PSY 250 Lecture Notes - Lecture 10: Lateral Sulcus, Edema, Neuroplasticity
Chapter 3: The Organization and Functions of the Nervous System
- Lissencephalic: smooth-brained; meaning the brain doesn’t have the folds on the surface
like a normal brain does
- The Central Nervous System
- Central Nervous System (CNS): the brain and the spinal cord
- Neuron: single neural cell
- Nerve: a bundle of axons running together like a multiwire cable; this term is only
used when talking about the peripheral nervous system (PNS)
- Tracts: bundles of axons
- A group of cell bodies is called a nucleus in the CNS and a ganglion in the
peripheral nervous system
PNS
CNS
Bundle of Axons
Nerve
Tract
Group of Cell Bodies
Ganglion
Nucleus
- Begins as a hollow tube and preserves the shape as it develops
- Upper end of the tube develops three swellings which eventually become the
forebrain, midbrain, and hindbrain
- Lower part of the tube becomes the spinal cord
- The Forebrain
- Made up of the two cerebral hemispheres, the thalamus, and the
hypothalamus
- Cortex: the outer layer of the hemispheres that has the highest level of
processing in the brain
- The Cerebral Hemispheres
- Dominate the brain’s appearance
- Longitudinal Fissure: runs the length of the brain separates the two
cerebral hemispheres
- The simplest form of asymmetry is that each hemisphere receives
most of its sensory input from the opposite side of the body and
provides most of the control of the opposite side of the body
- Each ridge is called a gyrus; the groove or space between two gyri
is called a sulcus or, if it is large, a fissure
- The cortex is mostly made up of the cell bodies of neurons and is
called gray matter because the cell bodies are not myelinated
- The axons come together in the central core of each gyrus, where
their myelination gives the area a whitish appearance (hence white
matter)
- Cortex is in about six layers and each layer varies
- Cortex is made up of groups of about 80 to 100 interconnected
neurons that are in columns
- Each cell in a column has similar responsibilities to carry out
- Brain size is more related to body size than to intelligence
- The CNS is arranged in a hierarchy
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- The Four Lobes
- Frontal
- Area anterior to (in front of) the central sulcus and superior
to (above) the lateral fissure
- Control of movement
- Precentral Gyrus: extends the length of the central sulcus, is
the location of the primary motor cortex, which controls
voluntary movement
- Homunculus: little man (controls precise movements)
- Primary motor cortex carries out its work in concert with
adjacent secondary areas (located anterior to the primary
area)
- Broca’s Area: controls speech production, contributing the
movements involved in speech and grammatical structure
- Prefrontal cortex is involved in planning and organization,
impulse control, adjusting behavior in response to rewards
and punishments, and some forms of decision making
(schizophrenia and depression involve dysfunction in the
prefrontal cortex)
- Prefrontal damage impairs the ability to learn from reward
and punishment and to control impulses
- Lobotomies: a surgical procedure that disconnects the
prefrontal area from the rest of the brain
- Psychosurgery: the use of surgical intervention to treat
cognitive and emotional disorders
- Parietal
- Located superior to the lateral fissure and between the
central sulcus and the occipital lobe
- Primary Somatosensory Cortex: located on the postcentral
gyrus, processes the skin senses and the senses that inform
us about body position and movement
- Association Areas: carry out further processing beyond
what the primary area does, often combining information
from other senses
- Neglect: a disorder in which the person ignores objects,
people, and activity on the side opposite of the damage
- Temporal
- Contain the auditory projection area, visual and auditory
association areas, and an additional language area
- Lateral fissure separates this lobe from the frontal and
parietal lobes
- Auditory Cortex: receives sound information from the ears,
lies on the superior (uppermost) gyrus of the temporal lobe,
mostly hidden from view within the lateral fissure
- Wernicke’s Area: an association area that interprets
language input arriving from the nearby auditory and visual
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areas; it also generates spoken language through Broca’s
area and written language by way of the motor cortex
- When damaged people have trouble understanding speech
and writing and it is located in the left hemisphere in most
people
- Inferior Temporal Cortex: in the lower part of the lobe as
the name implies, plays a major role in the visual
identification of objects
- Occipital
- The location of the visual cortex, which is where visual
information is processed
- Detects color, movement, and form
- The Thalamus and Hypothalamus
- Thalamus: lies just below the lateral ventricles, where it receives
information from all the sensory systems except olfaction (smell)
and relays it to the respective cortical projection areas
- Hypothalamus: a smaller structure just inferior to the thalamus,
plays a major role in controlling emotion and motivated behaviors
such as eating, drinking, and sexual activity
- Hypothalamus controls the autonomic nervous system and the
pituitary gland
- Pituitary gland is known as the master gland because its hormones
control the other glands in the body
- Hypothalamus contains the largest concentration of nuclei in the
entire brain
- Pineal gland
- The Corpus Callosum
- A dense band of fibers that carry information between the
hemispheres
- Can be severed in half in patients with incapacitating epileptic
seizures that can’t be controlled by drugs
- Left hemisphere is more specialized for language than the right
hemisphere and the the right hemisphere is better at spatial tasks
and recognizing faces
- The Ventricles
- The hollow interior of the nervous system
- Filled with cerebrospinal fluid, which carries material from the
blood vessels to the CNS and transports waste materials in the
other direction
- Lateral Ventricles
- Extend forward deeply into the frontal lobes and in the
other direction into the occipital lobes before they curve
around into the temporal lobes
- Third Ventricle: located between the two thalami and the
two halves of the hypothalamus
- Fourth Ventricle
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Document Summary
Chapter 3: the organization and functions of the nervous system. Lissencephalic: smooth-brained; meaning the brain doesn"t have the folds on the surface like a normal brain does. Central nervous system (cns): the brain and the spinal cord. Nerve: a bundle of axons running together like a multiwire cable; this term is only used when talking about the peripheral nervous system (pns) A group of cell bodies is called a nucleus in the cns and a ganglion in the peripheral nervous system. Begins as a hollow tube and preserves the shape as it develops. Upper end of the tube develops three swellings which eventually become the forebrain, midbrain, and hindbrain. Lower part of the tube becomes the spinal cord. Made up of the two cerebral hemispheres, the thalamus, and the hypothalamus. Cortex: the outer layer of the hemispheres that has the highest level of processing in the brain. Longitudinal fissure: runs the length of the brain separates the two cerebral hemispheres.
