Lecture 14, Muscles

Question 1

skeletal muscle structure

Answer 1

tendon- conn tissue, muscle to bone

body- generates force by contracting

Question 2

skeletal muscle function

Answer 2

movement via contraction

Question 3

what is a muscle made out of

Answer 3

bundles of fascicles

Question 4

what surrounds a muscle

Answer 4

epimysium

Question 5

what are fascicles made out of

Answer 5

bundles of muscle fibers

Question 6

what surrounds fascicles

Answer 6

perimysium

Question 7

what are muscle fibers made out of

Answer 7

myofibrils

Question 8

what are muscle fibers surrounded by

Answer 8

endomysium

Question 9

muscle fiber structure

Answer 9

long, length of muscle,
surrounded by sarcolemma containing t tubules
composed of myofibrils

Question 10

t tubules

Answer 10

continuous with sarcolemma, dip into cell interior

Question 11

myofibrils

Answer 11

rod-like structures 
surrounded by sarcoplasmic reticulum
# of myofibrils can change with muscle cell use

Question 12

what are myofibrils composed of

Answer 12

contractile filaments

Question 13

sarcoplasmic reticulum

Answer 13

endoplasmic reticulum

stores/releases Ca++ into cytosol of muscle fiber

Question 14

contractile filaments

Answer 14

arrange to form a sarcomere

2 types- thick, thin

Question 15

sarcomere

Answer 15

repeating functional contractile filaments

Question 16

thin filaments

Answer 16

composed of:
g actin
tropomyosin
troponin

Question 17

g actin

Answer 17

protein with myosin binding sites

Question 18

tropomyosin

Answer 18

protein that controls interaction with thick filaments

by blocking myosin binding sites

Question 19

troponin

Answer 19

moves tropomyosin off of binding sites during muscle stimulation
by binding with Ca++

Question 20

thick filaments (myosin)

Answer 20

composed of myosin proteins

• heads
• tails
• titan

Question 21

thick filament head sites

Answer 21

actin binding site
ATPase site (breaks down ATP)

Question 22

tails

Answer 22

no binding sites

compose bare zones

Question 23

sarcomere regions

Answer 23

A band
H zone
I band
Z line/disc
M line

Question 24

a band

Answer 24

length of myosin (length never changes)

Question 25

h zone

Answer 25

region of ONLY thick (myosin)

Question 26

i band

Answer 26

region of only thin filament

Question 27

z disc

Answer 27

ends of the sarcomere

Question 28

m line

Answer 28

middle of sarcomere

Question 29

excitation-contraction coupling

Answer 29

releasing NTs at neuromuscular junction cell

causes contraction of muscle cell

Question 30

steps of a muscle contraction

Answer 30

ach released from terminal at neuromuscular junction
ach binds to (nicotinic cholinergic) receptors on motor end plate-create AP
ap moves down sarcolemma, down t tubules
ap triggers ca++ from sr
ca++ binds to troponin, moving tropomyosin
crossbridge forms w/ actin (crossbridge cycle) -then contraction