ens365 test 3 review
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- Describe the structure of skeletal muscle from the muscle belly down to actin and myosin filaments
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1. belly
2. fasiculi
3. fiber - sarcomere
4. fibrils
5. myofibrils
a. actin
b. myosin - Endomysium
- surrounds individual muscle fibers
- Perimysium
- surrounds fasiculi
- Epimysium
- surrounds muscle belly
- sharpy's fibers
- connects tendon to periosteum
- fascia
-
sheet of CT to provide support & stability
ex. IT band - A motor unit consists of a motor nerve and _________.
- the motor end plate of the muscle fibers it innervates
- Define the path a stimulus takes from the motor nerve to muscle contraction
- motor nerve depolarization -> Ach released -> sarcolema depolarization -> t-tubules -> Ca++ released -> cross-bridges formed
- The strength and type of muscle contraction is dependent on
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a. # of fibers recruited
b. size of the axon
c. freq. of firing - Example of a parallel muscle
- gracilis
- example of a unipennate muscle
- flexor pollicus longus
- example of of a bipennate muscle
- gastroc
- example of a multipennate muscle
- deltoid
- Advantages and Disadvantages of isometric exercise
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+ use during immobilization
+ work muscle without jt movement
+ inexpensive/convenient
- only strengthening at a specific angle - advantages and disadvantages of isotonic exercise
-
+ strenghtening in full range of motion
+ difficult to cheat
+ substantial strength gains
- injury
- limited by weakest point in ROM - Isokinetic
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+ max effort throughout
+ various speeds
+ functional
+ used in research and diagnosis
- expensive
- requires training
- easy to cheat - Define agonist and antagonist
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agonist - shortening of the prime mover
antagonist - opposing muscle group that is relaxing - Why tension is less at shortened or elongated muscle lengths
- less cross bridge potential
- With regards to the velocity or speed of contraction, as speed increases, force _______.
- decreases
- What does passive tension in the muscle represent?
- stretch/elongation
- 8 factors affecting muscle function
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1. type of joint/location
2. # of joints crossed
3. passive insufficiency
4. sensory receptors
5. fiber type
6. shape
7. innervention ration
8. muscle temp - a _______ injury involves repetitive trauma that does not allow for complete repair
- chronic/overuse
- Delayed Onset Muscle Soreness is caused primarily by _____ exercise and peaks _____ days post activity.
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a. eccentric
b. 2-4 - Describe the effects of immobilization on muscle tissue
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1. decrease in sarcomere #
2. decrease in sarcomere length
3. increase and thickening of periomysium and endomysium
4. muscle atrophy
5. increase in collagen/CT ratio - differentiate between a muscle spasm and a trigger point
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a. muscle spasm occurs by over-firing of the muscle spindle
b. trigger point is a microspasm in the sarcomere - gray matter
- accumulation of cell bodies
- white matter
- accumulation of axons
- anterior horn
- efferent motor
- posterior horn
- periphereal afferent
- interneuron
- found in spinal cord, integration "minibrain"
- substantia gelatinosa
- gray matter around the central canal
- medulla oblongata
- regulates vitals
- pons
- respiration
- midbrain
- reflex for eyes, head movements, responds to stimuli
- cerebellum
- voluntary skeletal muscle movement
- hypothalamus
- PNS, SNS, hormones, water balance, temp regulation, appetite
- thalamus
- integration center for all sensory info
- cerebrum
- intellegence, cognition, emotion
- frontal lobe
- motor function
- parietal lobe
- taste and cutaneus sensation
- occipital lobe
- vision
- temporal lobe
- hearing and smell
- corpus callosum
- where 2 hemispheres join
-
specify the number of spinal nerve pairs for each of the following areas:
1. cervical
2. lumbar
4. sacral
5. coccygeal -
1. 8
2. 12
3. 5
4. 5
6. 1 - Compare and contrast the function of the sympathetic and parasympathetic nervous systems
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1. SNS - fight or flight
2. PNS - rest and digest - what is the difference between nerve cells and glial cells?
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a. nerve cells - transmitt, conduct stimulus
b. glial cells - provide nutrients and support - define the mechanism of saltatory conduction and its benefit
- allows for faster transmission by insulating nerves with myelin
- which type of efferent motor nerve is associated with the extrafusal muscle fibers? muscle spindle's intrafusal muscle fibers?
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1. extrafusal - alpha efferent
2. muscle spindle's intrafusal - gamma efferent -
Origin of impuls from the follwing afferent sensory nerves:
a. Ia (a-alpha)
b. Ib (a-alpha)
c. II (a-beta)
d. III (a-delta)
e. IV (c-fiber) -
a. muscle spindle
b. GTO
c. secondary receptor in muscle spindle (mechanoreceptor)
d. changes in temp in skin
e. nocious stimuli - describe the functions of the muscle spindle and the golgi tendon organ
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a. muscle spindle - senses changes in muscle lenght, tension, and position. reacts: contract or relax - recovery of movement
b. GTO - protective, senses tension in musculotendonus junction - passively inhibits motor nerve - acetylcholine
- reseased at the synapse to stimulate sarcolema and start cross bridge cycle
- catecholamine
- nervous system and cardio - metabolic rate
- endorphin
- endogenus opiate, increases pain threshold, breaks down bradykynin
- enkephalin
- blocks 1st and 2nd order.. "presynaptic" inhibition
- substance p
- in response trauma - trigers pain
- serotonin
- stimulated by descending, stimulates enkephalin neuron
- norepinephrine
- stimulated by descending, inhibits 2nd order, closes gate
- melatonin
- effects sleep/wake cycl, used to adjust to jet lag
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where the impulse is originating and going for:
a. first order neuron
b. second order neuron
c. third order neuron
d. corticospinal tract
e. dorsolateral tract
f. motor nerve -
a. from invironment to spinal cord
b. spinal cord to brain
c. brain to specific section of brain
d. brain to medulla
e. down length of spinal cord to motor nerve
f. out to muscle - A-beta afferent
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a. large - fast transmission
b. mechanoreceptor
c. touch, pressure, vibration - A-delta afferent
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a. small - slower
b. thermoreceptor
c. changes in temp - C Fiber
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a. smallest - slowest
b. nociceptor
c. pain/noxious - ruffini end organs
-
sense stretch
change in joint position
change in fluid pressure - golgi-mazzoni
- senses compression
- meissners corpuscles
- found in skin, sensitive to touch
- pacinian corpuscles
- sense high freq. vibration, acceleration and high velocity changes
- pathway the brachial plexus takes from the neck region down to the arm
- neck -> beneith clavica -> through armpit -> terminal branches in arm
- discuss the aspects of nerve healing and the ability of a nerve to re-generate
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- involvement of cell body: can't regenerate
- involvement of axon: regenerate 3-4mm a day - acute pain
- sudden onset, shorter duration, from trauma
- chronic pain
- slow onset, long duration, psych/emotional cycle
- referred pain
- perceived in an area other than injured
- radiculr pain
- radiating pain, follows course of nerve
- which area of the spinal cord is inhibited with all three levels of pain control
- enkephalin - inhibits transmission cell