Nueromuscloskeletal

Question 0

Acetycholinesterase

Answer 0

Breaks down acetylcholine to choline and acetate

Made by both muscles and neurons

Question 1

Motor neuron and muscle communicate via activation of _____ on ____

Answer 1

Nicotinic acetylcholine receptors

Muscle cells

Question 2

Choline Acetyltransferase

Answer 2

Synthesizes acetylcholine from choline + acetyl-CoA in the cytoplasm

Question 3

Acetylcholine is transported into synaptic vesicles via ____

Answer 3

Acetylcholine/H+ antiporter

Question 4

Proteoglycan that interacts with muscle specific kinase (MuSK) to trigger muscle cell to maintain clustered nicotinic acetylcholine receptors in area beneath neuronal contact

Answer 4

Agrin

Question 5

Protein critical in formation of normal neuromuscular junctions and re-establishing neuromuscular junction following damage

Answer 5

Agrin

Question 6

Kinase found in myocytes that helps with dispersal of nAChR clusters that have not been innervated by a motor neuron. ACh activation of nAChR helps to activate the kinase

Answer 6

Cyclin Dependent Kinase 5

Question 7

Voltage gated Ca channels are localized ____

Answer 7

near the active zone in the presynaptic membranes

Question 8

Endplate potential

Answer 8

Muscle cell response measured as local graded depolarization

Question 9

Alpha subunits of nicotinic acetylcholine receptor

Answer 9

Binding of 2 ACh molecules –> channel open and increase membrane permeability to cations –> muscle membrane depolarization

Question 10

Cholinergic agonists: binds to nAChR –> channel activation

Cause muscle spasms

Answer 10

Carbachol, nicotine

Question 11

Blocks neuromuscular transmission by binding to nAChR, preventing ACh from binding and activating the receptor. Does not interact w/ voltage-gated channels involved in action potentials

Answer 11

Curare

Question 12

Inhibit activity of acetylcholinesterase –> prolingation of endplate depolarization

Answer 12

Neostigmine, physostigmine, DFP

Question 13

Prevents re-uptake of choline by presynaptic terminals and eventual depletion of releasable ACh –> paralysis

Answer 13

Hemicholinium-3

Question 14

Subunit composition of adult nAChR

Answer 14

alpha2 beta gamma epsilon

Question 15

Neuromuscular junction comprised of 3 cells

Answer 15

motor neuron
muscle fiber
Schwann cell

Question 16

Ca2+ in the muscle is stored and released from ____

Answer 16

Terminal cisternae of the sarcoplasmic reticulum

Question 17

Voltage gated Ca2+ channel that’s a voltage sensor on the T Tubule

Answer 17

Dihydropyridine receptor (DHPR)

Question 18

Receptor on terminal cisternae of sarcoplasmic reticulum that is linked to dihydropyridine receptor on T tubule

Answer 18

Ryanodine receptor

Lets a lot of Ca out

Question 19

Junctional tetrad is formed by

Answer 19

Dihydropyridine receptor and ryanodine receptor

Question 20

SERCA

Answer 20

Ca2+ ATPase on SR membrane that pumps Ca2+ back into SR
Maintains low cytoplasmic concentration of Ca2+
Causes muscle relaxation

Question 21

Calsequestrin

Answer 21

In sarcoplasmic reticulum
Low affinity but high binding capacity for Ca2+
Binds Ca2+ to keep [free Ca2+] low
Easily releases Ca2+ when concentration in lumen of cisternae decreases

Question 22

Alignment protein of thick filaments

Answer 22

Titin

Question 23

Alignment protein for thin filaments

Answer 23

Nebulin

Question 24

Thin filament

Answer 24

Actin, tropomyosin, troponin

Question 25

Thick filament

Answer 25

Myosin

Question 26

Rigor mortis is caused when

Answer 26

myosin crossbridge stays bound to actin when depleted of ATP

Question 27

Rate limiting step of crossbridge cycle

Answer 27

ADP release from myosin head

Question 28

Myosin state(s) that have high affinity for actin

Answer 28

Unbound myosin

Myosin-ADP+P

Question 29

Myosin state that has low affinity for actin

Answer 29

Myosin-ATP

Question 30

Contraction where force is generated by muscle but no shortening of muscle fibers

Answer 30

Isometric contraction

Question 31

Contraction where load is help constant and shortening of muscle fibers occurs

Answer 31

Isotonic contraction

Question 32

Contraction where muscles relax against a load

Answer 32

Eccentric contraction

Question 33

Troponin

Answer 33

Binds 4 Ca2+

Question 34

Troponin T

Answer 34

Binds tropomyosin

Question 35

Troponin C

Answer 35

Binds Ca2+

Question 36

Troponin I

Answer 36

Binds actin