Anatomy exam 3 (final exam) 150 question multiple choice, 50 on old (more general) , 100 on new material (9,14,15,16), diagrams (human lab muscles page 26, identify on diagram, their function, general region where its at)

Sympathetic division continued

- more complex than parasympathetic -innervates smooth, cardiac muscle, and glands in body cavities -innervates smooth muscle and glands in superficial regions (sweat glands, arrector pili, smooth muscle in blood vessel walls) **controls size of blood vessels therefore, controls blood flow A) Anatomy: sympathetic division forms sympathetic trunk -preganglionic fibers leave spine via ventral root -fibers pass through white ramus communicans (carry pregang fibers to trunk), enter sympathetic trunk ganglion -sympathetic trunk ganglion is on both sides of spine

Skeletal muscle contraction: energy needs

-ATP is the only energy source used directly for contractile activity -Skeletal muscle stores very little ATP -Stored in glycogen, doest use glucose directly -ATP regenerated as fast as it is used -3 Pathways used to regenerate ATP..... 1) Direct phosphorylation 2) Anaerobic pathways 3) Aerobic pathways

ANS neurotransmitters: acetylcholine

-Acetylcholine (ACh): effect is not entirely excitatory or inhibitory, depends on receptor it binds to -released by cholinergic fibers at 1) all ANS preganglionic axons 2) all parasympathetic postganglionic axons at synapses with effector -cholinergic receptors that bind to ACh A) Nicotinic receptors: found on all postganglionic neurons (sympathetic and parasympathetic), hormone producing cells of adrenal medulla, sarcolemma of skeletal muscle cells -effect: binding is always stimulatory B) Muscarinic receptors: found on all parasympathetic effectors and some sympathetic effectors -effect: binding is stimulatory or inhibitory -EX: binding to muscarinic receptors of heart are inhibitory but of the smooth muscles of the gastrointestinal tract is stimulatory

Boney labyrinthine of cochlea

-Bony labyrinth of cochlea divided into 3 regions: 1) Scala vestibuli: part of bony labyrinth that begins at oval window -contain perilymph 2) Scala tympani: part of bony labyrinth that ends at round window -Vestibuli + tympani are continuous, meet at helicotrema -contain perilymph 3) Scala media (cochlear duct): part of membranous labyrinth -divided into.... a) Vestibular membrane: divides s. media from s. vestbuli b) Stria vascularis: secretes endolymph c) Basilar membrane: forms floor of scala media

Hormones: Chemical Structure

-Chemical structure determines longevity, transport in blood, receptivity -Two major classification of hormones.... 1) Amino acid-based* -Molecular size varies, amino acid derivatives, peptides, proteins -Water-soluble, circulate without carrier 2) Steroids -Synthesized from cholesterol -Gonadal hormones and adrenocortical hormones are only steroid hormones in body -Lipid-solubleàcirculatewith carrier

Gustation

-Chemoreceptors found on taste buds, must be dissolved in saliva in order to taste it -Most located (tastes bud) found on papillae of tongue -3 types of papillae.... 1) Fungiform papillae: found all over tongue, contain 1-5 taste buds each 2) Vallate papillae: found at back of tongue, have many taste buds each 3) Foliate papillae: found on side of tongue, taste buds number varies with age **roughly 10,000 tastes buds all together

Muscle functions

1) Movement: Voluntary or involuntary 2) Body posture & body position: Muscles work to hold us up against gravity 3) Joint stability: Muscles & tendons reinforce joints 4) Maintaining body temperature: Muscle contraction produces heat

Olfaction

-Chemoreceptors: respond to stimuli dissolved in solution -could be a warning system about non visual cues in ur environment -olfactory receptors found in olfactory epithelium -location: roof of nasal cavity -contains 3 cell types... 1) olfactory sensory neurons 2) supporting cells 3) olfactory stem cells

Aerobic Pathway: Cellular Respiration

-Creates 95% of ATP used by muscle during rest and light to moderate long-term exercise -Uses pyruvic acid produced in anaerobic pathway -Requires oxygen and mitochondria -1 glucose molecule produces 32 ATP, H20, and CO2 -Drawbacks.... a) Slow process b) Requires constant O2 and glucose

homeostatic imbalances of thyroid gland

-Deficiency in TH production & release causes metabolic disturbances 1) Hypothyroidism (myxedema): underactive thyroid activity -Effect: underactive metabolism, chills, constipation, edema, lethargy, mental sluggishness, etc. -Causes: variable, but may be related to lack of iodine in diet -Goiter: swelling of thyroid gland resulting from lack of proper iodine intake 2) Hyperthyroidism: overactive thyroid disorder -Effect: sweating, rapid/irregular heartbeat, nervousness, weight loss

Excess Post-exercise Oxygen Consumption (EPOC)

-EPOC used to completely restore muscle function -EPOC is "paying back an oxygen debt", the amount of oxygen required post-exercise to return muscle to pre-exercise state -EPOC includes..... 1) Restoring oxygen reserves 2) Accumulated lactic acid converted to pyruvic acid 3) Glycogen stores replenished 4) ATP and CP stores replenished

Depth perception

-Each eye has a visual field of ~170 degrees -Complete visual fields of left & right eye overlap -Visual cortex combines two images to create depth perception -Importance: depth perception allows us to locate objects in space, allows us to reach for things -If one eye is lost or not used, depth perception is lost

Motor units

-Each muscle is served by at least one motor nerve -Motor neurons in motor nerve branch to form neuromuscular junctions with a single muscle fiber -a motor neuron can serve up to hundreds of muscle fibers simultaneously 1) Motor unit: a single motor neuron and all of the muscle fibers it supplies a) Rule 1: when the motor neuron fires--> all fibers it innervates will contract -Fibers are not clumped together! b) Rule 2: number of muscle fibers a single motor neuron innervates influences movement -Motor neuron innervating few fibers---> precise control (ex: fingers) -Motor neuron innervating many fibersàcoarsecontrol (ex: leg muscles)

Taste buds

-Each taste bud has two types of epithelial cells..... 1) Gustatory epithelial cells: receptor cells for taste -Gustatory hairs have microvilli projecting from tips of gustatory epithelial cells -Function: receptor membrane of gustatory epithelial cells -Sensory dendrites (propagate AP of cranial nerve) wrap around gustatory hairs 2) Basal epithelial cells: stem cells -Replace lost/damaged gustatory epithelial cells, can regenerate -Taste buds replaced every 7-10 days

Focusing light: distant vision

-Far point of vision: point at which the lens no longer needs to change shape to focus light -normal eye= ~20ft -when looking at distant object--> light rays entering eye are nearly parallel -cornea and lens easily focus light on retina -ciliary muscles are relaxed causing tension of suspensory ligaments resulting in flattening of lens

Muscle contraction: velocity and duration

-Fiber type influences velocity & duration of muscle contraction 1) Speed of contraction -Dependent on..... A) How fast ATP is split, how fast cross bridges can form & break B) Electrical activity of motor neurons--> fast neurons (large diameter and heavily myelinated) = fast contraction 2) Load and recruitment -Small loads allow faster contraction and longer duration -More motor unit recruitment = faster contraction 3) Pathway of ATP production -Oxidative fibers---> use aerobic pathways -Glycolytic fibers---> use anaerobic pathways -Three fiber types created from the above: fast glycolytic, fast oxidative, & slow oxidative ****learn table

Role of outer hair fibers

-Fibers that wrap around outer hair cells are efferent -Outer hair cells change flexibility of basilar membrane -Two functions.... 1) Increases responsiveness of inner hair cells which amplifies motion of basilar membrane 2) Protection: outer hair cells stiffen in response to loud sound -Effect: basilar membrane becomes stiffer so inner hair cells move less to prevent damage

Muscle contraction: force

-Force is determined by the number of cross bridges formed between myosin and actin filaments -Influenced by 4 factors... 1) Frequency of stimulation---> temporal summation -Higher frequency of stimulation = greater force generated 2) Number of muscle fibers recruited---> motor unit summation -More motor units recruited = greater force generated 3) Size of muscle fiber -Bulkier muscle generates more tension, creates more force -Why?: Larger muscle fibers have larger motor units -Hypertrophy: increase size of muscle fibers in muscle to increase force generated -How? Weightlifting & resistance training -Rate dependent on genetics, sex, nutrition, etc. 4) Degree of muscle stretch -Force a muscle creates varies with how much it is stretched -Length-tension relationship

Anterior pituitary hormones

-Four of six hormones are tropins (target cells are in another endocrine gland, inhibits or stimulates an endocrine gland), affect activity of another endocrine gland -controlled by hypothalamus A) Growth hormone (GH) -Function: aids in metabolic and growth-promoting actions -Metabolic effects..... 1) Decreases glucose uptake by cells , anti-insulin effect (glucose sparing effect) 2) Mobilizes fat stores, releases fatty acids to blood (to use fatty acids to spare glucose) 3) Increases amino acid uptake by cells (allow cells to build more shit for growth) -Growth effects -Liver, bone, skeletal muscle, etc. produce insulin-like growth factor (IGFs) in presence of GH -IGFs stimulate growth..... 1) Increase nutrient uptake by tissue 2) Formation of collagen and deposition of bone matrix -Release of GH controlled by growth hormone-releasing hormone (GHRH) or growth hormone-inhibiting hormone (GHIH)

