Sensorimotor Systems Flashcards
make up the majority of the human body’s tissues and are responsible for the movement of the body and the movement of materials within the body.
Muscles
The human body contains somewhere between how many muscles?
640 and 850 muscles
type of muscle found in the lining of the digestive tract, within arteries, and in the reproductive system.
Smooth muscle
type of muscle named for its striped appearance.
Striated muscle
produces the pumping action of the heart.
Cardiac muscle
attached to bones produce the majority of body movement.
Skeletal muscle
An individual muscle cell.
Muscle fiber
The contraction of a single muscle fiber.
Twitch
A long fiber strand running the length of a muscle fiber that is responsible for contraction.
Myofibril
A boundary line for each sarcomere within a myofibril.
Z line
A protein that makes up the thin filaments of the myofibril.
actin
A protein that makes up the thick filaments of the myofibril.
myosin
caused by the movement of the thick myosin filaments along the length of the thin actin filaments.
Muscle contractions
A muscle fiber containing Type IIa or Type IIb myosin filaments that contains few mitochondria, uses anaerobic metabolism, and contracts rapidly; primarily responsible for movement requiring explosive strength.
Fast-twitch fiber
A muscle fiber containing Type I myosin filaments and large numbers of mitochondria that contracts slowly using aerobic metabolism; primarily responsible for movement requiring endurance.
Slow-twitch fiber
Type IIb fibers can contract up to how many times faster than Type I fibers?
ten times
The average adult has approximately ____ amounts of fast- and slow-twitch muscles?
equal amounts
Muscle enlargement occurs in response to muscle fiber damage. When fibers are damaged due to weightlifting or other strenuous activity, more actin and myosin filaments are produced.
Exercise on Muscle Formation and Sex differences
A spinal motor neuron directly responsible for signaling a muscle fiber to contract.
alpha motor neuron
A synapse formed between an alpha motor neuron axon terminal and a muscle fiber.
neuromuscular junction
made up of a single alpha motor neuron and all the muscle fibers it innervates. A single motor unit includes either fast- or slow-twitch fibers but not a mixture of both.
motor unit
The process of gradually activating more motor units as an increasing load is placed on a muscle.
Recruitment
A sensory structure that provides feedback regarding muscle stretch. Each muscle spindle contains approximately a dozen intrafusal muscle fibers.
Muscle spindle
One of the fibers outside the muscle spindle that is responsible for contracting the muscle.
Extrafusal muscle fiber
A large, fast sensory axon that connects a muscle spindle to neurons in the spinal cord.
Ia sensory fiber
tells the intrafusal fibers regarding accurate information about how far the muscle was stretched.
Gamma motor neurons
A structure located in the tendons of muscles that provides information about muscle contraction.
Golgi tendon organ
A small, slower, sensory axon that connects the Golgi tendon organs to neurons in the spinal cord.
Ib sensory fiber
responsible for a number of reflex movements designed to protect us from injury, to maintain posture, and to coordinate the movement of our limbs.
spinal cord
A spinal reflex that requires the action of only one synapse between sensory and motor neurons.
monosynaptic reflex
A spinal reflex that requires interaction at more than one synapse.
polysynaptic reflex
A polysynaptic spinal reflex that produces withdrawal of a limb from a painful stimulus.
flexion reflex
lateral part of the spinal column, fine motor movements
Lateral pathway
ventromedial part of the spinal column, automatic movements in the neck, torso, and portions of the limbs close to the body.
Ventromedial pathway
inform the motor cortex about such factors as the direction, force, and timing required to carry out a skilled movement.
The Cerebellum
participate in the choice and initiation of voluntary movements.
Basal Ganglia
Motor area located in the gyrus rostral to the precentral gyrus; involved with managing complex sequences of movement.
Supplementary motor area (SMA)
A motor area located in the gyrus rostral to the precentral gyrus; this area participates in holding a motor plan until it can be implemented.
Pre-SMA (supplementary motor area)
a major disorder of the motor systems that causes autoimmune damage to the nicotinic ACh receptor.
Myasthenia gravis
a major disorder of the motor systems that causes abnormalities in the gene that encodes for the protein dystrophin.
muscular dystrophy
a major disorder of the motor systems that causes virus.
polio
a major disorder of the motor systems that causes compression or laceration of the spinal cord.
accidental spinal cord damage
a major disorder of the motor systems that causes possible link to genetic inheritance, possible link to viral infection.
Amyotrophic lateral sclerosis (ALS)
a major disorder of the motor systems that causes possible link to exposure to toxins.
Parkinson’s disease
a major disorder of the motor systems that causes abnormalities in the gene that encodes for the protein huntingtin.
Huntington’s disease
