muscular system and nerves Flashcards
1
Q
types of muscle
A
. Smooth: non-striated; involuntary
• Skeletal: striated; voluntary
• Cardiac: striated; involuntary
2
Q
facia
A
thin covering of connective tissues around the muscle
3
Q
tendon
A
Cord-like mass of connective tissue that connects muscle to a bone
4
Q
Connective tissue in and closely surrounding a muscle
A
epimysium, endomysium, perimysium
5
Q
epimysium
A
surrounds whole muscle; lies beneath fascia
6
Q
• Perimysium:
A
surrounds fascicles within a muscle.
7
Q
• Endomysium:
A
surrounds muscle fibers (cells) within a fascicle
8
Q
what is whole muscle made of
A
fascicles
9
Q
what are fascicles made of
A
Muscle fibers (myocytes or muscle cells)
10
Q
o Muscle fibers have multiple:
A
nuclei and are striated from lines of the sarcomeres
11
Q
sacromeres
A
from z-disc to z-disc
12
Q
Muscle fibers are made of what?
A
Myofibrils
13
Q
Myofibrils look like?
A
Z’s
14
Q
what is the location of the M-line
A
M-line is located at the middle of the sarcomere
15
Q
what are myofibrils made of
A
myofilaments
16
Q
what are the Myofilaments of proteins
A
actin and myosin
17
Q
actin myofilament is?
A
Thin
18
Q
Myosin filament is
A
thick, Has heads that attach to actin
19
Q
• Sarcolemma
A
Cell membrane of muscle fiber
20
Q
sarcoplasm
A
Cytoplasm of muscle fiber
21
Q
• Sarcomeres
A
Units that connect end-to-end, to make up myofibrils
22
Q
• Sarcoplasmic reticulum (SR):
A
Endoplasmic reticulum of muscle; stores calcium
23
Q
what does the motor neuron get?
A
a stimulus from the brain and directs this signal to the muscle cell
24
Q
what is released at the neuro muscular junction (space between the muscle cell and neuron)
A
the neurotransmitter, ACh (acetylcholine), is released
25
ACh effects cause
calcium channels to open up
26
calcium binds to
troponin
27
calcium
is key
28
• Calcium binds to troponin (the lock on actin) and releases the
troponin and tropomyosin (“bike chain on actin”) to expose the actin for myosin to attach
29
• ATP binds to the myosin head which causes
the myosin to cock back and the actin slides across
30
when myosin cocks back and actin slides past, what is this called
The power stroke.
31
what does the power stroke do?
SHORTENS THE MYFIBRIL AND CAUSES THE MUSCLE FIBERS TO SHORTEN AND THEN THE FASICLES -muscle contraction
32
when the neuron impulse stops, what happens?
The ACh stops producing
33
when the ACh stops producing, what happens?
Calcium stops releasing
34
when calcium stops releasing what happens
troponin and tropomyosin to “lock up” the actin myofilament again until the next contraction
35
• For a contraction needing to last for a longer period of time, the body produces
creatine phosphate
36
what is creatine phosphate used for
to store energy to use when not enough ATP is present.
37
• Myoglobin
protein used to specifically carry oxygen to muscles
38
what are the two types of smooth muscle
Multi unit and visceral
39
Multi unit smooth muscle cells are
less organized
40
multi unit smooth muscle functions as
separate units
41
multi unit fibers function
independently
42
multi unit is stimulated by
neurons and hormones
43
multi unit examples
Iris of the eye, walls of the blood vessel
44
visceral smooth muscles cells
move as a unit; single unit smooth
45
visceral muscles have sheets of spindle shaped muscle fiber
46
visceral fibers are held together by?
Gap junctions
47
visceral smooth muscle exhibit
rhythmicity
48
visceral smooth muscle conduct
peristalsis
49
what is the most common type of smoot muscle
visceral smooth muscle
50
where is visceral smooth muscle located
the walls of mostly hollow organs
51
Peristalsis
involuntary muscle contraction that rhythmically push contents through different organs or organ to organ
52
muscle origin
describes the attachment of a muscle on the more stable bone.
53
muscle insertion
is the attachment of a muscle on the more moveable bone.
