Chapter 3 Flashcards
Roughly speaking, the ____ ____ ____ is the division of the nervous system
that is located within the skull and spine; the ___ ___ ___ is the division that is located outside the skull and spine.
central nervous system (CNS), peripheral nervous system (PNS)
The somatic nervous system (SNS) is the
part of the PNS that interacts with the external environment. It is composed of _____ nerves that carry sensory
signals from the skin, skeletal muscles, joints, eyes, ears,
and so on, to the central nervous system, and ____
nerves that carry motor signals from the central nervous
system to the skeletal muscles.
afferent, efferent
The ____ ____ ____ is the part of the peripheral nervous system
that regulates the body s internal environment. It is composed of afferent nerves that carry sensory signals from internal organs to the CNS and efferent nerves that carry
motor signals from the CNS to internal organs.
autonomic nervous
system (ANS)
The _____ nerves are those autonomic motor
nerves that project from the CNS in the lumbar (small of
the back) and thoracic (chest area) regions of the spinal
cord.
sympathetic
The ____ nerves are those autonomic
motor nerves that project from the brain and sacral
(lower back) region of the spinal cord.
parasympathetic
Most of the nerves of the peripheral nervous system
project from the spinal cord, but there are 12 pairs of
exceptions: the 12 pairs of _____ nerves, which project
from the brain.
cranial
The cranial nerves include purely sensory
nerves such as the olfactory nerves (I) and the
the optic
nerves (II), but most contain both sensory and motor
fibers.
The brain and spinal cord (the CNS) are the most protected
organs in the body. They are encased in bone and covered
by three protective membranes, the three ______
meninges (pronounced men-IN-gees ).
The outer meninx (which, believe
it or not, is the singular of meninges) is a tough membrane
called the ___ ____
dura mater (tough mother).
Immediately inside
the dura mater is the ___ ___ ___
fine arachnoid membrane (spiderweblike membrane).
Beneath the arachnoid membrane is a
space called the ____ ____, which contains many
large blood vessels and cerebrospinal fluid;
subarachnoid space
then comes the
innermost meninx, the delicate ___ ____,
which adheres to the surface of the CNS.
pia mater (pious mother)
Also protecting the CNS is the ____ ____, which fills the subarachnoid space, the central
canal of the spinal cord, and the cerebral ventricles of the
brain.
cerebrospinal fluid
CSF
The ____ _____ is a small central channel that
runs the length of the spinal cord
central canal
the ____ _____
are the four large internal chambers of the brain: the two
lateral ventricles, the third ventricle, and the fourth ventricle
cerebral ventricles
Cerebrospinal fluid is continuously produced by the
____ _____ networks of capillaries (small blood
vessels) that protrude into the ventricles from the pia
mater. The excess cerebrospinal fluid is continuously absorbed from the subarachnoid space into large bloodfilled spaces, or dural sinuses, which run through the dura
mater and drain into the large jugular veins of the neck.
choroid plexuses
Fortunately, there is a mechanism that impedes the passage of many toxic substances
from the blood into the brain:
the blood brain barrier
The ______ system is composed of the brain and the
spinal cord.
(1) central nervous
The part of the peripheral nervous system that regulates the body s internal environment is the ______
system.
(2) autonomic nervous
Nerves that carry signals away from a structure, such
as the CNS, are ______ nerves.
(3) efferent,
The ANS nerves that project from the thoracic and lumbar regions of the spinal cord are part of the ______
system.
(4) sympathetic nervous
______ nerves stimulate, organize, and mobilize
energy resources in threatening situations.
(5) Sympathetic
The vagus nerves are the longest ______.
(6) cranial nerves
The olfactory nerves and optic nerves are the only two
purely sensory ______.
(7) cranial nerves
The innermost meninx is the ______.
(8) pia mater,
The cerebral ventricles, central canal, and subarachnoid
space are filled with ______.
(9) cerebrospinal fluid
______ is continuously produced by the choroid
plexuses.
(10) Cerebrospinal
fluid
A tumor near the ______ can produce hydrocephalus.
(11) cerebral aqueduct
The ______ blocks the entry of many large molecules
into brain tissue from the circulatory system.
(12) blood brain barrier
_____ are cells that are
specialized for the reception, conduction, and transmission of electrochemical signals. They come in an incredible variety of shapes and sizes
neurons
___ ____. The metabolic center
the neuron; also called the soma.
Cell body
____ _____.The semipermeable
membrane that encloses the neuron
Cell membrane
_______ The short processesemanating from
the cell body, which receive most of the synaptic
contacts from other neurons.
Dendrites.
___ _____ The cone-shaped
region at the junction between the
axon and the cell body.
Axon hillock.
____ .The long, narrow process
that projects from the cell body.
Axon
_____ .The fatty
insulation around
many axons.
Myelin
___ ____ ____. The gaps
between sections of myelin.
Nodes of Ranvier(pronounced
RAHN-vee-yay )
______. The buttonlike endingsof
the axon branches, which release
chemicals into synapses.
Buttons
_______. The gaps between
adjacent neurons across which
chemical signals are transmitted.
Synapses
\_\_\_\_\_ \_\_\_\_\_\_ . A system of folded membranes in the cell body; rough portions (those with ribosomes) play a role in the synthesis of proteins smooth portions(those without ribosomes) play a role in the synthesis of fats.
Endoplasmic reticulum
_____ .The clear internal
fluid of the cell.
Cytoplasm
_____. Internal cellular
structures on which proteins are
synthesized; they are located
on the endoplasmic reticulum
Ribosomes
___ _____.A connected
system of membranes that
packages molecules in vesicles.
Golgi complex
_____ . The spherical
DNA-containing structure of the
cell body.
Nucleus
______. Sites of aerobic
(oxygen-consuming) energy
release
Mitochondria