Muscles

Question 1

which part does epimysium cover

Answer 1

whole muscle belly and extends beyond muscle to form tendon

Question 2

perimysium

Answer 2

surrounds a bundle of muscle fibres call a fascicle. thinner layer of CT

Question 3

endomysium

Answer 3

covers a dozen muscle fibres. thinnest layer of areolar tissue surrounding each cell

Question 4

fn of endomysium

Answer 4

allows room for capillaries and nerve fibres

Question 5

cardiac muscle has which layers

Answer 5

perimysium and endomysium

Question 6

smooth muscle has which layers

Answer 6

endomysium only

Question 7

skeletal muscle has which layers

Answer 7

epimysium, perimysium and endomysium

Question 8

sarcoplasmic reticulum stores

Answer 8

calcium

Question 9

histology of smooth tissue

Answer 9

spindle shaped
no striations due to irregular myofilament
no t tubules arrangement
contract by sliding fragment

Question 10

where are smooth tissue found

Answer 10

walls of hollow organs and blood vessels

Question 11

fn of skeletal muscle tissue

Answer 11

movement; stabilize body position; heat production

Question 12

fn of smooth muscle tissue

Answer 12

regulation of organ volume; transport of organ contents

Question 13

fn of cardiac muscle tissue

Answer 13

movement of blood

Question 14

properties of all muscle (4)

Answer 14

excitability, contractility, extensibility, elasticity

Question 15

define excitability

Answer 15

generate + propagate an electrical signal (axn ptnl). neuromuscular junction and Ca2+ release from SR

Question 16

define contractility

Answer 16

ability to contract forcefully resulting in muscle matching or overcoming load/resistance. sliding filament mechanism and muscle tone

Question 17

define extensiblity

Answer 17

ability to stretch without damage. CT layers. smooth muscles most extensible

Question 18

define elasticity

Answer 18

muscles ability to return to original shape and length after contraction. proteins of muscle fibres

Question 19

fn of myofbrils

Answer 19

fill + extend length of individual muscle fibres in all 3

Question 20

organization of myofibrils in skeletal and cardiac

Answer 20

arranged in lines gives striated appearance

Question 21

structure of myofibrils

Answer 21

thin (actin filaments) and thick (myosin) filaments

Question 22

thick filaments structure

Answer 22

composed of myosin with tails arranged in parallel

Question 23

what do myosin head do

Answer 23

bind to thin actin filaments during muscle contraction. forming cross bridge

Question 24

thin filament structure

Answer 24

composed of actin, troponin and tropomyosin

Question 25

fn of troponin

Answer 25

anchors tropomyosin in place (over the myosin binding site)

Question 26

fn of tropomyosin

Answer 26

blocks the myosin binding site of actin molecule

Question 27

define sacromere

Answer 27

basic fnal unit of a myofibril. thick and thin filaments

Question 28

what separates sacromeres

Answer 28

protein end plates called Z discs

Question 29

sliding filament mechanism

Answer 29

during contraction thin filaments slide over thick towards centre of sacromere. amount of overlap increases btwn thick and thin. sacromere and muscle shortens

Question 30

do myofilaments change length

Answer 30

not changing length, simply ovelapping causing muscle contraction

Question 31

sliding filament mechanism in smooth muscle

Answer 31

thin filaments attach to dense bodies (similar to Z disc) located in sarcolemma or sarcoplasma