellular activity (True/False)

False (Most corticospinal pathways cross overto the opposite side of the spine and innervate motor neurons via interneurons)

Most corticospinal pathways don't cross over to the opposite side of the spine and directly innervate the motorneurons in the spine (True/False)

Peptide

Most hormones are ___________ (peptide/steroid/amine) hormones

True (Not many mechanoreceptors are tonic [exception - Merkel receptors] which explains why you can sense more texture when running a hand along a surface than if you stall your hand against the surface)

Most mechanoreceptors are phasic (True/False)

Interneuronal

Most of the descending axons from the motor cortex to the spinal cord go to the ___________(dorsal/interneuronal/ventral) neurons

Most postganglionic parasympathetic neurons secrete *acetylcholine* onto *muscarinic receptors*

Most postganglionic parasympathetic neurons secrete this hormone onto their respective receptors (Which hormone? Which receptor?)

Most postganglionic sympathetic neurons secrete *norepinephrine* onto *adrenergic receptors*

Most postganglionic sympathetic neurons secrete this hormone onto their respective receptors (Which hormone? Which receptor?)

True (Required for ATP hydrolysis)

Most primary active transport channels are ATPases (True/False)

Thalamus

Most sensory pathways run through this brain centre first, which is near the centre of the brain, before going out to the sensory cortices on the surface of the cerebrum

False (While most thyroid hormone in the plasma is in the form of T4, T3 is the more active hormone - target cells make most of their T3 by using deiodinase enzymes to remove an iodine from T4)

Most thyroid hormone in the plasma is in the form of T4, and T4 is the active hormone (True/False)

False (A muscle fibre is a single muscle cell that runs between tendons -- it is developed from the fusion of multiple embryonic myoblast cells and thus has several nuclei)

Multiple muscle cells form a single muscle fibre and is formed from several different myoblast cells during development (True/False)

False (Muscle contraction begins with small motor units being activated first for more precise movements)

Muscle contraction begins with large motor units being activated first (True/False)

True

Myelin sheaths have a plasma membrane that allows it's low permeability to ions (True/False)

True

Myelinated axons can conduct action potentials up to speeds of 80-100 m/s (True/False)

True (these areas do not have high density voltage- gated Na+ channels)

Neuronal dendrites and cell bodies cannot initiate an action potential (True/False)

True

No two sensory neurons will have the same receptive field (True/False)

False (DESCENDING pathways through the thalamus can block nociceptive cells in the spinal cord in emergency situations)

Nociceptive pathways can be blocked in the spinal cord via ascending pathways in the spinal cord in emergencies where survival depends on ignoring pain (True/False)

Hypothalamus Limbic system (Amygdala, hippocampus, cingulate gyrus)

Nociceptive signals reach these organs in the brain to cause symptoms such as emotional distress, nausea, vomiting, and sweating

True

Nociceptors are free nerve endings (True/False)

True (Nodes of Ranvier have a high density of voltage gated sodium which squeeze any other channels out so that an action potential can propagate down the length of the axon)

Nodes of Ranvier don't contain any potassium channels (True/False)

Alpha, beta (Beta-1 > Beta-2)

Norepinephrine is a potent ______ receptor agonist and a modest _____ receptor agonist

True

Of the millions of sperm in a single ejaculation, only about 100 reach the ampullary of the fallopian tube and are able to fertilize an egg (True/False)

True

Olfaction adapts slowly (True/False)

Pinocytotic

Olfactory cells are _________ - this means they continually sip in fluid and send it along the nerves into the brain

True (Olfactory cells degenerate after a month or two before being replaced)

Olfactory receptor cells can regenerate (True/False)

True

Olfactory receptor cells fire action potentials (True/False)

Olfactory bulb

Olfactory receptor cells project onto this extension of the cerebrum which lies underneath the frontal lobes

Cribriform plate

Olfactory receptor cells send their axons into the brain through tiny holes in this bone -- this bone is found at the base of the cranial cavity

False (As few as *1000* fibers may carry temperature information up the spinal cord to the brain since precise localization isn't crucial for temperature)

Only 50 fibers are required to carry temperature information up the spinal cord to the brain since precise localization isn't crucial for temperature (True/False)

False (Only type III cells form synapses with sensory neurons)

Only type II taste receptor cells form synapses with sensory neurons (True/False)

Activated, excites

Orexinergic neurons are ____________(activated/inhibited) by the suprachiasmatic nucleus and ____________(excites/inhibits) the Tuberomamillary nucleus

Supraoptic nucleus

Osmoreceptors are found in this nucleus region of the hypothalamus

LH

Ovulation is triggered by high levels of which hormone?

Increases

PTH indirectly _________ (increases/decreases) intestinal calcium absorption

Increasing, increase, decrease

PTH works on the bone by ______________ (increasing/decreasing) cAMP to ______________ (increase/decrease) the level of RANKL and ______________ (increase/decrease) the level of OPG

True

Peptide hormones are water soluble (True/False)

Short (Dissolve easily in the extracellular fluid)

Peptide hormones have a _______ (short/long) half life

True (Threshold is the weakest stimulus a receptor can detect, perceived threshold is usually less accurate)

Perceptual threshold is always at least as high as the actual threshold, but is usually higher (True/False)

Propriospinal tracts

Phase linking between the legs and the arms during a step cycle is regulated by these tracts in the spinal cord

Alpha

Phenylephrine primarily works on _______ receptors

False (Postganglionic axons project from the periphery [outside the CNS] to the target tissues)

Postganglionic axons project from the CNS to the target tissues (True/False)

Some efferents use *Nitrous oxide (NO)*, such as for *penile erections*

Postganglionic parasympathetic efferents project to target tissues using acetylcholine as the neurotransmitter; what is the exception to this?

For *skin sweat glands*, the neurotransmitter used is *acetylcholine*

Postganglionic sympathetic efferents project to target tissues using norepinephrine (AKA noradrenaline) as the neurotransmitter; what is the exception to this?

Reticular formation

Postural CPGs in this region of the brain coordinate the upper body motion during a step cycle with the lower body

Pons, medulla

Postural maintenance is organized in these two regions of the brain located in the reticular formation

False (Preganglionic axons project to ganglia located between the CNS and target tissues)

Preganglionic axons project to ganglia located between the brain and the ventral horn of the spinal cord (True/False)

Long, short

Preganglionic neurons projecting to the parasympathetic chain are ______(short/long), while postganglionic neurons projecting from the parasympathetic chain are ______(short/long)

Short, long (Pre and postanglia linked together in sympathetic chain)

Preganglionic neurons projecting to the sympathetic chain are ______(short/long), while postganglionic neurons projecting from the sympathetic chain are ______(short/long)

Intermedio-lateral horn

Preganglionic sympathetic efferents project from this region of the thoracic cord to postganglionic efferents in the peripheral nervous system (Number 6 on diagram)

False (Premotor cortex neurons are typically only active before a movement -- *preparatory phase* - they facilitate appropriate synergies in motor cortex)

Premotor cortex neurons are typically active directly before and during the action of a movement (True/False)

False (Primary oocytes are only produced prenatally and females are born with all their primary oocytes)

Primary oocytes are produced twice during a female's lifetime: prenatally and during puberty (True/False)

False ([Cortisol is converted to cortisone because of their structural similarity - equal affinity to binding onto aldosterone receptors in kidneys] Cortisone has a smaller affinity for the mineralocorticoid receptors - the conformational change ensures that cortisol doesn't bind to these receptors and allows more aldosterone to bind to the receptors and take effect in the nephrons)

Principal cells in the distal tubule express 11β-hydroxysteroid dehydrogenase which converts cortisol to cortisone and allows the cortisone molecules to bind more easily to the mineralocorticoid receptors (True/False)

Symmetric (1 neuronal progenitor divides into 2 neuronal progenitor cells - increases progenitor cell pool)

Prior to 6 weeks embryonic development, neuronal progenitors experience _____________(symmetric/asymmetric) division

Luteal Phase

Progesterone is dominant during which phase(s) of the ovarian cycle?

False (INHIBITORS of 5α-reductase are used to treat benign prostate enlargement and male pattern baldness - DHT is potent 'form' of testosterone)

Promoters of 5α-reductase are used to treat benign prostate enlargement and male pattern baldness

Pretectal area of the midbrain

Pupillary light reflex is organized in this region of the brain

Slow-twitch oxidative > Fast-twitch oxidative > Fast-twitch glycolytic

Rank the capillary densities of the skeletal muscle types

Slow-twitch oxidative > Fast-twitch oxidative > Fast-twitch glycolytic

Rank the skeletal muscle types in terms of how much mitochondria they hold onto (or use)

1. Directly open ion channels (Ionotropic) 2. Activate enzyme via G-protein coupling (Metabotropic)

Receptor proteins embedded within neurons are similar to postsynaptic proteins in that they can trigger one of two mechanisms - what are they?

False (When co-contraction of antagonists desired [for joint stiffness] reciprocal inhibition is suppressed)

Reciprocal inhibition is always active (True/False)

Higher (Red = 700nm, Violet = 400nm)

Red light has a ___________(lower/higher) wavelength than blue light

Coated pits

Regions of the plasma membrane where receptor-mediated endocytosis takes place; most common protein found here are clathrins

Biorhythm

Regulated variables that change predictably and create repeating patterns or cycles of change; coincides with predictable environmental changes such as daily light-dark cycles or the seasons (Eg. Circadian rhythm)

Prevent (Calcium is an important cofactor in coagulation cascade)

Removal of Ca2+ from a blood sample will ____________ (prevent/promote) the specimen from clotting in the test tube

Increase (Through Long-term potentiation)

Repeated high frequency stimulation of a synapse results in a(n) __________(increase/decrease) of EPSP size

False (Rhodopsin absorbs light best in blue-green wavelengths [498nm])

Rhodopsin absorbs light best at around 400nm (True/False)

More (Rods can detect single photons)

Rods are ________(more/less) sensitive to light than cones

Dorsal (Since sensory signals arrive on the dorsal root)

Sensory nuclei are in the ________ horn of the spinal cord grey matter

Ectohormone

Signal molecules secreted into the external environment

Ventroposterolateral nucleus (VPL)

Signals from the spinal cord travel via this section of the thalamus

Gap junctions (Neurotransmitters are dropped off over a broad region, and they can be propagated through adjoining smooth muscle cells so the entire sheet of cells acts as a singular unit)

Single-unit smooth muscle cells are connected together by these junctions

Somatic

Skeletal muscles are activated by the _________(somatic/autonomic/central) nervous system

False (Somatosensory receptor cells are all neurons)

Somatosensory receptor cells all have a graded potential (True/False)

Primary somatosensory cortex (S1)

Somatosensory signals from both the head and spinal cord pass to this cortex of the brain

True (They don't synapse at the medulla like the large fibres)

Small fibres of the somatosensory neural system synapse directly into the brain (True/False)

False (Smooth muscle cells lack sarcomeres and therefore lack striations)

Smooth muscle cells have sarcomeres (True/False)

Smaller

Smooth muscle cels are ________(smaller/larger) than skeletal muscles

Troponin Tropomyosin (Myosin is also longer)

Smooth muscles lack these proteins on the myofibrils (in comparison to skeletal muscles)

Transverse tubules (Since cells are smaller)

Smooth muscles lack this organelle compared to skeletal muscles

Extended

Smooth muscles sustain contractions for a(n) ____________(shorter/extended) period of time in comparison to skeletal and cardiac muscles

False (Signals from the head travel via the *ventroposteromedial nucleus *[VPM])

Somatosensory signals from the head connect to signals from the spinal cord and eventually to the ventroposterolateral nucleus of the thalamus (True/False)

Pheromone

Specialized ectohormones that act on other organisms of the same species to elicit a physiological or behavioural response

Homeostasis

Stability of the body's internal environment

True

Stretch reflex is responsible for stabilizing posture (True/False)

False (A centrally coordinated response [CPG] would be required)

Stretch reflexes can restore postural stability after a perturbation (True/False)

False (Striations are the functional units of the myosin structures)

Striations of skeletal and cardiac muscles are caused by contractions of muscle cells

True

Summation can occur in skeletal muscles (True/False)

False (ALL NMJ synapses are excitatory, so they do not release inhibitory NT's such as Glycine)

Synapses of the neuromuscular junctions mainly release either Glycine and Acetylcholine (True/False)

Trophoblasts

Syncito____________ (Exterior) and Cyto____________ (interior) will help with invasion of the endometrium, formation of the placenta, and the secretion of hormones - hCG, Estrogen, progesterone, and human placental lactogen

False (TRP channels are found on the walls of the mouth)

TRP channels sensitive to temperature and chemicals (Eg. vanilloid, TRPM8) are found on the tongue (True/False)

Gs

TSH stimulates the production of thyroid hormones by attaching to the _____ receptor on the follicular thyroid cells - this activates specific transcription factors that turn on genes involved in T4, T3 synthesis (eg., thyroglobulin, peroxidase) and thyroid growth (e.g. c-fos, c-myc)

False (Taste buds are EPITHELIAL CELLS [don't fire action potentials] that contact the oral cavity through a small opening called the taste pore)

Taste buds are neurons that contact the oral cavity through a small opening called the taste pore (True/False)

False (Temperature remains fairly constant in the body)

Temperature is a major factor that affects the rate of simple diffusion in the body (True/False)

False (The cornea is continuous with the sclera)

The cornea and the sclera are separate and segmented regions of the eye (True/False)

False (Female external genitalia develops 'by default' unless DHT (if present) promotes the development of male external genitalia)

Testosterone is present during female external genitalia development in the fetus (True/False)

False (The cardiac muscles don't experience summation, and their contraction is always regular)

Tetanus can affect the heart (True/False)

Positively

The S4 segment of a voltage gated channel is _____________ (negatively/neutrally/positively) charged

Polarized (The voltage-gated channel functions to maintain a charge gradient such that the cell is internally negatively charged)