Pineal gland

-Function: secretes melatonin -Effect: regulates night-day cycles, sleeping schedule -High levels of melatonin = sleepy -Low levels of melatonin = alert -Release controlled indirectly by visual pathways, intensity & duration of sunlight

Anaerobic Pathways: Glycolysis & Lactic Acid Formation

-Glucose broken down to form 2 ATP & lactic acid -Lactic acid not used by muscle diffuses into blood vessels -Does not require oxygen, can take place whether O is there or not -Fast method to create ATP -Drawbacks..... a) A lot of glucose used for low ATP yield b) Lactic acid build-up results in DOMS (delayed onset muscle soreness) - Stored ATP, creatine phosphate, & glycolysis provide ~1 minute of ATP

Graded muscle contractions

-Graded muscle contractions: smooth muscle contractions that vary in strength when different demands are placed on them -Muscle contractions can be graded 2 ways... 1) Temporal summation--> increasing the frequency of stimulation of a muscle 2) Recruitment/Motor Unit summation--> increasing the strength of stimulation of a muscle

Smooth Muscle Tissue: Gross Anatomy

-Hollow organs in the body have smooth muscle tissue -Only exception: heart -Most organs have 2 layers of smooth muscle tissue..... 1) Longitudinal layer: muscle fibers run the length of the organ -More superficial layer -When contracted, organ shortens 2) Circular layer: muscle fibers run the circumference of the organ -Deep to longitudinal layer -When contracted, organ lengthens **both layers never contract at the same time, generally contact in a wave-like motion -concerned with pushing food through an organ

Hormone actions

-Hormones can only affect target cells with appropriate receptors -Different receptors = different response -Changes produced by hormone binding.... 1) Altering plasma membrane permeability or membrane potential 2) Stimulates synthesis of enzymes/proteins inside cell 3) Activates/deactivates enzymes 4) Induces secretory activity 5) Stimulates mitosis

Pancreas

-Hormones produced in pancreatic islets -Function: controls blood sugar levels -Glucagon: produced by alpha cells -Hyperglycemic effect (high blood glucose level) -Effects: Stimulates liver to break down glycogen, convert non-carbohydrate molecules to glucose, release glucose from liver cells -Release controlled by dropping blood glucose levels

Pathway to olfactory cortex

-In olfactory bulb, olfactorysensory neurons synapse with mitral cells -Site of synapse is called glomeruli -Impulses flow from olfactory bulb via olfactory tract -Information from olfactory tract takes 1 of 2 pathways... 1) Sent to olfactory cortex--> smell consciously interpreted/identified 2) Sent to limbic system---> smell elicits an emotional response -Activation of sympathetic (dangerous or unwanted smells) or parasympathetic system (smells goo food) -Activation of protective reflexes such as coughing, sneezing

Temporal summation

-Increasing the firing rate of a motor neuron can generate more force at the muscle -How does it happen?: Fire stimulus in rapid succession--> the second twitch hits the muscle before the first twitch has ended -Effect: muscle tension increases 1) Unfused (incomplete) tetanus: rate of stimulation creates a sustained & quivering muscle contraction 2) Fused (complete) tetanus: rate of stimulation creates smooth, sustained muscle contraction -No relaxation occurs, maximal tension reached

Recruitment: motor unit summation

-Increasing the voltage of the stimulus causes more muscle fibers to contract--> increases muscle contraction force -How does it happen?: 1) Increase the number of motor units used for contraction 2) Size principal of motor unit summation a) Motor units with smallest muscle fibers recruited first b) Motor units with largest muscle fibers recruited last, creates most powerful contractions -Motor units recruited asynchronously, some contracting, others relaxing

Pathway to vestibular nuclei or cerebellum

-Information sent directly to reflex centers of brain stem to correct posture before you even relate you're falling over -Impulses travel to 1 of 2 destinations.... 1) Vestibular nuclei: major integrative area for balance -Also receives visual ( help catch yourself) & somatic receptors (help skeletal tissue adjust body) -Vestibular nuclei sends impulses to brain stem which uses info to correct body position 2) Cerebellum -Function: coordinates skeletal muscle activity and muscle tone (particularly in neck) to maintain head position, posture, balance

Insulin

-Insulin: produced by beta cells -Hypoglycemic effect -Effects: Increases glucose uptake by body cells, inhibits glycogen breakdown, inhibits conversion of non-carbohydrate molecules to glucose -Release controlled by.... a) Elevated blood glucose b) Rising blood levels of amino acids & fats c) Acetylcholine release from parasympathetic d) Any hyperglycemic hormone

linear acceleration and head position: Maculae anatomy

-Maculae Anatomy.... -Flat patch with supporting cells + hair cells (stereocilia, kinocilia) -Base of hair cells supplied by vestibular nerve -Tips of stereocilia and kinocilia embedded in otolith membrane a) Otolith membrane: jelly-like base with small otolith stones embedded in membrane -Otoliths are dense is whenever the head moves, tend to drag which bends hairs to one side

neuromuscular junction

-Motor neurons stimulate muscle tissue -Neurotransmitter: Acetylcholine(ACh), always stimulatory -Types of ion channels important for contraction 1) Voltage-gated-->T-tubules 2) Chemically-gated--> sarcoplasmic reticulum A) Neuromuscular junction between motor neuron and muscle fiber -Axon terminals contain synaptic vesicles -Synaptic cleft filled with gel-like substance -Sarcolemma at cleft folded--> forms junctional folds -Importance: folds increase surface area for ACh binding

Micro-anatomy of muscles

-Muscle fibers are among largest and longest in body A) Sarcolemma: plasma membrane of muscle fibers B) Sarcoplasm: cytoplasm of muscle fibers -Contain high numbers of 1) Glycosomes: store glycogen 2) Myoglobin: red pigment that stores oxygen C) Myofibrils: make up bulk of individual muscle fiber -Composed of alternating A bands and I bands 1) A band: Contains H zone at center, bisected by M line 2) I band: Contains Z disc at center D) Sarcomere -Formed by 1 full A band and 1/2 I band on other side, region between 2 successive Z discs Importance: the smallest contractile unit of skeletal muscle tissue

ANS Neurotransmitters: norepinephrine/epinephrine

-Norepinephrine (NE)/epinephrine: effect not entirely excitatory or inhibitory, depends on the receptor it binds to -released by adrenergic fibers at... 1) sympathetic postganglionic axons -adrenergic receptors that bind to NE... A) Alpha receptors: found on all sympathetic target organs (effector organ) B) Beta receptors: found on heart, adipose tissue, kidneys, lungs, blood vessels -binding of NE or epinephrine can be stimulatory or inhibitory -EX: NE binding at beta receptors of heart increases activity (stimulatory) -EX: epinephrine binding at beta receptors of bronchioles causes dilation (inhibitory)

Localized vs diffuse effects of two divisions

-Parasympathetic division exerts highly localized, short lived control -how... 1) one preganglionic neuron synapses with one (or few) postganglionic nuerons 2) all parasympathetic fibers release ACh--> quickly broken down by acetylcholine esterase -synpathetic division exerts diffuse long lasting control -how... 1) preganglionic neurons synapse with multiple postganglionic nuerons 2) NE and epinephrine prolong effects of sympathetic division activation

Posterior pituitary and hypothalamic hormones

-Posterior Pituitary & Hypothalamic Hormones 1) Oxytocin -Functions: stimulant for uterine contraction, milk ejection, "cuddle hormone" -Neurotransmitter in brain, promotes nurturing, couple bonding, trust, affectionate behavior -Stretching of cervix during childbirth sends afferent impulses to hypothalamus, stimulates posterior pituitary to release hormone -Release increases as labor progresses, stops soon after birth -Stimulates milk-producing glands to contract during breastfeeding 2)Antidiuretic Hormone (ADH) -Function: prevents formation of urine by kidneys -Importance: prevents dehydration or water overload -Osmoreceptorsin hypothalamus monitor solute concentration -Solute concentration high: release ADH -Solute concentration low: prevent ADH release -Other stimuli for ADH release: Pain, low blood pressure, some drugs (nicotine, morphine, barbiturates)

The thyroid gland

-Produces, secretes, and stores hormones -Retains ~3 months normal supply of hormone -Function: produces Thyroid Hormone (TH), major metabolic hormone -TH is two separate hormones, thyroxine (T4) and triiodothyronine (T3) -Production of TH depends on presence of iodine -Affects virtually every body cell... 1) Increases metabolic rate and body heat production 2) Regulates tissue growth/development 3) Maintains blood pressure

Muscle tone (slight consistent contraction)

-Relaxed muscles are always slightly contracted due to spinal reflexes, creates muscle tone -Does not produce movement -So why is it important?: Muscle tone keeps muscle tissue healthy and responsive, stabilizes joints, maintains posture, increase receptiveness to incoming stimuli -Loss of muscle tone leads to loss of responsiveness -Muscle will not respond to stimuli -Ex: stroke victims (dropping of one side of face/body due to loss of muscle tone)

