Ch 11-13 Flashcards
(129 cards)
1
Q
What are the three layers of connective tissue surrounding muscle and muscle fibers?
A
Epimysium=surrounds entire muscle, separates it from other tissue & sonnets to deep fascia
Perimysium=divides muscle into compartments called fascicles (bundles)
Endomysium=surrounds individual muscle fibers
2
Q
What are the functions of muscle?
A
movement (contraction pulls bones for movement), maintains posture/body position
supports soft tissue, holds in place as well as protects
guards openings, voluntary control of openings
maintains body temp
store nutrient reserves
3
Q
How is muscle attached to bone?
A
Directly=muscle to bone (rare)
Tendons=bundles of the ends of epi, peri & endo come together
aponeurosis=broad sheet attachment
4
Q
What makes up the anatomy of a muscle fiber?
A
sarcolemma=cell membrane around muscle fiber, maintains a transmembrane potential, sarcoplasm=cytoplasm, transverse tubules=extends into sarcoplasm, filled with ECF, electrical impulses conduct into cell, myofibrils=ea. fiber contains 1000s, contains protein filaments (myofilaments), sarcoplasmic reticulum=wraps around each myofibril, is connected to t-tubules, contains lots of Ca
5
Q
What is a sarcomere?
A
The smallest functional unit of muscle fiber. 10,000/myofibril.
thick filaments=myosin
thin filaments=actin
proteins stable and regulate filaments
6
Q
How are sarcomeres organized?
A
A band=(dArk) center of sarcomeres, length of thick filament
M Line=center point of thick filament
H Zone=area of thick filament with no thin filament
Zone of overlap=area where thin & thick filaments overlap (darkest of dark)
I Band=(lIght) thin filaments only
Z lines=mark boundary b/t adjacent sarcomeres
Titin=elastic protein, keeps thin & thick aligned
7
Q
What is tropomyosin?
A
Acts as the “door,” the strand that covers G actin to prevent binding with myosin
8
Q
What is troponin?
A
Acts as the “lock,” globular protein on tropomyosin strand, binds with Ca to unlock active sites
9
Q
What is myosin and its structure?
A
The thick filament that binds with actin during muscle contraction. Looks like a “golf club.” has a head that projects toward thin filament (actin) with a tail bound with other myosin molecules in thick filament, points toward M-line, a hinge that lets head pivot at its base=act of contraction.
10
Q
What is cross bridges?
A
the connection made when myosin head connects with G actin active sites
11
Q
What is the function of calcium in muscle contraction?
A
Acts as the “key.” binds to receptor on troponin molecule, troponin-tropomyosin complex changes, exposes active site of G actin
12
Q
What is the sliding filament theory?
A
thin filaments are sliding toward center of sarcomere (pulled by thick filaments
13
Q
Describe the sliding filament theory.
A
H-zones & I-bands get smaller (shorter)->Zones of overlap get larger->Z-lines move closer together->Width of A-band remains constant
14
Q
Where does the neuron meet muscle fiber?
A
neuromuscular junction
15
Q
what is the branch ends of the axon at the neuromuscular junction?
A
synaptic terminal
16
Q
What are the membranes that send and receive ACh (acetylcholine)?
A
motor end plates
17
Q
what is the sudden change in the transmembrane potential?
A
action potential (increase in sodium ions in sarcolemma)
18
Q
What is ACh?
A
acetylcholine, a neurotransmitter, changes permeability & properties of another cell’s membrane. (causes sodium-ion rush into sarcoplasm)
19
Q
What is the process of muscle stimulation?
A
- action potential arrives
- release of ACh
- ACh binds at motor end plate
- action potential in sarcolemma
- repolarize
20
Q
What is the process of the contraction phase?
A
- expose active site
- Form cross-bridges
- myosin heads pivot
- cross-bridge releases
- reactivation of myosin
21
Q
What is the relaxation phase?
A
end of stimulation at neuromuscular junction, runs out of Ca in sarcoplasm, runs out of energy (ATP) to power contraction -> contraction stops, muscle returns to initial length passively
22
Q
What is rigor mortis?
A
a fixed muscular contraction after death, lasts 15-25 hours, no ATP to release cross-bridges
23
Q
What are the phases of twitches?
A
Latent Period=action potential moves thru sarcolemma causing Ca2+ release
Contraction Phase=calcium ions bind, tension builds to peak
Relaxation Phase=Ca2+ levels fall, active sites covered, tension falls to resting levels
24
Q
What is treppe?