54
The muscle that is contracting
agonist
55
the muscle that is stretching/relaxing and lengthening
antagonist
56
the nervous system has 2 parts called?
central nervous system, peripheral nervous system
57
PNS has 2 types
somatic and autonomic
58
somatic (voluntary)
relays info to and from skin and skeletal muscles
59
autonomic (innvoluntary)
relays info to internal organs
60
the autonomic has two types called
sympathetic and parasympathetic
61
Sympathetic nervous system
controls organs in times of stress
62
parasympathetic
controls organs when body is at rest
63
central nervous is involved with the
brain and spinal cord
64
peripheral nervous system
cranial nerves and spinal nerves
65
nerve
A cable-like bundles of axons that make up the peripheral nervous system.
66
Autonomic Nervous System (ANS):
Controls all involuntary activities not under conscious control like breathing (broken down into sympathetic and parasympathetic)
67
Somatic Nervous System (SNS)
Controls voluntary activities that are under conscious control.
68
what are the two types of cells that make up nervous tissue
neurons and neuroglia
69
Neuron
: The structural and functional units of the nervous system.
70
A neuron consist of four parts
cell body, dendrite, axon, myelin sheath
71
There are gaps on the myelin sheath that allow the electrical signal to
move along the axon quickly.
72
Nerve Impulse
Electrical signal transmitted by a neuron
73
Synapse
Where an axon terminal meets another neuron cell
74
Neurotransmitter
Chemical that transmits signals across synapses from the axon terminal of one neuron to the dendrites of the next neuron.
75
types of neurons
sensory, motor and iterneurons
76
sensory neuron
Carry impulses from sensory organs to the brain.
77
motor neurons
Carry impulses from the brain to certain muscles and glands, and signals for them to carry out actions.
78
interneurons
Carry impulses between sensory and motor neurons.
79
neuroglia
Support neurons and produce myelin
80
what type of cells does the neuroglia have
microglial cells, oligodendrocytes, astrocytes, and ependymal cells.
81
what protects the cell bodies in the peripheral nervous system
Schwann cells form myelin sheaths, and satellite cells protect cell bodies.
82
Schwann cells and Oligodendrocytes
a type of glial cells that supply myelin to the axons
83
Ependymal cells
produce the cerebrospinal fluid (CSF)
84
Astrocytes
maintain the blood brain barrier and are the most numerous
85
• Nerve impulses occur when
there is a change in electrical charge across the membrane of a neuron.
86
• All cells have an electrical charge based on
concentration on ions inside and outside of the cell.
87
• Sodium ions (Na+) and potassium ions (K+) are important in transmitting
nerve impulses.
88
• When a neuron is in its resting state (not transmitting any nerve impulses), it has a negative charge at around
70 milliVolts (its resting potential).
89
The sodium-potassium pump maintains a difference in charge across the cell membrane–the inside of the
neuron is negatively charged compared to outside the cell.
90
what happens during an action potential
the charge of a neuron suddenly reverses from negative to positive.
91
o Fisrt step of action potential: Dendrites receive a stimulus
usually from the previous neuron
92
second step of action potential: If the stimulus is strong enough, the first sodium channel opens up, allowing Na+ ions to flow into
the cell along the concentration gradient.
93
Third step of action potential: This causes other sodium channels to open up one by one, and the nerve impulse is
transmitted down the neuron like a wave.
94
fourth step of action potential: To prevent the signal from going backwards,
each sodium channel closes after the next one opens.
95
fifth step of action potential: The neuron becomes positively charged, which signals the
next neuron to open its sodium channels and pass on the signal.
96
Neurons communicate with each other
at synapses
97
types of synapses
chemical synapses, electrical synapses
98
chemical synapses
: chemical signaling molecules are used as messengers
99
electrical synapses
: ions are messengers
100
what happens once a signal reaches the axon terminal
a neurotransmitter is released across the synapse
101
The neurotransmitter binds to receptors on the
next neuron and passes on the signal
102
The neurotransmitter binds to receptors on the
next neuron and passes on the signal
103
steps of a reflex arc
• Signal is received
• Sensory neuron is activated
• Interneuron passes the info to a motor neuron
• Motor neuron is activated and causes a reaction
• The signal never goes through the brain–it’s just directly executed; that’s what makes reflexes so fast
