Module 6

Question 1

CT components of skeletal muscle:

Answer 1

• epimysium
• perimysium
• endomysium

Question 2

skeletal muscles are surrounded by a fibrous

Answer 2

epimysium

Question 3

subdivides the muscle into fascicles

Answer 3

perimysium

Question 4

each fascicle is subdivided into muscle fibers surrounded by

Answer 4

endomysium

Question 5

plasma membrane of skeletal muscle fibers

Answer 5

sarcolemma

Question 6

multi nucleated; form a syncytium, are striated

Answer 6

skeletal muscle fibers

Question 7

site where a motor neuron stimulates a muscle fiber

Answer 7

neuromuscular junction

Question 8

varied contraction strength due to different numbers of motor units being stimulated

Answer 8

graded contractions

Question 9

motor neuron and all the muscle fibers it innervates

Answer 9

motor unit

Question 10

area of the muscle fiber sarcolemma where a motor neuron stimulates it using the neurotransmitter,

Answer 10

motor end plate

Question 11

each fiber has densely packed subunits of thick and thin myofilaments called myofibrils

Answer 11

myofibrils

Question 12

only thin filaments, primarily of the protein, actin

Answer 12

I bands

Question 13

contain all of the thick filament with some thin filament overlap; the thick filament is the protein, myosin

Answer 13

A bands

Question 14

are the center of the A band with no thin filament overlap

Answer 14

H bands

Question 15

are found in the center of each I band.

Answer 15

z discs

Question 16

The basic subunit of striated muscle contraction

Answer 16

sacromere

Question 17

protein that runs from the Z disc to the M line and allows elastic recoil

Answer 17

titin

Question 18

are found in the center of each A band and help hold down thick filaments

Answer 18

M lines

Question 19

thick myofilament

Answer 19

myosin

Question 20

thin myofilament

Answer 20

actin

Question 21

skeletal muscle contract only when stimulated by a

Answer 21

somatic motor unit

Question 22

axon terminal of motor neuron —- vesicles contain what type of neurotransmitter?

Answer 22

Ach

Question 23

calcium binding site in skeletal muscle

Answer 23

troponin

Question 24

blocks actin binding site from myosin when unactivated

Answer 24

tropomyosin

Question 25

troponin complex

Answer 25

I T C

Question 26

inhibits binding of myosin

Answer 26

troponin I

Question 27

binds to tropomyosin

Answer 27

troponin T

Question 28

binds to calcium

Answer 28

troponin C

Question 29

most of the calcium is stored where in the SR

Answer 29

terminal cisternae

Question 30

voltage-gated calcium channels located in the transverse (T) tubules

Answer 30

DHP

Question 31

calcium release channels in the sarcoplasmic reticulum

Answer 31

RyR

Question 32

move Ca2+ back into SR (active transport).

Answer 32

SERCA (ca-atpase

Question 33

When a second shock is applied immediately after the first, a second twitch will partially piggyback the first. This is called

Answer 33

summation

Question 34

time between the stimulus and the contraction (excitation-contraction coupling to the attachment of myosin cross bridges to actin).

Answer 34

latent period

Question 35

stronger contractions result in recruitment of more fibers, until all fibers are contracting.

Answer 35

graded contractions

Question 36

Increasing the frequency of electrical shocks decreases the relaxation time between twitches. This is called

Answer 36

incomplete tetanus

Question 37

At a certain frequency, there will be no relaxation. This is called ______a smooth, sustained contraction.

Answer 37

complete tetanus, `

Question 38

Muscles are made of thin muscle cells called

Answer 38

intrafusal fibers

Question 39

regular muscle fibers

Answer 39

extrafusal fibers

Question 40

respond to tension a muscle puts on a tendon

Answer 40

golgi tendon organs

Question 41

respond to muscle length

Answer 41

muscle spindle apparatus

Question 42

two types of intrafusal fibers

Answer 42

nuclear bag fibers | nuclear chain fibers

Question 43

nuclei in loose central aggregates

Answer 43

nuclear bag fibers

Question 44

nuclei in rows

Answer 44

nuclear chain fibers

Question 45

two types of sensory cells wrap around the fibers

Answer 45

- primary | - secondary

Question 46

(annulospiral) – most stimulated at the beginning of the stretch

Answer 46

primary

Question 47

(flower-spray) – respond more during sustained stretch

Answer 47

secondary

Question 48

Striated and involuntary Myosin and actin filaments form sarcomeres. Contraction occurs by means of sliding thin filaments.

Answer 48

cardiac muscle

Question 49

fibers are short, branched, and connected via gap junctions called

Answer 49

intercalated discs

Question 50

a mass of cardiac muscle cells connected to each other via gap junctions.

Answer 50

myocardium

Question 51

blood vessel walls, bronchioles, digestive organs, urinary and reproductive tracts

Answer 51

smooth muscle

Question 52

2 types of cells in cardiac muscle

Answer 52

pacemaker and myocardial cells

Question 53

in cardiac muscle everything is the same except what depolarizes the voltage gated DHP channel to open

Answer 53

sodium

Question 54

depolarization of both DHP and RYR

Answer 54

calcium-induced calcium release

Question 55

cardiac muscles can produce action potentials automatically without any innervation. how?

Answer 55

pacemaker

Question 56

does not contain sarcomeres, more actin than myosin, contains gap junctions

Answer 56

smooth muscle

Question 57

Also unlike the situation in skeletal muscles, action potentials can cross from one myocardial cell to another.

Answer 57

cardiac muscle

Question 58

two types of smooth muscle

Answer 58

single unit and multi unit

Question 59

connected via gap junction, co-ordianted contraction, gross control

Answer 59

single unit/visceral

Question 60

individually innervated, independent contraction, fine control

Answer 60

multi-unit

Question 61

Neurotransmitter (many different NT's)k is released along the length of an autonomic neuron from ____ (Smooth muscle)

Answer 61

varicosities

Question 62

smooth muscle contraction

Answer 62

1. SR and ES producing Calcium 2. Ca will bind and activates calmodulin 3. Calmodulin actives MLCK 4. MLCK ---- Myosin Head 5. Cross-Bridge contraction