Exam 2 (muscles)

Question 1

T-tubule

Answer 1

action potential goes deep into muscle bed
triggers ca2+ release

Question 2

delay b/w action potential and muscle contraction

Answer 2

time required for ca2+ to be released and bind to troponin
twitches can also play a factor

Question 3

sliding filament theory

Answer 3

thick and thin filaments do not change length, but slide past one another

Question 4

functions of skeletal muscle

Answer 4

support
kinectic energy
thermoregulation

Question 5

myosin

Answer 5

binds actin and ATP
thick filament

Question 6

sarcoplasm

Answer 6

cytoplasm

Question 7

actin

Answer 7

thin filament

Question 8

titin

Answer 8

allows sarcomere to go back to original form
largest protein known

Question 9

thick filament

Answer 9

stays the same

Question 10

thin filament

Answer 10

changes size

Question 11

ATP hydrolysis

Answer 11

conformation change

Question 12

no ATP

Answer 12

no contraction (rigor mortis)

Question 13

benefits of 2 binding sites

Answer 13

smoother contraction

Question 14

Ca2+

Answer 14

allows for the formation of crossbridges

Question 15

slow twitch

Answer 15

less mitochondria
for posture
found in dark meat
generate ATP through oxidative phosphorylation
sustained contraction
more common in athletes
builds endurance

Question 16

fast twitch

Answer 16

for standing or walking
more mitchondria
found in white meat
fast
high ca2+ ATPase activity in SR

Question 17

pheripheral fatigue

Answer 17

changes in NMJ, MMP, calcium signaling
depletion of certain metabolites, ATP
glycogen accumulation of certain metabolites
low pH, lactate

Question 18

force

Answer 18

determined by frequency of muscle action potentials and stimulation of the muscle fiber

Question 19

motor unit

Answer 19

consists of one motor neuron and all the muscle fibers it innervates
may have many motor units of different types

Question 20

smooth muscle

Answer 20

vascular
gastrointestinal
urinary
respiratory
reproductive
ocular
no sarcomeres
actin more abundant
longer mysoin heads
no tropnin
uses calmodulin

Question 21

gap junctions

Answer 21

allow contraction to occur as a whole unit

Question 22

lack of gap junctions

Answer 22

allow contraction to occur independently

Question 23

MLC

Answer 23

myosin light chains

Question 24

MLCK

Answer 24

kinase which increases myosin ATPase activity

Question 25

MLCP

Answer 25

phosphate which decreases myosin ATPase activity

Question 26

NE

Answer 26

slows digestion
causes bronchioles to dilate (relax airways)

Question 27

ACh

Answer 27

increases digestion
vasodilation of vascular smooth muscle-> decrease BP

Question 28

myosin ATPase

Answer 28

contraction

Question 29

Ca2+ ATPase

Answer 29

relaxation

Question 30

Na+ K+ ATPase

Answer 30

restore ion concentration across sarcolemma

Question 31

creatine kinase

Answer 31

used clinically as a biomarker for muscle damage

Question 32

phasic smooth muscle

Answer 32

muscles that undergo periodic contraction and relaxation cycles

Question 33

tonic smooth muscle

Answer 33

muscles that are continuously contracted