Test 3 (Muscle Tissue) Flashcards
Makes up muscular system
Skeletal muscle
Found only in the heart
cardiac muscle
Appears throughout the body systems as components of hollow organs and tubes
smooth muscle
Single skeletal muscle cells
muscle fiber
Number of muscle fibers bound by connective tissue
muscle
Connective tissue surrounding a single muscle fiber
endomysium
Connective tissues surrounding its facile
Perimysium
Surround entire muscle
Epimysium
Cell membrane of the muscle fiber
sarcolemma
Site where a motor neuron stimulates muscle fiber
neuromuscular junction
Area of the muscle fiber sarcolemma where a motor neuron stimulates it using the neurotransmitter, acetylcholine
Motor end plate
Contractile elements of muscle fiber
Myofibrils
Function unit between 2 Z lines
Sarcomere
What is the main protein component of thick filaments?
Myosin
What is on the myosin heads?
actin binding sites
ATP binding site
What are the 2 regulatory proteins in thin filaments?
Tryomyosin
Troponin
Lies alongside groove of actin and covers myosin binding sites blocking interaction
Tropomyosin
Functions of ATP in contraction
Energizes X-bridge, providing energy for force
Binding of ATP disassociates X-bridge from actin
How is calcium released?
AP propagated into interior of fiber along transverse tubules to sarcoplasmic reticulum
Opening of voltage gated channgels
Force exerted on an object by contracting muscle
Tension
Force exerted on the muscle by weight of object
Load
Mechanical response of a single muscle fiber to a single AP
Twitch
The time between stimulus and contraction
Latent period
Force Velocity Curve
For muscles to contract, they must generate force that is greater than the opposing forces
Two primary types of muscle contraction
Isotonic
Isometric
Change in muscle length
Isotonic
Concentric Contractions
Muscle shortens
Eccentric contractions
Muscle lengthens
Muscles can’t shorten because the load is too great
Isometric
What is the motor unit?
Motor neuron and the muscle fibers it innervates
How do you control muscle tension?
amount of tension developed by each fiber
Number of fibers contracting at any time
Increasing the number of active motor units
Recruitment (increases velocity)
How do you control the amount of tension developed in a skeletal muscle?
Frequency of stimulation
Muscle fiber is stimulated so rapidly that it does not have a chance to relax between stimuli
Tetanus
What are the major types of muscle fibers?
slow oxidative fibers
fast oxidative fibers
fast glycolytic fibers
