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