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
Parkinson’s disease appears to result from lack of the neurotransmitter
dopamine
a quick. automatic response
reflex
the simplest nerve pathway
reflex arc
SECTION 8.3
the largest, most important part of the nervous system
brain
the three parts of the brain
cerebrum
cerebellum
brain stem
the upper part of the brain that coordinates thought, memory, and learned behaviors
cerebrum
the lower part of the brain that helps control balance and coordinate voluntary muscle activity
cerebellum
connects to the spinal cord, controls involuntary muscles and activities of the autonomic nervous system
brain stem
the largest part of the brain and is the physical organ that helps in areas of consciousness, memory voluntary action, thinking, and intelligence
cerebrum
two halves of the cerebrum called
hemispheres
a deep grove that split the hemispheres
longitudinal fissure
the right hemisphere is connected to the ______ side of the body
the left hemisphere is connected to the ______ side of the body
right hemi: left side of body
left hemi: right side of body
the brain which specializes in details, known procedures, and formal logic
left brain
the brain which specialized in the “big picture”, creativity, and intuitive approaches to problems
right brain
the two hemispheres communicate with each other through a mass of nerve fibers located at the base of the cerebrum called the
corpus callosum
the outer layer of the cerebrum in which much of the gray matter is located
cerebral cortex
is deeply grooved in order to allow the maximum amount of gray matter to fit in a limited space
cerebral cortex
various regions in which the hemispheres are divided into that correspond to the major bones of the cranium
lobes
each hemisphere has its own lobes
TRUE
the forward portion of the __________ lobes is associated with personality, judgment, and self-control
frontal
controls voluntary movement of skeletal muscles
rear of the frontal lobes
lobes located behind the frontal lobe that allow the body to feel sensations such as temperature, pressure, and pain
make judgments about shape and texture
parietal lobes
lobes located at the back of the brain which interpret the sense of vision
if damaged, person cannot see even if have perfect eyes
occipital lobes
the right and left _________ lobes which are located on either side of the brain which are associated with senses of hearing, taste, and smell
temporal lobes
damage to the cerebral motor area
cerebral palsy
results of cerebral palsy
inability to walk
poor speech
irregular contractions of face neck or extremities
the second largest brain region
cerebellum
the function of the cerebellum is primarily to
coordinate skeletal muscle activity
most complex muscle coordination is handled by the
cerebellum
located between the cerebrum and the spinal cord
brain stem
the lowest part of the brain stem
regulates breathing, heartbeat, blood pressure, and other vital bodily function such as swallowing
medulla oblongata
all major sensory and moto pathways between the body and cerebrum cross over in
medulla oblongata
just above the medulla oblongata and links the cerebrum with the cerebellum
assists medulla oblongata in regulating breathing and coordinate movements and facial expressions
pons
above the pons lies the _______________
nerve centers here help coordinate the movement of both eyes, adjust the size of pupils in response to light, and operate the lens muscles to focus the eyes on the object of your attention
midbrain
an intricate network of neurons within the brain stem
reticular formation
the most important function of the reticular formation
serving as a master-switch
aka
it switches on your cerebral cortex to bring you to consciousness
a state of prolonged unconsciousness in which a person would go into if the reticular formation was not working correction
coma
complex brain structures that lie clustered around the brain stem at the core of the brain are collectively called
limbic system
job of limbic system
- coordinate activity of different brain parts
- generate and regulate emotions and desires
two important structures of the limbic system
thalamus
hypothalamus
acts like a switchboard, routing activation signals from the reticular formation and sensory impulses
thalamus
the control unit for the body’s automatic systems
controls autonomic nervous system and the endocrine system
hypothalamus
responsible for the physical effects of emotions
hypothalamus
part of the limbic system that processes factual memories for storage
hippocampus
part of the limbic system that helps generate emotions and processes emotional memories
amygdala
says that a person’s actions can be completely explained as responses to particular stimuli
the behavior of a person is determined by his environment, not by his mind
behaviorism
the ________ and the _________ are not the same thing
physical brain
mind
the seat of the mind
brain
SECTION 8.4
habits that can affect the nervous system from within
alcohol
smoking
nutrition
exercise
external factors that can affects the nervous system
repeated loud noises
rest or sleep
repeated or prolonged exposure to excessively loud sounds results in a form of partial or complete hearing loss known as
sounds that exceed 90-100 decibels
