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
______. Tubules
responsible for the rapid transport
of material throughout neurons.
Microtubules
_____ _____. Spherical
membrane packages that store
neurotransmitter molecules ready
for release near synapses.
Synaptic vesicles
________ . Molecules
that are released from active
neurons and influence the activity
of other cells.
Neurotransmitters
The neuron cell membrane is
composed of a ___ ____
lipid bilayer
A neuron with more than two processes extending from its
cell body is classified as a _____ _____
multipolar neuron; most neurons are multipolar.
A neuron with one process extending
from its cell body is classified as a _____ _____
unipolar neuron
and a
neuron with two processes extending from its cell body is
classified as a ____ ______
bipolar neuron.
Neurons with a short axon or no axon at all are called \_\_\_\_\_\_\_; their function is to integrate the neural activity within a single brain structure, not to conduct signals from one structure to another.
interneurons
In
the central nervous system,
clusters of cell bodies are called
______
nuclei (singular nucleus)
in the
peripheral nervous system, they
are called ______
ganglia (singular
ganglion).
In the central nervous system, bundles of
axons are called ____; in the peripheral nervous system,
they are called _____.
tracts, nerves
Neurons are not the only cells in the nervous system; _____
cells are found throughout the system. Although they
have been widely reported to outnumber neurons 10 to 1,
this view has been challenged by recent research
glial
__________, for example, are glial
cells with extensions that wrap around the axons of some
neurons of the central nervous system.
Oligodendrocytes
These extensions
are rich in _____, a fatty insulating substance, and the
____ _____ that they form increase the speed and efficiency of axonal conduction.
myelin, myelin sheaths
A similar function is performed in the peripheral nervous system by \_\_\_ \_\_\_\_, a second class of glial cells.
Schwann cells
That is why effective axonal regeneration in
the mammalian nervous system is restricted to the ___ ____ ____
PNS
The greatest blessing to befall neuroscience
in its early years was the accidental discovery of the ___ ____, an Italian physician, in the early 1870s; see Rapport (2005). Golgi
was trying to stain the meninges, by exposing a block of
neural tissue to potassium dichromate and silver nitrate,
when he noticed an amazing thing.
Golgi
stain by Camillo Golgi (pronounced GOLE-jee )
Although the Golgi stain permits an excellent view of the silhouettes of the few neurons that take up
the stain, it provides no indication of the number of neurons in an area or the nature of their inner structure. The
first neural staining procedure to overcome these shortcomings was the ___ ____
Nissl stain, which was developed by Franz
Nissl, a German psychiatrist, in the 1880s.
A neuroanatomical technique that
provides information about the details of neuronal structure is ____ _____
electron microscopy
______ tracing methods are used when an
investigator wants to trace the paths of axons projecting
away from cell bodies located in a particular area.
Anterograde
_____ tracing methods work in reverse; they are
used when an investigator wants to trace the paths of
axons projecting into a particular area.
Retrograde
First, _____ means toward the nose end (the _____ end), and _____ means toward the tail end (the
_____ end); these same directions are sometimes referred to as rostral and caudal, respectively.
anterior, posterior
Second, _____
means toward the surface of the back or the top of the
head (the _____ surface), and ______ means toward the
surface of the chest or the bottom of the head (the _____
surface)
dorsal, ventral
Third, ____ means toward the midline of the
body, and ____ means away from the midline toward
the bodys _____ surfaces.
medial, lateral
To circumvent this complication, the terms ____ and
_____ are often used to refer to the top and bottom of
the primate head, respectively.
superior, inferior
_____ and _____ are two other common directional
terms. In general, _____ means close, and _____
means far. Specifically, with regard to the peripheral
nervous system, _____ means closer to the CNS, and
_____ means farther from the CNS.
Proximal, distal
brain cut in one of three different
planes: horizontal sections,
frontal sections (also termed
coronal sections), and
sagittal
sections.
A section cut down the center of the brain, between the
two hemispheres, is called a
midsagittal section. A section cut at a right angle to any
long, narrow structure, such as the spinal cord or a nerve,
is called a cross section.
