Question | Answer |
Contractility | Ability of muscle to shorten with force. |
Excitability | Capacity of skeletal muscle to respond to a stimulus. |
Extensability | Ability for muscle to be stretched. |
Elasticity | Ability tp recoil to their original resting length after they have been stretched. |
Muscle | Helps produce heat essential for maintenance of normal body temperature. |
Epimysium | Connective tissue sheath surrounding the muscle. |
Fascia | Connective tissue located outside of the epimysium. |
Muscle Fasciculi | (Fascicle) Numerous visible bundles that are surrounded by loose connective tissue. |
Perimysium | Loose connective tissue that surrounds muscle fasciculi. |
Fibers | Single muscle cells that compose fasciculi. |
Endomysium | Connective tissue sheath that surrounds each fiber. |
Myofibrils | Threadlike structure that extends from one end of the fiber to the other. Also fills the cytoplasm of each fiber. |
2 types of protein fibers | Actin Myofilaments and Myosin Myofilaments. |
Actin Myofilaments | Thin myofilament that resemble to minute strands of pearls twisted together. |
Myosin Myofilaments | Thick myofilaments that resemble bundles of minute golf clubs. |
Sarcomeres | Highly ordered units formed by Actin and Myosin myofilaments. |
Myofibrils | Formed by highly ordered units (Sarcomeres) that join end to end. |
Resting Membrane Potential | Charge difference across the membrane. |
Action Potential | The brief reversal back of the charge. |
Motor Neurons | Nerve cells that carry action potentials to skeletal muscle fibers. |
Axons | Enter the muscle and branch. |
Neuromuscular Junction | (Synapse) Each branch that connects to the muscle near the center of the wall. |
Motor Unit | Single motor neuron and all the skeletal muscle fibers it innervates. |
Presynaptic Terminal | Enlarged nerve terminal. |
Synaptic Cleft | The space between the Presynaptic Terminal and the Muscle Cell. |
Postsynaptic Terminal | Muscle fiber. |
Synaptic Vesicles | Contained in each presynaptic terminal and secretes a nerotransmitter. |
Acetycholine | Neurotransmitter that diffuses across the synaptic cleft and binds to the postsynaptic terminal causing change in the postsynaptic cell. |
Acetycholinesterase | The acetycholine is rapidly broken down by enzymes. |
Sliding Fialment Mechanism | Sliding of actin myofilaments during contraction. |
Muscle Twitch | Contraction of an entire muscle in response to a stimulus. |
Threshold | A point in which the muscle fiber will contract maximally. |
Lag Phase | The beginning of a contraction. |
Contraction Phase | The time of contraction. |
Relaxation Phase | The time which during a muscle relaxes. |
Tetany | Muscle remains contracted without relaxing. |
Recruitment | The increase in number of motor units being activated. |
Origin | (Head) 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 origin and the insertion. |
Synergists | Muscles that work together to accomplish specific movements. |
Antagonists | Muscles that work opposite of each other. |
Prime Mover | One muscle playing the major role in accomplishing the desired movement in a group of synergists. |
Creatine Phosphate | High energy molecule that is stored in muscle cells. |
Anaerobic Respiration | Without oxygen. |
Aerobic Respiration | With oxygen (more efficient). |
Oxygen Debt | The amount of oxygen needed in chemical reactions to convert lactic acid to glucose. |
Muscle Fatigue | Results when ATP is used faster than it is produced. |
Isometric | (Equal Distance)Length of muscle doesn't change. Tension increases during contractions. |
Isotonic | (Equal Tension) The tension produced is constant during contractions. The length of the muscle changes. |
Muscle Tone | Keeps head up and back straight. Refers to constant tension produced by muscles of the body for long periods of time. |
Fast Twitch Fibers | Contract and fatigue quickly. |
Slow Twitch Fibers | Contract slowly and more resistant to fatigue. |
Occipitofrontalis | Raises the eyebrow. |
Orbicularis Oculi | Closes the eyelid. |
Orbicularis Oris | Pucker the lips (kissing muscle). |
Buccinator | Flattens the cheeks (trumpeters muscle). |
Orbicularis Oris & Buccinator | Work together for kissing. |
Zygomaticus | Smiling. |
Levator Labii Superiorous | Sneering. |
Depressor Anguli Oris | Frowning. |
Mastication | Chewing. |
4 pairs of mastication | Masseter, Temporalis, and 2 pair of pterygoids. |
2 toungue muscles | Intrensic and Extrensic. |
Intrensic Tongue Muscle | Changes the shape of the tongue. |
Extrensic Tongue Muscle | Moves the tongue. |
Sternocleidomastoid | Rotates and abducts the neck (Twisted neck). |
Z Line | Extension of a sarcomere. |
I Band | Light area on each side of the Z Lines. |
A Band | Extends the length of the myosin. The darker region in the sarcomere. |
H Zone | The light area in the center of each sarcomere consisting of myosin only. |
M Line | A dark staining band in the center of a sarcomere where myofilaments are anchored. |
ATP | (Adenosine Triphosphate) Needed for energy for muscle contractions. |
ADP | (Adenosine Diphosphate) Plus Phosphate. |
8 ways muscles recieve names: | Location, Size, Orientation of fibers, Shape, Origin, Insertion, Function, Ect. |