PG 15-23 Vocab Flashcards
Connects muscle to bone via bone periosteum. Bridges muscle and bone together in order to produce movement
Tendon
Forms fasciculi. Can consist of up to 150 individual strands covered by connective tissue (perimysium). 3 kinds of these. Type I type IIa Type IIx.
Muscle fibers
Slow, oxidative muscle fibers “slow twitch” fatigue resistant. Produce low levels of force
Type I muscle fiber
Fast oxidative and glycolytic fibers. “Fast twitch” produce medium amount of force. Highly fatigue resistant
Type IIa muscle fibers
Glycolytic fibers. “Fast twitch” produce large amounts of force. Rapidly fatigued
Type IIx muscle fibers
Cytoplasm of muscle fiber. Glycogen, fat, enzymes, mitochondria, and sarcoplasmic reticulum found here
Sarcoplasm
Internal structure of the muscle fiber. Contain long proteins responsible for muscle fiber contraction (actin, titin, and myosin)
Myofibrils
Long thin chains of protein that comprise the myofibril. Smooth muscle, obliquely striated muscle and striated muscle (contains actin and myosin).
Myofilament
Basic unit of muscle fibers. Where actin, titin and myosin are found. Area occurring between the two Z lines. Location where all muscular contraction takes place. Can be divided 4 segments (A band, H zone, I band, Z line)
Sarcomere
Both actin and myosin filaments are located.
A band
Part of the A band, located in the center of the sarcomere where only myosin filaments occur (thick filaments)
H zone
Area that only consists of thin filaments (actin). Made of two sarcomeres
I band
Occurs in the middle of the I band. Appears as a line running lengthwise throughout.
Z line
System of tubules surrounding each myofibril. Responsible for pumping calcium ions into the muscle to generate contraction. Also the site of calcium storage
Sarcoplasmic reticulum
Site of ATP hydrolysis. Thicker myofilament, responsible for cross linking to actin filaments to produce the shortening of the sarcomere, resulting in muscular contraction.
Myosin
Thin filament. Serves as the binding site for myosin, with the hydrolysis of ATP, generates a power stroke where _____ will slide over the myosin fiber.
Actin
______ fiber binds with ______ fiber. After binding ______ fiber then slides over _______ fiber.
Actin, Myosin.
Actin sliding over myosin that causes a muscle to generate tension and movement
Sliding filament theory
Either there is a stimulus and a response or there is nothing
All or none principle
Central communication point of the nervous and musculoskeletal systems that leads to muscular contraction. Translation point where electrical signal is converted into a bio mechanical reaction and then into movement
Neuromuscular junction
Located in CNS. Responsible for transmitting signals from the spinal cord to the muscles in order to produce muscular contraction. Site of the release of an action potential into the neuromuscular junction
Motor neuron
Electrical impulse that is triggered by the rapid depolarization of the cell membrane of a neuron. Sets in motion the release of calcium ions into the sarcomere and ends with muscular contraction
Action potential
During muscular contraction, a chemical cascade takes place that causes a conformational change in ______ that allows the myosin filament to bind with the actin filament. In a relaxed state, the head of the ______ wraps helically around the trope in on the actin filament, preventing the formation of the myosin cross bridge
Tropomyosin
Responsible for initiating the movement of tropomyosin from the binding site after Ca+ has initiated a conformational change.
Troponin
Primary neurotransmitter involved in muscular contraction.
Acetylcholine
Once an action potential is released from the nerve terminal, _____ is released from the nerve terminal and diffuses across the neuromuscular junction, causing excitation of the sarcolemma
Acetylcholine
Responsible for inhibiting tension overload in muscles and tendons when placed under stretch. Very rapid and prevents excessive loading injuries.
Golgi tendon organ GTO
Responsible for the “fight or flight” response in humans. Releases adrenaline and norepinephrine which causes increased rate of respiration, elevated the heart rate, raises mental focus, and increases body temperature
Sympathetic nervous system
Responsible for relaxation periods of decreased activity which governs various passive activities such as digestion
Parasympathetic nervous system
Performs a protective action, working to decelerate force acting on the body. Hamstrings during the squat
Antagonist muscle action
Primarily responsible for generating the force to produce movement. In sprinting the primary muscles the propel the body forward are the hip flexors, quads, glutes, and hamstrings
Agonist muscle action
Either stabilizes the agonist as force is produced or indirectly assists in force production
Synergistic muscles
Allows for force to be produced about a fixed point, or pivot, and will increase the amount of force that produced through this arrangement. 3 different classes.
Lever
Muscle and resistive force apply on opposite sides of the fulcrum
1st class lever
Muscular and resistive forces occur on the same side of the fulcrum
2nd class lever
Muscular and resistive forces act on the same side of the fulcrum through a distance shorter than the distance through which the resistive force is acting
3rd class lever
Point of rotation for a lever.
Fulcrum
True or false
The fulcrum position determines the mechanical advantage
True
The distance from the muscles line of action to the joints center of rotation and is oriented in the direction of the force being produced
Moment arm