____ ____ is composed largely of cell
bodies and unmyelinated interneurons, whereas ___ ____ is composed largely of myelinated axons.
Gray matter, white
matter
The two dorsal arms of the spinal gray matter are called
the ____ _____, and the two ventral arms are called the
____ ____
dorsal horns, ventral horns
All dorsal root axons, whether somatic or autonomic,
are sensory (afferent) unipolar neurons with their cell
bodies grouped together just outside the cord to form the
____ _____ ____
dorsal root ganglia
The other four divisions of the brain are often referred to collectively as
the ___ ___ the stem on which the cerebral hemispheres sit. The _____ is often referred to as the
medulla.
brain stem, myelencephalon
Not surprisingly, the myelencephalon (or medulla), the
most posterior division of the brain, is composed largely of
tracts carrying signals between the rest of the brain and the
body. An interesting part of the myelencephalon from a
psychological perspective is the ____ _____. It is a complex
network of about 100 tiny nuclei that occupies the central core of the brain stem
from the posterior boundary of the myelencephalon to the anterior boundary of
the midbrain.
reticular
formation
The ______, like the myelencephalon, houses
many ascending and descending tracts and part of the
reticular formation. These structures create a bulge, called
the ____, on the brain stem s ventral surface
metencephalon, pons
The ____
is the large, convoluted structure on the brain stem s dorsal surface. It is an important sensorimotor structure;
cerebellar damage eliminates the ability to precisely control one s movements and to adapt them to changing conditions.
cerebellum
The ______, like the metencephalon, has two divisions. The two divisions of the _______ are the
tectum and the tegmentum
mesencephalon
The _____
(roof) is the dorsal surface of the midbrain. In mammals,
the ____ is composed of two pairs of bumps, the
colliculi (little hills).
tectum
The posterior pair, called the ____ _____, have an auditory function; the anterior pair,
called the ____ _____, have a visual function. In
lower vertebrates, the function of the tectum is entirely
visual; thus, the tectum is sometimes referred to as the
optic tectum.
inferior
colliculi, superior colliculi
The ______ is the division of the mesencephalon
ventral to the tectum. In addition to the reticular formation
and tracts of passage, the ______ contains three colorful structures that are of particular interest to biopsychologists: the periaqueductal gray, the substantia nigra, and the
red nucleus
tegmentum
The ____ _____ is
the gray matter situated around the ____ _____, the
duct connecting the third and fourth ventricles; it is of special interest because of its role in mediating the analgesic
(pain-reducing) effects of opiate drugs.
periaqueductal gray, cerebral aqueduct
The _______ _____ (black substance) and the ___ _____ are both important components of the sensorimotor system.
substantia
nigra, red nucleus
The ______ is composed of two structures: the
thalamus and the hypothalamus
diencephalon
The
_____ is the large, two-lobed structure that constitutes
the top of the brain stem.
thalamus
One lobe sits on each side of the
third ventricle, and the two lobes are joined by the ___ ___, which runs through the ventricle
massa
intermedia
The most well understood thalamic nuclei are the
____ _____ _____ that receive signals from
sensory receptors, process them, and then transmit them
to the appropriate areas of sensory cortex.
sensory relay nuclei
For example,
the lateral geniculate nuclei, the medial geniculate nuclei, and the
ventral posterior nuclei are important relay
stations in the visual, auditory, and somatosensory systems, respectively.
