Physiology Quiz 3

Front 1

General Roles of Muscle Tissue

Back 1

-Motion
-Stabilize body positions & regulate organ volume
-thermogenesis

Front 2

Functional Properties of Muscle Tissue

Back 2

Excitability
Contractility
Extensibility
Elasticity

Front 3

Structural Statements to Skeletal Muscles

Back 3

cylindrical (multinucleate)
striated

Front 4

Structural Statements to Cardiac Muscles

Back 4

branching (single cell)
intercalated discks
striations

Front 5

Structural Statements to Smooth Muscles

Back 5

2 types: Single & Multi unit
Spindle Shaped, no striations, no neuromuscular juncion,
no T Tubule, no troponin,
uses calmodulin

Front 6

Myofiber

Back 6

muscle fiber

Front 7

Myofibril

Back 7

rodlike bundle of contractile filaments found in muscle fibers

Front 8

Triad

Back 8

successive groupings of the 3 membranous structures: terminal cisterna, T tubule, and terminal cisterna

Front 9

Sarcomere

Back 9

Piece of Myofibril

Front 10

How to Z discs, I bands, and A bands of myofibril change with contraction

Back 10

--I bands shorten
--Distances between successive Z discs is reduced
--H zones disappear
--Contiguous A bands move closer together but don't change in length

Front 11

4 steps of cross bridge cycling

Back 11

Binding
Bending
Unbinding
Straightening

Front 12

Binding stage of cross bridge cycle

Back 12

Ca2+ required
activated myosin heads are strongly attracted to exposed binding sites on actin and cross bridges are formed cross

Front 13

Bending stage of cross bridge cycle

Back 13

ADP released

Front 14

Unbinding stage of cross bridge cycle

Back 14

As a new ATP molecule binds to the myosin head, myosin's hold on actin loosens and the cross bridges detach from actin

Front 15

Straightening stage of cross bridge cycle

Back 15

ATP hydrolosis energy to "cock" cross bridges

Front 16

3 parts of neuromuscular junction

Back 16

axon end( neuromuscular junction)
Neuromuscular Gap
Motor End Plate

Front 17

What are the events that occur at the Neuromuscular junction?

Back 17

When a nerve impulse reaches the end of an axon, the voltage gated calcium channels in its membrane open, allowing calcium to flow in from the ECF. Prescence of Calcium inside axon terminal cause some of synaptic vesicles to fuse w/axonal membrane and release ACh into synaptic cleft by exocytosis. ACh diffuses across the cleft and ataches to Ach receptors on sarcolemma. Then, the Ach is quickly broken down to its building blocks, acetic acid and choline by acetycholinesterase.
This destruction of Ach prevents continued muscle fiber contraction.

Front 18

What is meant by excitation-contraction coupling?

Back 18

It is the sequence of events by which transmission of an action potention along the sarcolemma leads to the sliding of myofilaments
Calcium binds to troponin
Troponin then pulls on tropomyosin
Open binding sites on actin

Front 19

Botulinis toxin

Back 19

Blocks exocytosis, Ach can't be released.
Individual dies of suffocation, diaphram can't contract
(flaccid paralysis)

Front 20

Curare

Back 20

ACh mimicer
Doesn't open channels
Contractions are prevented
(flaccid paralysis)

Front 21

AchE

Back 21

an Ach antagonist

Front 22

Motor Unit

Back 22

a motor neuron and all the muscle cells it stimulates

Front 23

All or None Law

Back 23

A motor neuron delivers a threshold stimulus to all of the cells of the motor unit and each cell contracts fully and completely. There is no partial contraction of the motor unit. The muscle either contracts or it doesn't

Front 24

How are graded contractions achieved? What four factors effect the amount of force (tension) a muscle can generate?

Back 24

1. Frequency of stimulatino of muscle fiber by motor neurons
2. Length of muscle fibers before they begin to contact
3. The # of muscle fibers contracting at any one given time (# of activated motor units)
4. Structural compnents of the muscle itself

Front 25

Twitch

Back 25

response of a motor unit to a single actino potential of its motor neuron
3 phases: latent, contraction, relaxation

Front 26

Tetanus

Back 26

state of sustained contraction of a muscle during which the muscle does not relax to its initial length or tension, induced by a rapid succession of stimuli

Front 27

Summation

Back 27

Process by qhich multiple or reeated stimuli can produced a response in a nerve muscle or other part that one stimulus cannot produce

Front 28

Tone

Back 28

sustained, small contractions of motor units give skeletal muscles a firmness without producing movement. This is essential for maintaining posture

Front 29

Isometric contraction

Back 29

occur when muscle does not or cannot shorten, but tension within it greatly increases.
No length change, 0% efficient, all energy lost as heat
ex- holding a book in a steady position

Front 30

isotonic contraction

Back 30

occur when you move a constant load through the range of motions possible at a joint. In this type of contraction, the tension within the muscle stays the same during contraction, while the length of the fibers shortens (Most movements in body)
Length changes 25% efficient

Front 31

Concentric and eccentric contraction fall under what type of contraction?

Back 31

Isotonic

Front 32

Concentric

Back 32

muscl eshortens and soes work, like picking up a book or kicking a ball

Front 33

Eccentric

Back 33

muscle generates force as it lengthens
Ex- calf muscle as you walk up a hill

Front 34

_____ contractions put the body in position to contract _______.

Back 34

Eccentric, concentrically

Front 35

Treppe

Back 35

Muscle begins to contract after a long period of rest, its initial contractions to the stimuli get stronger and stronger. Even thought the stimuli are of same intensity & speed, the 1st few contractions produce a staircase effect. No summation- warm up period for athletes

Front 36

Oxygen Debt

Back 36

extra amount of oxygen body must take in for restorative processes

Front 37

Why does oxygen debt occur?

Back 37

For a muscle to return to its resting state, its oxygen reserves must be replenished, the accumulated lactic acid must be reconverted to pyruvic acid, glycogen stores must be replenished, glycogen stores must be replaced, ATP and creating phosphate reserves must be resynthesized. Also, the liver must convert any lactic acid persisting in the blood to glucose or glycogen. Oxygen debt represents the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used