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
What disease can occur when invading microorganisms enter the nerve tissue and infect the meninges?
Meningitis
In severe cases, the pressure on the brain impairs its functioning, causing the patient to become delirious or slip into a ________, a state of prolonged unconsciousness.
Coma
What serious disease that attacks the spinal cord is caused by a virus which enters the motor neurons of the spinal cord and destroys them?
Poliomyelitis
What nervous system consists of nerves?
Peripheral nervous system
What are bundles of nerve fibers branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body?
Nerves
How many pairs of cranial nerves (branching directly from the brain) are there?
12
How many pairs of spinal nerves (connected to the brain by way of the spinal cord) are there?
31
Most nerves contain both sensory and motor fibers and thus are known as:
Mixed nerves
What carry impulses from light, taste, sound, touch, and pain from other parts of the body to the spinal cord and brain for analysis?
Sensory nerve fibers
What carry impulses from the brain and spinal cord to produce action in muscles and organs?
Motor nerve fibers
What is a biologist who studies the nervous system?
Neurobiologist
What is a bundle of axons branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body?
Nerve
What is the part of the peripheral nervous system that controls the heart and other internal organs?
Autonomic nervous system
Each organ or gland must be turned on and off at specific times; what two parts of the autonomic nervous system are responsible for this and are controlled by the hypothalamus of the brain?
Sympathetic division
Parasympathetic division
The axons that extend from the nerve cell bodies in peripheral nerves are surrounded by special glial cells called:
Schwann cells
What is a disease of the brain and spinal cord and usually strikes adults, and occurs when the body’s immune system attacks the glial cells that provide myelin sheaths for nerve cell axons?
Multiple sclerosis
Permanent damage of multiple sclerosis leads to gradual __________, the inability of the muscles to move.
Paralysis
What is a wave of electrical activity that is propagated by fast-acting, voltage-sensing ion gates that quickly open and close, allowing sodium and potassium ions to briefly flow into and out of the cells?
Action potential
The axons of sensory neurons and Interneurons usually end at a ________, an enclosed junction between the axon of one neuron and the dendrites or cell body of another.
Synapse
When the action potential reaches the synapse, it causes a chemical known as a _________ to be released into the synapse.
Neurotransmitter
What serious disease of the nervous system affects the patient’s control of posture and movement and is characterized by tremors and the stiffness of the limbs?
Parkinson’s disease
What is a quick, automatic response, and is the simplest act of the nervous system?
Reflex
The simplest nerve pathway is a ________, which may involve as few as two or three nerve cells.
Reflex arc
What are the three main parts f the brain?
Cerebrum
Cerebellum
Brain stem
What is the largest part of the brain and is the physical organ that helps you in the areas of consciousness, memory, voluntary actions, thinking, and intelligence?
Cerebrum
The cerebrum consists of two halves called the:
Right hemisphere
Left hemisphere
The two hemispheres of the cerebrum communicate with each other through a mass of nerve fibers called the ________, located at the base of the cerebrum.
Corpus callosum
Much f the brain’s gray matter is located in the ________, the outer layer of the cerebrum.
Cerebral cortex
A physician who specializes in disorders of the nervous system is called a:
Neurologist
The convulsions of each of the cerebral hemispheres are divided by shallow grooves into various regions, __________, that correspond to the major bones of the cranium.
Lobes
What is the rear portion of the frontal lobe of the brain that controls the voluntary movement of the skeletal muscles?
Motor area
Damage to the cerebral motor area of the brain is known as:
Cerebral palsy