Psych 130: Physiological Psychology
Chapter 3: Anatomy of the Nervous composed of afferent nerves and
System efferent nerves.
▪ Afferent nerves: carries
Division of the Nervous System sensory signals from the skin,
skeletal muscles, joints, eyes,
The vertebrate nervous system is composed
ears, and so on, to the central
of two divisions: the central nervous system
nervous system.
and the peripheral nervous system.
▪ efferent nerves: carries
motor signals from the
The central nervous system (CNS) is the central nervous system to the
division of the nervous system located within skeletal muscles.
the skull and spine, and the peripheral
nervous system (PNS) is the division located
Autonomic Nervous System
outside the skull and spine.
- It is the part of the peripheral
nervous system that regulates the
body’s internal environment. It is
composed of afferent and efferent
nerves.
▪ afferent: carries sensory
signals from internal organs
to the CNS.
▪ efferent: carries motor
signals from the CNS to
internal organs.
The autonomic nervous system has two
kinds of efferent nerves: sympathetic nerves
and parasympathetic nerves.
The peripheral nervous system is also
composed of two divisions: the somatic
nervous system and the autonomic nervous
system.
Somatic Nervous System Sympathetic nerves: are autonomic motor
nerves that project from the CNS in the
- It is the part of the PNS that interacts lumbar (small of the back) and thoracic
with the external environment. It is (chest area) regions of the spinal cord.
,Psych 130: Physiological Psychology
Parasympathetic nerves: are those of cranial nerves, which project from the
autonomic motor nerves that project from brain.
the brain and sacral (lower back) region of
the spinal cord.
All sympathetic and parasympathetic nerves
are two-stage neural paths: The sympathetic
and parasympathetic neurons project from
the CNS and go only part of the way to the
target organs before they synapse on other
neurons (second-stage neurons) that carry
the signals the rest of the way.
However, the sympathetic and
parasympathetic systems differ in that the
sympathetic neurons project from the CNS Meninges
synapse on second-stage neurons at a
substantial distance from their target organs, The brain and spinal cord (the CNS) are the
whereas the parasympathetic neurons most protected organs in the body. They are
project from the CNS synapse near their encased in bone and covered by three
target organs on very short second-stage protective membranes, the three meninges.
neurons.
dura mater (tough mother)
Sympathetic nerves stimulate, organize, and - the outer meninx, a tough membrane.
mobilize energy resources in threatening
situations, whereas parasympathetic nerves arachnoid membrane
act to conserve energy; each autonomic
target organ receives opposing sympathetic - spider-web-like membrane, inside
and parasympathetic input, and its activity is the dura mater.
thus controlled by relative levels of
sympathetic and parasympathetic activity; subarachnoid space
and sympathetic changes are indicative of
- beneath the arachnoid membrane
psychological arousal, whereas
which contains many large blood
parasympathetic changes are indicative of
vessels and cerebrospinal fluid.
psychological relaxation.
pia mater
- innermost meninx which adheres to
the surface of the CNS.
Ventricles and Cerebrospinal Fluid
cerebrospinal fluid (CSF)
- fills the subarachnoid space, the
Most of the nerves of the peripheral nervous central canal of the spinal cord, and
system project from the spinal cord, but the cerebral ventricles of the brain.
there are 12 pairs of exceptions: the 12 pairs - supports and cushions the brain.
, Psych 130: Physiological Psychology
- patients who have had some of their The subarachnoid space, central canal, and
cerebrospinal fluid drained away cerebral ventricles are interconnected by a
often suffer raging headaches and series of openings and thus form a single
experience stabbing pain each time reservoir.
they jerk their heads.
- produced by the choroid plexuses
(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 blood-
filled spaces, or dural sinuses, which
run through the dura mater and
drain into the large jugular veins of
the neck.
Hydrocephalus: this happens when the flow
of cerebrospinal fluid is blocked by a tumor
near one of the narrow channels that link the
ventricles—for example, near the cerebral
aqueduct, which connects the third and Blood-brain barrier
fourth ventricles. The resulting buildup of
fluid in the ventricles causes the walls of the A mechanism that impedes the passage of
ventricles, and thus the entire brain, to many toxic substances from the blood into
expand, producing a condition called the brain. This barrier is a consequence of the
hydrocephalus (water head). Hydrocephalus special structure of cerebral blood vessels.
is treated by draining the excess fluid from
the ventricles and trying to remove the In the rest of the body, the cells that compose
obstruction. the walls of blood vessels are loosely packed;
as a result, most molecules pass readily
central canal through them into surrounding tissue. In the
brain, however, the cells of the blood vessel
- a small central channel that runs the walls are tightly packed, thus forming a
length of the spinal cord. barrier to the passage of many molecules—
particularly proteins and other large
cerebral ventricles molecules.
- the four large internal chambers of
The blood–brain barrier does not impede the
the brain: the two lateral ventricles,
the third ventricle, and the fourth passage of all large molecules. Some large
ventricle molecules that are critical for normal brain
function (e.g., glucose) are actively
Chapter 3: Anatomy of the Nervous composed of afferent nerves and
System efferent nerves.
