Nervous + Muscular system Flashcards
what is actin?
a thin filament protein involved in muscle contraction
what is myosin?
a thick filament protein involved in muscle contraction
what is an A band?
the dark band in a sarcomere representing where myosin filaments are present
what is an I band?
the light band in a sarcomere representing where actin filaments are present
describe aerobic exercise
physical activity that uses oxygen to produce energy, promoting cardiovascular health and endurance
define contractility
the ability of muscle tissue to shorten and generate force
define elasticity
the ability of a muscle tissue to return to its original length after being stretched
define endomysium
sheath of connective tissue that surrounds each muscle fiber
define epimysium
a sheath of connective tissue that surrounds the entire muscle
define perimysium
a sheath of connective tissue that surrounds a fascicle
define Golgi tendon organ (GTO)
a sensory receptor located in tendons that detects changes in muscle tension
stops contraction/mm relaxation
define irritability/responsivity
the ability of muscle tissue to respond to stimuli, typically from the nervous system
define an isometric contraction
no movement occurs
ex: holding a plank position
define an isotonic contraction
movement occurs
concentric vs eccentric
ex: lifting a box or squatting
explain the 5 golden rules of skeletal muscle activity
- With a few exceptions, all muscles cross at least 1 joint
- The bulk of a muscle mass lies proximal to the joint it crosses
- All skeletal muscles have an origin and insertion
- During contraction, the insertion moves toward the origin
- All skeletal muscles can only pull, never push
tendons vs ligaments
Tendons: connect muscle to bone
Ligaments: connect bone to bone
define muscle spindle
Skeletal muscle (intrafusal fibers)
- Measures: muscle stretch and length
- Reflex: resist stretch
what are the 4 muscle movers and what do they do?
- Agonist: prime mover
- Antagonist: opposes prime mover
- Synergists: assists prime mover, reduces undesirable movements
- Fixators: specialized synergist, stabilizes to allow the prime mover to move the insertion point
describe cardiac muscle type
- branching chains, uninucleate, striations, intercalated discs
- involuntary, slow contraction
- controls pacemaker (SA node) and nervous system
describe skeletal muscle type
- single, long and cylindrical, multinucleate, striations
- voluntary contraction, speed varies
- controls the nervous system
describe smooth muscle type
- single, fusiform, uninucleate, no striations
- involuntary contraction, speed varies
- controls nervous system, hormones, chemicals, and stretch
what are the 4 skeletal muscle functions?
- Produce movement
- Maintain body posture and position
- Stabilize joints
- Produce heat
describe the 4 skeletal muscle fiber properties
- irritability/responsivity
- Contractility
- Extensibility
- Elasticity
describe the key components of a neuromuscular junction
The neuromuscular junction is where a motor neuron communicates with a muscle fiber. It includes the axon terminal of the neuron, the synaptic cleft, and the motor end plate (specialized region of the sarcolemma) on the muscle fiber.