Ch. 7.6 Nervous System Key Terms
what is Nervous System
A complex, highly organized system that coordinates all the activities of the body, enabling the body to respond and adapt to changes inside and outside the body.
what is Neuron (or nerve cell)
The basic structural unit of the nervous system, consisting of a cell body, dendrites (carry impulses toward the cell body), and a single axon (carries impulses away from the cell body).
what are Nerves
A combination of many nerve fibers located outside the brain and spinal cord.
what is the Central Nervous System (CNS)
One of the two main divisions of the nervous system, consisting of the brain and spinal cord.
what is Peripheral Nervous System (PNS
Consists of the nerves and has two divisions: the somatic nervous system and the autonomic nervous system.
whjat is Somatic Nervous System:
A division of the PNS that carries messages between the CNS and the body, consisting of 12 pairs of cranial nerves and 31 pairs of spinal nerves.
what is Autonomic Nervous System
A division of the PNS that works to control involuntary body functions and maintain balance (homeostasis). It contains the sympathetic and parasympathetic nervous systems.
what is Sympathetic (Nervous System)
Prepares the body to act in times of emergency (fight or flight response), increasing heart rate, respiration, and blood pressure, and slowing activity in the digestive tract.
what is Parasympathetic (Nervous System)
Counteracts the actions of the sympathetic system, slowing heart rate, decreasing respiration, lowering blood pressure, and increasing activity in the digestive tracts.
what is Brain
A mass of nerve tissue protected by membranes and the cranium (skull), which interprets sensory information and immediately directs the correct response.
what is Spinal Cord
The structure that continues down from the medulla oblongata and is protected by the vertebrae, responsible for many reflex actions and carrying sensory and motor messages.
what is Cerebrum
The largest and highest section of the brain, responsible for reasoning, thought, memory, judgment, speech, sensation, sight, smell, hearing, and voluntary body movement.
what is the Cerebellum
The section below the back of the cerebrum, responsible for muscle coordination, balance, posture, and muscle tone.
what is Diencephalon
The section located between the cerebrum and midbrain, containing the thalamus and hypothalamus.
what is Thalamus
Part of the diencephalon that acts as a relay center, directing sensory impulses to the cerebrum, and allowing conscious recognition of pain and temperature.
what is Hypothalamus
Part of the diencephalon that regulates and controls the autonomic nervous system, temperature, appetite, water balance, sleep, and is involved in emotions.
what is Midbrain
The section located below the cerebrum at the top of the brainstem, responsible for conducting impulses between brain parts and for certain eye and auditory reflexes.
what are Pons
The section located below the midbrain in the brainstem, assisting with respiration and responsible for reflex actions including chewing, tasting, and saliva production.
what is Medulla Oblongata
The lowest part of the brainstem, which connects with the spinal cord, responsible for regulating heartbeat, respiration, swallowing, coughing, and blood pressure.
what is Meninges (singular: meninx)
Three membranes (dura mater, arachnoid membrane, and pia mater) that cover and protect the brain and spinal cord.
what is Ventricles
Four hollow spaces in the brain that connect with each other and are filled with cerebrospinal fluid.
what is Cerebrospinal Fluid (CSF)
A clear, colorless fluid that circulates within the ventricles and subarachnoid space, serving as a shock absorber, carrying nutrients, and removing wastes.