Ch. 7.6 Nervous System Key Terms
autonomic nervous system
Part of the peripheral nervous system that contains the sympathetic and parasympathetic nervous systems, which work together to control involuntary body functions.
cerebrum
The largest and highest section of the brain; it is responsible for reasoning, thought, memory, judgment, speech, sensation, sight, smell, hearing, and voluntary body movement.
midbrain
The section located below the cerebrum at the top of the brainstem; it is responsible for conducting impulses between brain parts and for certain eye and auditory reflexes.
peripheral nervous system (PNS)
Consists of the nerves and has two divisions: the somatic nervous system and the autonomic nervous system.
thalamus
Acts as a relay center and directs sensory impulses to the cerebrum. It also allows conscious recognition of pain and temperature.
brain
A mass of nerve tissue well protected by membranes and the cranium, or skull.
diencephalon
The section located between the cerebrum and midbrain; it contains the thalamus and hypothalamus.
nerves
A combination of many nerve fibers located outside the brain and spinal cord.
pons
The section located below the midbrain and in the brainstem; it is responsible for conducting messages to other parts of the brain, for certain reflex actions (including chewing, tasting, and saliva production), and for assisting with respiration.
ventricles
Four hollow spaces in the brain that connect with each other and with the space under the arachnoid membrane.
central nervous system (CNS)
Consists of the brain and spinal cord.
hypothalamus
Regulates and controls the autonomic nervous system, temperature, appetite, water balance, sleep, and blood vessel constriction and dilation. It is also involved in emotions.
nervous system
A complex, highly organized system that coordinates all the activities of the body, enabling it to respond and adapt to changes inside and outside the body.
somatic nervous system
Carries messages between the CNS and the body. It consists of 12 pairs of cranial nerves and 31 pairs of spinal nerves.
cerebellum
The section below the back of the cerebrum; it is responsible for muscle coordination, balance, posture, and muscle tone.
medulla oblongata
The lowest part of the brainstem; it connects with the spinal cord and is responsible for regulating heartbeat, respiration, swallowing, coughing, and blood pressure.
neuron
The basic structural unit of the nervous system, or nerve cell.
spinal cord
Continues down from the medulla oblongata and is surrounded and protected by the vertebrae. It is responsible for many reflex actions and for carrying sensory messages to the brain and motor messages from the brain.
cerebrospinal fluid
A clear, colorless fluid that fills the ventricles; it circulates continually between the ventricles and through the subarachnoid space. It serves as a shock absorber, carries nutrients, and helps remove metabolic products and wastes.
meninges
Three membranes that cover and protect the brain and spinal cord.
parasympathetic
The parasympathetic nervous system counteracts the actions of the sympathetic system by slowing heart rate, decreasing respiration, lowering blood pressure, and increasing activity in the digestive tract.
sympathetic
The sympathetic nervous system prepares the body to act in times of emergency by increasing heart rate, respiration, and blood pressure, and by slowing activity in the digestive tract (the "fight or flight" response).