cumulative portion questions - final exam

Question 1

ascending spinal cord pathways

Answer 1

dorsal spinocerebellar pathway (DSC)

Question 2

DSC function

Answer 2

unconscious proprioception - cerebellum uses to coordinate movement

Question 3

DSC Pathway

Answer 3

i. mechanoreceptors activated (1a, 1b, A-beta
ii. DRG
iii. spinal cord; synapse in Grey matter (column of Clark)
iv. ascends dorsal spinocerebellar tract
v. signal goes to ipsilateral cerebellum

Question 4

descending spinal cord pathway

Answer 4

rubrospinal tract (RST) pathway

Question 5

rubrospinal tract (RST) pathway function

Answer 5

voluntary appendicular movements - role is minimal in humans because we have larger cortex

Question 6

rubrospinal tract (RST) pathway

Answer 6

i. “begins” in red nucleus (brainstem)
ii. axons decussate immediately and descend thru RST
iii. synapse in spinal cord

Question 7

driving force definition

Answer 7

v(cell) - v(eq pot)ion; tells which way and how powerful an ion would flow if open ion channel selectivable for it

Question 8

permeability definition

Answer 8

determines if an ion can go through an open ion

Question 9

point A/resting potential

Answer 9

Na+: driving force and permeability are low
K+: both are high

Question 10

point B/repolarization

Answer 10

Na+: VG Na+ ion channels just closed; ion flow = low
K+: VG K+ ion channels open; ion flow high - K+ out

Question 11

life cycle of a NT

Answer 11

synthesis, vesicle uptake, binding to receptor, removal from synapse

Question 12

GABA life cycle

Answer 12

synthesis: glutamine –> glutamate – GAD –> GABA
vesicle uptake: VGAT
binding to receptor: GABAa and GABAb
removal from synapse: GAT

Question 13

GABAa receptor

Answer 13

hyperpolarize via Cl- influx; ionotropic

Question 14

GABAb

Answer 14

metabotropic; inhibits AC, coupled to Gai

Question 15

sensory transduction definition

Answer 15

converting different types of stim in environment into APs/electrical signals in NS

Question 16

phototransduction - vision

Answer 16

photoreceptors are responsible; light -> rhodopsin isomerization -> retinal cis -> trans -> transducin activation -> activate cGMP PDE -> decrease cGMP -> hyperpolarization because no Na+, Ca2+ influx thru cGMP gated cation channels -> decrease GLUT to bipolar cell