68C Phase I - Exam #4

negative feedback systems

1. hypothalamus regulation (releases hormones); 2. nervous system stimulates glands directly; 3. glands respond directly to changes in internal environment

brainstem

1/4 major portion of brain; connects cerebrum to spinal cord; connects part of the nervous system & regulates certain visceral activities

cerebrum

1/4 major portion of brain; exterior surface called "cerebral cortex"; associated with sensory/motor functions, and memory & reasoning.

cerebellum

1/4 major portion of brain; located in occipital lobe coordinates voluntary muscular movement (inferior peduncles, middle peduncles, superior peduncles)

diencephalon

1/4 major portion of brain; process sensory information

cell body

"soma"; part of a nerve cell that includes cytoplasmic mass & nucleus from which nerve processes extend

mcg = mL

1mcg = 0.001mL

threshold potential

-55mV; the minimum potential that must be reached in order for an action potential to be generated

resting potential

-70mV; potential difference between inside & outside the membrane

retina

Light sensitive layer of the eye; contains photoreceptors(rods & cones)

vagus nerves (X)

MOTOR&SENSORY; SPEECH & SWALLOWING; impulses to heart, smooth muscles & glands in thorax/abdomen

facial nerves (VII)

MOTOR&SENSORY; TASTE receptors on the tongue; conduct impulses to muscles of FACIAL expression

trigeminal nerves (V)

MOTOR&SENSORY; largest; from the pons; ophthalmic (eyes), maxillary (upper MOUTH) & mandibular divisions (lower mouth); chewing

glossopharyngeal nerves (IX)

MOTOR/SENSORY; tonsils, back of tongue and pharynx; gag reflex & swallowing

trochlear nerves (IV)

MOTOR; from midbrain; smallest; conducts motor impulses to MOVE the EYE

abducens nerves (VI)

MOTOR; kinda small; remaining muscles that MOVE the EYE

hypoglossal nerves (XII)

MOTOR; move the TONGUE (speaking, chewing, swallowing)

accessory nerves (XI)

MOTOR; two branches: CRANIAL (soft palate, pharynx, larynx) & SPINAL (neck {shrug, tilt head} & back)

oculomotor nerves (III)

MOTOR; voluntary muscles that raise the eyelid, move EYES & ADJUST the amount of light entering the eyes; focus

nodes of ranvier

Narrow gaps between Schwann cells (myelin sheaths)

medulla oblongata

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion.

optic nerves (II)

SENSORY; associated with VISION

olfactory nerves (I)

SENSORY; sense of SMELL, located in nasal cavity

vestibulocochlear nerves (VIII)

SENSORY; sensory nerves; two branches: vestibular (EQUILIBRIUM) & cochlear (HEARING)

glucagon

Stimulates the liver to break down glycogen, raises blood sugar concentration

pia mater

Very thin and contains many nerves and blood vessels that nourish underlying cells of the brain and spinal cord; contours over these organs

lateral born

a protrusion of gray matter in the thoracic & upper lumber segments

action potential

a rapid change in membrane potential; neuron membrane polarization, return to resting state; forms an impulse along an axon; all or none response

Glasgow Coma Scale (GCS)

a scale used to assess the consciousness of a patient; 1. eye opening, 2. verbal response, 3. motor response (best score is 15, 8 or less is comatose, 3 is lowest; totally unresponsive)

graded potential

a shift in the electrical charge in a tiny area of a neuron

preganglionic fibers of the sympathetic division secrete which neurotransmitters

acetylcholine

paracrine secretions

affecting neighboring cells

cortisol

affects glucose metabolism; influences protein & fat metabolism

thymosin

affects the production of lymphocytes (white blood cells)

middle ear

air-filled space within temporal bone; contains auditory ossicles; auditory tube

association areas

analyze and interpret sensory experiences and oversee memory, reasoning, verbalizing, judgment & emotion; neither primarily sensory or motor

adrenal glands

anterior to kidneys; secrete the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline), which help to arouse the body in times of stress.

cell membrane surface polarization

arises from unequal distribution of positive & negative ions across the membrane; important in the conduction of impulses in muscle cells & neurons

Decerebrate posturing

arms & legs are extended and the wrists are flexed; problems with midbrain or pons