The Parathyroid Gland

-Secretes Parathyroid Hormone (PTH) -Function: controls calcium balance in blood, calcium homeostasis -humoral hormone -Falling blood Ca2+ levels stimulate PTH release: 1) Stimulates osteoclasts to increase bone degradation, increasing calcium release to blood 2) Enhances Ca2+ reabsorption by kidneys 3) Activates vitamin D, increases absorption of Ca2+ from digestive system

linear acceleration and head position: sensation of movement

-Sensation of movement..... -Otoliths are dense and causes membrane to move in response to head movement -Movement of otolith membrane bends hair cells a) Bending toward kinocilium --> hair cells depolarize, more neurotransmitter released -forward b) Bending away from kinocilium --> hair cells hyperpolarize, less neurotransmitter released -backwards 1) In utricle: maculae are horizontal, hair cells are vertical -Best suited for forward/backward motions 2) In saccule: maculae are vertical, hair cells are horizontal -Best suited for up/down motions ***Maculae only respond to changes in head position

Contraction of smooth muscle

-Similarities to skeletal muscle contraction: 1) Ca2+ is final trigger for contraction 2) Actin and myosin interact, sliding filament model 3) ATP is energy source -Differences: 1) Gap junctions spread depolarization, muscle contracts as entire unit 2) Pace maker cells set pace for contraction of muscle 3) Calmodulin binds Ca2+ 4) Activates light-chain kinase to activate myosin heads

The Sliding Filament Model of Muscle Contraction

-Sliding Filament Model of Contraction: During contraction, thin filaments slide past thick filaments -Myosin heads of thick filament form cross bridges with actin on thin filament -Cross bridges form and break multiple times during contractionàmyosinheads "slides" thin filament -Here is what is observed during this model: 1) I bands shorten 2) Z discs come closer together 3) H zone disappears 4) A bands move closer together

load, muscle fiber, tension, prefixes

1) Muscle fiber: individual cells that make up a single muscle 2) tensions: force exerted by a contracting muscle 3) load: opposing force exerted on the muscle y the weight of the object being moved 4) Sacro, msy or myo: refers to a structure that related to muscle tissue

Hormone release

-Stimulating hormone release -Hormone synthesis & release is controlled by negative feedback mechs -Importance: hormone levels need to be precisely regulated -Stimulus mechanisms.... 1) Humoral stimuli: changing blood levels of critical ions & nutrients -Ex: monitoring Ca2+ levels by parathyroid gland 2) Neural stimuli: nerve fibers stimulate hormone release -Infrequent -Ex: norepinephrine & epinephrine release by sympathetic nervous system 3) Hormonal stimuli: hormone released in response to other hormones -Ex: hypothalamic hormones stimulate or inhibit anterior pituitary gland

Basic taste sensation

-Taste has five basic modalities...... 1) Sweet: produced by most sugars, alcohols, some amino acids, lead salts 2) Sour: produced by acids 3) Salty: produced by metal ions (inorganic salts) 4) Bitter: produced mostly by alkaloids, some nonalkaloid 5) Umami: produced by amino acids glutamate & aspartate, beef, tang of aging cheese, MSG -Maybe a 6th: long-chain fatty acids (found in lipids) why sone people like really fatty/deep fried foods -Most substances produce a combination of the above -Single taste cell responds to only 1 modality -All areas of tongue can detect all taste modalities

The cochlea

-The Cochlea: spiral bony chamber of the inner ear involved with sound perception -Cochlear duct runs through center -Cochlear duct is membranous portion -Contains spiral organ which is the actual receptor organ for hearing -Cochlea ends blindly at helicotrema A) The Spiral Organ -Receptor region with two cell types.... 1) Cochlear hair cells (receptive cell) -One row of inner hair cells -Three rows of outer hair cells -Cochlear nerve fibers wrap around hair cells 2) Supporting cells: support hair cells -surround cochlear hair cells

3 layers that compose the eye: Fibrous layer

-The fibrous layer is the outermost coat of the eye with 2 regions a) sclera: whites of eyes -function: gives eyeball shape, provides sturdy anchor for extrinsic muscles b) cornea: transparent layer at the most anterior region of the eye -functions: allows light to enter eye, bends light as it passes -supplied with many pain receptors -high regenerative and repair capacity -no blood vessels, no immune system supple

Hearing

-Three major regions of the ear 1) External ear a) Pinna: outermost cartilaginous part of the ear -Function: funnels sound into inner parts of ear -cartilage holds ear open b) External acoustic meatus: tube extending from auricle to tympanum -Has sebaceous glands (prevent drying), some hairs, and ceruminous glands (secrete cerumen aka ear wax) -cerumen is noxious to keep bugs out and catching dirt particles c) Tympanic membrane: translucent membrane that divides outer ear from middle ear -Function: vibrates in response to sound, transmits vibrations to middle ear 2) Middle Ear -3 auditory ossicles: malleus, incus, stapes -have ligaments and joints in between them which allows them to move -malleus: most laterally, connect to tympanic membrane -stapes: most medial -Function: ossicles vibrate in response to incoming sound waves transmit sound to inner ear -Muscles associated with bones (for protection) .... a) Tensor tympani & stapedius contract in response to extreme sound vibrations -if moved too much you can damage/disconnect these bones b) Oval window and round window: small openings in middle ear -Stapes attaches to oval window -important to sound transduction c) Pharyngotympanic tube: runs from middle ear to nasopharynx -Function: opening of tube balances air pressure in middle ear -Importance: tympanic membrane only vibrates if pressure is equal on either side 3) Inner Ear: innermost portion of ear with 2 subdivisions a) Bony labyrinth: system of channels that weave through the temporal bone -The bony labyrinth is the cavity inside the bone -Filled with perilymph: fluid similar to CSF -Surrounds the membranous labyrinth b) Membranous labyrinth: membranous sacs and ducts found in the bony labyrinth -Filled with endolymph: fluid similar to ICF, important to transduction and equilibrium

Transmission of sound

-Transmission of sound to the inner ear takes the following path.... 1) Sounds waves vibrate the tympanic membrane 2) Malleus vibrates in response to tympanum -Incus & stapes also vibrate -Stapes transmits vibrations to the oval window in middle ear which sets perilymph into motion 3) Movement of oval window causes perilymph of scala vestibuli to move -Perilymph moves in pressure waves toward helicotrema -Round window acts as a pressure valve to allow perilymph movement (b/c the fluid cannot be compressed) -every time the oval window is pushed in, the round window is pushed out 4) A) Helicotrema path: low frequency (<20 Hz) pass completely around helicotremato round window -Sound does not stimulate spiral organ B) Basilar membrane path: sounds waves transmitted through cochlear duct -Pressure waves vibrate basilar membrane, stimulates hair cells in spiral organ -Stimulation of hair cells generates action potential ****Basilar membrane is "tuned" to specific frequencies in specific areas -Why: Fibers in basilar membrane differ in length & elasticity from oval window -->helicotrema a) Near oval window: fibers short & stiff -Respond to high-frequency waves b) Near helicotrema: fibers short & loose -Respond to low-frequency waves

Physiology of taste

-Two processes must occur for perception of taste to take place.... 1) Activation of taste receptors: -Chemical tastant must dissolve in saliva & diffuse into taste pore -Tastant binds gustatory epithelial cell, graded potential occurs -Neurotransmitter release to sensory dendrite elicits action potential 2) Transduction of taste: different mechanisms affect how we taste a) Salty--> Na+ influx through Na+ channels directly depolarizes gustatory epithelial cell b) Sour--> H+ acts intracellularly to open ion channels c) Bitter/sweet/umami--> G-protein gustducin activation leads to opening of cation channels to depolarize membrane

Physiology of smell

-Two things must take place for sensation of smell to occur: 1) Activation of sensory neurons A) Odorant in gaseous state dissolves in epithelium B) Odorant binds receptor proteins in olfactory cilium membrane 2) Transduction of smell -Transduction involves G-protein -Na+ influx depolarizes olfactory sensory neuronàcreatesreceptor potential -Ca2+ influx causes adaptationàdecreasedresponse to sustained odorant stimulus

Muscle Fatigue

-We can produce ATP, but it is not unlimited -Muscle fatigue occurs, muscle is physiologically incapable of contracting -Function: muscle fatigue prevents complete depletion of ATP in muscle -Rate & duration of fatigue depends on activity a) High intensity exercise of short duration, muscle fatigues quickly, recovers quickly (ex: weightlifting) b) Low intensity exercise of prolonged duration, muscle fatigues slowly, recovers slowly (ex: marathon running)

Direct phosphorylation

-after using stored atp, this process occurs -Creates ATP from ADP + Piusing creatine phosphate (CP) -Catalyzed by creatine kinase -Reaction is reversible -CP restored during rest -Does not require oxygen -Supplies ~15 seconds worth of ATP

special senses

-any of the senses with special sensory receptors -receptor cells are located in the head only -they are.... 1) vision 2) Olfaction (smell) 3) Gustation (taste) 4) Hearing 5) equilibrium

Sympathetic division: fibers forming synapses

-at trunk ganglion, pre and postganglionic fibers can form synapses 1 of 3 ways 1) preganglionic neuron and post can synapse at the same level 2) pre and postganglionic neuron can synapses at higher or lower levels 3) Pre and postganglionic neurons can synapses at a distant collateral ganglion in abdomen and pelvis

pathway to visual cortex continued

-each eye also receives visual input from the other side of the body -how: the lens flips/reverses an image 1) medial portion of eye receives input from temporal part of visual field 2) lateral portion of eye receives input from medial part of visual field -most fibers in optic tracts synapse with neurons at lateral geniculate nucleus of thalamus -these fibers then project to primary visual cortex -other fibers travel to.... 1) superior colliculi: visual reflex center that controls extrinsic eye muscles 2) pretectal nuclei: mediates pupillary response to light 3) suprachiasmatic nucleus: sets biorhythms