The S4 wing of a voltage gated channel will close the channel when the membrane is ___________ (polarized/depolarized)

False (TDF binds to DNA which will promote synthesis of additional proteins [SOX9, WT1, SF1] which will direct development of the gonadal medulla into a testis)

The SRY gene produces a protein known as Testis-determining Factor (TDF) which directly acts on the bipotential primordium to conduct testis development (True/False)

Rostral

The _______(rostral/caudal) half of the ventrolateral medulla excites sympathetic efferents which raises blood pressure and heart rate

Somatic (Both located in dorsal horns)

The ___________(somatic/visceral) sensory nuclei are located more dorsally on the spinal cord

Anterior

The ____________ pituitary is a true endocrine gland of epithelial origin, derived from embryonic tissue that formed the roof of the mouth

Posterior

The ____________ pituitary is an extension of the neural tissue of the brain and it secretes neurohormones made in the hypothalamus; the hormones are stored here in vesicles until a stimulus reaches the hypothalamus, and electrically signals the neuron cell connecting this gland to the hypothalamus - this opens voltage gated Ca2+ channels which allows the ions to cause exocytosis of the vesicles and releases the hormones into circulation

Somatic motor (Both located on ventral horn)

The ____________(somatic motor/autonomic efferent) nuclei are located more ventrally on the spinal cord

Acclimation

The adaptation of physiological processes to a given set of environmental conditions set in an artificial laboratory environment

False (The adrenal medulla is directly activated by the sympathetic nervous system [responses to a perceived threat])

The adrenal medulla is directly innervated by the parasympathetic nervous system to respond in secreting catecholamines (True/False)

False (Amount of insulin taken intravenously < amount of insulin taken orally - This is due to the release of GLP-1 and GIP peptides, both of which increase insulin production and decreases gastric acid [feedforward response])

The amount of insulin released from glucose taken intravenously is higher than the amount of glucose from glucose taken orally (collected in intestines) (True/False)

False (Frequency of APs transmits information about stimulus strength and duration -- strong stimulus causes more APs and releases more NT, weak stimulus releases little NT)

The amount of neurotransmitter released by an axon is binary similar to the creation of an action potential -- either released or not released (True/False)

True

The autonomic nervous system is responsible for things including: fight or flight, exercise, eating, emotions, among other things (True/False)

False (The basilar membrane is STIFF near the oval window and more flexible near the helicotrema)

The basilar membrane is more flexible near the oval window (True/False)

True (Basilar membrane is narrow near the oval window and becomes wider as it reaches the helicotrema)

The basilar membrane is more narrow near the oval window (True/False)

False (Chorionic villi from the placenta will take nutrients, gases, and exchange wastes with the maternal blood, but blood is never exchanged)

The blood of the mother and the growing embryo mix as the embryo is developing so that essential nutrients, gases, and other important factors can be shared (True/False)

False (white matter core, grey matter outside)

The brain has a grey matter core and white matter exterior (True/False)

False (The brain has ~2% of the body's mass, but gets 15% of the blood pumped by the heart and consumes half the body's glucose)

The brain has ~2% of the body's mass, but gets 25% of the blood pumped by the heart and consumes a quarter of the body's glucose (True/False)

Lateral

The cardiovascular and respiratory control centres are located in the _________(lateral/medial/frontal) medulla/pons

False (The caudal half of the ventrolateral medulla *inhibits the rostral half*'s activity which lowers blod pressure and heart rate)

The caudal half of the ventrolateral medulla excites parasympathetic efferents which lowers blood pressure and heart rate (True/False)

False (The lens has no blood supply and absorbs nutrients from the AQUEOUS humour)

The cells of the lens don't require any blood supply and absorb nutrients from the vitreous humour (True/False)

Phosphodiesterase (breaks phosphodiester bonds on cAMP) and Gi Protein (inhibits further production of cAMP)

The cellular response to the second messenger cAMP can be inhibited by activating ________________

False (The cornea can't adjust it's shape, the LENS can change shape to adjust focus)

The cornea can change shape to adjust the focus by altering the refraction within the eye (True/False)

False (Interact in a *negative feedback loop* [Tim/Per])

The circadian rhythm is regulated by gene transcription and translations interacting together in a positive feedback loop (True/False)

False (λ is a measure of potential difference decay and is directly related to conduction velocity)

The conduction velocity of an action potential is independent of the axon's membrane length constant (λ) (True/False)

Threshold

The minimum stimulus needed to set the reflex response in motion

False (The eustachian tube is an air-filled space connected to the pharynx)

The eustachian tube is connected to the larynx (True/False)

True

The extensor thrust reflex only operates when trying to support your weight (True/False)

False (Fertilized oocyte completes meiosis after sperm membrane fuses to it - the zona pelliculada will maintain it's small structure while it divides as it moves through the fallopian tube)

The fertilized oocyte will complete meiosis only after being implanted into the uterus where it can then proliferate and grow without hindering the fallopian tubes (True/False)

True

The flexion phase of the swing in the step cycle has a fixed duration, regardless of the speed of locomotion (True/False)

False (Mutually inhibit one another during step cycle -- when there is no leg movement, they are both spontaneously active)

The flexor burst generator and extensor burst generator work together at the same time while walking (True/False)

False (The central retinal region of the eye sends signals retinotropically -- the signal is sent such that the foveal region is processed centrally and peripheral visual signals are processed peripherally in the primary visual cortex [and LGN/other processing areas], however the foveal region does project to a large area due to it's large information density)

The foveal region (central retina) of the eye sends signals to the peripheral region of the primary visual cortex where it can occupy the most space since it has many photoreceptors and so carries a lot of information (True/False)

Cortical reaction

The fusion of sperm and oocyte membrane triggers a chemical reaction called the __________ __________ - Immediately, the oocyte depolarizes it's membrane (fast polysperm block) and membrane-bound cortical granules in the peripheral cytoplasm of the egg release their contents into the space just outside the egg membrane (slow polysperm block) - These chemicals rapidly alter the membrane and surrounding zona pellucida so that additional sperm cannot penetrate or bind

True (Faster depolarization leads to faster hyperpolarization and refractory period -- leads to higher frequency of action potentials)

The greater the depolarization caused by a stimulus, the faster the membrane will be brought up from hyperpolarization to generate a new spike (True/False)

True

The head stays stable while walking (True/False)

False (The hormones of the posterior pituitary [vasopressin, oxytocin] are made in the hypothalamus)

The hormones produced by the posterior pituitary gland are vasopressin and oxytocin (True/False)

True

The hypothalamus interacts with the brainstem, motor, and autonomic centers via axonal projections, as well as the pituitary gland (True/False)

True (Receives information from melanopsin)

The hypothalamus interacts with the retina (True/False)

Human chorionic gonadotropin (hCG)

The initial secretion of this peptide hormone is essential to maintain the corpus luteum which is required to maintain progesterone levels so menses doesn't occur and so the endometrium stays intact - this hormone is secreted by the chorionic villi and the developing placenta In male fetuses it is also required to stimulate testosterone production by their developing testes

Preprohormones

The large inactive peptide that comes off a ribosome; contains one or more copies of a peptide hormone (may be same or different), a signal sequence that directs the protein into the lumen of the rough endoplasmic reticulum, and other peptide sequences that may or may not have biological activity

37

The length constant (λ) is specifically defined as the distance a signal can travel, to the point where the voltage drops to about ___% of its original value

decreased, decreased (Larger diameter leads to less internal resistance - less voltage is lost across that resistance as the currents travel down the membrane) (Higher membrane resistance leads to less current leakage - current is forced down the membrane)

The length constant (λ) of an axon is ____________(increased/decreased) by decreasing diameter and ____________(increased/decreased) by decreasing membrane resistance

Crystallins

The lens is made of long cells without nuclei packed with these clear proteins which are 'zippered' together in concentric layers for flexibility

False (The main purpose of the sodium-potassium pump is to create opposing transmembrane gradients for [Na+] and [K+])

The main purpose of the sodium-potassium pump is to create a potential difference across cell membranes (True/False)

Chemical

The majority of synapses use ________(electrical/chemical) synapse junctions

True (motivation was tightly linked to smell in early animals -- emotions no longer so smell-related)

The olfactory bulb projects to the limbic system (True/False)

False (The olfactory epithelium lies at the top of the nasal cavity covering around ~*3*cm² on each of the two sides)

The olfactory epithelium lies in the centre of the nasal cavity covering around ~5cm² on each of the two sides (True/False)

False (the opening of voltage gated Na+ channels stimulates other voltage gated Na+ channels to open in a positive feedback loop)

The opening of voltage gated Na+ channels inhibits other voltage gated Na+ channels in a negative feedback loop (True/False)

Intermediate (Maximal overlap = Small distance to move by actin, Minimal overlap = Nothing for myosin to bind onto/not enough tension produced)

The optimal length of a myofibril (where tension is the highest) is determined by a __________(maximal/intermediate/minimal) overlap between the thick and thin fibres

False (The organ of corti contains auditory receptor cells [hair cells] which are EPITHELIAL CELLS that number around 20000 per cochlea)

The organ of corti contains auditory receptor cells (hair cells) which are neurons that number around 20000 per cochlea (True/False)

Basilar membrane, tectorial membrane

The organ of corti sits on the _____________(basilar membrane/tectorial membrane) and under the _____________(basilar membrane/tectorial membrane)

False (The refractive indices of water and collagen are very similar, so as light enters our cartilaginous corneas, refraction doesn't occur very well and hence isn't focussed well)

The refractive indices of water and collagen are very different and that is the reason why we aren't able to see clearly through water (True/False)

True (Loudness depends on both amplitude and frequency [Eg. A sound of 30000Hz is beyond the human hearing range and thus cannot be percieved as loud independent of it's amplitude])

The perception of loudness depends on frequency (True/False)

Sympathetic, darkness

The pineal gland is activated via the ___________ nervous system in _____________(lightness/darkness)

False (Blocked by small amounts of blue-green light [regulated by melanopsin which absorbs best at blue-green wavelengths])

The pineal gland will be blocked by even small amounts of red light (True/False)

True

The precursor prohormone for glucagon contains glucagon, GLP-1, and GLP-2 (True/False)

True (Neighbouring areas of skin project to neighbouring cells in the cortex and to the opposite hemisphere of the brain)

The primary somatosensory cortex is somatotopic and contralateral (True/False)

Signal Transduction

The process by which an extracellular signal molecule activates a membrane receptor that in turn alters intracellular molecules to create a response

False (The production of ATP [through glycolysis] in a beta cell CLOSES a potassium channel (potassium levels INCREASE in the cell) which depolarizes the cell and allows calcium to enter - the calcium can then trigger exocytosis which will stimulate the release of insulin)

The production of ATP (through glycolysis) in a beta cell opens a potassium channel (potassium levels decrease in the cell) which depolarizes the cell and allows calcium to enter - the calcium can then trigger exocytosis which will stimulate the release of insulin (True/False)

Long-loop negative feedback

The relationship when the last hormone in a pathway feeds back to suppress secretion of its trophic hormones - Eg. Cortisol secreted from the adrenal cortex feeds back to suppress secretion of hypothalamic corticotropin-releasing hormone (CRH) and adrenocorticotropin (ACTH) from the anterior pituitary

Short-loop negative feedback

The relationship when the pituitary hormones feed back to decrease hormone secretion by the hypothalamus (In contrast to the last hormone in the pathway feeding back to suppress secretion of it's trophic hormones)

False (Signal conduction is rapid and bi-derectional)

The signal conduction is rapid and uni-derectional in electrical synapses (True/False)

Constant

The signalling strength in any one neuron is __________ (constant/variable) in strength

False (Mutually inhibit one another)

The sleep switch centre and wake switch centre work exclusively together to form a sleep-wake cycle (True/False)

Inhibits, excites

The sleep-switch centre of the brain _________(inhibits/excites) the brain stem activating centre and the wake-switch centre of the brain _________(inhibits/excites) the brain stem activating centre

False (Step cycle controlled by neurons in the intermediate zone of the LUMBAR cord)

The step cycle of each leg during walking is programmed by a network of neurons within the intermediate zone of the thoracic section of the spinal cord (True/False)

False (The stereocilia extend into the tectorial membrane)

The stereocilia extend into the basilar membrane (True/False)

Prohormone

The smaller inactive preprohormone found in the endoplasmic reticulum/golgi apparatus after the signal sequence has been removed

Primary (Moves potassium and sodium against their concentration gradients -- requires ATP)

The sodium potassium pump is a ___________ (primary/secondary) transporter

Parietal lobe

The somatosensory cortex is located in this lobe of the brain

31

The spinal cord has _____ segments

True

The spinal cord has a grey matter core and white matter exterior (True/False)

False (Spinal cord = ~1 billion neurons, brain = ~86 billion neurons)

The spinal cord has more neurons than the brain (True/False)

True (Dependent on speed and sensory feedback) (Eg. Mechanoreceptors from the foot feed sensory information and regulate how much force is required and how long you will be standing)

The stance phase of the step cycle has a variable duration (True/False)

True (Stimulus depolarization below -55mV will always give a negative output [no action potential] and a depolarization above -55mV will always give a positive output [action potential])

The stimulus to generate action potentials has a binary output regardless of stimulus strength (True/False)

False (The stretch reflex operates at a subconscious level)

The stretch reflex can operate at a conscious level (True/False)

Endocrinology

The study of hormones

Parathyroid hormone, calcitriol (vitamin D), calcitonin

The three hormones that regulate the transport of Calcium between bone, kidney, and intestine?

