Autonomic Nervous System and Muscle Physiology Flashcards
(76 cards)
1
Q
what’s the thin/thick filament ?
A
thin = actin
thick = myosin
2
Q
how many steps are there of the neuromuscular junction ?
A
- AP travels down motor neuron, to presynaptic terminal
- activation and opening of the voltage-gated CA channels
- ACh-containing vesicles fuse with the post-synaptic membrane and release ACh
- binding of neurotransmitter to ligand-gated ion channels on muscle
- ACh brain down by acetylcholinesterase
3
Q
the more ACh released =
A
the more that binds
4
Q
what’s the breakdown of the structure of skeletal muscle ?
A
- muscle cell/fiber
- myofibrils
- myofilaments
- thick and thing myofilaments
5
Q
what are muscle fibers made of ?
A
myofibril
6
Q
what are muscle fascicle’s ?
A
When a group of muscle fibers is “bundled” as a unit within the whole muscle
7
Q
what type of muscle is long and cylindrical in length ?
A
skeletal muscle cells
8
Q
are skeletal muscles cells striated or non-strated ?
A
striated
9
Q
what is a myofibril ?
A
organelle composed of bundles of myofilaments
10
Q
what are sarcomeres ?
A
contractile unit of myofibril
11
Q
what does troponin A bind to ?
A
actin
12
Q
what does troponin C bind to ?
A
calcium
13
Q
what does troponin T bind to ?
A
tropomyosin
14
Q
what is troponin ?
A
protein attached to both actin and tropomyosin that holds tropomyosin over myosin binding site on actin
15
Q
once myosin binds to actin, what does this form ?
A
cross bridge
16
Q
what do myosin heads undergo ?
A
power stroke
17
Q
do thin myofilaments change in length ?
A
no
18
Q
do thick myofilaments change in length ?
A
no
19
Q
do sarcomeres change in length ?
A
no
20
Q
what three things happen during a contraction of the sliding filaments theory ?
A
- binding of myosin to actin forms a cross bridge
- myosin head changes shape and a power stroke occurs
- thin myofilaments slide past thick myofilaments - sarcomere shortens
21
Q
what is the autonomic nervous system ?
A
voluntary control of certain movements
22
Q
wha are the three main divisions of the ANS ?
A
- sympathetic nervous system
- parasympathetic nervous system
- eneteric nervus system
23
Q
how is the ANS split ?
A
left and right side
24
Q
which division of the ANS is left side/right side ?
A
left side = SNS
right side = PSNS
25
what is sympathetic nervous system ?
fight or flight
26
what is the parasympathetic nervous system ?
rest and digest
27
what is the primary role of the ANS ?
to maintain homeostasis
28
what does the ANS help regulate ?
- heart rate
- blood pressure
- body temperature
- gastrointestinal and bladder motility
- gland secretions
- regulates blood glucose levels
- sexual function, etc.
29
what do sensory afferent fibers do ?
these receptors send signals back to the CNS
30
what do sensory receptors do ?
monitor internal environment/organs
31
what does the CNS integration center do ?
interprets signals and activates hypothalamus
32
what interprets signals and activates the hypothalmus ?
CNS integration center
33
what is the master controller of ANS ?
hypothalmus
34
what are the two branches output go the ANS ?
SNS and PSNS
35
what target organs does the ANS exert its actions on ?
- smooth muscle in blood vessels, digestive tract, etc.
- specialized cardiac tissue and cardiac muscles
- glands
36
define efferent vs afferent ?
afferent arrives and efferent exits
37
what does efferent mean ?
info travels from the CNS to organs (target organs)
38
what does afferent mean ?
to bring info
39
what are some general characteristics of peripheral efferent nerves ?
- preganglionic neurons
- ganglion
- postganglionic neurons
- target tissue/oragn
40
what's the major difference between somatic motor system and autonomic motor system ?
somatic = no ganglion
autonomic = ganglion (postganglionic fiber branches off into three)
41
what are the three branches the postganglionic fiber of the autonomic motor system break off of ?
smooth muscle cell, gland cells, cardiac muscle cell
42
what do both the PSNS and SNS contain ?