Decorticate posturing

arms flexed inward and bent in toward the body and the legs are extended; problems with cervical spinal tract or cerebral hemisphere

two major functions of spinal cord

ascending tracts: carry sensory info to the brain; descending tracts: carry motor instructions from brain to muscles/glands

pituitary gland

attached to hypothalamus; regulates growth, reproduction & BP

diabetes mellitus type 1

autoimmune disease; the immune system destroys the beta cells (secrete insulin) of the pancreas

posterior pituitary gland

axons & neuroglia; controlled by nerve responses of the hypothalamus

temporal lobe

below the frontal & parietal lobes; senses for auditory(hearing); "Wernicke's area" (important for understanding written/spoken language)

diabetes mellitus type 2

beta cells produce insulin, but body loses ability to recognize it

barrier that helps prevent chemical fluctuations in the brain & blood

blood brain barrier

sensory (afferent) fibers

bring sensory information to the CNS

external auditory meatus

canal leading inward thru temporal lobe

motor (efferent) fibers

carry impulses from CNS to effectors (muscles/glands)

motor nerves

carry impulses to muscles or glands

ventricle

cavity filled with fluid (brain ventricle = cerebrospinal fluid; heart ventricle = blood)

common features of neurons

cell body (tubular), cytoplasm-filled dendrites, an axon

target cells

cells with specific receptors for a hormone

adrenal medulla

central portion of adrenal gland; secretes epinephrine & norepinephrine

4 major portions of the brain

cerebrum, cerebellum, diencephalon, brainstem

neurotransmitter

chemical that inhibits or stimulates an effector/neuron

middle layer of eye

choroid coat, ciliary body & iris

inner ear

cochlea (hearing), vestibule (static equilibrium), semicircular canals (dynamic equilibrium)

subdural hematoma

collection of blood under the dura mater

external ear

collects & transmits sound waves created by vibrations

iris

colored part of eye

cerebrospinal fluid (CSF)

completely surrounds the brain & spinal cord; occupies the subarachnoid space; maintains a stable ionic concentration; provides a pathway to the blood for wastes

peripheral nervous system (PNS)

composed of nerves that connect the CNS to other body parts; help provide sensory, integrative & motor functions

auditory (eustachian) tube

connects throat with middle ear; maintain equal air pressure on both sides of eardrums

central nervous system (CNS)

consists of brain & spinal cord; help provide sensory, integrative & motor functions

basal metabolic rate (BMR)

consumption at rest in order to maintain life

subarachnoid space

contains cerebrospinal fluid (CSF); between pia mater & arachnoid mater

stress response

controlled by hypothalamus; has immediate "alarm" stage & long term "resistance" stage

Adrenocorticotropic hormone (ACTH)

controls secretions of certain hormones of the adrenal gland

thyroid stimulating hormone (TSH)

controls thyroid gland secretions; regulated by hypothalamus

cAMP

cyclic adenosine monophosphate, second messenger

anterior pituitary gland

dense connective epithelial tissue; controlled by releasing hormones of the hypothalamus

fovea centralis

depression in the center of the retina; produces the sharpest vision

dynamic equilibrium

detect motion of the head & aid in balancing the head and body during sudden movement

channels in cell membranes

determine the distribution of ions; some are always open; other are "gated" or selective with the ions they allow inside

potential difference

difference in electrical charge between two regions

stuporous

difficult to arouse; follow simple commands, speak single words

semicomatose

does not follow commands or speak, withdrawal to painful stimuli

sympathetic division (ANS)

energy-expending, stressful, or emergency situations (fight-or-flight)

polydipsia

excessive thirst

EOM

extraocular movement (of the eyes)

accessory organs of the eye

eyelids, lacrimal apparatus, extrinsic muscles

sense of taste receptors found in

facial, glossopharyngeal, vagus cranial nerves

cochlea

filled with perilymph (fluid); contains organ of hearing (corti)

aqueous humor

fills space between cornea & lens; helps nourish those parts; aids in maintaining the shape of the front of the eye

ependymal cells

form membrane around choroid plexuses; form inner linings that enclose ventricles & central canal

Schwann cells

form myelin sheath in PNS

frontal lobe

forms the anterior portion of each cerebral hemisphere; control of voluntary muscles (motor); concentration, planning, problem solving; speech production

occipital lobe

forms the posterior part of each cerebral hemisphere; sight, visual reception & recognization

astrocytes

found between neurons & blood vessels; provide structural support, join parts by their abundant cellular process; regulate nutrients & ions

unipolar neurons

found in masses of nervous tissue (ganglia); located outside of brain & spinal cord

interneurons

found only in the brain or spinal cord; multipolar; conduct impulses from one part of brain/spinal cord to another part

4 lobes of the brain

frontal, parietal, occipital, temporal, (+/- insula)

synapse

functional connection between two neurons; not in direct physical contact (separated by synaptic cleft)

auricle (pinna) (external ear)

funnel-like; gathers & directs sound waves to the eardrum

sensory receptors

gather information by detecting changes inside/outside the body; monitor external environmental factors; convert info into impulses

endocrine system

glands that secrete hormones into the internal environment

glycosuria

glucose in the urine

basal nuclei

gray matter deep within each cerebral hemisphere; produce dopamine; inhibitor that facilitates voluntary movement

neuronal pools

groups of neurons that make hundreds of synaptic connections with each other & work together to perform a common function

ossicles

help amplify the force of vibrations from eardrum to the oval window

what do endocrine glands & their hormones do?