False (High [K+] levels, Angiotensin II [Aka. LOW blood pressure], and ACTH)

The three stimulators of the release of aldosterone are: High [K+] levels, high blood pressure, and ACTH (True/False)

2.5mM

The total plasma calcium concentration is _______

False (The receptor determines the response of the cell)

The type of transmitter which binds to the receptor determines the response of the cell (True/False)

False (SCN controls 24hr oscillator)

The ultradian rhythms of sleep are controlled by the suprachiasmatic nucleus (True/False)

Identifying an object -- this allows the proper shaping of your hand in order to interact with the object

The ventral visual stream projects to the ventral premotor cortex -- what is it responsible for?

Outer (Counterintuitive system since outer segment is further from the light - Not all animals have this orientation)

The visual pigments which respond to light in both cones and rods are found on disk-like layers in the ________(inner/outer) segments of the cell

False (~120 million rods, ~6 million cones per retina)

There are more cones in the retina than rods (True/False)

False (Typically, neuron signals tend to converge so secondary and higher neurons combine data from many receptors)

There are typically more tertiary neurons than primary neurons (True/False)

Higher secretion in summer than winter

There is a higher secretion of melatonin in the ___________(summer/winter) than ___________(summer/winter)

True

Thermoreceptors are free nerve endings (True/False)

False (Thermoreceptors are phasic-tonic which is why we might respond quickly to a sudden change in temperature but won't respond to a gradual change)

Thermoreceptors are tonic which is why we get used to a hot bath or cold lake (True/False)

Osteocytes

These are bone cells responsible for maintaining bone (these are previous osteoblasts that are completely surrounded by bone matrix and therefore just maintain bone in its immediate vicinity)

Troponin

These are calcium binding structures on thin myofilaments

Ventricles

These are cavities found deep within the brain and responsible for CSF production among other things

Sertoli Cells

These are cells found in the seminiferous tubules and the function of these cells is to regulate sperm development by providing them with necessary proteins and enzymes

Target cells

These are cells that respond to chemical or electrical signals

Chorionic villi

These are cells that will become the placenta which form fingerlike projections that penetrate into the vascularized endometrium - enzymes from this structure break down the walls of maternal blood vessels in the endometrium until it is surrounded by pools of maternal blood

Mechanically-gated channels

These are channels primarily located in sensory cells (Eg. ears, nose) and respond to physical stimuli (Eg. Stretch, pressure)

Chondrocytes

These are collagen-producing cells of cartilage and are responsible for adding length to bone (found in the epiphyseal plate) (As the collagen layer thickens, the older cartilage calcifies and older cells degenerate, leaving spaces that osteoblasts invade; osteoblasts then lay down bone matrix on top of the cartilage base)

Spectral colors

These are colors that can be evoked by light of a single wavelength (rainbow colors)

Extraspectral colors

These are colors which are evoked only by a mix of wavelengths (Eg. purple, white)

Meissner Corpuscles

These are egg-shaped receptor cells found at the top of the dermis and are mainly found in the tongue and hairless skin (Eg. Palms, fingertips)

Protein kinases

These are enzymes that transfer a phosphate group from ATP to a protein

Semicircular canals (When your head turns, fluid sloshes which will activate hair cells and notify the brain)

These are fluid filled hoops that sense head rotation found in the vestibular apparatus

Myelin sheaths

These are formed by concentric layers (~150) of single oligodendrocytes or schwann cells and act as an insulating layer around axons

Cajal-Retzius Cells (Secretes glycoprotein Reelin)

These cells are involved in neuron migration during neocortex development and function to secrete a glycoprotein (what is the glycoprotein called?) which signals neurons to stop migrating and take their spot in the cortex

Glial cells

These cells assist the nervous system and are required for nutrition and increased membrane resistance

Hippocampal Place Cells

These cells respond to spatial locations in the environment as you pass through them by consolidating the memory of that location (probably not involved with memory storage)

Receptor cells

These cells, which may or may not be neurons, conduct stimuli (light, sound, ...) into electrical signals through transduction -- required as first step for sensory systems

Granulosa Cell

These cells, which surround the primary follicle, are primarily influenced by FSH and functions to secrete steroid hormones (synthesizes estrogen from androstendione released from theca cells) and AMH

Theca cells

These cells, which surround the primary follicle, are primarily influenced by LH and functions to synthesize androgens that diffuse into the neighbouring granulosa cells, where aromatase (an enzyme) converts them to estrogens

Neural crest cells

These embryonic cells make up the sensory and motor neurons of the peripheral nervous system (PNS)

Zonules

These ligaments suspend the lens within the eye

Leak channels (Eg. Potassium leak channel)

These membrane channels are kept perpetually open

Orexinergic neurons

These neurons are found in the dorsal hypothalamus and stabilize the waking state in relation to the circadian cycle -- this also provides a circadian drive for feeding (via the paraventricular nucleus)

Transverse tubules (T-Tubules)

These organelles within muscle cells create 'holes' in muscle cells to allow action potentials to go deep within the cell and trigger the release of calcium from sarcoplasmic reticulums

Tonic

These receptor types maintain their activity when the stimulus is not changing -- firing rates carry information about the present level of the stimulus

Phasic

These receptor types respond briefly to any change in input and then cease firing

Glucoreceptors

These receptors are found within the arcuate nucleus and the ventromedial nucleus and they sense the glucose levels in the blood

Adrenergic receptors (For noradrenergic vasoconstriction)

These receptors are tonically active to maintain blood pressure and is extremely important for the regulation of blood pressure (part of baroreflex)

Ciliary muscles

These ring-shaped smooth muscles control the contraction or relaxation of the lens

Androgens (from adrenal cortex)

These sex hormones are responsible for pubic and axillary hair and sex drive among other things (Androgens [from adrenal cortex] or Estrogen?)

Estrogen

These sex hormones are responsible for the development and maintenance of secondary sex characteristics such as breast development, fat distribution on hips and upper thighs among other things (Androgens [from adrenal cortex] or Estrogen?)

Oligodendrocytes

These specialized glial cells are found in the central nervous system and wrap around successive sections of an axon

Schwann cells

These specialized glial cells are found in the peripheral nervous system and wrap around successive sections of an axon

TRPM8

These specific TRP channels respond to cold and to menthol

Vanilloid receptors (TRPV1)

These specific TRP channels respond to damaging heat and to chemicals including the capsaicin in chilli peppers

Descending tracts (Mainly ventral since outgoing signals leave CNS through ventral horn)

These spinal cord tracts carry signals away from the brain and are mainly ventral

Ascending tracts (Mainly dorsal since sensory signals arrive at the dorsal horn)

These spinal cord tracts carry signals to the brain and are mainly dorsal

Cholecystokinin (CCK) (Hormone) Oleoylethanolamine (OEL) Glucagon-Like Peptide-1 (GLP-1)

These three peptides secreted by the duodenum activate vagal afferents in order to regulate feeding and satiety

Convex lens (Includes lens in eyes and magnifying glass)

These types of lenses converge light to a single focal point behind the lens

Concave lens

These types of lenses disperse light in different directions whose rays can be extrapolated to a single focal point in front of the lens

Gi Protein

This G protein targets the Adenylate Cyclase and inhibits it's enzymatic action

Gq Protein

This G protein targets the Phospholipase C enzyme responding in a stimulatory activity in the cell amplifying secondary messengers

Gs Protein

This G protein targets the adenylyl cyclase enzyme responding in a stimulatory activity in the cell amplifying secondary messengers

Adenylyl Cyclase (Aka Adenylate Cyclase)

This amplifier enzyme converts ATP to the second messenger molecule cyclic AMP (cAMP); Cyclic AMP then activates protein kinase A (PKA), which in turn phosphorylates other intracellular proteins as part of the signal cascade

Sarcoplasmic Ca2+ ATPase (Causes decrease in free cytosolic Ca2+)

This channel pumps calcium from the cytosol into the sarcoplasmic reticulum

White matter

This consists of myelinated axons running in bundles called tracts

Grey matter

This consists of nerve cell bodies, unmyelinated axons, and dendrites - the cell bodies are arranged either in layers (in parts of the brain) or in clusters called nuclei

Optic tracts

This denotes the optic nerve bundles emerging from the chiasm

Inhibitory Post Synaptic Potential (IPSP)

This describes an ion channel specific for Cl- or K+ ions and hyperpolarizes the cell

Excitatory Post Synaptic Potential (EPSP)

This describes an ion channel specific for cations (Na+, K+) and depolarizes the cell

Post-Synaptic Potential (PSP)

This describes the binding of the transmitter to the post-synaptic membrane resulting in a change in the post-synaptic membrane potential

Noradrenergic system

This diffuse modulatory system regulates attention, arousal, learning, memory, anxiety, pain, mood, etc. It functions through the thalamus, cerebellum, hypothalamus, and locus coeruleus NT: Norepinephrine

Serotenergic system

This diffuse modulatory system regulates mood, emotional behaviours, aggression, depression, etc. It functions through the basal nuclei and raphé nuclei NT: Serotonin

Cholinergic system

This diffuse modulatory system regulates the level of attention, sleep-wake cycle, arousal, learning, memory etc. It functions through the cingulate gyrus, fornix, and pontine nuclei NT: Acetylcholine

Dopaminergic system

This diffuse modulatory system regulates the reward centre It functions through the prefrontal cortex, basal nuclei, substantia nigra, and ventral tegmental area NT: Dopamine

Histaminergic system

This diffuse modulatory system regulates the sleep wake control and supports the waking state It functions through the posterior thalamus and projects through the forebrain and other regions (amygdala, pineal glands) NT: Histamine

Congenital analgesia

This disorder characterized from birth usually causes people to die before they are 20 because they are insensitive to pain or damage

Angiotensin Converting Enzyme

This enzyme converts Angiotensin I into Angiotensin II

Phospholipase C

This enzyme converts a membrane phospholipid (phosphatidylinositol bisphosphate) into two lipid-derived second messenger molecules: diacylglycerol (DAG) and inositol trisphosphate (IP3)

Proteolytic enzyme

This enzyme is packaged into the secretory vesicle with the prohormone and cuts the prohormone into it's active hormone and other fragments during post-translational modification

Myosin light chain phosphatase (MLCP) -- This removes phosphates from myosin light chains and decreases myosin ATPase activity

This enzyme reverses the effects of Myosin light chain kinase (MLCK)

Nernst equation (E = RT/F * ln([ion - outside]/[ion - inside])) R = gas constant F = Faraday's constant

This equation can be used to calculate the equilibrium potential

Neural tube

This forms from fused neural plate cells and eventually forms the CNS

Adenocorticotropin (ACTH)

This hormone acts on certain cells of the adrenal cortex to control synthesis and release of the steroid hormone cortisol

Vasopressin (Aka Antidiuretic Hormone [ADH])

This hormone acts on the kidneys to regulate water balance in the body

Growth Hormone (GH) (Aka Somatotropin)

This hormone affects the metabolism of many tissues in addition to stimulating hormone production by the liver

Thyrotropin (TSH)

This hormone controls hormone synthesis and secretion in the thyroid gland and is released by the anterior pituitary gland

Prolactin (PRL)

This hormone controls milk production in the female breast, along with other effects -- In both sexes, this hormone appears to play a role in regulation of the immune system

Oxytocin

This hormone controls the ejection of milk during breastfeeding and contractions of the uterus during labor and delivery for women - also believed to play an important role in social, sexual, and maternal behaviours

Anti-Müllerian Hormone (AMH)

This hormone is produced by ovarian follicles (in the granulosa cells) in the first part of the ovarian cycle -- It functions to act as a brake to keep too many follicles from developing at one time during the follicular phase of the ovarian cycle

Prostaglandins

This hormone is produced in the uterus in response to oxytocin and CRH secretion - they are very effective at causing uterine muscle contractions at any time and are the primary cause of menstrual cramps (they have been used to induce abortion in early pregnancy) -- during labor and delivery, these hormones reinforce the uterine contractions induced by oxytocin

GLP-1

This hormone is released from the intestine in response to glucose/amino acids - stimulates insulin secretion, increases beta cell mass in the pancreas, anorexigen (hormone which increases appetite), decreases glucagon

Ghrelin

This hormone is released from the stomach and promotes feeding

Glucagon

This hormone is secreted by Alpha cells in the pancreas in response from low glucose, SNS - functions to increase blood glucose, gluconeogenesis, glycogenolysis - catabolic pathways to increase energy

Epinephrine

This hormone is secreted by the adrenal medulla among other glands and is responsible for activating the flight-or-fight response -- functions by increasing: blood glucose levels, force of arterial contractions, fatty acid release, bronchodilations (increase rate of oxygen exchange), etc.