sensorineural deafness
periods in which the sleeper’s closed eyes show rapid eye movements as though he were watching events of a dream
REM sleep (rapid eye movement)
one of the most commonly abused drugs in the world today
alcohol
alcohol acts as a
depressant
- quickly into bloodstream from stomach and liver
- carried to brain
- interferes with neurotransmitters and motor areas
- slows the functions of the of the neurons
- depressing control centers of the brain
- produces loss of self-control
- clumsiness and lack of coordination
- muscular control detiorates
- can cause unconsciousness
movement of alcohol
degeneration and inflammation of nerves
neuritis
a child’s nervous system is completely developed at (new cells will never be added to the brain)
2 years
dead nerve cells _________ regenerate
cannot
existing nerve cells ___________ reproduce
cannot
when the spinal nerves protrude from the spinal cord in the neck because of a sudden stop
whiplash
a condition characterized by pain in the lower back and the back of the thigh
caused by a pinching of the sciatic nerve of the lower spinal cord
sciatica
the most common serious injury os the nervous system
stroke
leading cause of death through the world
stroke
causes a stroke
internal blockage or rupture of a blood vessel in the brain
one of the most common causes of death among young adults is
injury to the head
a period of paralysis of the central nervous system accompanied by a short period of unconsciousness
concussion
a loss of memory
amnesia
a more prolonged loss of consciousness may result from severe effects of
injury
poison
disease
prolonged state of unconsciousness that may not be reversible
coma
disease of the nervous system that is commonly known as lockjaw because severe spasms of the jaw muscles make it hard to open the mouth
tetanus
one of the most commons mental disorders in the elderly
a disturbance of the brain caused by physical illness elsewhere in the body
acute confusion
the disorder that results from the slow process of natural nerve cell loss
senile dementia
is caused by the death of brain cells due to blockage in the arteries that restricts blood supply to the cells
arteriosclerotic dementia
disease in which the symptoms are more severe than dementia and leaves the vicitm mor physically and intellectually disabled
Alzheimer’s disease
one common neurological disorder that affects people of all ages is the condition of
caused when neurons occasionally malfunction and begin to fire together over and over, disrupting ordinary cerebral processing and causing unconsciousness
epilepsy
SECTION 8.5
living sensors in which information is obtained and relayed to the spinal cord or brain
sensory receptors
two broad groups of sensory receptors
somatic senses
special senses
senses of your skin (primarily touch and temperature)
somatic senses
sight, hearing, smell, taste, and balance
special senses
special senses are provided by a second group of neurons located in intricately designed _________
sense organs
the skin’s receptors may be classified in three categories:
pain receptors
mechanoreceptors
thermoreceptors
a bare dendrite that reacts to a certain type of strong stimulus
pain receptors
sensory receptors responsible for sensations of tough and pressure are called
mechanoreceptors
body parts that contain an abundance of nerve endings and are sensitive to light tough and pressure
fingertips
forehead
tip of tongue
respond to temperature changes
thermoreceptors
react to temperatures above normal body temperature
heat receptors
sensitive to temperatures below normal body temperature
cold receptors
the senses of taste and smell
chemical senses
the chemical senses result from the stimulation of_______________ on the tongue and in the nose
chemoreceptors
organs responsible for taste
taste buds
most of the flavors that we taste are affected by
odors we smell
the _________ sensory receptors are located in the upper part of the nasal cavity
nose’s
connect the nose’s sensory receptors to the brain
olfactory nerve
number of primary odors
7
a flap of cartilage designed to collect sound waves and direct them into the ear
outer ear
leads to the eardrum
ear canal
line the ear canal
hairs
wax glands
a taut membrane stretched across the canal like the surface of a drum
ear drum
the vibrations of the eardrum are relayed to the inner ear by three tiny bones
malleus,
incus
stapes
the chamber containing the malleus, incus, and stapes
middle ear
the actual organ of hearing
inner ear
the main component of the inner ear
a coiled tube resembling a snail’s shell
cochlea
carries electrical messages to the brain where they are translated
auditory nerve
balance sensors
semicircular canals
the type of hearing in which the inner ear receives vibrations from the jawbone
bone conduction
ringing in the ears
tinnitus
ear infections occur when microbes from the throat travel up the ____________ to the middle ear
eustachian tube
provides a surrounding protection of heavy bone for the eye
socket or orbit
reflexive to keep foreign objects from entering the eye
eyelids
lacrimal glands produce
tears
component of tears which destroys bacteria
lysozyme
a set of six muscles attached to the eye which moves the eye
extrinsic muscles
outermost layer of the eye