Focusing light on retina

-light is bent 3 times as it enters the eye 1) cornea 2) anterior surface of lens 3) posterior surface of lens -the cornea is responsible for being light but it cannot change shape -the lens is used to fine tune refraction to form a clear image

Refraction of light

-light travels at a constant speed through a give medium -refraction: occurs when light travels at an oblique angle from one medium into a medium with a different density (straw in a glass of water) -In the body: the lens refracts light that enters into eye -light rays bend so they converge at a single point (focal point) -But: the real image is upside-down and reversed

Effects of sympathetic and parasympathetic divisions

-most organs have dual innervation A) Antagonistic interactions of divisions -divisions have opposite effects, whichever dominates will influence overall organ activity -EX: increased sympathetic activity: increased HR, dilated airways, decreased digestion and elimination -EX: increased parasympathetic activity: resting HR and airway diameter, increased elimination of wastes 1) Vasomotor (sympathetic) tone: continuous partial constriction of vessels -sympathetic fibers supply blood vessels and control vessel diameter a) Low BP: vasomotor fibers fire more rapidly -effect: vessels constrict to increase BP b) high BP: vasomotor fibers fire less rapidly -effect: vessels dilate to decrease BP 2) Parasympathetic tone: present mostly in cardiac muscle tissue, smooth muscle tissue of digestive and urinary organs -effect: slows HR, maintains normal activity of digestive and urinary organs -sympathetic division can override parasympathetic tone

Muscle twitch

-muscle twitch : response of a muscle to a single stimulus where the muscle fibers quickly contract, then relax -Measured with a twitch myogram -3 phases of a myogram..... 1) Latent period: first few milliseconds following stimulation -Excitation-contraction coupling occurs, but no tension observable in muscle 2) Period of contraction -Active cross bridge-formation with building muscle tension 3) Period of relaxation -Cross bridge formation declines, muscle tension declines to resting value **takes longer for a muscle to contract than relax

focusing light: close vision

-near point of vision: closest point to face that still allows clear vision (finger closer until double) -normal eye=~4inches -declines with age -the closer the object, the more divergent light rays -result: lens has to work harder to refract and focus light -3 processes must occur for close vision.... 1) accommodation of the lens: increasing refractory power of lens by contraction of ciliary muscles -effect: suspensory ligaments slack causing lens to bulge 2) constriction of pupils -effect: prevents divergent rays from entering eye that would cause blurred vision -too many divergent rays can be confusing to the eye which is why the pupils limit the amount of light coming in 3) convergence of eyes (brings eyes together): medial rotation of the eyeballs -effect: keeps objects focused on fovea centralis -the closer the object, the more the eyes will converge

Other organs

-not specifically endocrine organs, but produce their own hormones 1) Adipose tissue: releases leptin -Function: alerts body as to how much fat is being stored, influences hunger & satiety, energy expenditure 2) Heart: released atrial natriuretic peptide (ANP) -Function: decreases blood volume, blood pressure drops 3) Kidneys: release erythropoietin and renin -Erythropoietin function: stimulates blood cell formation -Renin function: increases blood pressure 4) Thymus: releases several types of peptide hormones -Function: promotes normal and timely development of white blood cell T-lymphocyte

Phototransduction

-phototransduction: is the process of converting light energy into a graded receptor potential that begins when a photoreceptor catches light -there are 3 cells involved in light processing (chain of events b.c all synapse with each other in order) 1) photoreceptor cells: create graded potential in response to absorbing incoming light -never produces AP 2) Bipolar cells: create either IPSP or EPSP 3) ganglion cell: generate action potential that is propagated along optic nerve -no AP will occur unless light hits the photoreceptor occurs

Control of ANS

-recall: hypothalamus controls most visceral functions -Hypothalamic control of the ANS a) anterior hypothalamus areas: oversee parasympathetic division b) posterior hypothalamus areas: oversee sympathetic division -effects: coordinates heart activity, BP, body temperature, water balance, endocrine activity -hypothalamus is part of the limbic system---> emotional reactions to fear, danger, stress activate sympathetic division

Light and Dark adaptation

-retina adjusts to varying amounts of light entering the eye A) light adaptation: dark to light conditions -in the dark: rod vision dominates, retinal sensitively is high -in the light: photoreceptors bombarded with stimuli --> white light occurs due to temporary activation of cones and rods -rods turned off and cones on, retinal sensitivity decreases -adaptation to bright light takes 60 seconds. -highest visual acuity and color vision is reached in 5 minutes B) Dark adaptation: occurs when we move from light to dark conditions -in the light: cone vision dominates, retinal sensitivity is low -in the dark: sudden lack of light causes temporary vision loss -cones turn off and rods on, retinal sensitivity increases when you move to the dark -adaptation to dark takes 30 min

3 layers that compose the eye: Retina

-retina is the inner most layer of the eye -where photoreceptors of the eye are at -two layers.... 1) Pigmented layer: lies against choroid -pigment here absorbs light -phagocytes here help with photoreceptor renewal 2) neural layer: innermost layer of retina -contains photoreceptor cells a) Rods: used for dim light and peripheral vision -most numerous -found mostly in retinal periphery b) cones: used for bright light and high resolution color vision -found mostly in fovea centralis and macula lutea -also contains bipolar cells and ganglion cells which are used to generates APs in responses to light stimuli

Equilibrium

-sense of balance and where were at -Two structures responsible for equilibrium.... 1) Vestibule: most central portion of bony labyrinth -Contains 2 membranous sacs a) Saccule: continuous with the cochlea, filled with endolymph b) Utricle: continuous with semicircular canals, filled with endolymph -Function: saccule and utricle contain maculae receptors which respond to linear acceleration & head position 2) Semicircular Canals -System of three fluid-filled canals and each canal lies in different plane of space -Anterior, posterior, and lateral a) Semicircular duct passes through each canal b) Ampullae: swelling at the end of each duct with receptor crista ampullares -Function: respond to rotational movement

3 layers that compose the eye: vascular layer

-the vascular layer is the middle coat of the eye with 3 regions 1) choroid: well vascularize layer, dark in color -blood vessels here nourish surrounding layers of the eye -dark color= absorbs light 2) ciliary body: encircles lens a) ciliary muscle: smooth muscle bundles that control lens shape b) ciliary processes: secrete aqueous humor c) suspensory ligaments: extend from ciliary body to lens -holds lens in place, transmits tension from ciliary muscle to lens 3) Iris: the colored portion of the eye -color depends on amount of brown pigment in eye -pupil is the central opening of iris that lets light enter eye -smooth muscle layers of the iris allows for constriction or dilation of pupil a) sphincter papillae: when contracted, pupil contracts -used for near vision, bright light conditions b) dilator pupillae: when contracted, pupil dilates -used for distant vision, dim light conditions

ANS vs SNS

-three distinct differences 1) effector organs A) SNS: skeletal muscle tissue only B) ANS: cardiac muscle, glands, smooth muscle 2) efferent pathways and ganglia A) SNS: single neuron extends from CNS to effector -motor neuron cell bodies in the CNS, axons in the PNS extend to skeletal muscle -thick and heavily myelinated fibers -send quickly for fast and precise movements B) ANS: consists of two neuron chain to reach effector -Preganglionic neuron: cell body in CNS, axons synapse with second motor neuron -thin, lightly myelinated fibers -Postganglionic neuron: cell body outside CNS, axon extends to effector organ -thin nonmyelinated fibers ***ganglia in the ANS are sites of synapses b/t the preganglionic neuron and the post -entirely motor ganglia -SNS does not form ganglia 3) Neurotransmitter effects A) SNS: all release acetylcholine at synapses -effect: always excitatory B) ANS: release norepinephrine or acetylcholine -effect: excitatory or inhibitory

Photoreceptors: functional anatomy

-two photoreceptors: rods and cones -anatomy of both.... 1) outer segment: embedded in pigment layer of retina -contain photopigments (visual pigments) folded into discs -photopigments are replaced throughout life b/c absorption of light destroys them 2) inner segment: embedded in neural layer of retina 3) synaptic terminal: responsible for releasing any neurotransmitter as needed -photoreceptors are highly modified neurons which why they behave so different from other neurons

Focusing light on retina: changing lens shape

-use of ciliary muscles and suspensory ligaments around lens a) relaxation of ciliary muscles =increased tension in suspensory ligament -effect: suspensory ligaments are pulled tight, flattens lens, less refractory power (less it will bend light) b) contraction of ciliary muscles= decreased tension in suspensory ligaments -effect: suspensory ligaments slack, lens bulges, more refractory power (more it will bend light)

Light and optics

-wavelengths and light: human eyes only respond to electromagnetic radiation in the visible light spectrum (400-700nm) -most of what we see is light reflecting off a surface and entering eye -color of particular objects caused by what wavelengths are absorbed and what are reflected -EX: green grass reflects green and absorbs others -White: reflects all light wavelengths -black: absorbs all light wavelengths