- preganglion neurons
- ganglion
- postganglionic neurons
-target tissue / organ
43
differences between PSNS and SNS ?
- location of ganglion
- length of preganglionic neuron and postganglionic neuron
- types of neurotransmitters released
44
what does the adrenal sympathetic pathway release ?
epinephrine (with a little norepinephrine)
45
what happens in the upper body during fight or flight ?
- more light entering eye
- thick mucous
- increase blood output by the heart
- move air in and out of lungs easily
46
what happens to digestion during fight or flight ?
shut down digestion
47
what does the adrenal glands, kidney and bladder do during fight or flight ?
- releases epinephrine
- holds in urine
48
what does the upper body do during rest and digest ?
- less light entering eye
- watery saliva and enzymes for digestion
- decreases blood output from heart
49
what happens to digestion during rest and relax ?
increase digestion and absorption of nutrients
50
what does the adrenal glands, kidney and bladder do during rest and relax ?
- no PSNS innervation
- contracts bladder
51
what is mediated by the coordination activity of both SNS and PSNS ?
sexual responses (sexual activity)
52
what is excitation-contracting coupling ?
where and AP on the sarcolemma of the muscle cells lead to the release of Ca from the sarcoplasmic reticulum, leading to cross bridge activity and muscle contraction
53
in the steps of the NMJ, what serves as a signal to initiate future steps ?
activation and opening of the voyage-gated Ca channels
54
in the NMJ where does action potential travel down ?
t-tubules
55
how many steps of the actin-myosin-ATP cycle are there ?
5
56
what happens in step one of the actin-myosin-ATP cycle ?
- ATP has just attached to myosin
- myosin is not attached to actin
57
what happens in step two of the actin-myosin-ATP cycle ?
- ATP is hydrolyzed to ADP and Pi
- energy is transferred to myosin head
- myosin now has high affinity for actin
- myosin head is repositioned
58
what happens in step three of the actin-myosin-ATP cycle ?
- AP causes Ca release from SR
- Ca beins to troponin
- troponin pulls tropomyosin off myosin binding sites
- myosin attaches to actin forming cross bridge
(no powerstroke yet)
59
what happens in between step three and four of the actin-myosin-ATP cycle ?
- Pi is released
- powerstroke is triggered
- muscle contraction occurs (sliding filament)
60
what happens in step four of the actin-myosin-ATP cycle ?
- ADP is released
- cross bridges still formed
61
what happens in step five of the actin-myosin-ATP cycle ?
- new molecule of ATP attaches to myosin
- crossbridge breaks
- cycle repeats
62
how long does the actin-myosin-ATP cycle go ?
cycle keeps going as long as there is ATP and Ca
63
during the NMJ where is calcium released from ?
the sarcoplasmic reticulum
64
what is rigor mortis ?
the stiffening of muscles after dead
65
when does rigor mortis usually occur ?
3 to 4 hours after death
66
when does rigor mortis reach a maximum ?
at 12 hours
67
what causes rigor mortis ?
- no oxygen (no ATP)
- no ATP = actin and myosin cant dissociate (no calcium, etc.)
68
what is a motor unit ?
one motor neuron + muscle fibers it innervates
69
what is a muscle twitch ?
muscle contraction in response to one action attention on the motor neuron
70
what is motor unit recruitment ?
as more motor units are recruited, more muscle fibers contract (higher contractile force)
71
what are some main features of skeletal muscle ?
- striated
- voluntary
- multi nucleated
- usually attached to skeleton
72
what are some main features of smooth muscles ?
- non-striated
- uninucleated
- involuntary
- usually covering wall of internal organs
73
what is the arrangement of smooth muscle ?
has two layers ; longitudinal and circular layer
74
which muscle type has cavelae instead of SR ?
smooth muscles
75
what are caveoli/caveolae ?
- indentations in plasma membrane
- in close proximity to SR
- concentrate calcium from ECF
76
what are the six steps of excitation contraction coupling in smooth muscle ?
1. Ca most comes from ECF through a CaVTG
2. Ca binds to calmodulin
3. myosin inactive
4. calmodulin activated (myosin is active)
5. crossbridge formation and power stroke
6. phosphorylase remove phosphate from myosin heads when Ca levels fall
