Anatomy final

Question 1

Pathway to Sympathetic trunk

Answer 1

1. preganglionic fibers that originate at spinal cord exit the spinal cord via ventral root
2. preganglionic fibers pass through white ramus com (which allows fiber to enter trunk)
3. Fibers enter sympathericc trunk gaglion. this is where the pregaglionic fibers synpase with postganglionic fibers

Question 2

At sympathetic trunk ganglion, preganglionic and postganglionic fibers can form synapses 1 of 3 ways

Answer 2

1. Preganglionic and postganglionic neurons synpase at same level (the preganglionic fiber travels straight out, not up or down, and post. travels to effector)
2. Preganglionic and post ganglionic neurons synpase at up or down level
3. Preganglionic and post ganglionic neurons synapse at distant collateral ganglion in abdoman and pelvis

Question 3

Pathways with synapse in Trunk Ganglia

Answer 3

if synapse forms here–> postganglionic fibers travel through grey rami to leave trunk, which communicates to enter ventral or distal ramus of adjoining spinal nerve.
grey rami communication: carry postganglionic fibers from sympathetic trunk ganglion to periphery
from here it travels to effector organs

Question 4

Pathway to head (uses Pathways with synapse in Trunk Ganglia)

Answer 4

found at top of thoraxic portion of sympathetic division
-preganglionic fibers emerge from T1-T4, synapse with postagnglionic fibers at superior cervical ganglion of sympathtic trunk
-servs skin and blood vessles of head, stimulates dilator muscles of eyes-gets bigger (smooth muscle tissue control size of pupil), inhibits nasal and salivary glans, innervates muscle to upper eyelid, sends branches to heart (to increase heart rate)

Question 5

Pathway to thorax (Pathways with synapse in Trunk Ganglia)

Answer 5

-preganglionic fibers emerge from T1-T6-run tandom with plexus in parasympathetic division
-most postganglionic axons pass through cardiac(increase heart rate), pulmonary(dilation of airways-lets more oxygen into lungs), and esophageal plexus (less active) to effector organ

Question 6

Pathways with synapse in Collateral Ganglia

Answer 6

-preganglionic fibers from T5-L2 synapse
-form splachnic nerves:
–greater, lesser, least, lumbral, and sacral splanchnic nerves
–function: serve abdominal viscera and inhibit function to slow it down

Question 7

Pathways to abdoman (Pathways with synapse in Collateral Ganglia)

Answer 7

-Fibers T5-TL innervate abdoman
-function: serve to slow down stomach, most intestines, liver, spleen, and kidney

Question 8

Pathways to Pelvis (Pathways with synapse in Collateral Ganglia)

Answer 8

-Fibers T10-L2 inervate pelvis
-function: serves to slow down bladder, reproductive organs, distal half of large intestines

Question 9

Process for focusing light for close vision

Answer 9

1. Accommodation of lens: contraction of ciliary muscles–causes lends to bulge
2. Constriction of pupils
   –prevents divergent rays from entering eye
   –pupil is smaller in diameter overall, so limiting ho much light rays enter eye
3. Convergence of eye-medial roation of eyeballs
   –keeps objects focused on fovea centralis–>higher resolution
   –closer the object, more eyes must converge

Question 10

Info processing of Retina In Dark

Answer 10

1. Ion channels open, Na+ enters and photoreceptors depolarizes to -40mV
2. Ca2+ channel opens in terminal–> neurotransmitter released b/w photoreceptors and bipolar cells
3. Neurotransmitter causes bipolar cell to hyperpolarize–>IBSP
4. No neurotransmitter released b/w bp cell and ganglion cel–> no ap generated by ganglion cell bc Ion channels open

Question 11

Info processing of Retina In Light

Answer 11

1. Light stimulus causes ion channels to close, Na+ doesn’t enter and photoreceptors hyperpolarize to -70mV
   -Ca2+ channels close–> neurotransmitter not released b/w photoreceptor and bp cells
2. Bp cell depolarizes in absence of neurotransmitter–>EPSP
3. Ca2+ channels open, neurotransmitter released b/w bipolar cell and ganglion cell
4. ganglion cell generates ap–>sent via optic nerve

Question 12

G-Protein signaling system for Phototransduction
(in first step of info processing of Retina In Light)

Answer 12

1. Retinal absorbs light and changes shape
2. visual pigment activates transduction (g-protein)
3. Transducin activates phosphoisterie
4. PDE converts cGMP using causing cGMP levels to fall
5. As cGMP levels fall, cGMP gated cation channels close, resulting in hyperpolarization

Question 13

For smell to occur

Answer 13

1. Activation of sensory neurons
   –oderant dissolves in mucus
   –oderant binds receptor proteins in olfactory cilium membrane
2. transduction of smell–>binding created graded potential by sensory neuron
   –if strong enough, mitol cells generate an action potential.
   –Na and Ca2+ influx depolarizes sensory neurons and creates graded potential
   –continious refux causes adaptation

