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chapter 6 muscles

contractility the ability of skeletal muscle to shorten with force
excitability the capacity of skeletal muscle to respond to a stimulus
extensibility the ability to be stretched
elasticity ability to recoil to their original resting length after they have been stretched
each skeletal muscle is surrounded by a connective tissue sheath called the... epimysium
fascia another connective tissue located outside the epimysium
what are surrounded by loose connective tissue perimysium
the fasciculi are composed of single muscle cells called... fibers
each fiber is surrounded by a connective tissue sheath called the... endomysium
the cytoplasm of each fiber is filled with myofibrils
myobibrils a threadlike structure that extends from one end of the fiber to the other
myofibrils consist of 2 major kinds of protein fibers called actin myofilaments and myosin myofilaments
actin myofilaments thin myofilaments.
myosin myofilimaents thick myofilaments.
actin and myosin myofilaments form highly ordered units called... sarcomeres
Each sacromere extends to.. One Z line to another Z line
The charge difference across the membrane is called the... Resting membrane potential
The brief reversal back of the charge is called... Action potential
Nerve cells that carry action potentials to skeletal muscle fibers... Motor neurons
Each branch connects to the muscle forms a... Neuromuscular junction or synapse near the center of the cell
A single motor neuron and all the skeletal muscle fibers it inner ages are called... Motor unit
The enlarged nerve terminal is the... Presynaptic terminal
The space between he presynaptic terminal and the muscle cell is the... Synaptic cleft
The muscle fiber is the... Postynaptic terminal
Each presynaptic terminal contains... Synaptic vesicles
Each presynaptic terminal contains synaptic vesicles that secrete a neurotransmitter called... Acetylcholine
The acetylcholine released into the synaptic left between the neuron and muscle cell is rapidly broken down by enzymes called... Acetylcholinesterase
The sliding of action myofilaments past myosin myofilaments during contraction is called... The sliding filament mechanism
The H and I bands shorten but the A band.. Do not change in length
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
A muscle fiber will not respond to stimulus until that stimulus reaches a level called... Threshold
The phenomenon is called the... All-or-none response
The time between application of a stimulus to a motor neuron and the beginning of a contraction is the... Lag phase
The time of contraction is the... Contraction phase
The time during which the muscle relaxes is the... Relaxation phase
Tetany Where the muscle remains contracted without relaxing
The increase in number of motor units being activated is called... Recruitment
ATP is needed for... Energy for muscle contraction
ATP is producer in... The mitochondria
ATP is ... Short lived and unstable
When at rest they can’t stockpile ATP but they can store another high-energy molecule called... Creating phosphate
Anaerobic respiration Without oxygen
Aerobic respiration With oxygen
The — is the amount of oxygen needed in chemical reactions to convert lactic acid to glucose and to replenish the depleted stores of creatine phosphate stores in muscle cells Oxygen debt
— Muscle fatigue
What are the 2 types of muscle contractions Isometric and isotonic
The length of the muscle does not change, but the amount of tension increases during the contraction process Isometric
The amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes Isotonic
Muscle tone Muscle tone refers to the constant tension produced by muscles of the body for long periods of time
Fast twitch fibers Contract quickly and fatigue quickly
Slow twitch fibers Contract more slowly and are more resistant to fatigue
The — is the most stationary end of the muscle Origin
The — is the end of the muscle undergoing the greatest movement Insertion
The portion of the muscle between the origin and the insertion is the Belly
Some muscles have multiple... Origins or head
Muscles that work together to accomplish specific movements are called... Antagonists
Among a group of synergistic, if one muscle plays the major role in accomplishing the desired movement, it is the... Prime mover
Occipitofontalis Raises the eyebrows
Orbicularis oculi Closes the eye lids and causes “crows feet” wrinkles in the skin at the lateral corners of the eye.
Orbicularis oris Pucker the lips
Buccinator Flattens the cheeks
Zygomaticmaticus Smiling muscle
Lavatory labii superioris Sneering
Depressor Anguli oris Frowning
Mastication Chewing
What are the 4 pair of mastication muscles 2 pairs of pterygoids, temporalis, and masseter
Intrinsic tongue muscles Change the shape of the tongue
Extrinsic tongue muscles Move the tongue
Sternlcleidomastoid Lateral neck muscle and prime mover
Erector spinae Group of muscles on each side of the back
Created by: destinysmith76