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Human Physiology FSU BASS exam
2
1. Motor unit: A motor neuron and all of the muscle fibers it innervates
2. cycle of Actin-Myosin contraction: 1 resting fiber, myosin head is: not at- tached to actin
3. cycle of Actin-Myosin contraction: 2 myosin head binds to and forms
cross bridge to actin: actin
4. cycle of Actin-Myosin contraction: 3 is released from myosin head, causing
conformational change in myosin: Pi
5. cycle of Actin-Myosin contraction: 4 causes filaments to slide
is released: ADP
6. cycle of Actin-Myosin contraction:5 a new binds to myosin head allowing it to release from
: ATP, actin
7. cycle of Actin-Myosin contraction:6 ATP is and phosphate binds to
myosin, causing energized myosin head to return to its original orientatiom: - hydrolyzed
8. Role of Ca++ in muscle contraction: attachment of Ca++ to causes
movement of the - complex which exposes binding site on the actin:
Troponin, Troponin-tropomyosin
9. Role of Ca++ in muscle contraction: once the binding site on actin is exposed myosin
can then attach to actin and undergo a power stroke: cross-bridge
10. Rigor mortis: Occurs after death due to lack of ATP, causing myosin heads to remain bound
to actin, resulting in stiffened muscles.
11. rigor mortis immediately after death: no circulation/breathing little ATP
production
12. rigor mortis 4-12 hrs after death: sarcoplasmic reticulum allows Ca++ to leak muscle
contraction
no energy for relaxation
13. rigor mortis 48-72 hrs after death: lactic acid build up drop in pH
causes damages
muscle fibers relax as filament degrade
14. Neuromuscular junction: motor neurons release onto neuromus-
cular junctions: acetylcholine
15. Neuromuscular junction: acetylcholine binds to receptors (lig-
and-gated Na+ channels): nicotinic
16. Neuromuscular junction: receptors let Na+ into cell causing
across entire muscle fiber and down through : Nico-
tinic
muscle action potential transverse
tubes (t-tubes)
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9
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Human Physiology FSU BASS exam
2
17. Neuromuscular junction: Action potential causes opening of voltage-gated Ca++ channels,
causing Ca++ release from: sarcoplasmic reticulum
18. Neuromuscular junction: [ ] rise in cytoplasm causes muscle contraction.-
: Ca++
19. Neuromuscular junction: pumps transport Ca++ from cy- toplasm
back into sarcoplasmic reticulum: Ca++ ATPase
20. Neuromuscular junction: degrades ACh; terminates chemical
transmission: Cholinesterase
21. Muscle contraction summary:
release of from neurons synaptic terminal. the enters into
the synaptic cleft (space between nerve and muscle)
Acetylcholine causes muscle fibers to
Muscle depolarization causes release from the sarcoplasmic reticulum (located
inside the cell)
Released enters the inside of the muscle fiber and "unlocks" the thin filament so it can
interact with the filament
Thick/thin filament are now able to interact and "slide along" each other causing muscle
contraction (uses energy in form of ): acetylcholine,
acetylcholine
depolarize
Ca++
Ca++, thick
ATP
22. Transverse Tubes (T Tubes): connected to sarcolemma, transfers signals deep into the middle
of muscle fiber
23. Sarcoplasmic reticulum: muscle cells smooth ER used to
store Ca++
24. sarcoplasmic reticulum is stimulated to release Ca++ when : action
potential arrives in T-tubes
25. 3 phases of contracting muscle: phase 1 - the time between the
stimulation and beginning of contraction: latent
26. 3 phases of contracting muscle: phase 2 - myofilament (thick/thin) sliding:
contraction
27. 3 phases of contracting muscle: phase 3: end of contraction -
: muscle returns to normal length
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9
Human Physiology FSU BASS exam
2
1. Motor unit: A motor neuron and all of the muscle fibers it innervates
2. cycle of Actin-Myosin contraction: 1 resting fiber, myosin head is: not at- tached to actin
3. cycle of Actin-Myosin contraction: 2 myosin head binds to and forms
cross bridge to actin: actin
4. cycle of Actin-Myosin contraction: 3 is released from myosin head, causing
conformational change in myosin: Pi
5. cycle of Actin-Myosin contraction: 4 causes filaments to slide
is released: ADP
6. cycle of Actin-Myosin contraction:5 a new binds to myosin head allowing it to release from
: ATP, actin
7. cycle of Actin-Myosin contraction:6 ATP is and phosphate binds to
myosin, causing energized myosin head to return to its original orientatiom: - hydrolyzed
8. Role of Ca++ in muscle contraction: attachment of Ca++ to causes
movement of the - complex which exposes binding site on the actin:
Troponin, Troponin-tropomyosin
9. Role of Ca++ in muscle contraction: once the binding site on actin is exposed myosin
can then attach to actin and undergo a power stroke: cross-bridge
10. Rigor mortis: Occurs after death due to lack of ATP, causing myosin heads to remain bound
to actin, resulting in stiffened muscles.
11. rigor mortis immediately after death: no circulation/breathing little ATP
production
12. rigor mortis 4-12 hrs after death: sarcoplasmic reticulum allows Ca++ to leak muscle
contraction
no energy for relaxation
13. rigor mortis 48-72 hrs after death: lactic acid build up drop in pH
causes damages
muscle fibers relax as filament degrade
14. Neuromuscular junction: motor neurons release onto neuromus-
cular junctions: acetylcholine
15. Neuromuscular junction: acetylcholine binds to receptors (lig-
and-gated Na+ channels): nicotinic
16. Neuromuscular junction: receptors let Na+ into cell causing
across entire muscle fiber and down through : Nico-
tinic
muscle action potential transverse
tubes (t-tubes)
1/
9
,\
Human Physiology FSU BASS exam
2
17. Neuromuscular junction: Action potential causes opening of voltage-gated Ca++ channels,
causing Ca++ release from: sarcoplasmic reticulum
18. Neuromuscular junction: [ ] rise in cytoplasm causes muscle contraction.-
: Ca++
19. Neuromuscular junction: pumps transport Ca++ from cy- toplasm
back into sarcoplasmic reticulum: Ca++ ATPase
20. Neuromuscular junction: degrades ACh; terminates chemical
transmission: Cholinesterase
21. Muscle contraction summary:
release of from neurons synaptic terminal. the enters into
the synaptic cleft (space between nerve and muscle)
Acetylcholine causes muscle fibers to
Muscle depolarization causes release from the sarcoplasmic reticulum (located
inside the cell)
Released enters the inside of the muscle fiber and "unlocks" the thin filament so it can
interact with the filament
Thick/thin filament are now able to interact and "slide along" each other causing muscle
contraction (uses energy in form of ): acetylcholine,
acetylcholine
depolarize
Ca++
Ca++, thick
ATP
22. Transverse Tubes (T Tubes): connected to sarcolemma, transfers signals deep into the middle
of muscle fiber
23. Sarcoplasmic reticulum: muscle cells smooth ER used to
store Ca++
24. sarcoplasmic reticulum is stimulated to release Ca++ when : action
potential arrives in T-tubes
25. 3 phases of contracting muscle: phase 1 - the time between the
stimulation and beginning of contraction: latent
26. 3 phases of contracting muscle: phase 2 - myofilament (thick/thin) sliding:
contraction
27. 3 phases of contracting muscle: phase 3: end of contraction -
: muscle returns to normal length
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