VPHY EXAM 2: MUSCLE PHYSIOLOGY
what controls the skeletal muscles? - ANSWERSsomatic motor system
3 muscle types - ANSWERS- smooth
- cardiac
- skeletal
5 categories of skeletal muscle function - ANSWERS- movement
- support
- posture
- temperature regulation
- communication
the two parts of myofilaments - ANSWERS- myosin
- actin
what gives the skeletal muscle its rod appearance? - ANSWERSmyocyte/muscle cell
what gives the skeletal muscle its striped appearance? - ANSWERSmyofilament parts
motor unit - ANSWERSa single motor neuron and all of the muscle cells (fibers) it innervates
how many muscle cells does a typical motor neuron innervate? - ANSWERS100-1000 muscle cells!
a muscle is comprised of one or many motor unit(s) - ANSWERSmany
are all muscle fibers in the same motor unit the same or different type? - ANSWERSsame type!
, NMJ (neuromuscular junction) - ANSWERSspecialized synapse between the somatic motor neuron's nerve
terminal and the motor end plate of the skeletal muscle cell
what sends the signal in the neuromuscular junction - ANSWERSsomatic (alpha) motor neuron
what recieves the signal in the neuromuscular junction - ANSWERSskeletal muscle cell
E/C coupling - ANSWERS- excitation/contraction coupling
- transformation of the electrical signal in the muscle cell into contraction of sarcomeres
what kind of receptors are on the motor end plate in the neuromuscular junction? - ANSWERSnicotinic
9 steps from motor neuron APs to skeletal muscle contractions - ANSWERS1. ACh binds to skeletal muscle
fiber
2. AP moves into T-tubules
3. sarcoplasmic reticulum releases Ca2+
4. Ca2+ binds troponin; active cross-bridge cycling
5. skeletal muscle contraction
6. acetylcholinesterase degrades ACh
7. Ca2+ pumped into ECF and SR
8. tropomyosin blocks cross-bridge formation
9. skeletal muscle contraction is pervented
the firing of motor neuron's AP leads to - ANSWERScontraction of muscle cell
what causes muscle contraction - ANSWERSthe Ca2+ release from the SR after Muscle APs are sensed in the T-
tubules
parts of the sarcolemma - ANSWERS- t (transverse)-tubules invaginate the myofibrils
- t0tubules are continuous with the sarcolemma
what controls the skeletal muscles? - ANSWERSsomatic motor system
3 muscle types - ANSWERS- smooth
- cardiac
- skeletal
5 categories of skeletal muscle function - ANSWERS- movement
- support
- posture
- temperature regulation
- communication
the two parts of myofilaments - ANSWERS- myosin
- actin
what gives the skeletal muscle its rod appearance? - ANSWERSmyocyte/muscle cell
what gives the skeletal muscle its striped appearance? - ANSWERSmyofilament parts
motor unit - ANSWERSa single motor neuron and all of the muscle cells (fibers) it innervates
how many muscle cells does a typical motor neuron innervate? - ANSWERS100-1000 muscle cells!
a muscle is comprised of one or many motor unit(s) - ANSWERSmany
are all muscle fibers in the same motor unit the same or different type? - ANSWERSsame type!
, NMJ (neuromuscular junction) - ANSWERSspecialized synapse between the somatic motor neuron's nerve
terminal and the motor end plate of the skeletal muscle cell
what sends the signal in the neuromuscular junction - ANSWERSsomatic (alpha) motor neuron
what recieves the signal in the neuromuscular junction - ANSWERSskeletal muscle cell
E/C coupling - ANSWERS- excitation/contraction coupling
- transformation of the electrical signal in the muscle cell into contraction of sarcomeres
what kind of receptors are on the motor end plate in the neuromuscular junction? - ANSWERSnicotinic
9 steps from motor neuron APs to skeletal muscle contractions - ANSWERS1. ACh binds to skeletal muscle
fiber
2. AP moves into T-tubules
3. sarcoplasmic reticulum releases Ca2+
4. Ca2+ binds troponin; active cross-bridge cycling
5. skeletal muscle contraction
6. acetylcholinesterase degrades ACh
7. Ca2+ pumped into ECF and SR
8. tropomyosin blocks cross-bridge formation
9. skeletal muscle contraction is pervented
the firing of motor neuron's AP leads to - ANSWERScontraction of muscle cell
what causes muscle contraction - ANSWERSthe Ca2+ release from the SR after Muscle APs are sensed in the T-
tubules
parts of the sarcolemma - ANSWERS- t (transverse)-tubules invaginate the myofibrils
- t0tubules are continuous with the sarcolemma
