ch.6 muscle notes

Question Answer
1. What are the 4 major characteristics of skeletal muscles ? Contractility, Extensibility, Elasticity, Excitability.
2. Contractility the ability of skeletal muscle to shorten with force.
3.Extensibility the capacity of skeletal muscle to respond to a stimulus.
4. Elasticity the ability to be stretched.
5. Excitability ability to recoil to their original resting length after they have been stretched.
6. epimysium connective tissue sheath that surrounds skeletal muscle.
7. fascia another connective tissue located outside the epimysium.
8. perimysium loose connective tissue that surrounds muscle fasculi.
9. Fibers muscle cells
10. endomysium surrounds fibers
11. myofibrils structure that extends from one end of the fiber to the other
12. 2 the amount of protein fibers myofibrils consist of
13 actin thin myofilaments
14 myosin thick myofilaments
15 sarcomere joined end to end to form the myofibril
16 Where does the sarcomere extend to and from ? Each sarcomere extends from one Z line (disc) to another Z line (disc).
17 Z line attachment site for actin
18 resting membrane potential The charge difference across the membrane
20 action potential he brief reversal back of the charge
21 Motor neurons nerve cells that carry action potentials to skeletal muscle fibers.
22. neuromusclular junction branch between axons and muscles.
23. synapse synonym for neuromuscular junction.
24.motor unit A single motor neuron and all the skeletal muscle fibers it innervates
25. presynaptic terminal enlarged nerve terminal
26. synaptic cleft the space between the presynaptic terminal and the muscle cell
27. postsynaptic terminal the muscle fiber
28 synaptic vesicles Each presynaptic terminal contains
29 acetylcholine neurotransmitter secreted by synaptic vessels
30 acetylcholinesterase The acetylcholine released into the synaptic cleft between the neuron and muscle cell is rapidly broken down by an enzymes,
31 E. Muscle Contraction 1. Occurs as actin and myosin myofilaments slide past one another causing the sarcomeres to shorten.
32sliding filament mechanism 2. The sliding of actin myofilaments past myosin myofilaments during contraction is called
33 3. Muscle twitch is a contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers.
34threshold 4. A muscle fiber will not respond to stimulus until that stimulus reaches a level called
35 all-or-none response. his phenomenon is called
36 he time between application of a stimulus to a motor neuron and the beginning of a contraction lag phase
37 contraction phase. 6. The time of contraction
38relaxation phase 7. The time during which the muscle relaxes
39 Tetany where the muscle remains contracted without relaxing.
40. muscle tone amount of muscle a person has
41recruitment. where the muscle remains contracted without relaxing.The increase in number of motor units being activated is called
42 ATP needed for energy for muscle contraction.
43 ATP needed for energy for muscle contraction.
44 ATP needed for energy for muscle contraction.
45 ADP (adenosine diphosphate)
46 types of muscle contractions 2
47creatine phosphate. high-energy molecule
48 Anaerobic respiration without oxygen.
49 Aerobic respiration with oxygen (more efficient).
50 oxygen debt the amount of oxygen needed in chemical reactions to convert lactic acid to glucose
51 Muscle fatigue results when ATP is used during muscle contraction faster than it can be produced in the muscle cells
52 Muscle fatigue results when ATP is used during muscle contraction faster than it can be produced in the muscle cells
53 muscle fatigue results when ATP is used during muscle contraction faster than it can be produced in the muscle cells
54 isometric (equal distance)
55 isotonic equal tension
56 facial muscles facial muscles
57 Occipitofrontalis raises the eyebrows
58 Orbicularis oculi closes the eyelids and causes “crows feet” wrinkles in the skin at the lateral corners of the eye.
59 Orbicularis oris puckers the lips.
60 buccinator kissing muscle
61orbicularis oris kissing muscle
62 mastification chewing
63mastification chewing
64mastification chewing
65 4 pairs of mastication muscles 2 pair of pterygoids, temporalis, and masseter
66Intrinsic Tongue Muscles changes shape
67Extrinsic Tongue Muscles moves tongue
68Neck Muscle Sternocleidomastoid
69Levator labii superioris sneering
70Levator labii superioris sneering
71 Depressor anguli oris frowning
72Depressor anguli oris frowning
73 zygomatic smiling
74zygomatic smiling
75 origin most stationary end of the muscle

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