help regulate the metabolic process

hyperglycemia

high blood sugar

Cushing's syndrome

hypersecretion of adrenal cortical hormones; hyperglycemia; alters carb & fat metabolism

limbic system

hypothalamus, thalamus & basal nuclei; controls emotional experience & expression; can produce fear, anger, pleasure & sorrow

saltatory

impulse conduction where an impulse travels along a myelinated axon & appears to jump from node to node

receptive aphasia

inability to understand spoken or written words (receiving the message)

mixed nerves

include both sensory & motor fibers

parathyroid hormone (PTH)

increases blood Ca2+ concentration & decreases blood phosphate ion concentration; affects bones, kidneys & intestine

thyroid gland

inferior to larynx, anterior to trachea; vascular structure of two large lobes connected by an isthmus

phrenic nerve

innervates the diaphragm (breathing)

steroid hormone receptors

internal receptor that turns on specific genes when it is activated by binding a signal molecule

vitreous humor

jelly-like fluid; between lens & retina; supports the internal parts of the eye & helps maintain shape

patellar reflex

knee jerk reflex

lacrimal apparatus

lacrimal gland; located in the orbit; secretes tears

cones (photoreceptors)

less sensitive to light; detect color; sharp clear images; react quickly to light

thymus

lies in the mediastinum, posterior to sternum, between lungs; secretes thymosin; plays an important part in immunity

myelin

lipid material that forms a sheath-like cover around some axons

pineal gland

located deep between cerebral hemispheres, attached to upper part of thalamus; 3rd ventricle of brain; secrete melatonin

static equilibrium

maintaining stability while the head & body are still

part of brainstem that controls blood pressure & breathing rate

medulla oblongata

hyperpolarization

membrane potential may briefly become overly negative (slow closing K+ channels; sodium/potassium pump can fix it)

synaptic vesicles

membranous sacs that store/release neurotransmitters; found inside axon

neuroglia in the central nervous system

microglial cells, oligodendrocytes, astrocytes, ependymal cells

resting cell membrane

more permeable to potassium ions than sodium ions (potassium diffuses out more than sodium diffuses in)

sensory neurons

mostly unipolar; conduct impulses from body parts into the brain or spinal cord

conjuctiva

mucous membrane that lines the inner surfaces of the eyelid & folds back to cover the anterior surface of the eyeball

brain & spinal cord neurons are

multipolar (one process; each neuron is axon, rest are dendrites)

motor neurons

multipolar; conduct impulses out of the brain or spinal cord to effectors; motor impulses control muscle contraction & secretion of glands

sensory nerves

nerves that conduct impulses to the brain or spinal cord

nuclei

nervous tissue of cell bodies; located INSIDE the CNS

ganglia

nervous tissue of cell bodies; located OUTSIDE the CNS

Addison's disease

occurs when the adrenal glands do not produce enough of the hormones cortisol or aldosterone; dehydration, increased skin pigmentation, hypoglycemia

extrinsic muscles

on the eye's tough outer surface

oligodendrocytes

only in CNS; along axons (nerve fibers); provide insulating layers of myelin within the brain & spinal cord

insulin

opposite of glucagon; regulated by negative feedback; stimulates liver to decrease blood sugar concentration by diffusing glucose across all membranes that have insulin receptors

parasympathetic division (ANS)

ordinary, restful conditions; restores body to resting state following a stressful experience (CHILL)

spiral organ

organ of corti; hearing receptors (hair cells); enables us to hear sounds of different pitch simutaneously

dura mater

outermost layer; tough, white, fibrous connective tissue; contains many blood vessels & nerves; forms the internal periosteum of the skull bones

effectors

outside the nervous system; muscles & glands whose actions are controlled by neurons

hyperthyroidism

overactive thyroid condition; high metabolic rate

somatic nervous system

part of PNS; consists of cranial & spinal nerve fibers; controls skeletal muscle(effectors); voluntary control

autonomic nervous system

part of PNS; motor neurons; functions independently without conscious effort; controls muscles(effectors) that are involuntary; cardiac muscle, smooth muscle & glands; regulates HR, BP, breathing rate, temp; responds to emotional stress

major endocrine glands

pituitary, thyroid, parathyroid, adrenal, pancreas, pineal, reproductive (testes & ovaries), kidneys & thymus

oxytocin (OT)

posterior lobe; Stimulates contraction of the uterus and release of milk from breast; controlled by hypothalamus

antidiuretic hormone (ADH)

posterior lobe; causes kidneys to conserve water; increases blood pressure

parathyroid glands

posterior surface of thyroid gland; 4 small glands on the posterior of the thyroid gland

pancreas

posterior to stomach, behind parietal peritoneum; functions as an exocrine (digestive juice) & endocrine gland(hormones); alpha cells secrete "glucagon", beta cells secrete "insulin"

parietal lobe

posterior to the frontal lobe; skin/touch (cutaneous) sensations, help in understanding speech & choosing words to affect thoughts/feelings;

major contribution to membrane polarization

potassium ions (they pass thru cell membranes much more easily than sodium)

expressive aphasia

problems with speaking or finding words (sending the message)

neuroglia

produces myelin, communicate between cells, maintain ionic environment, nurture differentiation of neurons

luteinizing hormone (LH)

promotes sex hormones; promotes ovulation (releasing egg)