A
repeated stimulations IMMEDIATELY AFTER relaxation phase
25
What is wave summation?
repeated stimulations BEFORE THE END of relaxation phase, causes increasing tension of summation of twitches
26
What is incomplete and complete tetanus?
Incomplete=if rapid stimulation continues & muscle is not allowed to relax, twitches reach maximum level of tension
Complete=if stimulation if high enough, muscle never begins to relax, and is in continuous contraction (not allowed to relax completely)
27
What are motor units?
they contain hundreds of muscle fibers, contract at the same time and controlled by a single motor neuron
28
What is recruitment R/T muscles?
in a whole muscle or group of muscles, smooth motion & increasing tension is produced by slowly increasing size or number of motor units stimulated
29
What is the tension and firmness of a muscle at rest called?
muscle tone
30
What are isotonic contractions?
Skeletal muscle changes length, resulting in motion
Concentric=muscle tension>resistance, muscle shortens
Eccentric=muscle tension
31
What are isometric contractions?
skeletal muscle develops tension, but is prevented from changing length (pushing on door frame, FAH)
32
How is ATP generated?
aerobic=metabolism in the mitochondria WITH OXYGEN
| Anaerobic=glycolysis in the cytoplasm WITHOUT OXYGEN
33
What happens at peak exertion? And muscle fatigue?
muscles lack oxygen to support mitochondria, muscles rely on glycolysis for ATP, pyruvic acid builds ups, is converted to lactic acid.
when muscles can no longer perform a required activity, they are fatigued due to lactic acid build-up
34
What happens during the recovery period?
the time required after exertions for muscles return to normal, oxygen becomes available, mitochondrial activity resumes.
35
What is the Cori Cycle?
the removal & recycling of acetic acid by th liver, back to glucose
36
What are the hormones that affect the muscular system?
Growth hormones and testosterone stimulate synthesis & enlargement of skeletal muscles
Thyroid hormones raise the level of metabolism (energy consumption)
Epinephrine increases duration of stimulation & force of contraction
37
What is the difference between white and red fibers?
White=fast, contract very quickly, strong contractions, fatigue quickly, have large diameter, large glycogen reserves, few mitochondria, pale (ex: chicken breast)
Red=slow, are slow to contract, slow to fatigue, have small diameter, more mitochondria, have high oxygen (blood) supply, contain myoglobin (binds oxygen), dark (chicken legs)
38
What are most human muscles made of?
Intermediate fibers=pink, mid-sized, have low myoglobin, have more capillaries than fast fiber, slower to fatigue, mixed fibers=pink
39
What is hypertrophy and atrophy?
Hypertrophy=muscle growth from heavy training
| Atrophy=lack of muscle activity reduces muscle strength, mass, tone
40
What is the origin, insertion and belly of a muscle?
Origin=1 FIXED point of attachment
Insertion=1 MOVING point of attachment
Belly=central, body portion of muscle
41
What is the action and innervation?
action=movements produced by muscle contraction
| innervation=distribution of nerves to muscle or muscle group
42
What are the agonist and antagonist?
agonist=prime mover, produces a particular movement
| antagonist=opposes movement of particular agonist
43
What is a smaller muscle that assists a larger agonist by starting motion or by stabilizing origin of agonist?
Synergist
44
What are fixators (r/t synergists)?
synergist that assists by preventing movement at another joint or by stabilizing the origin of a muscle
45
What are parallel muscles?
fibers parallel to the long axis o muscle (biceps)
46
What are convergent muscles?
broad area converges on attachment site, fibers pull in different directions, depending on stimulation (pectoralis)
47
What are pennate muscles?
forms an angle with the tendon
unipennate=fibers on one side of tendon
bipennate=fibers on both sides of tendon
multipennate=tendon branches within muscle
48
What are circular muscles?
sphincter=guards entrances of body (mouth, eye, rectum)
49
How is each bone a lever?
mechanically, each bone is a lever
joint=fulcrum
muscles=applied force
applied force required to overcome resistance
50
What are the classes of levers?
First=see-saw, force and resistance are balanced
Second=wheelbarrow, small force moves a large weight
Third=MOST COMMON in body, greater force moves smaller resistance, maximizes speed & distance traveled..
51
What is the CNS and PNS?
CNS=Central Nervous System, consists of spinal cord, brain. Processes, coordinates sensory data and motor commands
PNS= Peripheral Nervous System, nervous tissue outside of CNS, (eyes, ears, special senses)
52
What are the different type of nerves in the PNS?
nerves=nerves of the body, beside brain & spinal cord
cranial nerves=CN I-XII, connects directly to brain
Spinal nerves=nerves that attach to the spinal cord
53
What are the divisions of the PNS?
