Exam 3 study Guide Flashcards
Main functions of the muscular system
Movement of Bones or fluids example blood. Maintaining posture and body position. Stabilizing joints. Heat generation (especially skeletal muscle) Addition functions include protects organs, forms, valves, controls pupil size, causes “goosebumps”
Responsiveness or ability to receive and respond to stimuli; plasma membranes changes electrical state (- to +)
Excitability
Ability of muscle tissue to pull on its attachment points and shorten with force.
Contractility
Ability to return to original length when resting, recoil due to presence of elastin.
Elasticity
Striated and involuntary.
Cardiac Muscle
Non-striated and involuntary.
Smooth Muscle
Striated and Voluntary.
Skeletal Muscle
Dense irregular connective tissue surrounding entire muscle; may blend with fascia.
Epimysium
Fibrous connective tissue surrounding fascicle; contains nerves and bundles
Perimysium
thin layer of areolar connective tissue covering each muscle cell.
Endomysium
Organized bundle of muscle cells.
Fascicle
term used to describe the entire muscle
Belly
A individual muscle cell
Myocyte/muscle fiber
Muscle cell plasma membrane
Sarcolemma
Muscle cell cytoplasm, contains myoglobin, glycogen
Sarcoplasm
: Unique in-folding of the sarcolemma that allow for electrical signal transmission to opposite side of cell.
T-Tubules
Specialized smooth endoplasmic reticulum that stores, releases and retrieves calcium.
Sarcoplasmic Reticulum
Repeated units of contractile and regular proteins that enable shortening and lengthening of the myocyte.
Sarcomere
Arranged in a bundle with heads directed outward in a spiral array around the bundled tails. The central area (tail) is a bare zone with no heads. The thick/darker filament and the A band.
Myosin
Two intertwined strands fibrous actin; globular actin with a binding site. Regulatory proteins associated with this filament. The thin/lighter filament and the I band.
Actin
Each motor neuron and all the muscle fibers it innervates. Motor neuron sitmulates the myocyte by releasing a neurotransmitter.
Motor Unit
Overly contracted – thick filaments too close Z-discs and can’t slide
Compressed
Resting length produces greatest force when muscle contracts. Central nervous system maintains optimal length producing muscle tone.
Optimum
Stretcher out little over lapped of thin an thick does not allow for very many cross bridges to form.
Stretcher
Graph of muscle tension
Myogram
Involuntary contraction of the fibers that make up a muscle
Twitch
Events of excitation- contraction coupling; no muscle tension.
1.) Latent Period
Crossbridge formation; tension increases.
2.) Period of Contraction
2.) Period of Contraction
3.) Period of Relaxation