Muscular System Flashcards
Basic functions
structure, balance, posture, movement, heat
Can conduct an action potential
Conductivity
Reacts when stimulated
Irritability
Can shorten and produce tension between its ends
Contractability
Can return to resting properties after contraction
Relaxation
Can be stretched
Distensibility
Opposite of distensibility, resist elongation, return to og position after elongation
Elasticity
3 types of muscles
Smooth, Skeletal, Cardiac
Striates or striped are further divided into
Skeletal and cardiac
Weakest muscle
Smooth
Involuntary
Cardiac and smooth
Controlled by sinus node
Cardiac
Connected by lateral branches
Cardiac
Voluntary
Skeletal
Indiv bundle of muscle fibers in skeletal muscles
Fascicle
Where are diff muscles located + function
Skeletal - skeleton; move bones
Cardiac - heart; pump blood
Smooth - var organs; var functions like peristalsis
Cell membrane of muscle fiber
Sarcolemma
Gel-like substance inside the muscle cell
Sarcoplasm
Storage ng calcium
Sarcoplasmic reticulum
Regular arrangement of myofibrils
Sarcomeres
Thick filaments are made up of
Myosin
Thin filaments are made up of
Actin, topomyosin, troponin
Separates sarcomeres from each other
Z-disc
Dark, middle, overlap ng myosin and actin
A band
Lighter, thin filament lang
I band
Thick filament lang
H zone
Protein that causes muscles to contract
Myosin
Contains myosin-binding sites
Actin
Wraps around actin and covers myosin binding sites on actin
Tropomyosin
Moves tropomyosin away from myosin-binding sites
Troponin
Contractile proteins
Myosin and actin
Regulatory proteins
Troponin and tropomyosin
Largest sa structural proteins
Titin
SFT: begins w/ what
Calcium release from sarcoplasmic reticulum
SFT: Ca binds first to..
troponin
SFT: Ano after sa troponin
Troponin moves tropomyosin, which exposes the actin active site
SFT: Ano next when exposed na actin active site
Myosin head forms cross-bridge and bend towards M-line
SFT: What releases cross-bridge
ATP
Focal point where motor neuron attaches to muscle
Neuromuscular junctions
Neurotransmitter used in skeletal muscle contraction
Acetylcholine
When is acetylcholine released
When action potential reaches synapse
Short muscle contraction
Muscle twitch
Very prolonged contraction
Tetanus
What produces paralysis
Loss of function at the junction
Muscle tension less than opposing force, muscle remains at the same length
Isometric contraction
Muscle tension greater than opposing force, muscle shortens
Isotonic contraction