MUSCLE TISSUE (Lecture 6)

Question 1

3 types of muscle

Answer 1

skeletal
cardiac
smooth

Question 2

function of muscle fibers

Answer 2

produce force, contraction / movement, heat

Question 3

muscle fibers are surrounded by __________ matrix

Answer 3

connective tissue matrix, bound by external lamina

Question 4

sarcolemma aka ?

Answer 4

plasma membrane

Question 5

sarcoplasm aka ?

Answer 5

cytoplasm

Question 6

what causes contraction in muscle fibers

Answer 6

the interaction of cytoplasmic protein chains (myofilaments)

Question 7

interactions of cytoplasmic protein chains are called?

Answer 7

myofilaments

Question 8

what muscle cells are striated?

Answer 8

skeletal and cardiac

Question 9

what muscle cells are non-striated?

Answer 9

smooth muscle

Question 10

the cell diameter of a muscle cell is proportional to its _____ production

Answer 10

force production

Question 11

skeletal muscle is usually attached to ____ or other muscles

Answer 11

bone

Question 12

what are triads composed of and where are they located

Answer 12

triad = 2 terminal cisternae + 1 T tubule
located: junction of A and I bands

Question 13

what is a motor unit composed of

Answer 13

motor neuron + muscle fibers it innervates

Question 14

skeletal muscle has a rich blood supply that comes from _____?

Answer 14

surrounding connective tissue

Question 15

term for a bundle of muscle fibers

Answer 15

Fascicle

Question 16

term for single muscle fiber

Answer 16

myocyte

Question 17

term for long rows of myofilaments

Answer 17

myofibrils

Question 18

the dark bands are ____ bands

Answer 18

A

Question 19

the light bands are ____ bands

Answer 19

I

Question 20

the dark line in the I band is called the ____ disk/line

Answer 20

Z disk/line

Question 21

what causes striations in skeletal muscle

Answer 21

the overlapping myofilament arrangement

Question 22

a sarcomere is ?

Answer 22

smallest contractile unit

Question 23

a sarcomere spands from ____ disk to ___ disk

Answer 23

Z disk to Z disk

Question 24

An ‘I’ band is ______ myofilament

Answer 24

thin only

Question 25

An 'H' band is ____ myofilament

Answer 25

thick only

Question 26

muscle fiber aka _____ aka ______

Answer 26

muscle fiber = muscle cell = myocyte

Question 27

Skeletal muscle has an abundance of what

Answer 27

- mitochondria - glycogen (E source inside muscles) - myoglobin (like hemoglobin but has more O2)

Question 28

sarcoplasmic reticulum (SR) aka | the muscle term for...

Answer 28

smooth ER

Question 29

what ion is needed for muscle contraction to occur

Answer 29

Calcium

Question 30

CT that surrounds muscle fibers

Answer 30

endomysium: made of type IV, III collagen | similar function to the basal lamina, reticular lamina

Question 31

CT that surrounds fascicles

Answer 31

perimysium: type I collagen

Question 32

CT that surrounds the entire muscle

Answer 32

Epimysium: type I collagen

Question 33

What is the sliding filament theory

Answer 33

the Z lines get closer together as the myofilaments slide past eachother

Question 34

what are t tubules (transverse tubules)

Answer 34

extensions of the sarcolemma | sarcolemma = muscular plasma membrane

Question 35

the sarcolemma of the myocyte has ______ folds and ______ receptors

Answer 35

junctional folds and ACh receptors

Question 36

explain why rigor mortis occurs

Answer 36

lack of ATP prevents the dissociation of action and myosin = no muscle movement

Question 37

where is smooth muscle found?

Answer 37

- hollow organs, blood vessels, dermis, respiratory passages

Question 38

smooth muscle characteristics

Answer 38

- often in perpendicular layers - produce their own "CT matrix" -fusiform shape - single and centrally located nucleus - not striated - NO t-tubules - barely any SR - have caveolae

Question 39

where does smooth muscle get a majority of its Calcium?

Answer 39

Ca2+ source is mainly extracellular

Question 40

role of caveolae in smooth muscle?

Answer 40

caveolae are membrane invaginations that facilitate the INTAKE of Ca2+

Question 41

type of muscle tissue that has a crisscross pattern of myofilaments - the crisscross pattern facilitates contraction of the fusiform shape

Answer 41

smooth muscle

Question 42

type of muscle tissue with a "corkscrew" nucleus

Answer 42

smooth muscle

Question 43

smooth muscle cells can be relaxed or _______

Answer 43

relaxed or contracted