Types of muscle contraction

1) Isotonic contraction: muscle tension develops to overcome the load (do work), muscle shortening occurs -Two subtypes..... a) Concentric contraction: muscle shortens and does work -Ex: upward motion of a bicep curl b) Eccentric contraction: muscle generates force as it lengthens -Ex: downward motion of a bicep curl 2) Isometric Contraction: tension develops in a muscle, but the length of the muscle does not change -Occurs when the load is not moved -Cross bridge formation still occurs, but the thin filaments do not slide -Ex: trying to pick up something that is too heavy for you

Information processing in the light steps

1) Light stimuli cause ion channels to close, photoreceptor hyperpolarizes to -70 mV 2) Ca2+ channels ion channels closeàneurotransmitternot released 3) Bipolar cell depolarizes in absence of IPSP, cell depolarizes (so this an EPSP for bipolar cell) 4) Ca2+ channels open, neurotransmitter released between bipolar cell & ganglion cell 5) Action potential generated on the ganglion cell

Production numbers of atp production

1) ATP stored 2) Direct phosphorylation: 1 creatine phosphate= 1 ATP

Exercise & Changes in Skeletal Muscle Tissue

1) Aerobic (endurance/cardio) exercise -Ex: swimming, distance running, biking, etc. -Use mostly aerobic pathways -Effects..... a) Vascularization increases in muscle tissue b) Mitochondria in muscle fibers increase c) Fibers synthesize more myoglobin -Importance of change: increased endurance and resistance to fatigue, more efficient muscle metabolism -Little hypertrophy occurs (not putting on muscle tissue) -Health benefits: cardiovascular health, muscle tissue health 2) Resistance (weight) training -Ex: Olympic weightlifting, powerlifting, bodybuilding, HIIT -Use mostly anaerobic pathways -Effects..... a) Muscle hypertrophy so fibers grow in size b) More mitochondria stored c) increased myofilament number d) Increased glycogen storage -Importance of change: increased fiber size = increased contractile force -Health benefits: muscle tissue health, bone & joint health, possible neuro health benefits, burn more calories at rest

Internal chambers and fluids of the eye

1) Anterior segment: in front of the lens -contains aqueous humor (watery fluid) -function: supplies nutrients and oxygen to structures in anterior chamber and some retinal cells, removes waste -aqueous humor is continuously drained and produced 2) posterior segment: behind the lens -contains virtuous humor (jelly like fluid) -functions: transmits light, stabilizes lens and holds retina in place, contributes to intraocular pressure -vitreous humor lasts a lifetime

Rotational acceleration

1) Cristae Ampullares Anatomy... -Contains hair cells and supporting cells a) Ampullary cupula: gel that surrounds hair cells -Vestibular nerve fibers supply hair cells 2) Sensation of Rotational Movement.... -Endolymph flows through canals in opposite direction as rotational -Hair cells deflected, depolarization occurs, increased neurotransmitter released a) Consistent speed of rotation--> endolymph travels at same speed as rotation -Hair cells not stimulated b) Stop rotating--> endolymph flows in opposite direction -Hair cells hyperpolarize--> less neurotransmitter released

Homeostatic imbalances: the ear

1) Deafness: complete or partial loss of hearing -Types..... a) Conduction deafness: anything that inhibits sound conduction through the ear -problem in middle ear -Ex: ruptured tympanum, excessive cerumen, fusion of ossicles*, otitis media* (*=most common) b) Sensorineural deafness: hearing loss due to damage to neural structures -Typical cause: loss of hair cells over time -How: Explosive sounds, degeneration of cochlear nerve, stroke, tumor in auditory cortex -Treatment: cochlear implant 2) Meniere's Syndrome: affects all parts of the inner ear -Cause: excessive endolymph production in inner ear -Symptoms: extreme vertigo, nausea vomiting, tinnitus (ringing in ears), deafness -Treatment: motion-sickness medication, diuretics to decrease endolymph production

Homeostatic imbalance : posterior pituitary

1) Diabetes insipidus: ADH deficiency in body -Causes: tumor on posterior pituitary or severe head trauma -Effects: extreme thirst, massive urine production & output -Usually manageable, individual has to drink enough water to maintain blood volume -Can be life threatening in unconscious or comatose individuals 2) ADH hypersecretion -Causes: neurosurgery, cancer (especially lung), hypothalamic injury, meningitis (in children), post-anesthesia administration -Effects: water retention, weight gain, headache & disorientation, decreased solute concentration in blood

Homeostatic imbalance: pancreas

1) Diabetes mellitus: inadequate (or absent) release of insulin by pancreas -Effect: consistently high blood sugar levels -Normal range: 90-110 mg glucose/dl blood -Two types.... a) Type 1: autoimmune condition, no insulin released -Several genes contribute to condition -Treatment: insulin shots before meals, or continuous fusion pumps -Long term, development of vascular & neural problems b) Type 2: insulin resistance, insulin released, but cells do not respond -Correlated more with lifestyle -Some genetic component, but almost all are overweight and underactive -Similar complications to type 1 diabetes -Can be managed with diet and exercise

Homeostatic imbalances of eye

1) Emmetropic eye (20/20): the "normal" eye ball shape, roughly spherical -focal point is easily and efficiently focused on retina 2) myopia (near sightedness/can see unclose not far): elongated eyeball shape -effect: objects are focused in front of retina, more pronounced in distant objects -focal point sits in virtuous humor instead of retina -correction: concave shaped corrective lens which pushes focal point back 3) hyperopia (farsightedness/can see objects a far not close): shortened eyeball shape -focusing light past where eyeball ends -effect: objects are focused behind retina, more pronounced in close objects -correction: convex shaped corrective lens

For stimulation of muscle fiber by motor neuron to occur, to following steps must take place

1) Events at the neuromuscular junction -Review chapter 11, transmission of action potential 2) Generation of action potential across sarcolemma -Opening of chemically-gated ion channels on sarcolemma creates end plate potential (EPP) -EPP depolarizes sarcolemma -If strong enough, action potential generated -Action potential spreads along sarcolemma, muscle contraction occurs -Repolarization and electrical condition of sarcolemma restored 3) Excitation-Contraction Coupling -Action potential spreads from sarcolemma to T-tubules -Voltage-gated proteins of T-tubules change shape, forces open Ca2+ channels in terminal cisterns -Result: Ca2+ pours out of sarcoplasmic reticulum & into cytosol of muscle fiber 4)Cross Bridge Formation & Muscle Contraction -When Ca2+ enters cytosolàcrossbridge formation can begin -Process.... a) Ca2+ binds troponin, troponin changes shape b) Change in troponin shape causes tropomyosin to roll to the side c) When tropomyosin is moved, myosin binding site on actin exposed -Myosin heads bind to binding site d) Myosin binds ADP + Pi--> myosin head bends & pivots -Actin filament is "pulled" when myosin head bends e) Myosin binds ATP--> myosin head breaks free f) Myosin hydrolyzes ATP--> ADP + Pi -Myosin is capable of binding another site farther along the actin filament **Repeated formation/breaking of cross bridges between myosin and actin results in myosin "walking" along actin filament -Ending cross-bridge formation & muscle contraction -Ca2+ is reclaimed from cytosol, stored in sarcoplasmic reticulum -When Ca2+ levels drop---> it can not longer bind troponin -Troponin returns to original shape -Result: Tropomyosin movesàcoversactin binding sites

Vision and anatomy of the eye: accessory structures

1) Eyebrows: provides shade, prevent sweat from running into eyes 2) conjunctiva: transparent mucous membrane -produces lubricating mucous a) palpebral conjunctiva: covers inner eye lids b) Bulbar conjunctiva: covers anterior surface of eye (except cornea) 3) Palpebrae (eye lids): open and close eyes a) lacrimal caruncle (on the medial portion): sebaceous and sweat glands here produce oily secretion b) eyelashes: project from upper and lower eye lids, protect the eye 4) Lacrimal apparatus: production and drainage of tears -composed of.... a) lacrimal glands: produces and releases dilute aline solution (tears) b) lacrimal canaliculi: drains tears from eye surface at medial portion of eye c) nasolacrimal duct: drains tears from lacrimal canaliculi into nasal cavity -function: contains lysosome, lubricates eye surface, -enhanced tear production washes away foreign bodies 5) extrinsic eye muscles: allows movement of eye in orbit -all muscles attach to sclera a) superior rectus: elevates and turns eye medially (oculomotor nerve) b) inferior rectus: Depresses eye and turns it medially (oculomotor nerve) c) lateral rectus: move eye laterally (abducens nerve) d) medial rectus: moves eye medially (oculomotor nerve) e) superior oblique: depresses eye and turns it laterally (trochlear) f) inferior oblique: elevates and and turns it laterally (oculomotor nerve)

Gonads and placenta

1) Gonads a) Females: ovaries produce estrogens & progesterone -Estrogen function: maturation of reproductive organs, appearance of secondary sex characteristics -Progesterone function: breast development, cyclic changes in uterine mucosa b) Males: testes produce testosterone •Function: maturation and maintenance of reproductive organs, appearance of secondary sex characteristics, sex drive, normal sperm production 2) Placenta: temporary endocrine organ -Produces estrogens, progesterone, human chorionic gonadotropin (hCG) -Function: maintains pregnancy