The ______ is located just below the anterior
thalamus (hypo means below ) see Figure 3.24. It plays
an important role in the regulation of several motivated
behaviors (e.g., eating, sleep, and sexual behavior).
hypothalamus
It exerts
its effects in part by regulating the release of hormones
from the ____ _____, which dangles from it on the
ventral surface of the brain. The literal meaning of pituitary
gland is snot gland ; it was discovered in a gelatinous state
behind the nose of an unembalmed cadaver and was incorrectly assumed to be the main source of nasal mucus.
pituitary gland
The ____ ____ is the point at which the optic nerves
from each eye come together.
optic chiasm
The X shape is created because some of the axons of the optic nerve ______
(cross over to the other side of the brain) via the optic chiasm.
decussate
The decussating fibers are said to be _______
(projecting from one side of the body to the other), and
the nondecussating fibers are said to be ipsilateral (staying on the same side of the body).
contralateral
The _____ ______, which are often considered to be part of the
hypothalamus, are a pair of spherical nuclei located on the
inferior surface of the hypothalamus, just behind the pituitary.
mammillary bodies
The _________, the largest division of the human
brain, mediates the brain s most complex functions. It initiates voluntary movement, interprets sensory input, and
mediates complex cognitive processes such as learning,
speaking, and problem solving.
telencephalon
The cerebral hemispheres are covered
by a layer of tissue called the ____ _____. Because the cerebral cortex is mainly composed of
small, unmyelinated neurons, it is gray and is often
referred to as the gray matter.
cerebral cortex (cerebral bark)
The large furrows in a convoluted cortex are called
fissures, and the small ones are called sulci (singular
sulcus).
fissures, sulci
The ridges between fissures and sulci are called
____
gyri (singular gyrus)
It is apparent in Figure 3.25 that the
cerebral hemispheres are almost completely separated
by the largest of the fissures: the ____ _____
longitudinal fissure.
The cerebral hemispheres are
directly connected by a few
tracts spanning the longitudinal fissure; these hemisphere connecting tracts are called ____ _____
cerebral commissures.
The
largest cerebral commissure, the ____ _____
corpus callosum
About 90% of human cerebral cortex is ______
; that is, it is six-layered cortex of relatively
recent evolution
neocortex
First, it is apparent that
many cortical neurons fall into one of two different categories: _____cells and ____ cells. _____ cells are large multipolar
neurons with pyramid-shaped cell bodies, a large dendrite called an apical dendrite that extends from the
apex of the pyramid straight toward the cortex surface,
and a very long axon
pyramidal (pyramid-shaped) cells, stellate
star-shaped
In contrast,
_____ cells are small star-shaped interneurons (neurons with a short axon or no axon).
stellate
This vertical flow of information is the
basis of the neocortex s ______ _______; neurons in a given vertical column of neocortex often form
a mini-circuit that performs a single function
columnar organization
The _______ is one important area of cortex that is not
neocortex it has only three
major layers
hippocampus
The hippocampus is located at the medial edge of
the cerebral cortex as it folds back
on itself in the medial temporal
lobe (see Figure 3.25 on page 67).
This folding produces a shape that
is, in cross section, somewhat reminiscent of a sea horse ( hippocampus
means sea horse ). The hippocampus plays a major role in
some kinds of memory, particularly memory for spatial location
The ______ system is a circuit of midline structures that
circle the thalamus (______ means ring ). The _____ system
is involved in the regulation of motivated behaviors
including the four Fs of motivation: fleeing, feeding, fighting,
and sexual behavior.
limbic
Let s begin tracing the limbic circuit (see Figure 3.28
on page 70) at the _______ the almond-shaped nucleus in the anterior temporal lobe (______ means
almond and is pronounced a-MIG-dah-lah ) see
Swanson & Petrovich (1998). Posterior to the ______ is
the hippocampus, which runs beneath the thalamus in
the medial temporal lobe.
amygdala
Next in the ring are the _____ cortex and the fornix. The ______ cortex is
the large strip of cortex in the _____ gyrus on the
medial surface of the cerebral hemispheres, just superior
to the corpus callosum;
cingulate, cingulate
The _____, the major
tract of the limbic system, also encircles the dorsal thalamus; it leaves the dorsal end of the hippocampus and
sweeps forward in an arc coursing along the superior surface of the third ventricle and terminating in the septum and the mammillary bodies (_____ means arc )
fornix
The ______ is a midline nucleus that is located at the
anterior tip of the cingulate cortex. Several tracts connect the ______ and mammillary bodies with the amygdala and hippocampus, thereby completing the limbic
ring.
septum