Afferent division=brings sensory info to CNS, (receptors=sensory structures that detect change or stimuli)
Efferent division= carries out motor command from CNS (effector=target organs that respond by doing something)
54
What is the somatic nervous system?
controls skeletal muscle contractions & reflexes
55
What is the autonomic nervous system?
controls automatic regulation of cardiac & smooth muscle (visceral) and glandular secretions.
Sympathetic division=has a stimulating effect (fight or flight)
parasympathetic division=relaxing effect
56
What is the anatomy of a neuron?
Cell body=contains nucleus, centrally located
dendrites=receives info
axon=long cytoplasmic process, carries action potential (electric impulse)
synapse=specialized area where neuron communicates with another cell
57
What are the type of synapses, the chemical released for communication between cells, and the structures that release and receive the chemical?
Neuromuscular junction=synapse b/t neuron & muscle cell
Neuroglandular junction=synapse b/t neuron & gland cell
Neurotransmitter (action potentials)=chemical
presynaptic membrane=area of synapse that releases neurotransmitter
postsynaptic membrane=area of synaptic terminal that receives neurotransmitter
58
What are the functions of sensory neurons (afferent)?
Delivers info from receptors to CNS, cell bodies located in a ganglion
somatic=monitors outside world & body position
visceral=monitors internal conditions & organ systems
interoceptors=monitors digestive, respiratory, cardio, urinary & reproductive, taste, deep pressure & pain
exteroceptors=monitors outside environment, touch, temp smell, & hearing
propiocepters=monitors position & movement of muscles & joints
59
What are the functions of motor neurons (efferent)?
Carries instructions from CNS to peripheral effectors
somatic=innervates skeletal muscles
visceral=innervates smooth & cardiac muscles, glands (uses pre & post ganglionic fibers)
60
What are interneurons?
located inside spinal cord & brain, distributes sensory & motor info, involved w/ memory & learning
61
What is considered nerve glue?
Neuroglia & it makes up 1/2 of nervous system volume, cells that support neurons
62
What are ependymal cells?
neuroglia that secrete, monitor & circulate CSF=cerebrospinal fluid, surrounds brain & spinal cord, provides protective cushion & material transport
63
What are the functions of astrocytes?
large & numerous neuroglia, "maintenance"
Maintain blood-brain barrier, separates blood from CNS interstitial fluid
CNS framework=cytoskeleton provides structural framework for brain & spinal cord
repairs damaged neural tissue, can make structural repairs
64
What are the functions of oligodendrocytes (neuroglia)?
forms membranous wrapping called myelin (myelination= ^speed of action potentials)
white matter=appears white due to myelinated axons
nodes=area b/t internodes (not myelinated)
intermode=large area of axon that is covered in myelin
gray matter=appears gray due to cell bodies, dendrites & un-myelinated axons
65
What is microglia (neuroglia)?
engulfs cellular debris, waste & pathogens
66
What are satellite cells and Schwann cells?
satellite=surrounded cell bodies in ganglia, regulates environment, "builders"
Schwann=myelinates PNS axons "electricians," neurolemma=myelin sheath in PNS, ganglia=cell bodies found in PNS
67
What is the process of electrical signals?
Resting potential -> (stimulus) graded potential -> (produces) action potential -> synaptic activity -> information processed
68
What are transmembrane changes and how does it happen?
TC=membrane channels control the movement of ions
passive channels=are always open, but permeability can vary
active channels=open and close in response to stimuli. chemically regulated=bind with specific chemicals to open or close. voltage-regulated=changes in transmembrane potential to open or close. mechanically regulated=physical distortion of membrane to open or close (touch, pressure, vibration)
69
What is graded potential?
changes in transmembrane potential that cannot spread far from site of stimulation
70
What are depolarization, repolarization, hyper polarization?
depolarization=any shift from the resting potential toward zero (sodium rushes in)
repolarization=restoring the normal resting potential after depolarization
hyper polarization=loss of positive ions (potassium), increasing negativity of resting potential
71
What is action potential?
propagates membrane changes (chain reaction across surface of membrane -> down axon)
72
What are the steps for generation?