Homeostatic Imbalance: Parathyroid Gland

1) Hyperparathyroidism -Cause: usually parathyroid tumor -Effect: Ca2+ leached from bones, replaced with fibrous connective tissue -Bones can fracture spontaneously -Excessive Ca2+ in blood can..... a) Depress the nervous system, abnormal reflexes & weak skeletal muscle contraction b) Ca2+ forms salts in kidneys, kidney stones 2) Hypoparathyroidism -Cause: trauma or removal of parathyroid glands -Effects: Low Ca2+ blood levels -Highly excitable neurons: tetany (contraction of muscle tissue with no relaxation) , tingling, convulsions -If untreated: respiratory paralysis, death

Homeostatic imbalances of ANS

1) Hypertension: high BP -cause: overactive sympathetic vasoconstrictor response -effect: heart met work harder to circulate blood through narrow blood vessels -future problems: heart disease, enlarged arteries, kidney failure -treatment: adrenergic-receptor blocking drugs 2) Raynaud's disease -cause: exaggerated vasoconstriction response to cold or emotional stress -effect: skin of fingers or toes become pale, skin can eventually become cyanotic, painful -severity can be minimal to severe 3) Autonomic dysreflexia: affects individual who are quadriplegic or have spinal cord injuries above T6 -cause: uncontrolled activiation of autonomic neurons -usually triggered by some type of pain stimulus to skin or overfilled visceral organ -effect: arterial blood pressure skyrockets -can rupture blood vessels causing stroke -symptoms: headache, flushed face, sweating above injury, cold/clammy skin below injury

Sympathetic pathways with synapses in collateral ganglia

1) In collateral ganglia -preganglionic fibers from T5-L2 synapse in collateral ganglia -form splanchnic nerves.... a) greater, lesser and least splanchnic nerves b) Lumbar and sacral splanchnic nerves -Function: serves abdominal viscera -these ganglia usually reach effector organ by traveling with a blood vessel 2) Pathways to abdomen -fibers T5-L2 innervate abdomin -function: serve stomach, most of intestines, liver, spleen, and kidneys 3) Pathways to pelvis -fibers T10-L2 innervate pelvis -function: serves bladder, reproductive organs, distal half of large intestines ****the effect of sympathetic innervation on the abdominopelvic visceral organs is mostly inhibitory

Skeletal Muscle Tissue: Gross Anatomy

1) Innervation -Each muscle receives 1 nerve -Function: nerve ending controls activity -Motor neuron stimulates muscle fibers to contract -Nerve branches several times to supply muscle fibers in one muscle -One nerve can serve ~150 muscle fibers 2) Vascularization -Each muscle receives 1 artery, 1+ vein -Functions: Bring in nutrients (glucose and O), remove waste (lactic acid) 3) Connective Tissue Sheaths -Function: supports muscle, holds muscle together -3 layers that are all continuous with one another.... a) Endomysium: innermost layer -Surrounds individual muscle fiber b)Perimysium: middle layer -Discrete bundles of muscle fibers grouped together, forms fascicles c) Epimysium: outermost layer -Surrounds entire muscle -is continuous with tendons 4) Skeletal muscle attachments -Attachments can be direct or indirect a) Direct: epimysium of muscle fuses directly to bone (or cartilage) b) Indirect:tendon connects muscle to bone or another muscle -more common and tendons take up less space 5) Origin: where muscle attaches to a less movable bone -Always proximal (closer to body) -Ex: biceps brachii long head = lip of glenoid fossa, short head = coracoid process 6) Insertion: where muscle attaches to a movable bone -Always distal (farther from body) -Ex: biceps brachii and radial tubersity

Micro-anatomy: myofibrils

1) Myofilaments: actin- and myosin-containing portion of sarcomere -Function: actin and myosin interact to allow muscle contraction -Types of contractile myofilaments...... a) Thick filament (myosin) -Extends entire length of A band b) Thin filament (actin) -Extends entire length of I band, part of A band 2) Molecular Composition of Myofilaments -Myosin filaments -Composed of grouping of 6 chains -4 light chains -2 heavy chains -Twist together to form tail -Myosin head found at end of each heavy chain -Importance: myosin head uses ATP to link thick and thin filaments during contraction (binding)

Regulation of contraction

1) Neural Regulation -Neurotransmitter can excite or inhibit smooth muscle tissue -Response is dependent on receptor molecules on sarcolemma -Ex: acetylcholine binding in bronchioles is stimulatory, contract -Ex: norepinephrine binding in bronchioles is inhibitory, relax 2) Hormones & Local Chemical Factors -Some smooth muscle has no innervation, respond only to local chemicals -Others spontaneously depolarize -Enhance or inhibit Ca2+ entry into sarcoplasm

other structures associated with retina

1) Optic disc: point at which the optic nerve exists the back of the eye -no photoreceptors found here so blind spot -we can't see the blind spot b/c the brain fills in missing info 2) macula lutea: retinal structures are displaced to the side -result: light passes directly to photoreceptors so there is increased visual acuity here 3) fovea centralis: found at center of macula lutea -contains only cones so it provides extremely detailed color vision -only 1/1000th of total vision

sarcomere length

1) Optimal: ideal cross bridge formation -sliding of filaments 2) Shortened sarcomere length: no sliding/too little sliding for contraction, so no shortening 3) stretched sarcomere length: acton/myosin cannot interact, cross bridge formation

Two division of the ANS: parasympathetic division

1) Parasympathetic division -Rest and digest--> keeps boyd energy use as low as possible when we are relaxed -function: directs housekeeping activities such as digestion, elimination of wastes, low BP and HR, pupil constriction -origin of fibers: the brain and sacral spinal cord -preganglionic fibers are long and postganglionic fibers are short -Location of ganglia: in or near effector organ A) cranial portion -function: supplies parasympathetic fibers to head, neck, thoracic and abdominal regions -preganglionic fibers run in oculomotor, facial, glossopharyngeal, and vagus cranial nerves 1) Oculomotor nerve: innervates smooth muscle in eyes and muscles associated with lens -pupils constrict and lens bulge 2) Facial nerve: stimulates large glands of head (salivary, nasal and lacrimal glands) 3) Glossopharyngeal nerve: activates parotid salivary gland 4) Vagus nerve: provide fibers to neck and almost every organ in the thoracic and abdominal cavities -supplies 90% of innervation in this division a) cardiac plexus: supplies fibers to heart, inhibitory so it slows hr b) pulmonary plexus: supplies fibers to lungs, inhibitory so maintains resting breathing rate c) esophageal plexus: serves esophagus -fibers extend into abdominal cavity from esophageal plexus to innervate gallbladder, small intestine, liver, pancreas, increase waste production and half of large intestine B) Sacral portion -form pelvic splanchnic nerves -function: serves pelvic organs, genitals and distal portion half of large intestine -mainly stimulatory

Auditory processing

1) Pitch: impulses from specific hair cells interpreted as specific pitch -Multiple frequencies stimulate multiple parts of basilar membrane 2) Loudness: louder sounds = more movement of fluid in cochlea -Larger waves of fluid = more movement of basilar membrane, more deflection of inner hair cells 3) Localization of sound: intensity and timing localize sound source -If intensity & timing are identical: above, below, in front, or behind -If intensity & timing are different: left or right side

Visceral reflex arc components

1) Receptor in viscera (free/nonencapsulated nerve ending) 2) sensory neurons -non encapsulated nerve endings -function: send sensory info about changes in chemical composition, stretch, temperature an irritation of viscera 3) integration center 4) motor nuerons -pre and postganglionic neurons 5) visceral effector -smooth muscle, cardiac muscles and glands

Unique features

1) Response to stretch -Smooth muscle responds to stretch by contracting -Importance: increases ability to push substances through organ -Stress-relaxation response: if an organ is filled slowly, it will not contract strongly (visa versa) 2) Length and tension changes -Smooth muscle can stretch more, can generate more tension while stretched -Can still contract when stretched 150% its length before it loses its ability to stretch

Two mechanisms of hormone action

1) Second messenger-systems: uses receptors found on surface of plasma membrane -Amino-acid based hormones -Receptors are usually coupled to regulatory G-proteins -G-protein activates intracellular second messenger, causes response in cell **The hormone does not directly send a message -Extremely efficient! -A single hormone binding a receptor results in millions of product molecules being produced 2) Intracellular systems -Steroid-based hormones & thyroid hormone -Hormone enters cell, bind to intracellular receptors -Receptor-hormone complex binds specific regions of DNA, DNA transcription occurs -Effect: certain proteins produced in larger numbers

Types of muscle tissue

1) Skeletal muscle tissue -Voluntary muscle tissue -Function: movement of body parts -Striated & multinucleate (per muscle fiber) -Attaches to & uses skeleton -Creates the most force, but needs the most rest -Adaptable 2) Smooth Muscle Tissue -Involuntary muscle tissue -Function: moves fluids & substances through body -No striations -Uninucleate (per muscle fiber) 3) Cardiac Muscle Tissue -Involuntary muscle tissue -Function: moves blood through body -*Rate of contraction set by pacemaker cells -Striated -Uninucleate (per muscle fiber)

2 Branches of the peripheral NS

1) Somatic NS (SNS): system responsible for voluntary muscle movements and reflex arcs -a branch of the PNS--> efferent division -mostly voluntary 2) Autonomic NS (ANS): branch of PNS---> efferent division -almost all effectors re visceral-->involuntary -function: helps maintain a stable internal environment (homeostasis) -EX: pupil size, body temperature, regulation of heart rate, blood vessel diameter, increases/decreases stomach secretions ***difference is what is being innervated

