neuromuscular junction
DESCRIPTION
Neuromuscular junction. Schwann cell sheath. Somatic motor neuron . The neuromuscular junction. Axon terminal. Mitochondria. Muscle fiber. Terminal bouton. Motor end plate. Synaptic vesicle (ACh). Presynaptic membrane. Synaptic cleft. Postsynaptic membrane. Nicotinic ACh - PowerPoint PPT PresentationTRANSCRIPT
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Neuromuscular junction
Fig. 11-12
Somatic motor neuron
Musclefiber
Theneuromuscularjunction
Motor end plateTerminalbouton
Mitochondria
Synaptic vesicle (ACh)
PresynapticmembraneSynaptic cleftPostsynapticmembrane
Schwann cell sheath
Axon terminal
Nicotinic AChreceptors
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Neuromuscular junction
Fig. 11-13
Skeletal muscle
fiber
AChE
Voltage-gatedCa2+ channel
Action potential
ACh
Ca2+Ca2+
Acetyl + choline
Nicotinicreceptor
Motor endplate
Somatic motor neuron
Axon terminal
K+
Na+
Na+
K+
AChClosed channel Open channel
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T-tubules and SR
Fig. 12-4
Sarcolemma
Thin filament
Thick filament
T-tubule brings actionpotentials into interiorof muscle fiber.
Sarcoplasmic reticulumstores Ca2+
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Excitation-contraction coupling
Axon terminal ofsomatic motor neuron
Myosin head
Myosin thick filament
M line
Motor end plate
Sarcoplasmicreticulum
ACh
DHP
RyR
T-tubule
Muscle fiber
Troponin
TropomyosinActinZ disk
Na+
Ca2+
Ca2+ released
Myosin thick filament
Fig. 12-11
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Troponin and tropomyosin
Fig. 12-3
Thin filaments
Tropomyosin
Troponin
Actin chain G-actin molecule
Nebulin
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Cross-bridge cycle
Fig. 12-9
ADP ADP
Actinmoves
Cytosolic Ca2+
Tropomyosin shifts,exposing bindingsite on actin
TN
Power stroke
Initiation of contraction
Troponin G-Actin
Tropomyosinblocks binding
site on actin
Myosin head
TN
Relaxed state. Myosin head cocked.
Pi
Pi
1
2 3
4
5
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Types of Muscle Fibers
Fig. 12-15
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SPINAL CORD
Neuron 1Neuron 2Neuron 3
Motornerve
Muscle fibers
Motor unit 2
Motor unit 1
Motor unit 3
One muscle may havemany motor units ofdifferent fiber types.
KEY
Motor Units
Fig. 12-15
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Basic circulatory system
Fig. 9-2c, p.360
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Peristaltic heart
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One-way valves
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Chambered Heart
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Extrinsic Muscle Pump
Extrinsic muscle
Blood
Valve
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Blood vessel structure
Fig. 15-2
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Schematic view of mammalian circulation
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Mammalian circulation
Fig. 14-1
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External anatomy of the heart
Superiorvena cava
Rightatrium
Auricle ofleft atrium
Aorta
Pulmonaryartery
Rightventricle
Leftventricle
Coronaryarteryand vein
Fig. 14-7
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Internal anatomy of the heart
Right atrium Left atrium
Pulmonarysemilunar valve
Rightpulmonary
arteries
Right ventricle
Superiorvena cava
Left pulmonaryarteries
Aorta
Left pulmonaryveins
Cusp of the AV(bicuspid) valve
Cusp of a right AV(tricuspid) valve
Chordae tendineae
Inferiorvena cava
Papillary muscles
Left ventricle
Descendingaorta
Fig. 14-7
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Cardiac muscle structure
Intercalateddisks
Myocardial musclecell
Fig. 14-7
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Intercalated discs