Insulin

This hormone is secreted in response to glucose, GLP1, PNS by Beta cells (islet of Langerhans) in the Pancreas - functions to decreases blood glucose, promotes anabolic pathways, involved with growth

Blind spot

This is a region of the eye which has no receptors due to it being a hole where axons carrying visual information exit the eyeball to form the optic nerve

Corticotropin-releasing hormone (CRH)

This hormone is the initiator of the HPA axis and is directly responsible for the production of POMC and indirectly responsible for the release of ACTH and cortisol - it is triggered by the circadian rhythm and stress and synthesized in the hypothalamus (released into anterior pituitary to stimulate POMC post-translation modification)

Circadian rhythm

This is a biorhythm governed by a neuronal oscillator with a near-24h period -- entrained to the exact day-night cycle by retinal inputs from ganglion cells with melanopsin

Remak bundle

This is a bundle of neurons which have some insulation from schwann cells or oligodendrocytes that engulf several axons without wrapping around them

Macula

This is a central disk in the eye which is most densely packed with photoreceptors

Cochlear duct

This is a central duct in the cochlea which contains which contains the auditory receptor cells

Fovea

This is a central pit in the eye located within the macula and is the most densely packed region within the eye and contains essentially all the cones of the eye

Neurocrine

This is a chemical signal secreted by neurons

Catecholamine

This is a class of amine hormones categorized as neurohormones that bind to cell membrane receptors the way peptide hormones do (Includes epinephrine, norepinephrine, and dopamine)

Thyroid hormones

This is a class of amine hormones which behave more like steroid hormones, with intracellular receptors that activate genes (Thyroxine [T4], Triiodothyronine [T3])

Glomerulus

This is a cluster of capillaries around the end of a kidney tubule, where waste products are filtered from the blood

Acromegaly

This is a condition caused by an excessive secretion of growth hormone and characterized by lengthening of the jaw, coarsening of facial features, and growth of the hands and feet

Perirhinal cortex

This is a cortical region of the medial temporal lobe which stores memories of small visual objects

Down-regulation

This is a decrease in receptor number on a cell - the cell can physically remove receptors from the membrane through endocytosis

Lumbar puncture (Spinal tap)

This is a diagnostic therapeutic procedure involving a sample collection of CSF from the spinal column for biochemical, microbiological, and cytological analysis

Reticular Activating System

This is a diffuse network of nerve pathways in the brainstem connecting the spinal cord, cerebrum, and cerebellum, and mediating the overall level of consciousness

Tetanus (Caused by inhibition of neurotransmitter release - exocytosis block)

This is a disease caused by a toxin produced by a bacterium Clostridium tetani - these toxins binds to peripheral nerve terminals and prevent synaptic vesicles with neurotransmitters from anchoring to the presynaptic terminal - this prevents release of inhibitory neurotransmitters (Eg. GABA and Glycine) and a dangerous overactivity of the muscles from the smallest stimuli can occur *Symptoms* - Severe muscle spasm and back arching (can break the spine), - Lockjaw, paralysis, grinning and raised eyebrows; - Breathing problems, swallowing difficulties

Conn's syndrome

This is a disease caused by an excess of aldosterone - can be a tumor in the adrenal cortex - symptoms include [K+] depletion, [Na+] retention, weakness, hypertension, polyuria (abnormally large volumes of dilute urine), and tetany (malfunction of parathyroid glands)

Cushing's syndrome

This is a disease caused by an excess of cortisol in the body - can be a tumour in the pituitary gland/hypothalamus that increases production of ACTH/CRH - symptoms include hyperglycemia, muscle protein breakdown, lipolysis but build up of fat on trunk and face, increased appetite, mood elevation followed by depression, difficulty with learning and memory

Hypothyroidism (goitre in this case caused by excessive TSH release - hormone levels still low due to lack of iodine)

This is a disease most commonly caused by a lack of iodine in the diet and because of the lack of T3, T4 hormone release, negative feedback is compromised; TSH is released in excess which enlarges the target gland Symptoms: lethargy, fatigue, cold-intolerance, weakness, hair loss, weight gain, and goitre

Hydrocephalus

This is a disease where an increase in CSF causes the ventricles of the brain to enlarge -- Caused by overproduction of CSF or insufficient drainage of CSF

Central Diabetes Insipidus

This is a disease where the pituitary gland doesn't secrete vasopressin/the hypothalamus doesn't make enough vasopressin, so the kidneys make a lot of dilute urine

Peripheral Diabetes Insipidus

This is a disease where vasopressin can't bind to it's receptors properly on the distal convoluted tubule/collecting duct and results in the kidneys making a lot of dilute urine

21 hydroxylase deficiency

This is a disease which occurs when a specific enzyme in the adrenal cortex pathway is deficient/genetically null (loss of function) - This affects the synthesis of cortisol and aldosterone and the high remaining levels of cholesterol (which would've been used to make aldosterone/cortisol) are instead diverted into synthesizing sex hormones -- This is the most common cause of ambiguous genitalia in infants

Vestibular duct

This is a duct through which vibrations travel through immediately after entering the cochlea through the oval window

Tympanic duct

This is a duct through which vibrations travel through in the cochlea prior to exiting through the round window

Positive feedback loop

This is a feedback loop response which sends the regulated variable even farther from its normal value. It initiates a vicious cycle of ever-increasing responses and sends the system temporarily out of control until an event outside the loop stops the response (Eg. The cervix continually stretches due to oxytocin releases which increases uterine contractions and pushes the baby through the cervix until the baby is delivered, releasing the cervical stretch)

Endolymph

This is a fluid similar to intracellular fluid and is found within the cochlear duct

Perilymph

This is a fluid similar to plasma contained within the outer ducts of the cochlea

Blastocoel

This is a fluid-filled cavity that forms in the blastocyst -- this pulls in water osmotically (due to high Sodium content from Na+/K+ - ATP channels) enlargening the blastocyst and pushing the inner cell mass to one side

Gestational diabetes mellitus

This is a form of diabetes with elevated blood glucose levels caused by insulin resistance and similar to type 2 diabetes -- this affects a mother and her growing embryo

β Catenin

This is a gene regulatory protein that suppresses SOX9 expression in female reproductive organ development

Pituitary Gland

This is a gland about the size of a pea and is situated in a bony hollow, just behind the bridge of your nose attached to the base of your brain by a thin stalk; Controls several hormone secreting glands in the body (Adrenal, thyroid, gonads)

Thyroglobulin

This is a glycoprotein secreted by follicular cells in the thyroid into the colloid - Tyrosine residues are modified by enzymes on this protein to create the thyroid hormones T3 and T4

Iris

This is a group of muscles found in front of the lens of an eye

Pupil

This is a hole in the iris through which light passes from the cornea to the lens

Blastocyst

This is a hollow ball of about 100 cells that implants itself onto the uterus (formed from the dividing fertilized egg)

Negative feedback loop

This is a homeotic pathway in which the response opposes or removes the signal (Eg. Heater in aquarium turns on/off once past a certain temperature threshold)

Calcitriol (Vitamin D3)

This is a hormone made from vitamin D obtained through diet or made in the skin which is then modified, first in the liver, then in the kidney - This is the primary hormone responsible for enhancing Ca2+ uptake from the small intestine, facilitates renal reabsorption of Ca2+, and helps mobilize Ca2+ out of bone - Decreased plasma Ca2+ increases PTH secretion, which stimulates this hormone's synthesis in the kidneys (Can also be stimulated by prolactin in breast-feeding women)

GnRH (Gonadotropin Releasing Hormone)

This is a hormone produced in the hypothalamus that directly stimulates the hormone production of LH and FSH in the anterior pituitary gland

Cortisol

This is a hormone released by the adrenal gland which is responsible for several bodily functions such as: liver gluconeogenesis, skeletal muscle protein breakdown (source of aa), fat lipolysis (source of FFA), glucagon and epinephrine activity, [Ca2+] reduction (decreases intestinal absorption, increases renal excretion and stimulates bone resorption), and immune system suppression - It's release is controlled by the HPA axis

Insulin-like growth factors (IGF)

This is a hormone released by the liver (and other tissues) which is stimulated by GH - it functions to stimulate bone and soft tissue growth as well as inhibit GH and GHRH (through somatostatin)

T3 (Triiodothyronine)

This is a hormone released by the thyroid gland and is synthesized by the coupling reaction of monoiodotyrosine and diiodotyrosine

T4 (Tetraiodothyronine/Thyroxine)

This is a hormone released by the thyroid gland and is synthesized by the coupling reaction of two diiodotyrosine molecules

Leptin

This is a hormone secreted by adipose tissues, which provides long-term suppression of feeding by inhibiting NPY neurons within the arcuate nucleus

Parathyroid hormone (PTH)

This is a hormone secreted by four small glands behind the thyroid gland and acts as both the sensor and integrating centre; the glands sense the Ca2+ concentration levels in the blood plasma with the aid of G-protein coupled Ca2+ receptors - when the levels get too low, the gland secretes this hormone as a negative feedback response which will target the bones, kidneys, and intestines to respond to create more Ca2+ ions

Growth Hormone

This is a hormone synthesized in the anterior pituitary and is a single-chain polypeptide (~190 amino acids) - This acts directly on tissue to increase growth and indirectly by stimulating IGF-1 (Insulin-like growth factor 1) release (anabolic for protein, catabolic for fat and carbohydrates)

Addison's disease

This is a hyposecretion of all adrenal steroid hormones possibly caused by an autoimmune destruction of the adrenal cortex - symptoms include loss of weight, fatigue, water retention and danger of water intoxication, diffuse tanning of the skin and spotty pigmentation - can be treated with cortisol intake

Pro-opiomelanocortin (POMC)

This is a large glycoprotein found in the anterior pituitary which, upon signalling from CRH, undergoes post-translational processing to produce a variety of biologically active peptides in addition to ACTH - It also produces beta-endorphin (endogenous opioid that binds to receptors in the brain that block pain perception), and further processing of ACTH produces alpha-MSH which inhibits food intake in the brain and influences melanocytes (colour) in the skin

Corpus callosum

This is a large segment of the brain comprised of a bundle of myelinated axons which connects the two hemispheres of the cerebrum

Central Nervous System (CNS)

This is a layer of neuronal tissue surrounding a fluid filled central cavity lined with epithelium

Threshold Potential

This is a level of depolarization necessary to open voltage gated channels and elicit a response

Amygdala

This is a major centre for autonomic control and it functions on autonomic functions by inhibiting the PAG & hypothalamus (Also a part of the limbic system) This is also a centre for memory creation, especially fearful ones (Yellow in picture)

Length constant (λ)

This is a measure of how quickly a potential difference disappears (decays to zero) as a function of distance on a neuron

Secondary Active Transport

This is a mechanism to move a substance up its concentration gradient without ATP catabolism

Primary Active transport

This is a mechanism to move selected molecules across cell membranes, against their concentration gradient -- Requires ATP

Oval window

This is a membrane that separates the middle and inner ear

Round window

This is a membrane through which wave energy can exit the cochlea

Type 2 diabetes mellitus

This is a metabolic disorder characterized by a defect in insulin secretion and target cell responsiveness to insulin is reduced - Not an autoimmune attack on beta cells, but an inability to properly respond to insulin and (possibly) a deficiency in insulin as well

Type 1 diabetes mellitus

This is a metabolic disorder where insulin secretion is reduced or absent; Theory is that an auto immune response attacks the Beta cells in the pancreas - Symptoms include: severe dehydration, ketoacidosis, polyuria (lots of urination), osmotic diuresis (increase of urination rate caused by the presence of certain substances in the small tubes of the kidneys), etc.

Nebulin

This is a molecule that runs down the middle of the actin filament (between the two protofilaments) and stabilizes the formation of thin filaments during their development (mainly acts as a stabilizer)

Narcolepsy

This is a neurological disorder that affects the control of sleep and wakefulness and can be caused by lesions to the orexinergic neurons

Frequency coding

This is a neuron intensity representation method by which stronger stimuli may make individual neurons fire at a faster rate

Vasopressin (Antidiuretic Hormone [ADH])

This is a nine-amino acid hormone released by the posterior pituitary gland in response to high plasma osmolarity (most potent), low blood pressure, and low blood volume - responsible for water reabsorption in the kidneys by binding to the distal convoluted tubule/collecting duct cell membranes and causing a signal cascade to place aquaporin-2 channels on the apical (luminal) side of the cell (thus allowing water to enter the cell and eventually the bloodstream)

Diacylglycerol (DAG)

This is a nonpolar diglyceride that remains in the lipid portion of the membrane and interacts with protein kinase C (PKC), a Ca2+ activated enzyme associated with the cytoplasmic face of the cell membrane - PKC phosphorylates cytosolic proteins that continue the signal cascade

Enteric nervous system

This is a part of the autonomic nervous system which controls digestion and movements of the gut -- although it gets input from the spinal cord, it can also work independently

Exocytosis (Used to export large lipophobic molecules such as proteins and neurotransmitters)

This is a partial or complete fusion of vesicles with the cell membrane for bulk transmembrane transport of specific molecules, from inside the cell to out

Urethra

This is a pathway for both sperm and urine in males, although not simultaneously

Calcitonin

This is a peptide hormone produced by the C cells of the thyroid gland - it is released when plasma calcium levels are high and it functions to decrease bone resorption and increase renal calcium excretion

Human Placental Lactogen (hPL)

This is a peptide hormone secreted by the placenta which contributes to lactation (breast development and milk production [however not required]), but more importantly has a role in alteration of the mother's glucose and fatty acid metabolism to support fetal growth (function similar to growth hormone)

Peptide tyrosine tyrosine (PYY)

This is a peptide released by the intestine which inhibits feeding

Tetanic contraction

This is a physiological term denoting a prolonged contraction of myofibrils at a maximum tension

Red nucleus

This is a portion of the midbrain which contains rubrospinal cells that activate localized synergies, especially in distal limbs and in the face (Eg. Gripping and twisting movements)

Zona Pellucida

This is a protective glycoprotein coat surrounding the ovulated oocyte

Desensitization

This is a quick and easily reversible way to decrease the number of active receptors on a cell - it can be achieved by binding a chemical modulator to receptor proteins

RANK

This is a receptor found on osteoclast precursors which when attached to it's respective ligand, will differentiate the osteoclast precursor and allow it to function

Osteoprotegerin (OPG)

This is a receptor secreted by osteoblasts which prevents the RANKL ligand to bind to RANK receptors - the secretion of this receptor helps regulate the amount of bone break down caused by osteoclasts

Polysynaptic reflex

This is a reflex that has two or more synapses between the efferent and afferent neurons in the spinal cord

Monosynaptic reflex

This is a reflex which has a single synapse between the efferent and afferent neurons in the spinal cord

Cingulate motor area

This is a region of the brain located within the cingulate sulcus and is responsible for processing emotional and motivational drive for movements

Periaqueductal grey (PAG)

This is a region of the brainstem organized into longitudinal columns, according to behavioural patterns that interacts heavily with the hypothalamus and reticular formation

Premotor cortex

This is a set of regions projecting into the motor cortex (also has parallel routes to motor nuclei [in brain stem]) It functions to process sensory inputs, especially visual and auditory, for cueing movement phases 3 areas: Dorsal, ventral, and Broca's area

