Chapter 3: Movement Flashcards
brain and spinal cord forms
central nervous system
attach to the skeleton and span the joints, the sites where two or more bones come together
muscles
muscles that bend a joint bringing the bones closer together
flexors
muscles that straighten the joint, increasing the angle between the bones
extensors
these two muscles work in opposition
flexors and extensors
muscles that promote movement
agonists
muscles that stop movement of the agonists
antagonists
agonists and opposing antagonists contract at the same time
co-contraction
system that controls the movement of skeletal muscles
central nervous
neuron that controls muscle fibers
alpha motor neurons
muscle fibers that form a functional unit
motor unit
a disease where motor neurons die
amyotrophic lateral sclerosis (ALS)
type of involuntary movement
reflexes
best known reflex
knee jerk
stretch reflex is also called
myotatic reflex
tap below the knee with a small rubber produces a slight stretch of the
knee extensor muscle
stretch of the knee extensor muscle is sensed within the
muscle spindles
where are the senses in the spindles sent to to get to the brain
by the spinal cord to the brain
for the knee jerk response to go through
the antagonist flexor muscle must relax
set of neurons the brain uses to adjust sensitivity of the system
gamma motor neurons
receptors located where muscle fibers connect to the tendon
Golgi tendon organs
detect how much force or tension is applied to a muscle during ongoing movement
Golgi tendon organs
part of the brain essential for voluntary movement
motor cortex
regions of the brain also used to control complex or skilled voluntary movements
basal ganglia, thalamus, cerebellum, and neuron groups located within midbrain and brainstem
degeneration of neurons in a brain region called the substantia nigra
Parkinson’s disease
neurons send signals to basal ganglia using
neurotransmitter dopamine
symptoms of Parkinson’s
depletion of dopamine, tremor, rigidity
uncontrolled jerking or twitching movements
Huntington’s disease
symptoms of Huntington’s stem from
loss of inhibitory neurons in the basal ganglia
area of the brain crucial for coordinating and fine-tuning skilled movement
cerebellum
receives direct input from sensory receptors in the limbs and heads
cerebellym
poor coordination, disorders of balance, and difficulties of speech are caused by disturbance of
cerebellar function
long-term alcohol abuse is a common cause of
acquired cerebellar degeneration
