Term | Definition |
Contractility | the ability of a skeletal muscle to shorten with force |
Excitability | the capacity of a skeletal muscle to respond to a stimulus |
Extensesibility | the ability to be streched |
Elasticity | the ability to recoil to their original resting length after they have been streched |
epimysium | each skeletal muscle is surrounded by a connective tissue seath called? |
Fascia | Another connrctive tissue located outside of the epimysium |
Muscle Fasciculi (Fascicle) | a muscle id composed of nemerous visible bundles called? |
Perumysium | Fasciculi (Fascicle) are surrounded by loose connective tissue called/ |
Fibers | the fasciculi are composed of single muscles cells called? |
Endomysium | Each fiber is surrounded by a connective tissue seath called? |
Myofibrils | The cytoplasm of each fiber is filled with? |
Myofibrils | A thread like structure that extends from one end of the fiber to the other? |
Actin and Myosin Myofilaments | Myofibrils consist of 2 major kinds of protine fibers: |
Actin | Resembles 2 minute strands of pearls twisted together |
Myosin | Resembles bundles of minute golf clubs |
Sacromeres | Actin adn myosin myofilaments from highly ordered units called? |
Sacromers | the basic structural and functional unit of the muscles |
Resting membranes potential | The charge difference across the membrane is called? |
Action Pontential | When a muscle cell is stimulated the membrane characteristics change briefly, the brief reversal back of the charge is called? |
motor neurons | Nerve cells that carry action potentials to the skeletal muscles fibers |
A neuromuscular junction or synapse | Axons enter the muscles and branch, each branch that connects to the muscle forms? |
A Motor Unit | A single motor neuron and al the skeletal muscle fibers in innervates are called |
Presynaptic terminal | the enlarged nerve terminal |
Synaptic Cleft | Space between the presynaptic terminal and the muscle cell: |
Synaptic vesicles | Each presynaptic terminal contains |
Acetylcholine | Synaptic vesicles secret a neurotransmitter called? |
Acetylcholinesterase | The acetylcholine release into the synaptic cleft between the neuron and muscle cell is rapidly broken down by an enzymes |
Muscke Contraction | Occurs as action and myosin myofilaments slide past one another causing the sarcomers to shorten : |
Sliding Filament Mechanism | The sliding of action myofilaments past myosin myofilments during contraction is called |
Muscle Twitch | Contraction of an entire muscle in responce to a stimulus that causes the action potential in one or more muscles fibers: |
Threshold | A muscle fiber will not respond to a stimulus unit that stimulus reaches a level called? |
The lag phase | The time between application of a stimulus to a motor neuron and the beginning of a contaction is? |
Contraction Phase | Time of contraction |
Muscle Fatigue | Result when ATP is used during muscle contraction faster than it can be produced in the muscle cell |
Isometic (Equal Distance) | The length of the muscle does nto change, but the amount of tension increses during the contraction process |
Isometric (Equal Tension) | The amount of tension produced by the muscle id constant during contraction, but the length of the muscle changes : |
muscle tension | Constant tension produced by muscles of the body for long periods of time |
Fast-Twitch Fibers (white meat of a chicken brest) | Contract quickly and fatigue quickly |
Slow-Twitch Fibers (Dark meat of a ducks brest or leg of chicken) | Contract more slowly and are more resistant to fatigue |
origin | the most stationary end of the muscle |
insertion | the end of the muscle undergoing the greatest movement |
Belly | The portion of the muscle between the orgin and the insertion |
Synergists | Muscles that work together to accomplish specific movements are called? |
Antagonists | Muscles that work in opposition to one another are called? |
The Prime Mover | Among a group of synergists, if one muscle plays the major role in accomplishing the desired movement, it is: |
Occipitofrontales | Rasies eyebrows |
Orbicularis Oculi | Closes the eyelid |
Orbiccularis Oris | Puckers the lips |
Buccinator | Flattens the cheeks |
Orbicularis oris, buccanator | the two kissing muscles |
Zygomaticus | Smiling |
Levator Labii Superioris | Sneering |
Depressor Anguli Oris | Frowning |
Mastication | Chewing |
Masseter, Temporalis, 2 Pterygoids | 4 Pairs of Chewing muscles |
Extrinsic tougue muscles | moves the tongue |
Intrinsic tongue muscles | changes shape of the tongue |
Stero Cleido Mastoid | Rotates and Abducts neck |
Errector Spinae | Found in each side of the back, respondable for errect posture |
External intercostals | Contract During Inspiration |
Internal intercostals | Contract during forced expirations |
Diaphram | Dome shaped muscle, responcible for quiet breathing |
Rectus abdominis | Abs |
Linea Alba | White line of connective tissue that extends from the sternum of the pelvis |
Tendinous Inscription | Cross the Rextus Abdominis in 3 places and from a segmented look in abs |
Truck MusclesMuscles that move the verterbral column | Trunk muscles |
Thorasic Muscles | muscles that move the trunk |
Abdominal wall muscles | muscles of the anterior abdominal wall flex and rotate the verebral column, compress the abdominal cavity, and hold in the abdominal viscera |
trapezius | Pulls scapula anteriorly |
adducts and flexes the arm | Pectoralis major |
latissimus doris | Medially rotaes adducts, and powerfully extends the arm. "swimmers muscles" |
frontails | moves the eyebrows |
Orbicularis oculi | located around the eye (muscle) |
Masseter | chewing muscles |
Gluteus maximus | buttocks |
hamstring | posterior thigh muscles |