Exam 3 Flashcards
(114 cards)
1
Q
What are the three types of muscle
A
Skeletal Cardiac and Smooth
2
Q
What is the Endomysium
A
Thin sleeve of loose connective tissue around each fiber
3
Q
What does the Endomysium do
A
Allow room for capillaries and nerve fibers
4
Q
What is the Perimysium
A
Thick layer of connective that wraps fascicles
5
Q
What are Fascicles
A
Bundles of muscle fibers wrapped together
6
Q
What is the Epimysium
A
Fibrous sheath surrounding entire muscle
7
Q
What does the perimysium do
A
Carry nerves, blood vessels, and stretch receptors
8
Q
What is the fascia
A
Sheet of connective tissue between muscles or muscle groups
9
Q
What does the epimysium do
A
Blend with fascia and deeper tissues
10
Q
Describe fusiform muscles
A
Thick in the middle with fascicles converging on each tapered end
11
Q
Describe parallel muscles
A
Uniform width and parallel fascicles
12
Q
Describe triangular muscles
A
Broad at one end with fascicles converging on the other narrow end
12
Q
What is another name for triangular muscles
A
Convergent muscles
13
Q
What does the fascia do
A
Packages groups of functionally related muscles into muscle components
14
Q
What is a direct muscle attachment
A
Little separation between muscle and bone
15
Q
What is an indirect muscle attachment
A
Tendon connects muscle to bone
16
Q
What is the prime mover
A
The muscle that produces the most force of a movement
17
Q
What is the fixator
A
The muscle that prevents a bone from moving
18
Q
What is a synergist
A
The muscle that aids the prime mover
19
Q
What is the antagonist
A
The muscle that opposes prime mover
20
Q
What is innervation
A
The identity of the nerve that stimulates it
21
Q
What does it mean for a muscle to be innervated
A
A nerve enters the muscle
22
Q
What is skeletal muscle
A
Voluntary, striated muscle attached to bones
23
Q
What is the sarcolemma
A
Plasma membrane of a muscle fiber
24
What is the sarcoplasm
Cytoplasm of muscle fiber
25
What are myofibers
Long protein cords occupying most of sarcoplasm
26
What is glycogen
carbohydrate stored to provide energy for exercise
27
What is myoglobin
Red pigment; provides some oxygen for muscle activity
28
What is the sarcoplasmic reticulum
Smooth ER that forms network around each microfibril
29
What is in the Sarcoplasm
Myofibers, Glycogen, Myoglobin
30
What are terminal cisterns
Dilated end-sacs of SR that cross the muscle fiber from one end to the other
31
What are transverse tubules
Tubular infoldings of the sarcolemma which penetrate through the cell and emerge on the other side
32
What are Myoblasts
Stem cells that fused to form each muscle fiber early in development
Each one has a nucleus
33
What are satellite cells
Unspecialized myoblasts remaining between the muscle fiber and endomysium
34
What are thick filaments
Made up of several hundred myosin molecules
35
What are thin filaments
composed of three different protein types
36
What are the three types of thin filaments
Fibrous (f) actin, Tropomyosin, Troponin
37
What is Fibrous actin
Two intertwined strands of G actin subunits. Each has an active site that can bind to the head of a myosin molecule
38
What is tropomyosin
Each blocks six or seven active sites on G actin subunits
It is a regulatory protein
Has to move out of the way for myosin to get in
39
What is troponin
Small calcium-binding protein on each tropomyosin molecule
40
What is a Sarcomere
Segment from Z disk to Z disk
It is the functional unit of muscle fiber
40
What are Elastic Filaments
Filaments made of a huge springy protein called titin
they connect thick filaments to Z-disks and M line
41
What is the somatic nerve
The nerve that contracts skeletal muscle
42
What is the synapse
Where a nerve meets another cell
43
What are somatic nerve fibers
Axons of somatic motor neurons that lead to skeletal muscle
44
What is a motor unit
One nerve fiber and all the muscle fibers innervated by it
Behaves as a functional unit
45
What do large motor units do
Provide strength more than control
45
What do small motor units do
Provide a fine degree of control
46
What is a synapse
The point where a nerve fiber meets a target cell
47
What is a Neuromuscular Junction or Motor end plate
Where the target cell of a nerve fiber is a muscle fiber
48
What is the Axon Terminal
Swollen end of nerve fiber
49
What is acetylcholinesterase
The enzyme that breaks up acetylcholine
50
What does it mean to be polarized
To contain a negative charge
51
What does it mean to depolarize
To turn the charge positive from negative
52
What does it mean to repolarize
To turn the positive charge back negative
53
What is flaccid paralysis
State where the muscles are limp and cannot contract
54
What is excitation
Action potentials in motor nerve fiber lead to action potentials in the muscle fibers
55
What is Excitation contraction coupling
Events that link the action potential on the sarcolemma to activation of the myofilaments preparing them to contract
56
What is contraction
When the muscle fiber develops tension and may shorten
57
What is relaxation
When stimulation ends
58
