Shared Flashcard Set

Details

Muscular System
Test November 1st 2012
51
Anatomy
12th Grade
10/31/2012

Additional Anatomy Flashcards

 


 

Cards

Term
Skeletal Muscle
Definition
-striated muscle, (contains dark bands)
-40-50% of body weight
-many nuclei per cell
-voluntary muscle
-attaches to bone
Term
Smooth Muscle
Definition
-visceral muscle
-one nucleus per cell
-involuntary
-makes the walls of the digestive tract, iris of the eye
Term
Cardiac Muscle
Definition
-heart
-striations present, but one nucleus per cell
-involuntary
Term
Myofibril
Definition
-sub-unit of muscle cells
-contains contractile proteins which cause the muscle to move
Term
Sarcomere
Definition
-sub-unit of the myofibril
-the basic unit of muscle contraction
-know structure (myosin, actin, h-zone, z-line, a-band, i-band)
Term
Myosin
Definition
-contractile protein, thick filament (strand)
-contains extensions called cross bridges which pull the thin (actin) filaments together when a muscle contracts
Term
Actin
Definition
-contractile protein, thin filament
-pulled together when a muscle contraction occurs
Term
H-Zone
Definition
-the area between the actin filaments when a muscle is at rest
-reduces when the muscle contracts
Term
Z-Line
Definition
-the outer borders of the sarcomere
Term
A-Band
Definition
-(dark band), contains myosin & actin filaments
Term
I-Band
Definition
-(light band), contains actin filaments only
Term
Tropomyosin
Definition
-regulatory protein that blocks myosin binding sites in the actin
Term
Troponin
Definition
-regulatory protein that positions the tropomyosin
-when calcium ions bond with troponin, it changes the shape of the tropomyosin
Term
Sliding Filament Theory
Definition
-actin and myosin do not change their length, but do change their degree of overlap
Term
Steps for Muscle Contraction
Definition
1.) an impulse moves down a nerve cell and through the motor neuron
2.) the motor neuron stimulates the sarcolemma, causing it to release calcium
3.) calcium floods into the sarcomere and binds to the troponin complex. this exposes the myosin binding sites on the actin
4.) ATP on the myosin head hydrolyzes. the energy is then transferred to the myosin and changes the shape of the molecule. the myosin cross bridge connects to the actin
5.) cross bridges pull the actin filaments together, eliminating the H-zone
Term
Sarcolemma
Definition
-cell membrane of a muscle cell
Term
Motor
Definition
-movement of any sort
Term
Muscles need _____, _____, and ______ to function normally
Definition
-nerves, blood, oxygen
Term
ATP
Definition
-molecule that directly supplies energy for muscle contractions
Term
Aerobic Respiration
Definition
-glucose breakdown using oxygen
-recharges 38 ATP molecules
-(e.g. quiet, normal respiration)
-(physical activity does not exceed maximum ATP production)
Term
Anaerobic Respiration
Definition
-glucose breakdown w/o oxygen
-recharges only 2 ATP molecules
-(e.g. phyiscal stress)
-when muscles need more ATP than the mitochondria can normally produce
-lactic acid is produced (causes fatigue)
Term
2 Types of Muscle Contraction
Definition
-isometric and isotonic
Term
Isometric Contraction
Definition
-produces no movement
-(e.g. pushing against a wall, maintaining posture)
Term
Isotonic Contraction
Definition
-produces movement
-sit-ups, push-ups, curls, etc)
Term
Hypertrophy
Definition
-an increase in muscle size
-due to normal growth, exercise, steroids
-accompanied by an increase in blood flow
-strength training increases total muscle mass, not number of muscle fibers
Term
Atrophy
Definition
-a decrease in muscle size
-due to nonuse, aging
Term
Myopathy
Definition
-muscle disorder
Term
Strain
Definition
-from overexertion or trauma
Term
Myalgia
Definition
-muscle pain
-possibly from strain, flu
Term
Sprain
Definition
-overstretching or tearing of muscle fibers (includes tendinitis)
Term
Osgood Schlatter's
Definition
-tendinitis of the patellar tendon
Term
Cramps
Definition
-painful muscle spasms
-may be due to water or ion imbalance
Term
Contusion
Definition
-bruising
Term
Muscular Dystrophy
Definition
-muscular weakness/deterioration
-cause of death: paralyisis of respiratory muscle, by 21 yrs of age
Term
Polio
Definition
-viral
-muscle degeneration and paralysis
Term
Myoma
Definition
-benign muscle tumor
-common on the uterus
Term
Myosarcoma
Definition
-malignant muscle tumor
Term
Tetanus
Definition
-bacterial
-may cause lockjaw, severe body rigidity
Term
Flexion
Definition
-decreases angle of the joint
Term
Extension
Definition
-increases angle of the joint
Term
Abduction
Definition
-move away from the midline
Term
Adduction
Definition
-move toward the midline
Term
Supinate
Definition
-turn the palm up
Term
Palmate
Definition
-turn the palm down
Term
Origin
Definition
-fixed end of muscle attachement
Term
Insertion
Definition
-point of attachment to the bone which is moved
Term
Connective Tissue
Definition
-surrounds the skeletal muscle
Term
Tendons
Definition
-connect muscle to bone
Term
Epimysium
Definition
-surrounds the entire muscle
Term
Perimysium
Definition
-surrounds muscle fiber bundles
Term
Endomysium
Definition
-surrounds individual muscle fibers
Supporting users have an ad free experience!