Muscular System Flashcards
Identify the major functions of muscular system
Body movement, posture maintenance, communication, respiration, heat production, heart beat, constriction of organs and vessels
How many muscles are in our body?
About 650
Are long, cylindrical muscle attached to the bones.
Skeletal muscle
Muscle that is functional in heart contraction to supply blood throughout the body
Cardiac muscle
Located on walls of hollow organs, blood vessels, and glands
Smooth muscle
True or False.
Skeletal and Cardiac Muscle requires involuntary control.
False. Skeletal muscle has voluntary control.
Ability of the muscle to shorten, reducing the distance between parts of its content.
Contractability
Ability to respond to a stimulus.
Excitability
Ability of the muscles to be stretched
Extensibility
The ability of the muscle to return to its original states after stretching and/or elongation.
Elasticity
Muscle names according to location:
Pectoralis (chest)
Gluteus (buttocks)
Brachial (arm)
Muscle name according to size
Maximus (large) Minimus (small) Major (larger than two bones) Minor (smaller than two bones) Longus (long) Brevis (short)
Muscle name according to function
Abductor (away from midline)
Adductor (towards the midline)
Masseter (a chewer)
Muscle names according to shape
Deltoid (triangular)
Quadratus (rectangular)
Teres (round)
Muscle names according to orientation of fasciculi
rectus (straight)
oblique (at an angle)
Muscle names according to number of heads
Biceps (two)
Triceps (three)
The biological system of humans that produces movement.
Muscular system
A contractile tissue and is derived from the mesodermal layer of embryonic germ cells.
Muscle
A sudden, propagating signal or impulse generated by the nervous system
Action potential
The place where the motor neuron reaches a muscle cell
Neuromuscular junction
Skeletal muscle tissue is composed of cells called?
Muscle fibers
A neurotransmitter that binds to receptors on the outside of muscle fibers
Acetylcholine
Each skeletal muscle is surrounded by a connective tissue sheath called?
Epimysium
A loose connective tissue that separates muscles fascicles from each other
Perimysium
A loose connective tissue that surrounds each muscle fiber
Endomysium
Muscle contraction where the amount of tension increases but the muscle length is attained.
Isometric contractions
Muscle tension increases as the muscle shortens
Concentric contractions
The amount of tension produced by the muscle is constant during contraction, but the length of the muscle decreases
Isotonic contractions
Tension is maintained as the muscle lengthens
Eccentric contractions
The sliding of acting myofilaments past myosin myofilaments during contraction
Sliding filament model
The resistance of a muscle to active or passive stretch, or the overall stiffness of a muscle
Muscle Tone
Also known as a floppy baby syndrome
Hypotonia
A condition that involves low muscle tone with reduced muscle strength
Hypotonia
True or False
Hypotonia is considered as a specific health sickness.
False. It is a possible sign of several other disorder that affect muscle strength or motor nerve by the brain.
Two medical conditions that may cause Hypotonia
●Down syndrome ● Muscular Dystrophy ● Cerebral palsy 2 ● Prader-Willi syndrome ● Myotonic dystrophy ● Tay-Sachs disease
An increase in the rigidity of muscle tone and reduced capacity of the muscle to stretch brought by the injury to the central nervous system, causing disruptions in the nerve pathways in charge of muscle tone.
Hypertonia
Identify and describe two forms of hypertonia
- Spasticity - stiffness related to uncontrolled reflexes
2. Rigidity - stiffness not associated with reflexes
It is a network of protein fibers that forms a stationary anchor for acting myofilaments to attach
Z disks
The basic structural and functional unit of skeletal muscle
Sarcomere
Differentiate I bands from A bands in terms of shade
I bands - light stained
A bands - dark stained
I bands consist of only?
Actin myofilaments
The band that extends the length of the myosin myofilaments within the sarcomere
A-bands
A smaller, lighter-staining region in the center of each A-band
H zone
It consists of fine protein filaments that anchor the myosin myofilaments in place
M line
It is attached at specific interval along the myosin filaments
Troponin
These have attachment sites for the myosin myofilaments that resembled two minute strands of pearl twisted together
Actin
Filaments that block the myosin myofilament binding sites on the actin myofilaments
Tropomyosin
The electrical charge difference across the cell membrane of an unstimulated cell
Resting membrane potential
The cell membrane of muscle fiber
sarcolemma
The sarcolemma has man inward tubelike folds called?
T tubules
