Chapter 8-The Nervous System Flashcards
What nervous system includes the brain and the spinal cord, which are both encased in bone for protection?
Central nervous system
What nervous system consists of the nerves that branch from the brain and spinal cord?
Peripheral nervous system
What is the principal organ of the nervous system?
Brain
What is a thick bundle of nerve fibers located within the spinal cavity?
Spinal cord
What are the 31 pair of nerves that transmit nerve signals to and from the rest of the body?
Spinal nerves
What are the 12 pair of nerves that branch directly from the brain stem and transmit nerve signals to and from the eyes, ears, mouth, face, and scalp?
Cranial nerves
The spinal cord and brain are covered by a triple layer of protective tissues known as the:
Meninges
A clear fluid called _________ circulates through the fibers of the arachnoid, serving to cushion the brain when you bump your head.
Cerebrospinal fluid
The brain and spinal cord are both made of two basic kinds of cells:
Glial cells
Neurons
What cell of the brain and spinal cord supports and insulates nerve tissue?
Glial cells
What cell of the brain and spinal cord are the actual nerve cells?
Neurons
The __________ of each neuron contains a nucleus and most of the nerve cell’s cytoplasm.
Cell body
What is a short, branched extension of the cell that receives nerve impulses from other neurons and conducts them toward the cell body?
Dendrite
What is a neuron’s long extension which relays nerve impulses from the cell body to other neurons?
Axon
What is found within the brain and spinal cord and consists of the cell bodies of neurons and is gray because the cell bodies lack myelin?
Gray matter
What is a white, specialized covering?
Myelin
The _______ of a brain and spinal cord is composed of axons and glial cells that are white because of their myelin content?
White matter
What is a mass of cell bodies?
Ganglion
Some ganglia are grouped together to form a large nerve mass called a:
Plexus
A group of cell bodies in the brain or spinal cord are known as a:
Nerve center
Neurons that transmit information to the central nervous system from the sense of sight, hearing, taste, touch, and smell, as well as those that transmit pain signals are known as:
Sensory neurons
Neurons that relay signals from the central nervous system to the other parts of the body are known as:
Motor neurons
What are only found in the central nervous system and relay signals between neurons or groups of neurons, and are responsible for the processing of information by the brain?
Interneurons
What are the tightly sealed capillary walls that protect the central nervous system from being permanently damaged every time you get sick?
Blood-brain barrier