Properties of sound

1) Sound -Sound waves produced by compressions and rarefactions a) Compression: air molecules are pushed together b) Rarefaction: air molecules spread apart -Air molecules bump against one another, travel outward from source -Sound waves travel in one direction -Sound waves decrease in strength with distance (lose kinetic energy) -Speed at which sound travels is constant within a given medium -the more dense the material the faster it travels 2) Frequency: number of sound waves that pass a point in a given time a) Wavelength: distance between crests of a given sound wave -Shorter wavelength = higher frequency & higher pitch -Human hearing frequency range: 20-20,000 Hz, varies with age b) Tone: sound consisting of a single frequency/wavelength 3) Amplitude: height of crests for a given sound wave -Denotes loudness of sound -Look at difference in height between crest/trough for given sound wave -Human hearing: 0 dB-120 dB -Above 120 dB the sound is painful -Hearing loss occurs from prolonged exposure to 90+ dB

Activation of eyes

1) Sympathetic activation: nearly parallel rays from distant object -lens flattens for distant vision -sympathetic input relaxes ciliary muscle, tightening ciliary zonule, and flattening lens 2) parasympathetic activation: divergent rays from close object, needs more refractory period - lens bulge or close vision -parasympathetic input contracts ciliary muscle, loosening ciliary zonule, allowing lens to bulge

Importance of taste

1) Taste likes & dislikes have homeostatic value A) "Cravings" usually mean we are short on a macronutrient, ion, etc. -Cravings salt supplies body with minerals -Craving sweets supplies body with carbohydrates B) Some tastes indicate spoiled food (extreme sour) or poison (extreme bitter) -Function: protects us from consuming something that can harm us

Major endocrine organs: pituitary

1) The Pituitary Gland (Hypophysis) -Gland connected to hypothalamus by infundibulum -Two regions.... a) Anterior pituitary: manufactures and releases several different hormones b) Posterior pituitary: composed mostly of neural tissue and nerve fibers -Releases neurohormones received from hypothalamus 2) Release of hormones from the pituitary controlled by hypothalamus in 1 of 2 ways a) Action potentials from hypothalamus cause hormone release from axon terminals in posterior pituitary b) Hypothalamic hormones released into hypophyseal portal system stimulate or inhibit hormone release from the anterior pituitary

Unique roles of sympathetic division

1) Thermoregulatory response to heat -effects.. A) blood vessels dilate in response to heat and constrict in respond to cold B) sweat glands activated in response to heat 2) Renin release from kidneys -effects: increase BP 3) Metabolic changes -effects... A) increase metabolic rate of cells B) raises blood glucose levels C) mobilizes fats used fuel use

Types of smooth muscle

1) Unitary Smooth Muscle -Everything described so far are characteristics of unitary smooth muscle -Much more common, found in all hollow organs except the heart 2)Multi-Unit Smooth Muscle -Found in arrector pili, smooth muscle of airways, internal eye muscles -Have no gap junctions or spontaneous depolarization -Muscle fibers are structurally independent -Forms motor units -Have graded contractions with recruitment **last four bullets are things it has in common with skeletal muscle tissue

Sympathetic pathways with synapses at trunk ganglia

1) if synapse forms in trunk ganglion, postganglionic fibers enter ventral or dorsal ramus of adjoining spinal nerves via gray rami communicantes a) gray rami communicantes: carry only postganglionic fibers from sympathetic trunk ganglion to periphery -from here, travels to effectors **white ramus communicates carries only preganglionic fibers 2) Pathways to head -preganglionic fibers emerge from T1-T4, synapse with postganglionic fibers at superior cervical ganglion -function: serves skin and blood vessels of head, stimulate dilator muscles of eye, inhibits nasal and salivary glands, innervates upper eyelid and sends branches to heart (always stimulatory for heart, increases hr) 3) Pathway to thorax -preganglionic fibers energy from T1-T6 -most postganglionic axons pass through cardiac, pulmonary, and esophageal plexuses to effector organ

Transduction of smell via G-protein activation steps

1) odorant binds to receptor 2) receptor activates G-protein (G_olf) 3) G-protein activates adenylate cyclase 4) adenylate cyclase converts ATP to cAMP 5) cAMP opens a cation channel, allowing Na+ and Ca2+ influx and causing depolarization -Na responsible for depolarizes sensory neuron -Ca responsible for adaptation, when exposed to a smell for a long period of time to the point where you no longer smell it

things to remember

1) pre and postganglionic neurons are always motor neurons so they are always sending motor impulses to effector organs 2) neurons are named relative to position of ganglia -everything b/t CNS and ganglia are all pre -everything b/t ganglia and effector organ are post

G-protein signaling mechanism steps

1) retinal absorbs light and changes shape. Visual pigment activates 2) Visual pigment activates transducin (G-protein) 3) Transducin activates phosphoritesterase (PDE) 4) PDE converts cGMP into GMP causing cGMP levels to fall 5) As cGMP levels fall, cGMP-gated cation channels close resulting in hyper polarization

actin filaments

1)Actin filaments -Twisting chains of G actin with myosin binding sites -2 regulatory proteins..... a) Tropomyosin: arranged along length of thin filament -Importance: block myosin binding sites when muscle is relaxed b)Troponin: globular protein associated with tropomyosin -Importance: binds tropomyosin to position it on filament

Muscle characteristics

1)Excitability: Membrane potential changes in response to stimulus 2) Contractility: Muscle cells shorten 3) Extensibility: Muscles cells can lengthen/stretch 4) Elasticity: Healthy muscle cells return to their original shape

Information processing in the dark steps

1)Ion channels are open, photoreceptor depolarizes to -40 mV 2) Ca2+ channels open in terminal--> neurotransmitter (glutamate) is released between photoreceptor & bipolar cells 3) Neurotransmitter causes IPSP at bipolar cells, so it hyperpolarizes the bipolar cell 4) Hyperpolarization of bipolar cell prevents neurotransmitter release between bipolar cell & ganglion cell so no action potential generated since ion channels stay closed

Adrenal cortex: adrenal medulla

2) Adrenal Medulla: innermost region -Synthesize epinephrine & norepinephrine -Unequal amounts stored & released a) 80% epinephrine: greater influence on metabolic activity, dilator of airways in lungs b) 20% norepinephrine: greater influence on peripheral vasoconstriction, blood pressure -Release is initiated by sympathetic nervous system, short-lived -Hormones are not essential, sympathetic nervous system will work without adrenal medulla hormones -BUT: excessive secretion is problematic, long-term "fight or flight" symptoms

Two division of ANS: sympathetic division

2) Sympathetic division -flight or fight activated when we are scared, excited or embarrassed -function: mobilizes body ---> constriction of visceral body vessels, dilates bronchioles of lungs, increases glucose released, pupils dilate -origin of fibers: thoracolumbar region of spine (T1-L2) -preganglionic fibers are short and post are long -cell bodies form lateral horns of spinal cord -location of ganglia: near spinal cord

Pathway to primary auditory cortex

A) Action potentials generated in cochlea pass through spiral ganglion to cochlear nuclei B) Fibers project to superior olivary nucleus C) Pass through thalamus, project to primary auditory cortex D) Some fibers contralateral, other ipsilateral -ensures each auditory cortex receives information from both ears

Pathways to gustatory cortex

A) Facial nerve carries information from anterior 2/3 of tongue B) Glossopharyngeal nerve carries information from posterior 1/3 of tongue -Most fibers synapse at solitary nucleus, travel to primary gustatory cortex -Others travel to limbic system & hypothalamus which allows for appreciation for what you're eating

Sound transduction

A) Movement of basilar membrane stimulates inner hair cells -Inner hair cells have stereocilia embedded in tectorial membrane -Stereocilia joined together by tip links -Tip links connect to mechanically gated ion channels -->pulling tip links open ion channels -think of tip links as trap doors B) When basilar membrane is at rest... -Some tip links open, small amount of ion flow -Inner hair cell slightly depolarized C) When stereocilia pivot toward tallest hair.... -Increased tension between tip links -Tip links open, all ion channels open -K+ and Ca2+ flood into inner hair cell -Inner hair cell depolarizes, creates receptor potential -Neurotransmitter released to cochlear nerve causing action potential D) When stereocilia bend toward shortest hair.... -Tip link tension decreases -Tip links close -K+ and Ca2+ no longer enter inner hair cell -Inner hair cell hyperpolarizes -Neurotransmitter no longer released

Micro-anatomy of smooth muscle tissue

A) Muscle fibers a short, spindle-shaped -Covered only by endomysium -No neuromuscular junctions, innervation forms varicosities which are Bulb-like swellings of autonomic fibers scattered over smooth muscle tissue surface -Creates diffuse junctions which are wide synaptic clefts that release neurotransmitter B) Muscle fibers have no T-tubules, less sarcoplasmic reticulum (SR) -Sarcoplasmic reticulum releases some Ca2+ -Caveolae of sarcolemma has Ca2+ channels -Most Ca2+ for contraction comes from extracellular space -Muscle fibers have gap junctions -Depolarization spreads from cell to cell, important to have organ behave as an entire unit C) No striations or sarcomeres -There are still thick and thin filaments, but: Less thick filaments than thin filaments -Myosin heads found along entire length of thick filament -No troponin -Calmodulin (calcium binding molecule): protein that acts as Ca2+ binding site -Thick and thin filaments arranged diagonally -Filaments spiral down axis of muscle fiber -Effect: when a muscle fiber contracts, it twists D) Intermediate filament-dense body network -Intermediate filaments criss-cross across muscle fiber -Fibers are non-contractile -Attach to muscle at dense bodies -Function: forms a cytoskeleton, transmits pulling force to surrounding muscle tissue

