Lecture 17b

Question 1

Contraction in the absence of adequate oxygen produces ________ which contributes to muecle soreness

Answer 1

Lactic acid

Question 2

Heavy/ laboured breathing after excesise occurs to make up for ____

Answer 2

Oxygen debt

Question 3

Fatigue is

Answer 3

The continued metabolic effort required to remove excess lactic acid that can accumulate during long periods of exercise

Question 4

Repeated muscular contraction depletes cellular ______ store and outstrips the abilty to replenish ____ and _____ to make more

Answer 4

ATP

oxygen and nutrients

Question 5

The byproduct of skeletal muscle contraction is

Answer 5

Heat

Question 6

Breaking ATP bond results in ____ AND _____

Answer 6

Energy and heat

Question 7

Motor neurons are

Answer 7

Specialized nerve fibre that transmits an impulse to a muscle, causing a contraction

Question 8

Neuromuscular junction is what

Answer 8

Specialized point of contact between a nerve ending and the muscle fiber it innervates

Question 9

A motor unit = ______ + ________

Answer 9

A motor neuron + muscle cells it innervates

Question 10

The fewer number of fibres in a motor unit the more ______ the available movements are

Answer 10

Precise

Question 11

The greater the number pf fibres in a motor unit the more ____

Answer 11

Powerful the contraction available

Question 12

5 types of muscle contraction

Answer 12

Twitch 
Tetanic 
Tonic 
Isotonic
Isometric

Question 13

Myography is

Answer 13

Method of graphing the changing tension of a muscle as it contracts

Question 14

Twitch contraction is what type of movement

Answer 14

Quick, jerky response

Question 15

Twitch contractions are not generally

Answer 15

Related to normal muscle activity

Question 16

Twitch contractions are seen in wahat fibre

Answer 16

Isolated muscle fibres

Question 17

Twitch contractions are single contraction of muscle fibres caused

Answer 17

By a single threshold stimulus

Question 18

Tetanic contraction are

Answer 18

Sustained, steady muscle contractions

Question 19

Tetanic contractions are caused by a series of_____

Answer 19

Stimuli bombarding a muscle in rapid succession this series of stimuli join forces to produce a sustained/ prolonged contraction refered to as tetanus

Question 20

Tetanic contractions are ______ dependant

Answer 20

Calcium

Question 21

Tonic contractions are

Answer 21

Continual, partial contraction of a muscle

Question 22

Flaccid

Answer 22

Muscles have less tone than normal

Question 23

Spastic

Answer 23

Muscles have more tone than normal

Question 24

Muscle tone it maintained by

Answer 24

Negative mechanisms

Question 25

A few muscle fibers are always

Answer 25

Contracting to form a bit of tension

Question 26

What is graded strength principle

Answer 26

Skeletal muscles contract with varying degrees of strength

Question 27

What 4 things is graded strength principle

Answer 27

1. Metabolic condition of individual fibres
2. # of fibres contracting at the same time
3. The # of motor units involved
4. The intensity and frequency of the stimulation

Question 28

Length tension relationship (part of graded strength principle)

Answer 28

A muscles maximum strength is directly dependent on the initial length of its fibres (the longer, the more they can contract)

Question 29

If sacromeres are compressed,

Answer 29

It reduces the muscles contractile potential

Question 30

If the sarcromeres are overstretched,

Answer 30

Actin and myosin are too far apart to bind

Question 31

The strongest muscle contraction occurs when the

Answer 31

Muscle is stretched to its optimal length

Question 32

Stretch reflex (graded strength principle) is

Answer 32

The load a muscle is exposed to influenses the strength of its contraction

The body tries to maintain constant muscle length in response to an increased load… up to a point