Ch. 7.6 Key Terms
Autonomic Nervous System (ANS)
Contains the sympathetic and parasympathetic nervous systems, which work together to control involuntary body functions.
Brain
A mass of nerve tissue well protected by membranes and the cranium, or skull.
Nerves
: A combination of many nerve fibers located outside the brain and spinal cord.
Meninges
The three membranes that cover and protect the brain and spinal cord.
Nervous System
: A complex, highly organized system that coordinates all the activities of the body.
Neuron
The basic structural unit of the nervous system, or nerve cell.
Spinal Cord
: Continues down from the medulla oblongata and ends at the first or second lumbar vertebrae. It 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.
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.
Ventricles
: The brain has four hollow spaces that connect with each other and with the space under the arachnoid membrane
Central Nervous System
Consists of the brain and spinal cord.
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.
thalamus
Acts as a relay center and directs sensory impulses to the cerebrum.
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.
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.
Sympathetic
Prepares the body to act by increasing heart rate, respiration, and blood pressure, and by slowing activity in the digestive tract.
Diencephalon
The section located between the cerebrum and midbrain. It contains two structures: the thalamus and hypothalamus.
Somatic Nervous System
(SNS): Carries messages between the CNS and the body.
Cerebrospinal Fluid
A clear, colorless fluid that fills the ventricles and circulates continually between the ventricles and through the subarachnoid space. It serves as a shock absorber to protect the brain and spinal cord.
16. Peripheral Nervous System
Consists of the nerves and has two divisions: the somatic nervous system and the autonomic nervous system.
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.
Cerebellum
The section below the back of the cerebrum. It is responsible for muscle coordination, balance, posture, and muscle tone.
Parasympathetic
Counteracts the actions of the sympathetic system by slowing heart rate, decreasing respiration, lowering blood pressure, and increasing activity in the digestive tract.