Flashcards in Chapter 8 Deck (44)
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How many muscles do we have
600
1
Fibrous connective tissue covering muscles
Fascia
2
Add muscles to bone
Tendons
3
Sheet of connective tissue which attaches muscles to muscle
Aponeurosis
4
Single muscle cell
Muscle fiber
5
Fibers made out of proteins myosin (thick) and actin (thin) that plays a role
Myofibrils
6
What produces striations?
Myofibrils
7
Connection between motor neuron and muscle fiber
Neuromuscular junction
8
Motor neuron and muscle fibers it controls
Motor unit
9
Neurotransmitter that stimulates a skeletal muscle fiber
Acetylcholine
10
Steps for stimulus for contraction
Muscle impulses signals the release of calcium ions
Linkages form between actin and myosin and muscle fibers contract
Acetylcholine is decomposed by enzyme acetylcholinesterase
Calcium ion transported back
Linkages between actin and myosin break and muscle fiber relaxes
11
What is the energy source for contraction
ATP
12
Red pigment in blood that carries oxygen
Hemoglobin
13
Reddish brown pigment, only found in muscles that carries oxygen
Myoglobin
14
What is the advantage of having hemoglobin and myoglobin in the same place
This reduces muscle requirement for continuous blood supply
15
How does lactic acid form
During strenuous exercise, oxygen deficiency may cause lactic acid to accumulate in muscles
16
Amount of oxygen liver requires to convert lactic acid to glucose and to restore ATP and creatine phosphate
Oxygen debt
17
3 causes of muscle fatigue
Caused by lactic acid, poor blood supply, or lack of acetylcholine in motor neurons
18
Minimal strength required to cause contractions
Threshold stimulus
19
Recording of an electrically stimulated muscle
Myogram
20
Single contraction that lasts only a fraction of a second
Twitch
21
Delay between time stimulus was applied and time muscle responded
Latent period
22
Increased force of contraction by a muscle when twitches occur so rapidly that next twitch occurs before previous one relaxes
Summation
23
Forceful, sustained contraction without even partial relaxation
Tetanic contraction ????
24
Explain process of recruitment of motor units
Increase in # of motor units being activated as more motor neurons respond to higher stimuli
As stimulus increases, requirement of motor units continue until all possible units are activated and muscle contracts with maximum tension
25
Summation and recruitment together can produce sustained contraction of increasing strength
Sustained contractions
26
When a muscle is a rest, some sustained contraction occur
Muscle tone
27
Name 2 types of smooth muscle and differ them
Multiunit smooth muscle- fibers separated and less organized found in iris of eye and walls of blood vessels, contract only in respond to stimulation from motor nerves
Lisceral- sheets of cells in close contact, follow in walls of hollow organs, can stimulate each other and cause repeated contractions=rhythmically
28
Wavelike motion occurring in intestines to force contents along
Peristalsis
29
