MUSCULAR Flashcards
3 TYPES OF MUSCLE TISSUE
- Skeletal
- Cardiac
- Smooth or Visceral
Striated and a Voluntary muscle
Skeletal
What are the two types of involuntary muscle tissue?
Cardiac
Smooth or Visceral
Major Functions of Muscular System
Movement
Maintenance of posture
Respiration
Production of body heat
Communication
Constriction of organs and vessels
Contraction of the heart
Ability to shorten forcefully
Contractility
Capacity to respond to a stimulus
Excitability
Can be stretched beyond its normal length
Extensibility
Ability to recoil to its original resting length
Elasticity
Attached to the bone
Skeletal Muscle
Walls of hollow organs, blood vessels, and glands
Smooth Muscle
Muscle in the heart
Cardiac Muscle
Move the body
Skeletal Muscle
Move food through digest tract
Smooth or Visceral Muscle
Contract heart to pumpl blood through the body
Cardiac Muscle
Connective tissue sheath that surround entire skeletal muscle
Epimysium / Muscle Fascia
Bundles of muscle fibers
Muscle Fascicles
Loose connective tissue that separate muscle fascicles from each other
Perimyseum
Separate muscle cells in each fascicle
Muscle fibers
Loose connective tissue that surround each muscle fiber
Endomysium
Contains transverse tubules (t-tubules)
Sarcolemma
Tube like inward folds associated with sarcoplasm ; connect sarcolemma to terminal cisternae
T-tubules
A type of smooth er that surrounds myosin
Sarcoplasmic Reticulum
Enlarged portion of sarcoplasmic reticulum
Terminal Cisternae
Cytoplasm that contains bundles of microfibrils or microfibers
Sarcoplasm
Thread like bundles of proteins
Myofibrils
Protein fibers that make up the myofibrils
Myofilaments
Attachment sites for myosin filaments
Actin
Binding sites for Ca2+
Troponin
Cover the attachment sites on actin myofilament
Tropomyosin
2 Major Protein Fibers
Actin Myofilaments
Myosin Myofilaments
Thick myofilaments; contain mysosin head that rembles golf clubs
Myosin
The basic structural and functional contractile unit of skeletal muscle that contains actin and myosin myofilaments
Sarcomere
What composes of sarcomeres
Z disk
IA band
H zone
M line
Separate one sarcomere
Z disk
Light-staining band
I band
Central dark staining disk
A band
A disk that contains only myosin filaments ; center of sarcomere
H zone
Anchors the myosin filaments
M line
Cell membranes have a negative charge on the inside relative to positive charge outside
Resting Membrane Potential
Brief reversal of the membrane charge
Action potential
Na+ channels open causing the sodium ions to enter inside the cell membranes (becomes more positive)
Depolarization
Na+ channels are closed and Na movement into the cell stops. The inside of the cell is negatively charged
Repolarization
Weakest stimulus needed to produce a response
Threshold
Stimulate muscles to contract
Motor neurons
Nerve cells that carry action potentials to skeletal muscle
Motor neurons
group of muscle fibers that motor neuron stimulates
Motor unit
Where the neuron and muscle fibres meet
Neuromuscular junction or synapse
The rapid depolarization and repolarization of the cell membrane
Action potential
Enlarged axon terminal
Pre-synaptic terminal
Contains the acetylcholine (ACh)
Synaptic vesicle
Neurotransmitter contained in the vesicles
Acetylcholine (aCh)
Enzyme that prevents the overstimulation of muscle fibers
Acetylcholinesterase
Briefly discuss the sliding filament theory
Thin and thick filaments overlaps during muscle contraction
Myosin head attach to the myosin
Cross bridges
A high energy molecule produced from the energy
Atp
Stiffening of muscle fibers that occurs after death
Rigor Mortis
Contraction of muscle fiber in response to a stimulus
Muscle twitch
Three types of muscle twitch
Lag phase / latent phase
Contraction phase
Relaxation phase
Time between the application of stimulus and beginning of contraction
Lag phase or latent phase
Time during when muscle contracts
Contraction Phase
Time during when muscle relaxes
Relaxation phase
Two ways of increasing the force of muscle contraction
Summation
Recruitment
Individual muscles contract more forcefully through rapid stimulation
Summation
Sustained contraction that occurs when the frequency of stimulation is so rapid that no relaxation occurs; convulsive tension
Tetanus
More motor units are stimulated which INCREASED THE TOTAL NUMBER OF MUSCLE FIBERS CONTRACTING
Recruitment
Two types of fibers
Slow twitch fibers
Fast twitch fibers
Recquires oxygen for ATP production
Aerobic Respiration
Doesn’t recquires oxygen for ATP production
Anaerobic Respiration
Produced by skeletal muscles all the time, especially during exercise; alternate chemical form of lactic acid
Lactate
An energy storage molecule from excess atp
Creatine phosphate
State of reduced work capacity
Fatigue
Main function is to prevent complete exhaustion of atp
Fatigue
muscles may become incapable of either contracting or relaxing
Phsyiological contracture
Type of fatigue that involved cns
Psychological fatigue
Stores oxygen temporarily
Myglobin
Increase tension of the muscle without changing its length ; equal distance
Isometric
Constant tension produced by body muscles over the long periods of time
Muscle tone
Enlarging or muscle fibers
Hypertrophy
Constant amount of tension while decreasing the length of muscle
Isotonic
Muscle tension increases as the muscle shortens
Concentric
Muscle tension is maintained
Eccentric