1. depolarization in threshold, membrane reaches threshold
2. activation of sodium channels, rapid depolarization, Na+ rushes in
3. activation of potassium channels, repolarization
4. return to normal, action potential over
73
What are two types of propagation of action potential?
continuous=slower, action potential spreads across membrane in small steps
saltatory=myelinated neurons, action potential leaps from node to node, much faster
74
How is propagation speed determined?
by axon diameter & myelination, large diameter=less resistance
Type A Fibers=large diameter, myelinated, fastest (sensory, muscle)
Type B Fibers=small diameter, myelinated
Type C Fibers=very small diameter, unmyelinated (visceral, pain)
75
What are cholinergic synapses?
synapses that release ACh:
all neuromuscular junctions with skeletal muscle fibers
many synapses in CNS
all neuron-to-neuron synapses in PNS
all neuromuscular & neuroglandular junctions of ANS, parasympathetic division
76
What are three main types of neurotransmitters?
norepinephrine=released by adrenergic synapses, excitatory & depolarizing effect, found in brain & portions of ANS
Dopamine=CNS neurotransmitter, may be excitatory or inhibitory, involved in Parkinson'r disease, cocaine use
Serotonin=CNS neurotransmitter, affects attention & emotional states
GABA=gamma amino butyric acid, inhibitory effect, functions in CNS, not well understood
77
What are neuromodulators?
Other chemicals released by synaptic knobs similar in function to neurotransmitters (endorphins, endomorphins
78
What is postsynaptic potentials?
grade potentials in postsynaptic cell in response to neurotransmitter
79
What are EPSPs and IPSPs?
EPSP=Excitatory Postsynaptic Potential, graded depolarization, send signal
IPSP=Inhibitory Postsynaptic Potential, graded hyperpolarization, inhibit signal
80
What is summation?
triggers EPSP.
Temporal summation=multiple times, rapid repeated stimuli
Spatial Summation=multiple locations, many stimuli at once
81
What is facilitation?
a neuron becomes facilitated as EPSPs accumulate raising transmembrane potential closer to threshold until a small stimulus can trigger action potential
82
What is presynaptic inhibition and facilitation?
inihibition=action of axoaxonal synapse at a synaptic knob that decreases the neurotransmitter released by presynaptic membrane
facilitation=action of an axoaxonal synapse at a synaptic knob that increases the neurotransmitter released by presynaptic membrane
83
What is Wallerian Degeneration?
axon distal to injury degenerates
84
What are Schwann cells?
form path for new growth, wrap axon in myelin
85
What limits CNS regeneration & repair?
the chemical released by astrocytes that block growth & produce scar tissue
86
What and where are the posterior median sulcus and anterior median fissure?
posterior median sulcus=groove in the center of spinal cord on posterior side
anterior median fissure=deeper groove on anterior side
87
What is the thin, conical spinal cord below the lumbar enlargement?
conus medullaris
88
What is the thin thread of fibrous tissue at the end of conus medullaris that attaches to coccygeal ligament?
filum terminale
89
What are the nerve roots extending below medullaris?
cauda equina
90
How many spinal cord segments are there and how are they organized?
There are 31 spinal cord segments, based on vertebrae, where spinal nerves originate. Cervical nerves are named for inferior vertebra, al others named for superior vertebra
91
What are the dorsal root and the dorsal root ganglia?
root=contains axons of sensory neurons
| ganglia=contain cell bodies of sensory neurons
92
What does the ventral root contain?
axons of motor neurons
93
What are the meninges?
cranial meninges=membrane covering the brain
spinal meninges=membrane covering starting at foramen magnum
meningitis=viral or bacterial infection of meninges
94
What are makes up the meninges?
dura mater=tough fibrous outer layer
epidural space=between dura mater & walls of vertebral canal, epidural injection site
arachnoid mater=web-like layer, middle meningeal layer
subarachnoid space=area underneath arachnoid mater, filled with CSF=shock absorber, medium for exchange
pia mater=innermost layer, binds to neural tissue
95
What are denticulate ligaments?
anchors spinal cord, prevents lateral movement
96
What is gray matter?
"revolving door" - cell bodies of neurons, unmyelinated axons, neuroglia ->around central canal
97
What do sensory and motor nuclei do?
sensory nuclei=receives & relays sensory intro from peripheral receptors
motor nuclei=issue motor commands to peripheral effectors
98
What nuclei are found in the posterior gray horn, anterior gray horn, and lateral gray horn?
posterior gray horn=contain somatic & visceral sensory nuclei
anterior gray horn=contain somatic motor nuclei
lateral gray horn=(thoracic & lumbar only) visceral motor nuclei
99
What are the anterior & posterior gray commissures?
crosses over from one side of the cord to the other
100
What is white matter?