Corpora Cavernosa

This is a set of two columns of tissue which constitute the erectile tissue of the penis and fills with blood during an erection

Paracrine signal

This is a signalling chemical that acts on cells in the immediate vicinity of the cell that secreted the signal

Autocrine signal

This is a signalling chemical that acts on the cell that secreted it

Twitch

This is a single contraction-relaxation cycle of a myofibril

Epididymis

This is a single duct that forms a tightly coiled cord on the surface of the testicular capsule - sperm matures and is partially stored here

Islets of Langerhans

This is a small cluster of endocrine cells found within the pancreas, which make up less than 2% of it's total mass (Contains four cell types - Beta cells [insulin, amylin], Alpha cells [glucagon], D-cells [somatostatin], PP cells [pancreatic polypeptide])

Pineal gland

This is a small gland which sits on top of the thalamus and third ventricle - secretes melatonin into the CSF and blood stream to help regulate the sleep-wake cycle

Sarcoplasmic reticulum

This is a specialized form of endoplasmic reticulum in a muscle fibre and is the main storage for calcium

Motor end plate

This is a specialized muscle membrane at neuromuscular junctions

Adrenal medulla

This is a specialized neuro-endocrine tissue acting with the sympathetic nervous system and is responsible for secreting epinephrine

Capacitation

This is a sperm's final maturation step which occurs in the vagina - it enables the sperm to swim rapidly and fertilize an egg

Corpus Spongiosum

This is a spongy column of tissue which surrounds the urethra in males

Rigor state (This causes rigor mortis -- in deceased individual, there is no ATP to release myosin, so their muscles are immobilized in a fixed state for a certain period of time)

This is a state of tight binding between myosin and actin when ATP or ADP are not bound to the myosin head (Shown as step 1 and step 6 in image)

Aldosterone

This is a steroid hormone synthesized in the adrenal cortex - these hormones act on the principle cells of the distal tubule/collecting duct by increasing the expression of Na+, K+ channels, and Na+/K+ ATPases, prevents the degradation of apical Na+ channels, and has a net result of: Increased Na+ absorption, increased K+ secretion

Colloid

This is a sticky glycoprotein mixture which fills the hollow centre of each follicular cell - Stores a lot of hormone (2-3 months worth)

Labeled line coding

This is a strategy used by neurons to distinguish different modalities (types) of stimulus - each modality (e.g. vision) of stimulus has its own specific, distinct pathway (1:1 association of receptor with sensation)

Allantois

This is a structure developed from some of the inner cell mass of a blastocyst and becomes part of the umbilical cord that links the embryo to the mother

Yolk sac

This is a structure developed from some of the inner cell mass of a blastocyst, but is degenerated early in human development

Acrosome

This is a structure that develops on spermatids derived from the golgi apparatus and functions to help breakdown the zona pellucida, a glycoprotein coat that covers the oocyte

Central Pattern Generator (CPG)

This is a system where networks of interneurons in the spinal cord and brainstem coordinate the interaction of many different motor groups (locomotion, respiration)

Trichromats

This is a term denoting animals who sense colors with three types of cones

Hyperplasia

This is a term denoting the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells (often as an initial stage in the development of cancer, but also representative of effects of GH and IGF)

Hypertrophy

This is a term denoting the enlargement of an organ or tissue from the increase in size of its cells.

Motor unit

This is a term describing a motor neuron and all of the muscle fibres that it innervates

Sleep atonia

This is a term for sleep paralysis in which spinal motoneurons are hyperpolarized (up to 10mV) and immobilized by the reticulospinal system in the pons -- occurs during REM sleep

Presbycusis

This is a term to describe hearing loss as a result of old age (typically sensorineural [90%])

Diffuse modulatory system

This is a term to describe systems which use metabotropic mechanisms (i.e. neurotransmitters) to modulate a global shift in CNS activity

Tracts

This is a term which denotes myelinated axons arranged in bundles within the central nervous system

Cornea

This is a transparent bulge at the front of the eye through which light can enter

Lens

This is a transparent disc that focusses light in the eye

Simple reflex

This is a type of reflex where sensory neurons make synapses with spinal cord motoneurons - this is the simplest form of motor control

Hyperopia (Far-sightedness)

This is a visual disorder when the focal point of vision falls behind the retina

Myopia (Near sightedness)

This is a visual disorder when the focal point of vision falls in front of the retina

Dihydropyridine L-Type Calcium Channel (DHP)

This is a voltage gated receptor found on the T-tubules of muscle fibres and upon stimulation by depolarization, (in skeletal muscles) it opens a channel on the sarcoplasmic reticulum to release calcium into the cytoplasm

Inositol Triphosphate (IP3)

This is a water-soluble messenger molecule that leaves the membrane and enters the cytoplasm where it binds to a calcium channel on the endoplasmic reticulum (ER) - binding opens the Ca2+ channel, allowing Ca2+ to diffuse out of the ER and into the cytosol

Population coding

This is a way for the brain to efficiently code for qualities of stimulus within a modality (e.g. shades of red for vision stimuli) Brain uses ratio of activity from a limited number of different receptors in order to code a stimulus -- a given stimulus will induce varied intensities in receptors of a population and the brain will compare the activity ratios to code the stimulus (e.g. determine the shade of red being viewed -- shade may be determined by varying levels of different receptor responses) -- stronger stimuli activates more neurons, weaker stimuli activates fewer neurons

Enfolding

This is an adaptation to the dramatic growth in brain size; allows big brain to fit in small cranial vault to accommodate birth

Multiple sclerosis (MS)

This is an autoimmune disease characterized by the loss of myelin sheaths in the CNS -- attack on oligodendrocytes *Symptoms* - Blurred vision - Muscle weakness - Difficulty maintaining balance

Guillain-Barré Syndrome

This is an autoimmune disease characterized by the loss of myelin sheaths in the PNS -- attack on schwann cells *Symptoms* - Numbness, tingling, pain - Muscle weakness including in respiratory muscles - Autonomic dysfunctions that may affect heart rate and blood pressure

Graves' disease (most common cause of hyperthyroidism [goiter in this case is caused by excessive hormone release])

This is an autoimmune disease where abnormal antibodies against the TSH receptor are produced which continually stimulate the TSH receptors on the thyroid Symptoms: nervousness, insomnia, high heart rate, eye disease (exophthalmus), weight loss , anxiety, and goitre

Renin

This is an enzyme released by the juxtaglomerular cells upon detection of low blood volume - it's function is to convert an inactive plasma protein, angiotensinogen, into angiotensin I which initiates the pathway for the secretion of aldosterone

5α-reductase

This is an enzyme that takes testosterone from leydic cells and forms DHT (DHT binds to the same receptors as testosterone but creates a more potent response)

Goldman-Hodgkin-Katz Equation

This is an equation that can be used to sum all the equilibrium potentials of each ion across the membrane to calculate the total membrane potential of a cell

Chemoreception

This is an evolutionary old mechanism to guide an organisms movement by detecting chemicals in their vicinity -- Smell and taste are forms of this

Dendrites

This is an extension of the cell body on a neuron that receives signals from other neurons

Chorion

This is an extraembryonic membrane that will enclose the embryo and form the placenta - it is formed from some of the outer layer of cells found on the blastocyst

Up-regulation

This is an increase in receptor numbers on a target cell

Basal Metabolic Rate (BMR)

This is an individual's energy expenditure when resting, comfortable temperature, fasted

Endocytosis (Used for transport of protein hormones, growth factors, antibodies, plasma protein carriers)

This is an inward 'pinching' of the membrane to create a vesicle; usually receptor-mediated to capture proteins, from the outside to inside the cell

Vomeronasal organ (VNO)

This is an olfactory structure in the nasal cavity of rodents which is involved in their behavioural responses to sex pheromones

Corona Radiata

This is an outer layer of loosely connected granulosa cells which provide proteins essential for growth for the ovulated oocyte before fertilization

Botox (Caused by inhibition of neurotransmitter release - exocytosis block)

This is caused by a toxin (Botulinum toxin) produced by a bacterium Clostridium botulinum -- prevents neurosecretory vesicles from docking to the plasma membrane and releasing their content into a synaptic cleft at the peripheral presynaptic terminals *Symptoms* - Muscle paralysis due to inability to release Acetylcholine at neuromuscular junctions - Death is secondary to the respiratory muscle paralysis. double, blurred vision - Slurred speech - Difficulty swallowing, muscle weakness

After-hyperpolarization (Hyperpolarization to roughly -80mV)

This is caused by an efflux of potassium ions during action potential that decreases the membrane potential beyond it's resting state

Synergy

This is defined as a group of muscles contracting together for a specific purpose

Motor field

This is how one corticospinal axon synapses with a set of motor nuclei, in more than one spinal segment -- this provides potential for plasticity in motor movements since the connections of silent or active synapses can be rewired

Baroreflex

This is one of the body's homeostatic mechanisms that helps to maintain blood pressure at nearly constant levels -- found in the ventrolateral medulla

Suprachiasmatic nucleus (SCN)

This is the 'master clock' whose activity is highest during the day and lowest at night -- paired structure on either side of the third ventricle and situated right above the optic chiasm on the hypothalamus

Refractory period

This is the duration after an action potential is created in which all or some sodium channels are inactivated

Stretch reflex

This is the fastest reflex and uses a monosynaptic pathway

Follicular phase

This is the first part of the ovarian cycle, and is a period of follicular growth in the ovary - this phase is the most variable in length and lasts from 10 days to 3 weeks

Barr body

This is the X chromosome which becomes randomly (either paternal or maternal) inactivated in each cell of a females body and condenses into a clump of nuclear chromatin

Color constancy

This is the ability of our brains to infer the reflectance of an object despite the color it actually visually appears to show to our photoreceptors (Eg. A ripe banana in green light will appear yellow instead of green [which it actually is] because our brain infers it's colour doesn't change in different lighting)

Phagocytosis

This is the actin-mediated process by which a cell engulfs a bacterium or other particle into a large membrane-bound vesicle called a phagosome

Endocytosis

This is the actin-mediated process by which a cell indents to capture large molecules (rather than pinching out) into small vesicles

Guanylyl Cyclase

This is the amplifier enzyme that converts GTP to cyclic GMP (cGMP)

Adrenal Medulla

This is the area where catecholamines are produced

Blood-testes barrier

This is the barrier formed by tight junctions between sertoli cells which behave much like the impermeable capillaries of the blood-brain barrier, restricting movement of molecules between two compartments - this avoids the immune system from attacking sperm cells

Refraction

This is the bending of light as it enters different mediums

Limbic cortex

This is the border region of the cerebral cortex and is composed of the cingulate gyrus, amygdala, hippocampus, and insula Functions to subserve emotional experience, motivation and memory consolidation

Sarcolema

This is the cell membrane circling around the muscle fibre

Antrum

This is the central cavity in a secondary follicle - the fluid contained within this region contains hormones and enzymes needed for ovulation and are secreted within this structure by the granulosa cells

Receptor potential

This is the change in the membrane potential due to receipt of a signal from an exterior sensory cue - in general this causes depolarization of sensory receptors however an exception is photoreceptors which hyperpolarize

Near point of accommodation

This is the closest point a person can focus and is limited by the contractility of the lens

Primary follicle

This is the collection of the egg surrounded by the granulosa cells and the theca - it's formation is the first step in the follicular stage of the menstrual cycle

Hypercalcemia

This is the condition when a person suffers from higher than average calcium levels

Hypocalcemia

This is the condition when a person suffers from lower than average calcium levels

Antidromic conductance

This is the conduction of action potential backwards at a branch point (This can be used to detect a skin injury -- the injured sensory neuron will cause action potentials to move backwards at the branch points and reach adjacent terminals which can release substance P and trigger vasodilation)

Phototransduction

This is the conversion of light energy into electrical energy in cells

Primary visual cortex (V1) [Found in the occipital lobe]

This is the region of the brain to which the neurons from the lateral geniculate nuclei project to via the optic radiations (Nerve bundle that transmits information)

Ventrolateral medulla (Located next to respiratory centre)

This is the region of the medulla responsible for basal and reflex control of sympathetic activity associated with cardiovascular function

Optic chiasm (Crossing occurs in order to keep information from right side of both eyes [right visual field] on the left side of the brain and left side of both eyes [left visual field] on the right side of the brain)

This is the region of the optic nerve pathway where half of it's fibres cross to the other side of the brain

Helicotrema

This is the section of the cochlea where the vestibular and tympanic ducts meet and communicate

Epiphyseal plate

This is the site where bones grow and is located between the epiphysis (End of a long bone) and the diaphysis (shaft of a long bone)

Synaptic cleft

This is the space between a presynaptic axon terminal and the postsynaptic dendrite

Subarachnoid space

This is the space between the arachnoid membrane and pia mater and is filled with cerebrospinal fluid to allow the brain to float which protects it from mechanical stress

Receptive Field

This is the spatial area to which a sensory neuron responds to

Metabolism

This is the sum of all the chemical reactions in the body

Neuromuscular Junction (NMR)

This is the synapse between a motor neuron and a muscle fibre

Gluconeogenesis

This is the synthesis of glucose from non-carbohydrate substrates such as glycerol and amino acids

Reflectance

This is the tendency of a surface to reflect certain wavelengths of light and absorb others -- Eg. A yellow banana reflects yellow light more than other wavelengths and a green banana reflects more green

Parturition

This is the term denoted for the action of giving birth to young

Muscle fascile

This is the term for a bundle of muscle fibres

A band

This is the zone of a myofibril which covers the entire region of the myosin

I band

This is the zone of a myofibril which covers the region between the Z disk and the myosins

H zone

This is the zone of a myofibril which only includes the myosin that isn't bound to actin filaments

Acrosomal Reaction

This is used to denote the reaction when capacitated sperm release powerful enzymes from their acrosome in the sperm head - these enzymes dissolve cell junctions and the zona pellucida, allowing the sperm to wiggle their way toward the egg

