Ch. 7.6 Nervous System Key Terms
autonomic nervous system
The autonomic nervous system is an important part of the peripheral nervous system. It helps maintain a balance in the involuntary functions of the body and allows the body to react in times of emergency."
brain
The brain is a mass of nerve tissue well protected by membranes and the cranium, or skull
central Nervous system
The central nervous system (CNS) consists of the brain and spinal cord
cerebellum
the section below the back of the cerebrum. It is responsible for muscle coordination, balance, posture, and muscle tone
cerebrospinal fluid
a clear, colorless fluid called cerebrospinal fluid. This fluid circulates continually between the ventricles and through the subarachnoid space. It serves as a shock absorber to protect the brain and spinal cord. It also carries nutrients to some parts of the brain and spinal cord and helps remove metabolic products and wastes
cerebrum
Cerebrum: the largest and highest section of the brain... The cerebrum is responsible for reasoning, thought, memory, judgment, speech, sensation, sight, smell, hearing, and voluntary body movement
diencephalon
Diencephalon: the section located between the cerebrum and midbrain. It contains two structures: the thalamus and hypothalamus
hypothalamus
The hypothalamus regulates and controls the autonomic nervous system, temperature, appetite, water balance, sleep, and blood vessel constriction and dilation. The hypothalamus is also involved in emotions such as anger, fear, pleasure, pain, and affection
medulla oblongata
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
meninges
The meninges are three membranes that cover and protect the brain and spinal cord
midbrain
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
nerves
Nerves are a combination of many nerve fibers located outside the brain and spinal cord
nervous system
The nervous system is a complex, highly organized system that coordinates all the activities of the body
neuron
The basic structural unit of the nervous system is the neuron, or nerve cell
parasympathetic
After the emergency, 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
peripheral nervous system
The peripheral nervous system (PNS) consists of the nerves and has two divisions: the somatic nervous system and the autonomic nervous system
pons
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
somatic nervous system
The somatic nervous system carries messages between the CNS and the body
spinal cord
The spinal cord continues down from the medulla oblongata and ends at the first or second lumbar vertebrae. It is surrounded and protected by the vertebrae. The spinal cord is responsible for many reflex actions and for carrying sensory (afferent) messages up to the brain and motor (efferent) messages from the brain to the nerves that go to the muscles and glands
sympathetic
In times of emergency, the sympathetic nervous system prepares the body to act by increasing heart rate, respiration, and blood pressure, and by slowing activity in the digestive tract
thalamus
The thalamus acts as a relay center and directs sensory impulses to the cerebrum. It also allows conscious recognition of pain and temperature
ventricles
The brain has four ventricles, hollow spaces that connect with each other and with the space under the arachnoid membrane (the subarachnoid space)