"elevator" - surrounds gray mater, contains myelinated & unmyelinated axons
101
Where are the posterior, anterior, and lateral white columns?
posterior white column=lies b/t posterior gray horns
anterior white columns=lies b/t anterior gray horns
lateral white column=lies b/t anterior & posterior gray horns
102
what is the anterior white commissure?
axons cross to the other side of the spinal cord
ascending tracts=carry sensory info to the brain
descending tracts=carry motor commands to the spinal cord
103
What are the spinal nerves?
epineurium/perineurium=fascicles
| endoneurium=axons
104
Where does the white ramus send signals to?
travels to sympathetic ganglion -> sympathetic div. of ANS (visceral motor)/visceral sensory
105
Where does the gray ramus send signals to?
innervates smooth muscles and glands of the body wall and limbs, does NOT carry sensory signals
106
What travels through the dorsal and ventral rami?
dorsal ramus=somatic & visceral motor of skin & skeletal muscles of the back, somatic & visceral sensory info
ventral ramus=somatic & visceral motor of ventral & lateral surface, body wall & limbs, somatic & visceral sensory info
107
What are the dermatomes?
specific bilateral region of skin monitored by spinal nerves
108
What dermatomes are monitored by spinal nerves C5, C6, C7 & C8?
C5=lateral part of upper arm
C6="six-shooter" thumb & forefinger
C7=middle finger
C8=ring finger, pinky, medial side of forearm
109
What dermatomes are monitored by T1, L3, L4 & L5?
T1=medial side of upper arm
L3=medial side of quad
L4=medial side of lower leg
L5=top of foot/anterior leg
110
What dermatomes are monitored by S1 & S2?
S1=plantar/sole of foot, back of calf
| S2=hamstring area
111
What are peripheral neuropathies?
regional losses of sensory or motor function, due to trauma or compression, seen a lot with diabetics.
112
How are plexuses organized?
```
Roots
Trunks
Divisions
Cords
Branches
```
113
What are the roots of the Cervical Plexus and one of its major nerves?
C1-C5, phrenic nerve (controls diaphragm)
114
What are the spinal nerves of the brachial plexus and it's major peripheral nerves?
C5-T1, located in the pectoral girdle & upper limbs
Includes musculocutaneous nerve, axillary nerve, ulnar nerve, median nerve and radial nerve (MUMAR=musculocutaneous, ulnar, median, axillary, radial)
115
What are the spinal nerves of the lumbar plexus and its major peripheral nerves?
T12-TL4
| Femoral, Obturator, Genitofemoral
116
What are the spinal nerves of the sacral plexus and its major peripheral nerves?
L4-S4
Sciatic nerve->tibial & fibular nerves (splits below knee)
Gluteals
Pudendal (genitals)
117
What are neuronal pools?
functional groups of interconnected neurons (interneurons)
118
What is divergence and convergence in the spinal cord?
divergence=spreads stimulation to many neurons or neuronal pools in CNS (sensory info entering CNS)
convergence=brings input from many sources to a single neuron, many neurons can have the same effect (diaphragm)
119
What is serial and parallel processing?
serial=moves info in single line (step by step, ex: pain relay)
parallel=moves same info along several pathways (ex: many responses to one stimuli)
120
What is reverberation?
positive feedback mechanism, functions until inhibited, complicated, ex: maintain consciousness.
121
What are neural reflexes?
rapid, automatic responses to specific stimuli to preserve homeostasis
122
What are the steps of a neural reflex?
1. arrival of stimulus, activation of receptor - physical or chemical changes
2. activation of sensory neuron, graded depolarization
3. information processing by postsynaptic cell, triggered by neurotransmitters
4. activation of motor neuron, action potential
5. response of peripheral effector, triggered by neurotransmitters
123
What are innate and acquired reflexes?
innate=basic neural reflexes formed before birth (blinking, swallowing)
acquired=rapid, automatic learned motor patterns (brake pedal, sports)
124
What are somatic and visceral reflexes?
somatic=involuntary control of muscular system (patellar reflex)
visceral=control systems other than muscular system
125
What are cranial and spinal reflexes?
cranial=occurs in brain
| spinal=occurs in spinal cord
126
What are monosynaptic reflexes?
sensory neuron synapses, directly onto motor neuron
| ->stretch reflex=patellar and postural (neck)
127
What are polysynaptic reflexes?
at least one interneuron b/t sensory neuron & motor neuron
tendon reflex=prevents tearing or breaking of tendons
withdrawal (flexor)=pulling away from pain
reciprocal inhibition=antagonistic muscle must be inhibited
crossed extensor reflexes=straightens other leg to receive body weight
128
How can reflexes be interrupted ?
processing centers in the brain can facilitate or inhibit reflex motor patterns based in spinal cord
129
What is the Babinski sign?
how babies slowly curl their toes when bottom of foot is touched, may indicate CNS damage in adults