Spike Train

This is when a powerful synaptic input to the post-synaptic neuron persisting in time lasting up to 500ms is translated into continuous stream of action potentials

Reciprocal inhibition (e.g. activation of flexor motoneurons elicits inhibition of antagonist extensors)

This is when activation of one motor nucleus is coupled to inhibit the activation of antagonistic motor nuclei

Nocturnal Enuresis

This is when involuntary urination while asleep occurs - a theory for this is that there is a developmental delay where the normal pattern of increased vasopressin release at night doesn't occur, hence more urine is produced overnight

Polyspermy (Results in an inviable zygote)

This is when more than one sperm fertilizes a single egg

Referred pain

This is when pain in an internal organ is often felt on the body surface

Equilibrium potential

This is when the electrical force across a membrane is equal to the chemical force across a membrane and thus no net movement of ions across the membranes will exist

Spinal reflex

This is when the spinal cord responds to stimuli without consulting the brain

Habituation (response depends on the cell, some will show large degree of habituation and some won't)

This is when weaker responses are elicited by successive identical stimuli

Retina

This is where the cornea and lens focus light onto within the eye -- an inner lining of the eye which contains photoreceptors

Basilar membrane (Below organ of corti [where hair cells are])

This membrane responds to different frequencies at different wavelengths

Cranial nerve VIII

This nerve is also known as the auditory/cochlear nerve and is comprised of axons from primary sensory neurons activated by hair cells

Dorsal root

This segment of the spinal nerve carries afferent (incoming) signals

Ventral root

This segment of the spinal nerve carries efferent (incoming) signals

Tympannic membrane (Sound waves vibrate this)

This separates the outer ear from the middle ear and is the primary sensor to perceiving sound

Fast-twitch glycolytic (Slow-twitch and fast-twitch oxidative are fatigue resistant)

This skeletal muscle type is easily fatigued

Fast-twitch oxidative-glycolytic

This skeletal muscle type is most used for standing and walking

Slow-twitch oxidative (Doesn't get fatigued easily)

This skeletal muscle type is most used in posture

Fast-twitch glycolytic

This skeletal muscle type is the least used skeletal muscle type and used for quick, fine movements

Brain stem (Responsible for breathing, swallowing, vomiting, and regulating blood pressure)

This structure is made up of the medulla, pons, and midbrain and is responsible as the main control centre for several autonomic functions and reflexes (List 4 examples)

Amnion (Secretes amniotic fluid)

This structure secretes a fluid in which the embryo floats in - developed from some of the inner cell mass of a blastocyst

Reticulospinal tract

This tract controls motor synergies for very widespread (typically cover half of the body) movements, typically to support postures

Rubrospinal tract

This tract in the red nucleus controls the synergies between muscles in highly localized areas (hands, fingers, limbs)

Central fatigue

This type of fatigue is caused by psychological effects and acts as a protective reflex (triggered by the CNS to excite certain somatic neurons)

Peripheral fatigue

This type of fatigue prevents cell damage to the point where it can't effectively make ATP anymore -- it decreases neurotransmitter release, decreases Ca2+ release from the sarcoplasmic reticulum, etc.

Smooth muscle

This type of muscle is fond in internal organs and blood vessels and is under involuntary control by the ANS

Sympathetic signals will relax the ciliary muscles, making the lens more flat, so light rays bend less and the focal point moves backwards (towards the retina)

To bring an object that has moved further away from your eye into focus, what must happen (Describe stimulus nerve signals and how lens responds)

False (To generate a signal, membranes increase their conductance by opening channels permeable only to Na+ ions)

To generate a signal, membranes increase their conductance by opening channels permeable only to K+ ions (True/False)

Nucleus of the solitary tract (NST)

To get input from visceral sensory information, the hypothalamus interacts with this part of the midbrain

Frequency

To increase the signal intensity from a neuron, the ___________ (frequency/signal strength) of the neuron increases

Parasympathetic, sympathetic

To make the lens more round ______________ signals contract the ciliary muscles which reduces tension in the zonules - to make the lens more flat ______________ signals relax the ciliary muscles which puts tension in the zonules

Reticular formation

To receive inputs from the spinal cord, the hypothalamus interacts with this part of the brain

Warm-sensitive neurons -- Anterior hypothalamus Cold-sensitive neurons -- Posterior hypothalamus

To regulate temperature, the hypothalamus has temperature sensitive neurons -- where are the warm-sensitive neurons and cold-sensitive neurons located?

False (Rods are the most light sensitive and appear more frequently away from the fovea -- hence looking at a dimly lit start with your peripheral vision will be able to yield the best results in terms of noticing it's presence)

To see a dim star, although looking directly at it may damage your vision, it will yield the best results in terms of noticing it's presence (True/False)

True

Troponin is bound to tropomyosin (True/False)

True

Upon stimulation, the hair cell depolarizes and releases transmitter, activating a primary neuron (True/False)

True

Uterine contractions aid the transport of sperm (True/False)

A drug which works to relieve pain

What is an analgesic?

False (Vestibular hair cells activate primary sensory neurons of the vestibular nerve, which is a branch of cranial nerve VIII)

Vestibular hair cells activate primary sensory neurons of the vestibular nerve, which is a neural pathway separate from cranial nerve VIII (True/False)

Enhances, reabsorption

Vitamin D3 _________ (enhances/diminishes) the intestinal absorption and renal _________ (reabsorption/excretion) of phosphate

After-hyperpolarization of the signal at the trigger zone caused by voltage gated potassium channels - this allows voltage gated sodium channels to reconfigure

What allows a spike train to be generated by a single powerful long EPSP and not just create one action potential?

These are the individual globular monomers of actin (When attached together they make F-actin filaments)

What are G-actin molecules of thin filaments?

Chemoreceptors (Respond to specific molecules/ions) Mechanoreceptors Thermoreceptors Photoreceptors

What are four types of receptor cells?

- Hypothalamus (Communicates with blood stream) - Pituitary Gland (Releases/Senses hormones in blood) - Circumventricular organs (Around third ventricle), so neurons can sense specific chemical concentrations - Medulla Oblongata - Vomiting centre monitors for toxic substances

What are some areas where the blood-brain barrier are broken? (4)

*In Cardiac Muscles* 1. AP from pacemaker cells (vs. motor neurons) 2. ECF calcium is allowed to enter into muscle cells 3. RyR and DHP receptors are not linked together 4. DHP receptors allow the internalization of Calcium into the cell 5. RyR channel opening is induced by Calcium ions 6. Calcium is removed from the cytoplasm through sodium-calcium exchangers (NCX antiporters) on the plasma membrane

What are some differences between cardiac muscle contraction and skeletal muscle contraction? (6)

• Prevents movement • Acts in concert with stretch reflex to *stabilize posture* • *Suppressed when net motion* is desired

What are some golgi tendon reflex properties? (3)

Endorphins Enkephalins Dynorphins

What are some natural painkillers produced by the body? (3)

↑ Estrogen & oxytocin receptors in uterus increase ↑ Fetal cortisol ↑ Placental corticotropin-releasing hormone (CRH) ↑ Prostaglandins ↓ Progesterone (some animals)

What are some possible triggers for labour? (5)

• Reflex *strongest in postural muscles* • Latencies of about 25 ms for forearm muscles, 37 ms for ankle extensors • *Parallel multisynaptic paths* (NOT polysynaptic) through spinal cord, and a transcortical path • Stretch reflex and all other reflexes are designed for a specific function (e.g. stabilizing a joint) • *During movement, reflex suppressed*

What are some stretch reflex properties? (5)

1. Medulla 2. Pons 3. Midbrain 4. Diencephalon 5. Cerebrum 6. Cerebellum

What are the 6 major divisions of the brain?

1. Free nerve endings 2. Merkel receptors 3. Encapsulated receptors

What are the different types of nerve receptors in the skin? (3)

1. Sweet (Detects sugar) 2. Umami (Detects the amino acid glutamate) 3. Bitter (Detects poison) 4. Salty (Detects Na+) 5. Sour (Detects H+) (The tongue may also have receptors for fatty acids)

What are the different types of taste receptor cells and their biological roles? (5)

Cholinergic Serotonergic Adrenergic Dopaminergic Histaminergic

What are the five types of diffuse modulatory systems?

Frontal, temporal, parietal, occipital

What are the four lobes of each brain hemisphere?

*Touch* *Temperature* *Proprioception* (Awareness of position of body parts relative to each other) *Nociception* (Detection of tissue damage or threat to it)

What are the four somatic senses?

1. Remove neurotransmitters 2. Provide energy substrates (and more) for neurons 3. Regulate local blood flow

What are the functions of astrocytes?

Metabolic (↑metabolic rate, ↑oxygen consumption, ↑heat production, ↑protein degradation, ↑lipolysis) Nervous system (enhances speech, thinking, reflexes) Growth and development (essential in children, works with GH) Cardiovascular (enhances heart rate and contractility; peripheral blood flow, works in part by increasing numbers of β adrenergic receptors + other proteins) Muscular (too much causes muscle weakness)

What are the functions of thyroid hormones? (5)

Phosphates, negatively charged proteins

What are the major anions in the intracellular fluid of cells?

Superior, Posterior, Horizontal

What are the names of the semicircular canals found in the vestibular apparatus?

The ossicles are a chain of three small bones which convey vibrations from the tympanic membrane to the oval window: Malleus, incus, stapes

What are the ossicles and what is their function?

Cingulate gyrus, amygdala, and hippocampus Function: Concerned with motivation, emotion, and memory (Eg. Monkeys with amygdala lesions are not afraid of snakes -- fear is removed)

What are the parts of the limbic system and what is the function of the limbic system?

- Acetylcholine(Ach) - Glutamate - GABA - Glycine **These ligands can also act on metabotropic receptors

What are the principle ligands that can act on ionotropic receptors? (4)

Center-surround fields (Round center region and doughnut-shaped surround)

What are the receptive fields of ganglion cells called?

*Special Senses* Vision Hearing, Equilibrium Taste Smell *Somatic Senses* Touch Temperature Proprioception (Body's ability to sense movement within joints and joint position - enables us to know where our limbs are in space without having to look) Nociception (Response to injury - pain, itch)

What are the special senses and the somatic senses?

1. *REM sleep* (Important for learning/memory) *Light Sleep* 2. Stage 1 3. Stage 2 *Deep Sleep* 4. Stage 3 5. Stage 4

What are the stages of sleep? (5 stages)

*Stimuli* Pain *Responses* Contralateral extension -- flex one part of the body and extend the contralateral/same body part on the left/right side *Example* When you step on something sharp, you flex your leg where there is pain and extend the other leg

What are the stimuli and responses of a cross extension reflex?

*Stimulus* Noxious/harmful injury to limb *Response* flexion of joints proximal to stimulus and extension of joints distal to stimulus

What are the stimuli and responses of a flexion withdrawal reflex?

Golgi tendon reflex functions to regulate the level of activity of muscles *Stimulus* Active tension in muscles *Response* Relaxation/reduction of tension

What are the stimuli and responses of a golgi tendon reflex?

*Stimulus* Passive stretch of a muscle by applied load or contraction of antagonist muscle *Response* Active contraction of muscle *Example* Patellar tendon reflex in response to hammer hit against the patellar tendon

What are the stimuli and responses of a stretch reflex?

*Stimulus* Pressure on sole of foot (innocuous [not harmful]) *Responses* Activation of leg extensors

What are the stimuli and responses of an extensor thrust reflex?

*Stimulus* Downward deviation of head on one side → activates otolith afferents *Response* 'Downhill' limbs extend *Example* If you tilt your head, extension of the leg where there is tilt occurs

What are the stimuli and responses of the vestibulo-spinal reflex?

1. Forebrain (prosencephalon) 2. Midbrain (mesencephalon) 3. Hindbrain (rhombencephalon)

What are the three brain vesicles/pouches that make up the front of the neural tube at 4 weeks development?

1. Slow-twitch; Oxidative (Red muscle) 2. Fast-twitch; Oxidative-Glycolytic (Red Muscle) 3. Fast-twitch; Glycolytic (White muscle)

What are the three categories of skeleton muscle types?

Magnocellular ganglion cells (M cells) - provide information about the movement of objects [LARGE] Parvocellular ganglion cells (P cells) - Provide information about form and fine detail (eg. texture) [SMALL] Melanopsin ganglion cells - These are photoreceptors with their own visual pigment (melanopsin) - sends information to a region of the hypothalamus involved with circadian rhythm (Believed to not contribute to vision)

What are the three classifications of ganglion cells found in the eye?

1. Leg is not bearing weight 2. Hip is extended 3. Opposite leg is in stance position (bearing weight)

What are the three conditions which must be met for Extensor phase 3 to be stopped and allow the flexion phase to begin?

Type I -- Cells sense salt Type II -- Cells sense sweet, bitter, and umami Type III -- Cells sense sour

What are the three groups of taste receptor cells?

- Dura mater (very tough membrane, sac containing the brain and the spinal cord) - Arachnoid membrane (much more delicate tissue) - Pia mater (lies right on top of the brain; tethered to Arachnoid by Arachnoid 'Trabeculae')

What are the three sections of the meninges?

Red > Green > Blue

What are the three types of cones and order them in their prevalence in the retina (from greatest to least)

1. Conductive hearing loss - Sound can't be transmitted through the external/middle ear (Eg. fluid build up, earwax) 2. Sensorineural hearing loss - Damage to the hair cells or elsewhere in the ear 3. Central hearing loss - Damage to the cortex or pathway from the cochlea to the cortex (usually trouble in recognizing/interpreting sounds rather than detecting of them)

What are the three types of hearing loss and what differentiates them?

1. Skeletal muscle 2. Smooth muscle 3. Cardiac muscle

What are the three types of muscles?

1. Simple reflexes 2. Central pattern Generators 3. Complex/Volitional movements

What are the three types of organization patterns in controlling motor movement?