What is the length-tension relationship
Amount of tension generated by a muscle depends on how stretched or shortened it was before stimulated
59
What is the Latent Period
Delay just after stimulation of a muscle
60
What is the contraction phase
External tension is generated and a load is moved as the muscle fiber shortens
61
What is the relaxation period
Sarcoplasmic calcium levels fall as calcium gets reabsorbed into the sarcoplasmic reticulum
62
What is Anaerobic fermentation
Enables cells to produce ATP in the absence of oxygen
It yields little ATP and lactate
63
What is Aerobic fermentation
Produces ATP using oxygen
Doesn't generate lactate and produces a lot more ATP
64
What are myocytes
Involuntary cells not as long and fibrous as skeletal muscles
65
What are cardiac muscle cells called
Cardiomyocytes
66
What is the structure of a cardiac muscle
Striated, short, thick, surrounded by endomysium
67
What are intercalated disks
where cardiomyocytes join other cells
68
What does it mean to be autorhythmic
To contract rhythmically and independently
69
What is the structure of smooth muscle
Lacks striations and variable innervation
70
What is the Latch-bridge mechanism
Resistant to fatigue
Head of myosin molecules do not detach from actin immediately
71
How does the endocrine system work
Communicates by means of chemical messengers secreted into blood
72
How does the nervous system work
utilizes neurons to send messages from cell to cell using electrical and chemical means
73
Where is the central nervous system
The brain and spinal cord
74
Where is the peripheral nervous system
Nerves and ganglia
75
What is sensory division
AKA Afferent division
Carries signals from receptors to the CNS
76
What is somatic sensory division
Carries signals from receptors in the skin, muscle, bones, joints to the CNS
77
What is Visceral sensory division
Carries signals from the viscera (heart, lungs, stomach, urinary bladder)
78
What is motor division
AKA Efferent division
Carries signals From CNS to effectors
79
What is somatic motor division
Carries signals to skeletal muscles
Causes voluntary contraction and automatic reflexes
80
What is visceral motor division
AKA autonomic motor system
Carries signals to glands, cardiac and smooth muscle, no voluntary control
81
What is the sympathetic division of the ANS
Stimulates and prepares body for action
82
What is the parasympathetic division of the ANS
Calming effect on the body
83
What is conductivity
Produce electrical signal that are conducted to other cells
84
What is secretion
when signal reaches end of axon, the neuron secretes a neurotransmitter that stimulates next cell
85
What are interneurons
Processing neurons
Receive signals from other neurons and process this information and make decisions
86
What are glial cells
Regulate area around neurons so they can perform their functions
87
What are oligodendrocytes
form myelin sheath in CNS
88
What are Microglia
Macrophages that engulf debris and defend against pathogens
88
What are ependymal cells
Line internal cavities of brain and secretes/circulates cerebrospinal fluid
89
What are astrocytes
Framework for nervous tissue
90
What is the Myelin sheath
Spiral layers of insulation around an axon
91
What is the Node of Ranvier
Gap between segments
92
What are internodal segments
Myelin covered segments
93
What are initial segments
Bare section of axon between the hillock and first glial cell
94
What is the trigger zone
Axon hillock and initial segment
95
What is electrical potential
Difference in concentration of charged particles between one point and another
type of potential energy
96
What is a current
Flow of charged particle from one point to another
97
What is the resting membrane potential
The charge difference across plasma membrane
Negative
Inside is negative outside is positive
98
What does it mean to be graded
To vary in magnitude with stimulus strength
99
What does it mean to be decrimental
To get weaker the farther away they spread from point of stimulation
100
What does it mean to be reversible
If stimulation ceases membrane voltage quickly returns to normal resting potential
101
What is action potential
Rapid up and down change in voltage produced by the coordinated opening and closing of the voltage gated ion channels
102
What is a ligand
Anything that binds to a protein
103
What is the all or none law
If threshold is reached, neuron fires up to maximum voltage if its not reached it doesn't fire at all
104
What is non decremental
they do not get weaker with distance
105
What is irreversible
Once started an action potential travels all the way down
106
What is the refractory period
period of resistance to stimulation
107
What is the absolute refractory period
No stimulus of any strength will trigger another action potential
108
What is the relative refractory period
An unusually strong stimulus is needed to trigger a new action potential
109
What do refractory periods do
Ensure that the action potential goes down the axon and not towards the soma
110
Where do action potentials fire
at the Node of Ranvier