▪ Afferent nerves: carries
Division of the Nervous System sensory signals from the skin,
skeletal muscles, joints, eyes,
The vertebrate nervous system is composed
ears, and so on, to the central
of two divisions: the central nervous system
nervous system.
and the peripheral nervous system.
▪ efferent nerves: carries
motor signals from the
The central nervous system (CNS) is the central nervous system to the
division of the nervous system located within skeletal muscles.
the skull and spine, and the peripheral
nervous system (PNS) is the division located
Autonomic Nervous System
outside the skull and spine.
- It is the part of the peripheral
nervous system that regulates the
body’s internal environment. It is
composed of afferent and efferent
nerves.
▪ afferent: carries sensory
signals from internal organs
to the CNS.
▪ efferent: carries motor
signals from the CNS to
internal organs.
The autonomic nervous system has two
kinds of efferent nerves: sympathetic nerves
and parasympathetic nerves.
The peripheral nervous system is also
composed of two divisions: the somatic
nervous system and the autonomic nervous
system.
Somatic Nervous System Sympathetic nerves: are autonomic motor
nerves that project from the CNS in the
- It is the part of the PNS that interacts lumbar (small of the back) and thoracic
with the external environment. It is (chest area) regions of the spinal cord.
,Psych 130: Physiological Psychology
Parasympathetic nerves: are those of cranial nerves, which project from the
autonomic motor nerves that project from brain.
the brain and sacral (lower back) region of
the spinal cord.
All sympathetic and parasympathetic nerves
are two-stage neural paths: The sympathetic
and parasympathetic neurons project from
the CNS and go only part of the way to the
target organs before they synapse on other
neurons (second-stage neurons) that carry
the signals the rest of the way.
However, the sympathetic and
parasympathetic systems differ in that the
sympathetic neurons project from the CNS Meninges
synapse on second-stage neurons at a
substantial distance from their target organs, The brain and spinal cord (the CNS) are the
whereas the parasympathetic neurons most protected organs in the body. They are
project from the CNS synapse near their encased in bone and covered by three
target organs on very short second-stage protective membranes, the three meninges.
neurons.
dura mater (tough mother)
Sympathetic nerves stimulate, organize, and - the outer meninx, a tough membrane.
mobilize energy resources in threatening
situations, whereas parasympathetic nerves arachnoid membrane
act to conserve energy; each autonomic
target organ receives opposing sympathetic - spider-web-like membrane, inside
and parasympathetic input, and its activity is the dura mater.
thus controlled by relative levels of
sympathetic and parasympathetic activity; subarachnoid space
and sympathetic changes are indicative of
- beneath the arachnoid membrane
psychological arousal, whereas
which contains many large blood
parasympathetic changes are indicative of
vessels and cerebrospinal fluid.
psychological relaxation.
pia mater
- innermost meninx which adheres to
the surface of the CNS.
Ventricles and Cerebrospinal Fluid
cerebrospinal fluid (CSF)
- fills the subarachnoid space, the
Most of the nerves of the peripheral nervous central canal of the spinal cord, and
system project from the spinal cord, but the cerebral ventricles of the brain.
there are 12 pairs of exceptions: the 12 pairs - supports and cushions the brain.
, Psych 130: Physiological Psychology
- patients who have had some of their The subarachnoid space, central canal, and
cerebrospinal fluid drained away cerebral ventricles are interconnected by a
often suffer raging headaches and series of openings and thus form a single
experience stabbing pain each time reservoir.
they jerk their heads.
- produced by the choroid plexuses
(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 blood-
filled spaces, or dural sinuses, which
run through the dura mater and
drain into the large jugular veins of
the neck.
Hydrocephalus: this happens when the flow
of cerebrospinal fluid is blocked by a tumor
near one of the narrow channels that link the
ventricles—for example, near the cerebral
aqueduct, which connects the third and Blood-brain barrier
fourth ventricles. The resulting buildup of
fluid in the ventricles causes the walls of the A mechanism that impedes the passage of
ventricles, and thus the entire brain, to many toxic substances from the blood into
expand, producing a condition called the brain. This barrier is a consequence of the
hydrocephalus (water head). Hydrocephalus special structure of cerebral blood vessels.
is treated by draining the excess fluid from
the ventricles and trying to remove the In the rest of the body, the cells that compose
obstruction. the walls of blood vessels are loosely packed;
as a result, most molecules pass readily
central canal through them into surrounding tissue. In the
brain, however, the cells of the blood vessel
- a small central channel that runs the walls are tightly packed, thus forming a
length of the spinal cord. barrier to the passage of many molecules—
particularly proteins and other large
cerebral ventricles molecules.
- the four large internal chambers of
The blood–brain barrier does not impede the
the brain: the two lateral ventricles,
the third ventricle, and the fourth passage of all large molecules. Some large
ventricle molecules that are critical for normal brain
function (e.g., glucose) are actively