Nicotinic receptor blockers Exocytosis blockers Acetylcholinesterase inhibitors

What are the three types of toxins that can block the neuromuscular junctions of skeletal muscles?

Skull and meninges

What are the two brain encasings?

*Sleep switch* Ventrolateral preoptic (VLPO) nucleus of the anterior hypothalamus *Wake switch* Tuberomamillary nucleus (TMN) histamine activating system of the posterior hypothalamus

What are the two centres for the sleep-wake cycle and where are they located in the brain?

Preganglionic component/neurons Postganglionic component/neurons

What are the two components (and two types of neurons) that the autonomic nervous system consists of?

1. Small fibers (C and A-delta) 2. Large fibers (A-beta)

What are the two groups of somatosensory afferent neurons?

Cones Rods

What are the two main types of photoreceptors in the eye

One head is used for ATP hydrolysis One head is used for attaching onto actin

What are the two myosin heads responsible for?

Cerebrum and Diencephalon

What are the two segments of the forebrain which form at 6 weeks development?

- Metencephalon (pons, cerebellum) - Myelencephalon (medulla oblongata)

What are the two segments of the hindbrain which form at 6 weeks development?

*Light-on bipolar cells* Cells which have a metabotropic glutamate receptor that hyperpolarizes the cell when binded to glutamate -- active in light when less glutamate is secreted by photoreceptors *Light-off bipolar cells* Cells which have an ionotropic glutamate receptor that depolarizes the cell when binded to glutamate -- active in darkness when photoreceptors secrete the most glutamate

What are the two types of bipolar cells and their functions?

Meissner corpuscles Pacinian corpuscles

What are the two types of encapsulated receptors found in the skin?

C ("clear") cells [releases calcitonin], follicular cells [release thyroid hormone]

What are the two types of endocrine cell types in the thyroid?

*On-center ganglion cells* Cells excited by light in the center of their field and inhibited by light in the surround -- most active when center is illuminated and surround is dark *Off-center ganglion cells* Cells inhibited by light in the center and excited by light in the surround -- most active when center is dark and surround is illuminated

What are the two types of ganglion cells in terms of their stimulation variances?

Fast - Carried by Aδ fibres Slow - Carried by C fibres (Both small fibres)

What are the two types of pain and which somatosensory nerve fibres are they carried by?

1. Ionotropic (directly opens channels) 2. Metabotropic (initiates a metabolistic cascade to activate enzymes)

What are the two types of receptors the neurotransmitter binding receptors found on the postsynaptic membrane can be?

Single-unit smooth muscle Multi-unit smooth muscle

What are the two types of smooth muscles (classified by communication with neighbouring cells)

1. Spatial summation -- when a minimum of 10-30 synchronous EPSPs in are stimulated in the dendritic tree, each generated at a different synapse 2. Temporal summation -- when only a few synapses are active, but each generates EPSPs at high frequency - summated potentials reach threshold over a period of time

What are the two types of summation that can occur?

1. Electrical (Rapid communication) 2. Chemical

What are the two types of synapses?

1. Population coding 2. Frequency coding

What are the two ways groups of neurons can represent intensity?

Aβ (A-beta) fibres Signals mainly come from Merkel disks or encapsulated mechanoreceptors (Meissner/Pacinian corpuscles)

What are the type(s) of large somatosensory afferent neurons and which nerve endings do their signals typically come from (what stimuli)?

C fibres and Aδ (A-delta) fibres Signals mainly come from free endings (mechanical stimuli, chemicals, temperature)

What are the type(s) of small somatosensory afferent neurons and which nerve endings do their signals typically come from (what stimuli)?

- cAMP - cGMP - InP3

What are the types of 2nd messengers that can be stimulated by metabotropic receptors

1. Pacemaker neurons, diffuse excitation 2. Reciprocal inhibition (between legs) 3. Use of phase-dependent reflexes

What are three properties of the leg step cycle?

1. Increase frequency of action potential at excitable membrane (↑ in the intensity of the stimulus leads to an ↑ frequency of AP) 2. With increasing stimulus strength, recruit an additional receptor which has a higher threshold

What are two strategies to code for the strength of stimuli in post synaptic receptors?

1. NTs can be returned to axon terminals for reuse or transported into glial cells 2. Enzymes inactivate NTs 3. NTs can diffuse out of the synaptic cleft

What can terminate neurotransmitter activity? (3)

Estrogen (Rising Estrogen levels result in the closure of the epiphyseal growth plate in both males and females)

What causes the closure of epiphyseal plates to stop growth?

Prolonged stimulation of the CRH hormones in the hypothalamus can eventually lead to positive feedback regulation (instead of negative feedback) and neuronal degeneration

What conclusion was made by the stress studies from Dr. Sapolski?

C-peptide (A fragment produced during post-translational modification of insulin)

What do clinicians typically measure when checking the level of insulin a patient's pancreas is producing?

Free nerve endings detect mechanical stimuli, temperature, and chemicals

What do free nerve endings in the skin detect for?

Müllerian ducts develop into the: - Upper portion of the vagina - The uterus - The fallopian tubes

What do the Müllerian ducts develop into in female fetus'?

Mainly the differentiation of the external genitalia (scrotum, penis, prostate)

What does DHT do in male reproductive organ development?

Testosterone: - Converts the Wolffian ducts into male accessory structures (epididymis, vas deferens, and seminal vesicle) - Controls migration of the testes from the abdomen into the scrotum in late fetal development

What does testosterone do in male reproductive organ development? (2)

Outer layer of the brain - cortex Limbic system - Emotional/behavioural system Basal ganglia - Helps control movement

What does the cerebral grey matter comprise?

Thalamus, hypothalamus, pituitary, and pineal glands

What does the diencephalon comprise?

Pinna Ear canal Tympanic membrane (Ear drum)

What does the external ear consist of? (3)

Cochlea Vestibular Apparatus

What does the inner ear consist of? (2)

Eustachian tube

What does the middle ear consist of?

1. Ligand gated channels: Binding of chemical agent 2. Voltage gated channels: Voltage across the membrane 3. Mechanically gated channels: Physical forces (e.g., stretch, pressure)

What factors determine the channel protein shape for ligand-gated, voltage-gated, and mechanically-gated channels respectively?

- Amount of light that enters the eye (Constriction = less light enters) - Focus (Constriction = better focus) - Depth of view (Constriction = greater depth of view)

What functions does the pupil resolve? (3)

Sex-determining Region of the Y chromosome (SRY gene)

What gene is responsible for the differentiation of sex in embryo?

Refractory period (Voltage-gated sodium channels are inactivated by the inactivation gate temporarily, hence the ions can only flow in one direction)

What inhibits an action potential from travelling backwards to where it came from on an axon?

This is a pattern where the toes of the feet withdraw towards the body instead of away from the body when looking at the extensor thrust reflex

What is a Babinski pattern?

This is a method to increase the contrast between the activated/stimulated field and it's inactive neighbours - Primary neurons will respond in proportion to a stimulus, however secondary neurons most responsive to the stimuli will suppress the response in tertiary neurons lateral to it, where the stimulus is weak -- this will cause a contrast between the centre and sides of the stimulus and localizes the stimulus

What is lateral inhibition?

Adaptation is when the membrane potential decreases over time for an ongoing stimulus, even if the stimulus is constant 2 Types: Slow adaptation, rapid adaptation

What is membrane potential adaptation and what are the two types?

This is when the receptor potential is elicited by a change in stimulus energy, hence it decays to zero when the stimulus is constant (constantly absent or constantly present) -- the receptor will respond differently based on the velocity of the stimulus being delivered These receptors are referred to as phasic receptors

What is rapid membrane potential adaptation and what type of receptors are these called?

This is when the potential slowly decreases over time, however the potential remains present as long as the stimulus is present -- the receptor will respond differently based on the overall magnitude of the stimulus These receptors are referred to as tonic receptors

What is slow membrane potential adaptation and what type of receptors are these called?

Fast pain causes quick withdrawal which allows us to get away from the painful thing and slow pain causes prolonged immobilization to promote healing

What is the (evolutionary) reason for the two types of pain (fast and slow)?

2-4mm

What is the 2-point discrimination of lips and fingertips?

- Water, CO2 and O2, and lipid -soluble free forms of steroid hormones are freely penetrable - GLUT1 transporter for glucose - Transporters for thyroid hormones - Multidrug non-specific transporter (P- glycoprotein) transports drugs and peptides back into the blood from the brain

What is the BBB selective for and how? (4)

The Broca's area is a premotor zone for sequencing language elements for speech or writing-typing: input from Wernicke's area

What is the Broca's area?

Gustducin

What is the G-protein found on type II taste receptor cells?

The Rinne test is when a tuning fork is comparatively held against a patient's mastoid bone and then next to their ear canal - typically the sound is louder through their ear canal; If the sound is louder through their mastoid bone, then there is sign of conductive hearing loss

What is the Rinne test?

The Weber test is when a tuning fork is held against the midline of a patient's forehead In conductive hearing loss the sound will be louder through their bad ear In sensorineural hearing loss the sound will be louder through their good ear

What is the Weber test?

With saltatory conduction, a single node can travel along the length of an axon for 5-10 node lengths, hence if any of those nodes are damaged/non-functional, then the signal can still travel down the length of the axon -- a fair length of the membrane would have to be destroyed to stop the action potential

What is the benefit of saltatory conduction?

Rinne test

What is the clinical test used to detect for conductive hearing loss?

Weber test

What is the clinical test used to detect for sensorineural hearing loss?

*Peripheral* The endothelial lining of blood vessels mostly contains large gaps (fenestrations), through which molecules can pass *Central* Endothelial cells are tightly bound leaving no gaps through tight junctions - this constitutes the BBB

What is the difference between endothelial cells lining blood vessels in the peripheral nervous system compared to the central nervous system?

Thyroid peroxidase

What is the enzyme that adds iodine onto tyrosine residues/couples the reaction of different iodotyrosine residues together?

λ = √(Membrane Resistance/[Internal Resistance + Extracellular fluid resistance]) λ ≈ √(Membrane Resistance/Internal Resistance)

What is the equation for length constant?

Roughly -70mV

What is the equilibrium potential of Chloride ions?

-90 mV (This would be the membrane potential if ONLY K+ were involved)

What is the equilibrium potential of potassium ions?

+60mV

What is the equilibrium potential of sodium ions?

MLCK phosphorylates light chains in myosin heads and increase myosin ATPase activity and thus the allowance of crossbridges and power stroke formations (In smooth muscles)

What is the function of Myosin light chain kinases (MLCK)?

- To control the ionic composition of the extracellular fluid around neurons - To remove neurotransmitters floating in the CSF

What is the function of the blood-brain barrier? (2)

Hearing and equilibrium

What is the function of the ear? (2)

Contains high density voltage-gated Na+ channels and this is the only place on an axon where an action potential can be made

What is the function of the node of ranvier?

- Controls bilateral coordination of limbs when different motions are done on each side - Processes internal 'volitional' signals that drive movements

What is the function of the supplementary motor area? (2)

Thalamus - Processes information going to and from the cerebral cortex Hypothalamus - Regulates behavioural drives and endocrine/autonomic homeostasis Pituitary/pineal - Secrete hormones

What is the function of the thalamus, hypothalamus, pituitary, and pineal glands respectively?

The brain can deduce the frequency of the wavelength by noting which hair cells on the basilar membrane are most active

What is the functionality of the basilar membrane's different spatial responses to different wavelengths?

25ms in forearm muscles 37ms in ankle extensors

What is the latency of the stretch reflex in the forearm muscles vs. in the ankle extensors?

*Opening* An activation gate within the channel typically closes the gate at normal resting potential - however as the cell is depolarized and the extracellular space becomes more negative and the activation channel opens as a positive portion of it pulls it towards the extracellular space *Closing* Closing of the inactivation gate is also triggered by depolarization, BUT is triggered by 0.5ms to allow a sodium influx into the cell To remove the inactivation gate, the membrane potential needs to repolarize below -55mV which will reset the gates to their original conformations

What is the mechanism that regulates the opening and closing of voltage gated sodium channels?

Less than -50mV (Depolarization of the membrane to less than -50mV will no longer provide sufficient electrical attraction to hold the S4 wing downwards, so it migrates back up, effectively opening the voltage-gated channel and allowing potassium ions to exit the cell [thus repolarizing the cell])

What is the minimum threshold charge required to maintain the voltage-gated channel in the closed position?

-55mV (Depolarization required)

What is the minimum threshold potential required to open a voltage gated sodium channel?

1. Auditory nerve 2. Cochlear nuclei (medulla) 3. Midbrain 4. Medial geniculate nucleus (thalamus) 5. Auditory cortex

What is the nerve pathway from the auditory nerves to the auditory cortex?

Interneuron

What is the neuron that connects the dorsal horn to the ventral horn in the spinal cord and is used in spinal reflex reactions?

Receptor threshold: 1 odourant molecule Perceived threshold: Roughly 40 cells must react

What is the olfactory receptor threshold (how many ligands before activation) and what is the perceived threshold (how many cells must activate before perception) required to experience a smell?

Olfactory neurons in the olfactory epithelium are stimulated by odorants This stimulates the Cranial Nerve 1 > Olfactory bulb > Olfactory tract > Olfactory cortex

What is the order of neuron stimulation in the olfactory pathway?

1. Light hits photoreceptors at the back of the eye 2. Signal converged onto bipolar cells 3. Signal further converged onto ganglion cells (Signal from 126 million photoreceptors ultimately converges into 1 million ganglion cells)

What is the order of signal transduction in the eye? (3)

Central canal (Found in the middle of the spinal cord)

What is the part of the spinal column that carries CSF called?

G protein is activated and increases local concentration of cAMP -- cAMP-gated cation channels open which depolarize the receptor neurons and trigger an action potential which travel along the cell axon to the olfactory bulb

What is the pathway inside an olfactory receptor cell after it binds to an odourant?