PERRLA

pupils equal, round, reactive to light and accommodation

thalamus

receives all sensory impulses (except smell); pain, touch & temp

parts of a reflex arc

receptor, sensory neuron, interneuron, motor neuron, effector

non-steroid hormones

receptors located on cell membrane; water-soluble; delivers its message by binding to a "second messenger"(cAMP)

steroid hormones

receptors located on nucleus; insoluble in water; soluble in lipids; diffuse into target cells easily

optic disc

region at the back of the eye where nerve fibers exit, becoming part of the optic nerve; blind spot

aldosterone

regulates concentration of mineral electrolytes; stimulate water retention to maintain blood volume & blood pressure

hypothalamus

regulates heart rate, arterial BP, body temp, water/electrolyte balance; hunger & body weight; movements & glandular secretions; sleep/wakefulness; pituitary gland stimulation

midbrain

responsible for reflexes like moving eyes to view something as the head turned; contains auditory reflex to move head to hear sounds

depolarized membrane

resting potential decreases (inside of the membrane becomes less negative compared to outside)

Area stimulated by incoming sensory information

reticular formation

inner layer

retina

repolarization

return of the cell membrane to the resting potential

microglial cells

scattered thru CNS; support neurons & phagocytize (eat) bacteria cells & cellular debris; form scars in area of damage

Follicle-stimulating hormone (FSH)

secreted by the pituitary gland to stimulate maturation of the egg cell; controlled by hypothalamus

autocrine secretions

secretes within itself

axon

send information AWAY in the form of IMPULSES

taste buds

sensory organs of taste; taste/gustatory cell that functions as receptors

types of nerves

sensory/afferent, motor/efferent

pons

separates the midbrain from the medulla oblongata; relay sensory impulses form peripheral nerves to higher brain centers

dendrites

short, highly-branched; RECEIVE input from other neurons

melatonin

sleep-inducing hormone

spinal cord

slender nerve column; consists of 31 segments

choroid plexus

specialized capillaries that secrete cerebrospinal fluid into a brain ventricle

tract associated with pain, touch, temp

spinothalamic tract

types of hormones

steroid and non-steroid

growth hormone (GH)

stimulates cells to enlarge & divide more frequently

Prolactin (PRL)

sustains milk production after birth

neurotransmitters within the CNS

synthesized in the cytoplasm of the synaptic knobs, stored in the synaptic vesicles

placenta

temporary reproductive organ; produces testosterone, estrogen, progesterone & gonadotropin;

main central relay station for incoming impulses

thalamus

sciatic nerve

the largest nerve in the body; originates in the lumbosacral plexus and runs through the pelvis and down the leg

tympanic membrane (eardrum)

the membrane at the end of the ear canal that relays vibrations into the middle ear

adrenal cortex

the outer portion of adrenal glands; aldosterone, cortisol & certain sex hormones (VITAL)

lumbar enlargement

thickening in the lower back; supplies nerves to the lower limbs

cervical enlargement

thickening in the neck portion of the spinal cord; supplies nerves to the upper limbs

ciliary body

thickest part of the middle layer; secretes aqueous humor (clear fluid front of eye)

arachnoid mater

thin, web-like membrane without blood vessels; llies between dura & pia maters

meninges

three protective membranes that surround the brain and spinal cord; dura mater, arachnoid mater, pia mater

thyroid gland hormones

thyroxine (T4), triiodothyronine (T3), calcitonin

Prostaglandins

tissue hormones; produced by liver, kidney, heart, lungs, thymus, pancreas, brains & repro organs (respirations, BP, inflammation, etc)

insula

translating information into appropriate emotional responses

hypothyroidism

underactivity of the thyroid gland; low metabolic rate

comatose

unresponsive to stimuli; possible decerebrate or decorticate posture

choroid coat

vascular, pigmented middle layer; absorbs excess light; keep the inside of the eye dark

Rods (photoreceptors)

very sensitive to light; allow sight in dim light; black & white; slower to react

sclera

white portion of eye; protects the eye;

cornea

window of the eye & helps focus entering light rays; no blood vessels