skeletal muscle histology - Dr. Thomas

Question 1

thin filament is

Answer 1

actin

Question 2

thick filament is

Answer 2

myosin

Question 3

plasma membrane of muscle is

Answer 3

sarcolemma

Question 4

covers a single muscle fiber or cell?

Answer 4

endomysium

Question 5

covers several muscle fibers?

Answer 5

perimysium

Question 6

covers the muscle

Answer 6

epimysium

Question 7

3 diagnostic characterics of skeletal muscle

Answer 7

striated & non branching
peripheral nuclei
lots of cytoplasm

Question 8

contractile unit of a muscle

Answer 8

sarcomeres

Question 9

invaginations of sarcolemma extending into muscle fibers are called

Answer 9

Transverse/ T tubules
foudn at A-I junction
two per sarcomere

Question 10

closely associated sacs of SR to T tubulues

Answer 10

terminal cisternae

Question 11

actin made up of

Answer 11

double stranded chains of monomers

Question 12

strand running in grooves between actin chains

Answer 12

tropomyosin

Question 13

complex sitting on actin chain and attaching to tropomyson

Answer 13

troponin

Question 14

myosin made up of

Answer 14

2 heavy chains with globular heads and 2 light chains

shaped like golf clu

Question 15

which bands decrease during myofibril contraction?

Answer 15

H band and I band

Question 16

large molecules attaching to a-actinin molecules at z disc with actin filament

Answer 16

Nebulin and titin

Question 17

filaments that link desmin filaments together

Answer 17

plectin

Question 18

HSP that protecs desmin filament from stress

Answer 18

aB crystallin

Question 19

protein attaching the actin fibers to z-disc

Answer 19

alpha-actinin

Question 20

intermediate filament circling Z disc

Answer 20

desmin

Question 21

specialized sarcolemma attachment regions for desmin to insert into

Answer 21

costamere

Question 22

locaiton of satellite cells

Answer 22

between sarcolemma and basal lamina

Question 23

Type I fibers

Answer 23

red fibers
slow twitch
fatigue resistant

Question 24

Type II fibers

Answer 24

white fibers
fast twitch
fatigue more easily

Question 25

Type IIA

Answer 25

more intermediate types of fibers

Type 1 and IIa for endurance runners

Question 26

Type IIB

Answer 26

high in myosin ATPase activity
used by sprinters
GOT2B speedy

Question 27

located at junction of tendon and muscle - are in series with muscle fibers

Answer 27

golgi tendon organs

Question 28

interfusal fibers parts and innervation

Answer 28

nuclear bag fibers, nuclear chain fibers

innervated by gamma motor neurons