1. Turn upwards and run ipsilaterally (on same side) towards the brain in *dorsal tracts* 2. Synapse onto cells in the medulla oblongata 3. Axons of neurons in the medulla cross the midline to go to opposite hemisphere where information is recieved

What is the pathway that large fibres take upon entering the spinal column?

The either: 1. Pass directly to the cerebellum 2. Synapse in the medulla oblongata and then proceed to the cerebellum 3. Synapse in the medulla oblongata and then proceed to the thalamus to the cortex

What is the pathway that primary sensory neurons connected to vestibular hair cells take? (3)

1. Cross the midline in the spinal column 2. Turn upwards towards the brain on dorsal-horn neurons in *spinothalamic tracts* *OR* 1. Synapse to interneurons on motoneurons across the midline in the spinal column (in the ventral horn, for reflex responses) 2. Turn upwards towards the brain on dorsal-horn neurons in *spinothalamic tracts*

What is the pathway that small fibres take upon entering the spinal column?

-10mV

What is the potential difference across the cell membrane between sodium and potassium ions caused by the sodium-potassium pump?

The premotor cortex arranges motor cortical synergies into a proper sequence for a given movement -- this also gives it a pattern generation role for learned, highly evolved movements

What is the premotor cortex responsible for?

This is the process by which several EPSP's are required to be added together to depolarize the trigger zone to -50mV

What is the process of summation in regards to action potential creation?

Cranial Nerve I

What is the projection from the olfactory receptor cells to the olfactory bulb called?

16-20000 Hz (10 octaves)

What is the range at which humans hear sounds (how many octaves)?

80ms

What is the reflex latency in the legs?

Secrete Testosterone and DHT (Responsible for both internal and external differentiation)

What is the role of Leydig cells in the male fetus during reproductive organ development?

Pacemaker cells

What is the source of the action potential in the contractile cells of cardiac muscle?

215mL total volume 140mL in cranium (25ml in ventricles, 115ml in subarachnoid space) 75mL in spine

What is the total volume of cerebrospinal fluid and it's composition in the cranial and spine in an average person?

40mm

What is the two-point discrimination of calves?

Serotonin

What molecule do type III taste receptor cells release to activate sensory neurons?

Manipulation of objects (In the motor cortex) (This information must travel quickly up the brain)

What responses can signals from the large fibres of the somatosensory neural system illicit from the brain?

Simple responses to specific stimuli (Withdrawing from pain, themoregulatory/sexual responses) (Most of these are handled by the spinal cord without immediate input from the brain [reflex responses])

What responses can signals from the small fibres of the somatosensory neural system illicit from the brain?

Ring-shaped

What shape are the muscles found in the iris which are responsible for constricting the pupil?

-Increased plasma glucose (Stimulation) -Increased plasma amino acids (Stimulation) -GLP-1/GI hormones secreted by the intestine (Stimulation - anticipatory feedforward effect) -Parasympathetic system (Stimulation - During and following a meal) -Sympathetic system (Inhibition - stress inhibits secretion to provide extra fuel)

What stimulates/inhibits insulin secretion from the pancreas? (5)

1. Somatosensory - Especially proprioceptive 2. Vestibular - Gravitational reference 3. Visual - Important vertical and motion cues (slower system)

What three sensory sources does postural maintenance rely on?

Exocytosis is triggered by the depolarization of the AP, which opens voltage-gated Ca2+ channels (threshold -50mV) and triggers a cascade of reactions that result in vesicle exocytosis

What triggers exocytosis in axons?

1. Loudness (Louder sound in the right ear indicates that the sound is coming from the right) 2. Timing (If sound reaches the right ear before the left ear, then the sound is coming from the right)

What two factors does the brain account for when localizing sound?

1. Somatic nervous system - controls voluntary action via skeletal muscle 2. Autonomic nervous system - controls visceral functions such as heart rate or breathing

What two nervous systems does the peripheral nervous system comprise and what do each of them control??

1. Circadian rhythm 2. Sleep debt (Change in brain chemistry -- Decreased glycogen, increased adenosine)

What two things is the sleep-switch activated by?

Small lipid-soluble molecules (Steroid hormones) Gasses (CO2, N2, O2, ...) Some small polar molecules (Water, urea)

What type of molecules can move through simple diffusion?

Meissner corpuscles are phasic and sense sideways changes in shearing (stroking a surface/lift something with fingertips)

What type of receptors are meissner corpuscles (phasic/tonic) and what type of movement do they detect for?

Merkel receptors are mechanoreceptors with nerve endings in contact epithelial cells called Merkel disks - they are more *tonic* than phasic and send a sustained message as long as the deformation persists (signals contact)

What type of receptors are merkel receptors in the skin and what do they detect for?

Pacinian corpuscles are phasic cells that respond to tiny displacements if the motion is quick (Eg. vibrations)

What type of receptors are pacinian corpuscles (phasic/tonic) and what type of movement do they detect for?

Mechanoreceptors (Responds to change in pressure)

What type of receptors are the auditory receptor cells?

1. Damaging mechanical stimuli 2. Damaging heat/chemicals 3. Chemicals released from damaged cells (K+, histamine, prostaglandins) 4. Serotonin released by platelets (in response to injury)

What type of stimuli do nociceptors respond to? (4)

Contrast (In uniform lighting [bright or dim] ganglion cells don't respond since center and surround are evenly lit leaving the cell at its resting weakly active state)

What type of stimulus do ganglion cells respond best to?

Symporter (Moves sodium down it's concentration gradient into the cell and moves glucose up it's concentration gradient into the cell)

What type of transporter is the sodium glucose transporter?

Tonic

When at rest, both the parasympathetic and sympathetic nervous systems are complementary in their functions and the neurons fire with ________(tonic/phasic) acitivites

*Calcium will bind to troponin* complexes and cause the tropomyosin complexes to move and expose the myosin binding sites of actin -- crossbridges are fomed between actin and myosin and muscle can contract

When calcium is present, why does muscle contract?

Follicular phase just before ovulation (LH surge triggers the completion of meiosis I [primary oocyte is converted into a secondary oocyte and a polar body, which is extruded - While this division is taking place, antral fluid collects and the follicle grows to its greatest size, preparing to release the egg])

When does the oocyte undergo it's meiosis I?

Dilate

When epinephrine binds to a beta receptor on blood vessels, the blood vessel will ____________ (constrict/dilate)

Constrict

When epinephrine binds to an alpha receptor on blood vessels, the blood vessel will ____________ (constrict/dilate)

smaller

When fewer primary sensory neurons converge, the secondary receptive field is much ___________(smaller/larger)

False (When light hits photoreceptors, pigment molecules change shape which starts a cascade that HYPERPOLARIZES the cell and reduces the release of glutamate -- i.e. photoreceptors are more active in darkness)

When light hits photoreceptors, pigment molecules change shape which starts a cascade that depolarizes the cell and reduces the release of glutamate (True/False)

On

When the flexor burst generator is on for the right leg, the extensor burst generator is ____(on/off) for the left leg

False (OPENING of the Cl- channel [IPSP] will bring the membrane potential back down to -70mV)

When the membrane is depolarized, closing of the Cl- channel will bring the membrane potential back down to -70mV (True/False)

True (When the membrane is polarized [internal negative charge], the positive S4 wing is attracted to the inner surface and points downwards which will effectively close the channel)

When the membrane is polarized, the S4 wing of a voltage gated channel is attracted towards the inner surface of the membrane (True/False)

Unfused tetanus

When the myofibril consistently reaches it's maximum tension , however is allowed to relax between the AP signals, what is this known as?

Fused/Complete tetanus

When the myofibril is at it's maximum tension without being allowed to relax between AP signals, what is this known as?

When the osmolarity is greater than *295mOsmol/Kg*, the cells of the supraoptic nucleus shrink which *opens* cation channels and leads to increased ADH release

When the osmolarity is greater than _____, the cells of the supraoptic nucleus shrink which ______(opens/closes) the cation channels and leads to increased ADH (vasopressin) release

When the osmolarity is less than *295mOsmol/Kg*, the cells of the supraoptic nucleus swell which *closes* the cation channels and leads to decreased ADH release

When the osmolarity is less than _____, the cells of the supraoptic nucleus swell which ______(opens/closes) the cation channels and leads to decreased ADH (vasopressin) release

Left side of chest and left arm

Where would heart pains be referred to on the body surface?

Tryptophan

Which amino acid is the pineal gland hormone, melatonin, derived from?

Sertoli Cells (Sertoli cells secrete anti-müllerian hormone )

Which cells in the male fetus (after testes differentiation) will cause the müllerian duct to degenerate?

Cranial nerves III, VII, IX, X-vagus Note: ALSO originate from intermediolateral part of sacral cord

Which cranial motor nuclei do parasympathetic efferents originate from

Cranial nerves III to XII (3-12)

Which cranial nerves arise from the brain stem?

Tertiary neurons (Through lateral inhibition)

Which degree of neuron (primary, secondary, tertiary, etc.) would most likely function to detect edges/contrast?

Cranial nerves VII, IX, X Facial nerve (VII) Glossopharyngeal nerve (IX) Vagus nerve (X)

Which fibres and nerves do receptor cells in the taste buds excite en route to the medulla and thalamus? (6)

Seminal Vesicles (provides fructose [sperm nourishment]), Bulbourethral gland (mucus [lubrication], buffers [neutralize acids in vagina]), Prostate gland [nutrients and anticoagulant to inhibit clotting of sperm]

Which glands are necessary for the production of semen?

All from adrenal cortex (Aldosterone, Cortisol, Sex hormones)

Which hormone does ACTH (from the anterior pituitary) stimulate in the adrenal glands?

Dopamine

Which hormone inhibits prolactin release normally and is inhibited post-pregnancy?

Oxytocin

Which hormone stimulates contractile myoepithelial cells in the breasts after parturition? It is stimulated by environmental factors such as a child's cry or the thought of a child

Prolactin

Which hormone stimulates epithelial milk-producing cells in the breasts after parturition? It is stimulated by the mechanical stimulus of suckling

Catecholamines, Thyroid hormones

Which hormone(s) are derived from Tyrosine?

GH, prolactin

Which hormones is human placental lactogen structurally similar to?

Temporal lobe

Which lobe of the brain is the primary auditory cortex located?

Frontal and temporal lobes

Which lobe(s) is the olfactory cortex in?

Smooth muscle

Which muscle(s) don't have striations?

Cranial nerve V (trigeminal)

Which nerve(s) do TRP receptors in the walls of the mouth excite?

Malleus

Which ossicle recieves vibrations from the tympanic membrane?

Stapes

Which ossicle sends signals to the oval window by pushing against it like a piston?

Cochlea (Directly connected to the oval window which sends vibrations into this canal)

Which part of the ear contains the receptor cells?

Olfactory pathways (Goes directly to olfactory sensory cortical)

Which sensory pathway doesn't project via the thalamus before going to it's sensory cortices on the surface of the cerebrum

Fast-twitch glycolytic

Which skeletal muscle type has the largest diameter motor neurons?

Slow-twitch oxidative (Fast-twitch oxidative has a medium duration and fast-twitch clycolytic has the shortest duration)

Which skeletal muscle type has the longest contraction duration?

Nociception responds through Aδ and C fibres

Which somatosensory afferent neurons will synapse onto interneurons in the superficial dorsal horn from response to pain?

Tryptophan and Tyrosine

Which two amino acids are amine hormones derived from?

True

White matter contains myelinated axons (True/False)

Palms, fingertips, lips

Why body surface has the most somatosensory receptors and thus highest acuity? (3)

Both red and green cones absorb light in the yellow wavelength (A combination of red and green can produce same cone activities as a yellow light would)

Why can a combination of red and green pigment be visualized as yellow?

Energy conservation -- action potentials are energy intensive and the energy supply to the CNS can only support a low rate of firing

Why does the brain only fire ~4% of neurons at any one moment?

Plateau period occurs during hyperpolarization of the action potential -- this plateau makes it such that the refractory period of the action potential is just as long as the muscle contraction-relaxation period -- hence summation cannot occur and all the contraction-relaxation period will be the same

Why doesn't summation occur in cardiac muscle cells?

Convergence (Nociceptors from different locations converge on a single ascending tract - since pain is more common in skin than in internal organs, the brain assumes the problem is on the body surface)

Why is pain from internal organs generally felt on the skin?

This is because K+ ions have an equilibrium potential of around -90mV which has the greatest effect on membrane potential, however Na+ ions and Cl- ions which both have more positive equilibrium potentials which increase the overall membrane potential to roughly -70mV This means a small amount of positive sodium ions leak into the cell while a small amount of negative chloride ions exit the cells which increase the membrane potential to -70mV

Why is the membrane potential -70mV instead of -90mV?

Neuropeptide Y (NPY), melanocortin

Within the arcuate nucleus the _______ neurons drive feeding while the _______ neurons suppress feeding

True (Since red and green cones are found on X chromosomes, if 2 X-chromsomes code two different functional red cone pigments, then she may be a tetrachromat)

Women have a better chance at being tetrachromats than men (True/False)

True (Sodium gated channels propel increase of membrane potential)

You can only produce an action potential in membranes that contain voltage-gated Na+ channels (True/False)

High, low

_______(High/low)-frequency wavelengths maximally displace the basilar membrane near the oval window and _______(High/low)-frequency wavelengths maximally displace the basilar membrane near the helicotrema

High

________ (High/Low) osmolarity is an inhibitor of the release of aldosterone

True (hCG is structurally similar to LH)

hCG binds to LH receptors to maintain the corpus luteum (True/False)

True (Membrane properties can shape the form of the signal)

if we apply a voltage across a neuron at one location (i.e. step change in voltage) and measure the voltage across the membrane some distance away, the signal would be deformed (True/False)