Unit 5: Muscular System Flashcards
what are the functions of muscle tissue
motion posture regulation of organ volume thermogenesis protection
how does the muscular system help with motion
moving the skeleton levels of the body
how does the muscular system help with posture
stabilizes body positions
how does the muscular system help with regulation of organ volume
muscles compress around the organs to keep them in place
how does the muscular system help in thermogenesis
the muscles produce heat
how does the muscular system help in protection of internal organs
the abdominal muscles protect that vulnerable intestines that have no bone over them
what are the four characteristics of muscle tissue
Elasticity, Excitability (irritability), Extensibility, and Contractility
(EECE)
what is the characteristics of skeletal tissue
voluntary, striated, multiple ecentric nucleus(s)
what is the characteristics of smooth muscle
involuntary, non-striated, central nucleus
what is the characteristics of cardiac muscle
involuntary, striated, contains intercalated disks
what is the function of the skeletal system
movement, posture
what is the function of smooth muscle
controls diameter of blood vessels, peristalsis, muscular contractions to push urine out of bladder
(wave-like contractions) to propel food and wastes through the digestive system and to move urine from the kidneys to the urinary bladder
peristalsis
thin, light color myofilaments; thin muscle filaments
Actin
blocks actin’s active sites preventing cross-bridge formation with myosin
Tropomyosin
one subunit binds to actin, another binds to tropomyosin, and the last binds to calcium; contains three subunits
troponin
what are the two regulatory proteins
tropomyosin, and troponin
a nerve carrying impulses from the brain and stimulates muscles to contract
motor neuron
the end of the axon terminal where it attaches to the muscle fiber
neuromuscular junction
the location on the muscle fiber at the end of the axon terminal
motor end plate
the neurotransmitter released from the synaptic vesicles which initiates an action potential in the muscle fiber
Acetylcholine (Ach)
body segment with most mass, usually more proximal, has a larger surface area
origin
body segment with least mass, usually more distal, has a smaller surface area, moveable end
insertion
the muscle that is responsible for the majority of force when a movement is executed
agonist (prime mover)
the muscle which performs the opposite movement of the agonist
antagonist
a muscle that assists the agonist by providing additional force or directing the force of the agonist so the movement can be effectively executed
synergist
a muscle that functions to stabilize a point or body position
fixator (stabilizer)
where is the biceps brachii located and what is the function
anterior aspect of the upper arm, flexes the forearm
where is the triceps brachii located and what is the function
posterior aspect of the upper arm, extends the forearm
where is the sternocleidomastoid located and what is the function
anterior aspect of the neck, flexes the head and neck
where is the trapezius located and what is the function
posterior aspect of the neck, extends the head and neck (shrugs shoulders)
where is the deltoid located and what is the function
covers the shoulder, abducts the arm
where is the pectoralis major located and what is the function
chest, adducts the arm
where is the latissimus dorsi located and what is the function
superficial muscle on the back (lumbar), extends a flexed arm or hyperextends the arm from the anatomic position
where is the diaphragm located and what is the function
internal muscle that separates the thoracic and abdominal cavity, assists in breathing
where is the gastrocnemius located and what is the function
posterior aspect of the lower leg, plantar flexes the foot
where is the hamstring muscle group located and what is the function
posterior aspect of the thigh, flexes the lower leg
where is the quadriceps muscle group located and what is the function
anterior aspect of the thigh, extends the lower leg
where is the gluteus maximus located and what is the function
buttocks region, extends a flexed thigh or hyperextends the thigh from anatomical position
a widespread musculoskeletal pain and fatigue disorder for which the cause is still unknown. means pain in the muscles, ligaments, and tendons
fibromyalgia
group of genetic diseases characterized by atrophy of skeletal muscle tissue.
muscular dystrophy
involves soreness and pain in the front lower leg due to excessive straining of the flexor digitorum longus. results of walking up and down hills or overbuilding the gastrocnemius
shin splints
is characterized by muscle pain and involves the overstretching or tearing of muscle fibers
muscle strain
layers around the muscle from superficial to deep
epimysium, perimysium, and endomysium (ep-pe-en; epi-pen)
Is the functional unit in the muscular system
sarcomere
the area between two I bands of a sarcomere, marked by partial overlapping of actin and myosin filaments
A-band
the area between a sarcomere, occupied by myosin myofilaments only
H-zone
the area between a sarcomere, occupied by actin myofilaments only
I-band
where actin filaments are linked; forms borders of the sarcomere
Z-disk
area on the sarcomere that shortens during muscular contraction
H-zone
I-band
area on the sarcomere that stays the same during contraction
A-band