Question 14

Activation of taste bud receptors

Answer 14

-chemical tastant must dissolve in saliva
-tastant binds epithelial cell–>graded potential occurs
a) salty–> na+ influx through Na+ channels directly depolarizes gustatory epithelial cells
b)sour–> H+ acts intracellulary to open ion chennels and create graded potential
c) bitter/sweet/umami– G-protein gustducin activation leads to opening of ion channels to depolarize membrane
–neurotransmitter release of sensory dendrite elicts action potention

Question 15

Pathway to cortex

Answer 15

Facial nerve-2/3 of tongue
glossophargeal-1/3 of tongue
most fibers travel to primary gustatory cortex
others travel to limbic system and hypothalmus
brain combines infro from smell and taste to produce a more refined taste

portection method- can induce fight or flight

Question 16

transmission of sound to inner ear

Answer 16

1) sound waves vibrate typmanic membrane(same vibration as sound waves)–> transfered to inner ear
2) malleus vibrates in response to typmanum
–incus and stapes vibrate to
–medial portion of stapes vibrates to oval window that divides middle ear from inner ear (starts tranmission of sound to inner ear)
3) movement of oval window caues perlymph fluid of scala vestibuli to move as pressure wave towards helicotrema
–round window rleases pressure in inner ear so parlymph can move
4) once perliymph moves, 1 of 2 paths are taken
–a) basilar membrane path soun waves trnasmitted through scala media
–pressure waves vibrate it and hair cells stimulated
–b)heliocotrema path(low frequnecy)
–doesnt stimulate sensory receptors
–creates small wave of paralympth that cant bend basilar membrane.

Question 17

sound transduction

Answer 17

movement of basilar membrane stimulaets inner hair cells
-inner hair cells have sterecillia
–tallest sterecillia embedded in tectorial membrane which doesnt moves in response to bending
-sterecillia joined by tip-links; which open mechanically gated ion channels

when basilar membrne at rest, no sound is carrying. some tip links open and hair cells are slightly depolarized

Question 18

Stereocillia pivot towards tallest hair

Answer 18

all tip links open so all ion channels open
-K+ and Ca+ enter cell
inner hair cells depolarize creating a graded potential
-neurotrasmitters from inner ear cell released to cochlear nerve and produce action potential

Question 19

Stereocillia pivot towards shortest hair

Answer 19

all tip links closed
-no K+ and Ca+ enter cell
-inner hair cells hyperpolarize and no graded potential created
-neurotrasmitters dont creeate atp

Question 20

Outer hair cells

Answer 20

cange flexability of basilar membrane
1) increases responsivness of inner hair cells
2)protection–> stiffens in response to loud sound–> stabalizes basilar membrane

Question 21

Linear head and acceleration of head position In Utricle

Answer 21

maculae orineted horizontally in head and hair cells are verticle (back and forth movement)

Question 22

Linear head and acceleration of head position In Saccule

Answer 22

maculae oriented vertically and hair cells are horizontal

Question 23

Stimulation of muscle fibers to occur

Answer 23

1) Events at neuromuscular junction
–motor neurons release ACh at neurotransmuscular junction
–ACh binfs chemically gated ion channels on Sarcolemma
2) Generation of EPP and AP across sarcolemma
–ACh opens ion channels on sarcolemma to create end plate potential (EPP)
–EPP is graded potential specific to muscle tissue
–EPP depolarizes sarcolemma and if strong enough can generate ap
3) excitation contraction coupling
–ap spreads from sarcolemma to T-tubles. when ap arives Ca2+ channels are forced opem and Ca2+ is released
4) cross bridge formation and muscle contraction

Question 24

Cross bridge formation

Answer 24

A) ca2+ bonds troponin and it changes shape
B) after shape is changed, it rolls to the side
C) once it moves, myosin binding site on actin exposed
D) myosin head spilts ATP into ADP Pi
E)ADP Pi released from myosin head, causing myosin head to change shape increasing bend–myosin head pulls actin filament to center of sarcomere (power stroke)
F) myosin head binds to another ATP–> myosin head detaches from actin binding site
steps D-F occur along length of actin filament until muscle contraction ends or ATP/Ca2+ run short

Question 25

end cross bridging

Answer 25

motor impules no longer sent to muscle fiber ca2+ returned to sarcoplasmic reticulum troponin returns to og shape and tropomysin covers actin beinding site again

Question 26

Rules for motor neurons

Answer 26

1) when motor meuron fibers all fibers it innervates will contract 2) number of muscle fibers a motor neuron innervates influences movement --motor neuron innervates few fibers = precise control of movement --motor neuron innervating many fibers = more forces, not as precise

Question 27

changes produced by hormone binding

Answer 27

1) altering plasma membrane permiability or membrane potential 2) stimulates synthesis of enzymes/priteins inside cell 3) activates/deactivates enzymes 4) Induces secretory activity 5) stimulates mitosis (growth and tissue repair)

Question 28

Hormone concentration depends on:

Answer 28

1) how fast it is being released by endocrine organ 2) how fast it has been broken down --most hormones removed by kidney and/or liver --water souble hormones have shortest half-life