Olfactory sensory neurons: structure

A) Olfactory cilia: hair like projections found in the epithelium -function: increase receptor surface area of neuron -mucus surrounding cilia dissolves airborne odorants, if odorants doesn't dissolve in mucus you won't be able to smell it -axons of multiple sensory neurons form small fascicles which are filaments of the olfactory nerve -travel through cribriform foramen of cribriform plate -synapse with olfactory mitral cells in olfactory bulb B) specificity of olfactory receptors -the nose can identify 10,000-1 trillion odorants -olfactory epithelia has 350 different odorant receptors -each receptor responds to 1 or more odorants -each odorant an bind 1 or more receptors -but each receptor has only 1 type of receptor protein C) longevity of olfactory sensory neurons -unique to other neurons because these can regenerate via stem cells -superficial location = prone to destruction due to blowing your nose or extremely noxious cell could permanently damage the neurons -life span of olfactory sensory neuron= 30-60 days -olfactory stem cells replace damaged/ destroyed neurons

Rod vs. cone vision

A) Rods -sensitive to light -only 1 visual pigment (monochromatic) in rods so they have no color vision -converging pathways--> several rods all synapse on a single ganglion -effect: vision is often blurry, vision less efficient, so brain cat specifically locate which rod was stimulated -used at night/ dark vision, so nocturnal vision is ass B) Cones -low sensitivity -single cone has 1 of 3 (red, green or blue) visual pigments (trichromatic) for color vision -each cone synapses at its own ganglia -effect: vision is very clear

The endocrine system

A) Secretes various hormones -Hormones: long-distance chemical messengers that cause a change in metabolic activity of a cell -Effects are usually long-lasting -Effects are diverse B) Hormones control.... -Reproduction -Growth and development -Immune system activation -Maintenance of various blood components (glucose, electrolytes, water, etc.) C)Secrete hormones directly to tissue fluids -Glands highly vascularized D)Autocrines and paracrines sometimes considered as part of this system 1) Autocrine: short-distance chemical messengers, affect same cells that secrete messenger 2) Paracrine: short-distance chemical messengers, affect different cells that secrete messenger (but in the same tissue)

Information processes: the retina

A) in the dark: photoreceptor ion channels are open, photoreceptor cells are already depolarized -Result: receptor is depolarized to -40mv b) in the light: photoreceptor ion channels are closed -result: receptor is hyper polarized to -70mv -this process uses a G-protein signaling system

The pathway to the visual cortex

A) optic nerve: exits back of eye B) Optic chaism: location where medial fibers from each optic nerve cross over, bundle together to form optic tract -so they're contralateral -lateral fibers remain ipsilateral C) Optic tracts: continue to visual cortex -each optic tract.... 1) Carries fibers from the lateral portion of the eye on the same side 2) Carries fibers from the medial portion of the eye of the opposite side 3) Contains all information from the same half of the visual field

Cellular response

A)Target cells only respond to a hormone if it has a specific receptor protein for that hormone -Can be specific (i.e., only cells of certain tissue) or broad (all body cells) B) Activation of cell depends on... •1) Blood levels of hormone •2) Number of receptors for specific hormone on/in cell •3) Affinity of receptor to hormone C) Amount of hormone can change number of receptors -Up-regulation: increase receptor number in response to low hormone levels -Down-regulation: decrease receptor number in response to high hormone levels D) Rate of hormone release & breakdown -Hormone concentration in blood depends on.... 1) How fast it is being released by endocrine organ 2) How fast it is broken down -Most hormones removed by kidneys, liver -Water-soluble hormones have shortest half-life E) Duration of hormone effects on target cell -Hormone effect is not always immediate, effects seen after hours or days -Some hormones must be activated before binding can occur -Duration of effect varies -Effects can disappear as levels drop or can persist for hours after levels drop -Importance: variation of effects = strict control of hormone release F) Hormone Interactions at Target Cells -Hormone binding on the same target cell at the same time may result in: 1) Permissiveness: one hormone cannot have full effect without binding of a second, specific hormone -Lack of the second hormone may delay or completely inhibit effects of first 2) Synergism: 2+ hormones with similar effects bind target cell, amplification occurs 3) Antagonism: one hormone opposes the effect of another -Hormones can compete for the same receptor -Hormones act through different metabolic pathways -Hormones can down-regulate receptor of another hormone

anterior pituitary hormones continued

B) Thyroid-Stimulating Hormone (TSH), tropin hormone -Function: Stimulates development and secretory activity of thyroid gland C) Thyrotropin-releasing hormone (TRH) stimulates TSH release -Rising TSH and GHIH prevent TSH release -negative feedback mechanism D) Adrenocorticotropic Hormone (ACTH), tropin hormone -Function: stimulates adrenal cortex to release hormones -Corticotropin-releasing hormone (CRH) stimulates ACTH release E) Gonadotropins, tropin hormones -Two hormones: Follicle-stimulating hormone (FSH) andLuteinizing hormone (LH) -Function: regulate function of gonads -FSH: stimulates production of gametes -LH: stimulates production of gonadal hormones F) Gonadotropin-releasing hormone (GRH) stimulates release of FSH and LH -Rising gonadal hormone blood levels inhibit release -Gonadotropins only released after puberty G) Prolactin (PRL) -Function: stimulates milk production in breast tissue -In males?? -Release controlled by dopamine, inhibitory hormone -PRL release increases substantially toward end of pregnancy -Levels of PRL rise and fall in tandem with blood estrogens -Rising estrogen stimulates PRL release

Histology of muscle

Myofilaments (actin and myosin)---->make up: myofibrils------> make up: muscle fibers------> make up: muscles

Intracellular structures that regulate muscle contraction

Two intracellular structures regulate muscle contraction 1) Sarcoplasmic reticulum: smooth endoplasmic reticulum of muscle -Function: stores and releases intracellular Ca2+ for muscle relaxation & contraction -Highly branched, extends length of myofibril -Form terminal cisterns at A band-I band junction 2) T-Tubules: tube that protrudes deep into cell -Runs between terminal cisterns, forming triad -Continuous with the sarcolemma & T-tubules of surrounding myofibrils -Importance: increase surface area of muscle fiber--> changes in membrane potential penetrate deep in muscle fiber -Nerve impulse runs along sarcolemma---> T-tubules "pass" information to deep parts of muscle

Adrenal cortex: Adrenal cortex

a) -Two adrenals glands (Adrenal cortex and adrenal medulla) -Function: stress response, electrolyte balance -Two areas, each functions as different gland... 1) Adrenal Cortex: outermost region -Produces corticosteroids -Three subdivisions.... A) Zona glomerulosa: produce mineral corticoids B) Zona fasciculata: produce glucocorticoids C) Zona reticularis: produce adrenal sex hormones 2) Mineral corticoids: regulate electrolyte concentration in ECF, especially Na+ and K+ -Importance.... a) Na+ influences water movement, can effect blood volume and blood pressure b) K+ determines resting membrane potential, imbalance affects responsiveness of neurons 3) Glucocorticoids: influence energy metabolism of cells, provide resistance to stressors -Specific types: cortisol, cortisone, corticosterone -Cortisol release stimulated by ACTH -Negative feedback, rising cortisol prevents ACTH release -Release usually secretory bursts, when we first wake up, eating -Stress affects cortisol release, CNS overrides feedback mechanism, more cortisol released -Effects..... a) Mobilizes body stores to create more glucose b) Provokes sympathetic nervous system, vasoconstriction c) Excessive release causes.... -Depressed cartilage & bone formation -Inhibits inflammation -Depresses immune system -Disrupts normal cardiovascular, neural, gastrointestinal functions 4) Gonadocortioids: small amounts of androgens released -Some converted to testosterone, others converted to estrogen -Amount produced insignificant to amount produced by gonads -Effects.... a) Contribute to axillary and pubic hair development b) Women, contributes to sex drive, produce estrogens post-menopause

Muscles that allow eyelids to open or close

a) orbicularis oculi: encircles eye -when contracted, eyes close b) levator palpebrae superioris: when contracted, top eyelid is pulled up to open the eye -rectus eye muscles pull eye in eye in direction indicated by name of the muscle -oblique muscles either elevate or depress eye and turn it laterally -why do we need oblique muscles.... a) superior and inferior muscles naturally pull eye medially when contracted b) lateral pull of oblique muscles resists the medial pull

lens

lens: convex, transparent, flexible structure of the eye -function: used to bend light s it enters the eye a) anterior portion covered with lens epithelium -function: coordinates metabolic activities of lens, provides more cells for lens fibers b) lens fibers: bulk of what makes up lens -fibers are laid down over a lifetime, old fibers not broken down -disadvantage: lens become thicker and more dense with time leading to loss of ability to focus light -EX: cataracts