Chapter 8 Flashcards
SECTION 8.1
a biologist who studies the nervous system
neurobiologist
a physician who specializes in DISORDERS of the nervous system
neurologist
the two divisions of the nervous system
central nervous system
peripheral nervous system
includes the brain and the spinal cord
central nervous system
consists of the nerves that branch from the brain and spinal cord
peripheral nervous system
principal organ of the nervous system
brain
a thick bundle of nerve fibers located within the spinal cavity which
allows the brain to communicate with most of the body
spinal cord
pairs of nerves that branch from the cord and extend out of the spinal cavity through the gaps in the vertebrae
transmits nerve signals to and from the rest of the body
spinal nerves
number of spinal nerve pairs
31
nerves that branch directly from the brain stem and transmit nerve signals to and from the eyes, ears, mouth, face, and scalp
cranial nerves
number of cranial nerve pairs
12
the spinal cord and brain are covered by a triple layer of protective tissues known as
meninges
the outer layer of the meninges
one of the strongest tissues of the body that serves primarily as a flexible protective layer
dura mater
the middle layer of the meninges
form an intricate 3D network around the brain
arachnoid
the inner layer of the meninges
forms a delicate covering that rests directly against the brain and spinal cord
pia mater
a clear fluid that circulates through the fibers of the arachnoid mater and serves as cushion when you bump your head
cerebrospinal fluid
the two basic kinds of cells that make up the brain and spinal cord
glial cells
neurons
cells which support and insulate nerve tissue
glial cells
the actual nerve cells
neurons
contains a nucleus and most of the nerve cell’s cytoplasm
cell body
a short, branched extension of the cell that receives nerve impulses from other neurons and conducts them toward the cell body
dendrite
a long extension that relays nerve impulses from the cell body to other neurons
axon
nerve impulses travel in _________________ in a nerve fiber
one direction
dendrites travel toward the
cell body
travel from the cell body in a nerve impulse
axon
found within the brain and spinal cord and consists largely of cell bodies of neurons
gray matter
white specialized covering that is lacking in gray matter, making it gray not white
myelin
is composed of axons and glial cells that are white because of their myelin content
white matter
masses of cell bodies
ganglia
ganglia are grouped together to form a large nerve mass called a
plexus
plexus located at the back of the neck and shoulders and is the group of ganglia from which branch of median nerve and other arm nerves
brachial plexus
a group of cell bodies in the brain or spinal cord
nerve centers
nerve centers in the medulla oblangata of the brain stem control
breathing
neurons that transmit information to the central nervous system from the sense of sight, hearing, taste, touch, smell, and those that transmit pain signals
sensory neurons
neurons that relay signals from the central nervous system to other parts of the body
motor neurons
found only in the CNS and relay signals between neurons or groups of neurons
responsible for processing of information by the brain
interneurons
protect the central nervous system from being permanently damaged every time you get sick
bloodbrain barrier
brain’s white blood cells which help protect the brain from infection
microglia
disease that is caused when invading microorganisms enter the nerve tissue and infect the meninges
meningitis
a state of prolonged unconsciousness
serious brain damage can result
coma
a serious disease that attacks the spinal cord
is caused by a virus that enters the motor neurons of the spinal cord and destroys some of them
poliomyletis or POLIO
bundles of nerve fibers (axon) branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body
peripheral nervous system
one of the longest nerves in the body
sciatic nerve
nerve that connects the leg extremities with the spinal cord in the lower back
sciatic nerve
pairs of cranial nerves (branching directly from brain)
12
pairs of spinal nerves (connected to the brain through the spinal cord)
31
most nerves contain both sensory and motor fibers and thus are known as
mixed nerves
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
polio is a ________ disease
viral
meningitis is a ________________ disease
bacterial or viral
carry impulses from the brain and spinal cord to produce action in muscles and organs
motor nerve fibers
the part of the peripheral nervous system that controls the heart and other internal organs
responsible for routine activities (involuntary functions
autonomic nervous system
controls the digestive system, various glands, and thousands of other vital functions
autonomic nervous system
responds to your body’s needs during increased activity and in emergency situations by causing heartbeat and breathing rates to increase, thus supplying more blood so that you can respond quickly
sympathetic division
acts as a balance to counteract the actions of the sympathetic division
causes heart to slow down
parasympathetic division
can be likened to a two-way highway consisting of thousands of lanes in each direction, all of which are channeled to the ascending and descending nerve tracts of the spinal cord
peripheral nervous system
the two divisions of the autonomic nervous system
sympathetic
parasympathetic
in the stomach, the parasympathetic division _____________ while the sympathetic division _______________
parasympathetic– stimulates
sympathetic– inhibits
generally, the parasympathetic division stimulates while organs _________; and the sympathetic division stimulates organ when you are ____________
parasympathetic— rest
sympathetic— active
SECTION 8.2
nerve cells
neurons
special glial cells that surround the axons extending from the nerve cell bodies of peripheral nerves
Schwann cells
produce layers of myelin sheathing that acts much like the insulation on an electrical wire
Schwann cells
in the brain and spinal cord, myelin sheath for axons are provided by special glial cells called
oligodendrocytes
made by Schwann cells
myelin
disease of the brain and spinal cord that occurs when the body’s immune system attacks the glial cells that provide myelin sheaths for nerve cell axons (usually attacks adults
multiple sclerosis
symptoms of MS
blurred or double vision
disturbance of sensation
muscle weakness
MS occurs in the
occurs in nerves fibers related to sensations, vision, and movement of limbs
the inability of the muscles to move
paralysis
the 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 cell
action potential
a synapse between a neuron and muscle fiber
neuromuscular junction
an enclosed junction between two neurons or a neuron and another cell
synapse
when the action potential reaches the synapse, it causes a chemical known as a ______________ to be released into the synapse
neurotransmitter
a potent inhibitor of impulse transmission in motor nerves is
botulinum toxin
the most deadly type of food poisoning
botulism
one serious disease of the nervous system that affect the patient’s control of posture and movements;
is characterized by tremors and stiffness in limbs
Parkinson’s disease