The document discusses the neurobiological basis of psychology, outlining the structure and function of the nervous system including neurons, the central and peripheral nervous systems, and different parts of the brain. It provides learning objectives and covers topics like sensory and motor signals, heredity factors on behavior, and defines key terminology. The discussion includes a video presentation and group project to help students learn about the nervous system and apply the concepts.

1. DEPARTMENT OF PSYCHOLOGY AND GUIDANCE
College of Arts and Sciences
Xavier University – Ateneo de Cagayan
School Year 2009 – 2010, Second Semester
MODULE 2 – NEUROBIOLOGICAL BASIS OF PSYCHOLOGY
Learning Objectives:
At the end of the learning period, the students will be able to:
1. Familiarize and able to describe the nature of the basic unit of structure of the nervous system
in terms of its parts, types, functions and other properties.
2. Explain and stimulate interest on how different sensory and motor signals are conducted to and
from the brain.
3. Discuss the influences of the hereditary or biological factors on behavior.
CONTEXT:
Man is a biological, social, and psychological being. His behavior is governed not only by psychosocial
factors but also by biological determinants. When a man is confronted by a stressful stimuli, or by an
emotion-provoking events, his heart beats faster, his blood pressure rises, he may blush, may manifest
fine but continuous spasmodic contractions. These involuntary responses elicited by the stressful
stimulus are controlled by the nervous systems.
It is but necessary for student to look into these biological factors that affect human behavior to better
understand the complexity and dynamics of human behavior
ACTIVITY:
Video Presentation: A video clip entitled “The Human Body” will be shown to the class. It discusses the
role of the Human Brain and Nervous Systems as it acts as the superhighway of our body. The activity
will foster as different approach to students learning as it is gives visual and comprehensive examples to
further understand the subject matter.
DISCUSSION:
The Neuron or nerve cell, is the basic structural unit of the nervous system. It is composed of the
following:

2. 1. Cell body or soma – from which arise nerves processes of the axon and dendrites. It also
contains a nucleus that is centrally located.
2. Nucleus – it is regarded as a trophic center as the cell body serves as a center for nourishment.
3. Axon – described as cellulifugal which means it conducts neural impulses away from the cell
body.
4. Dendrites – describe as cellulipetal which means it conducts neural impulses to the cell body.
5. Synaptic terminals – or synaptic knobs is an end-brush, it is a branched terminal portion at the
peripheral ending of the axon. It terminates like in knob-like structure.
- It contains neurotransmitter substances such as acetylcholine, norepinephrine, and
gamma-aminobutyric acid, etc.
- Neurotransmitter substances released by the synaptic terminals are either
excitatory or inhibitory. An excitatory neurotransmitter brings about a transmission
of neural impulses, while an inhibitory neurotransmitter prevents the conduction of
neural impulses.
- The neurotransmitter substances play a significant role in the transmission of nerve
impulses from one neuron to the next at the junction known as the synapse.
Table 1. Some Neurotransmitter Substances and its corresponding function
Neurotransmitter Functions
1. Dopamine “Pleasure” neurotransmitter; little in Parkinson’s disease
2. Norepinephrine Affects arousal level such as depression and hyperactivity
3. Serotinen Lack of it makes going to sleep difficult; low level is
implicated in aggression and depression
4. GABA Lowers arousal level (inhibitory); an amino acid
(gamma aminobutyric acid)
5. Endorphin Pain-relieving effect; a neuropeptide
- Neurons are classified according to the function they perform. A sensory or afferent
neuron, sends neural signal impulses from the receptor to the brain, whereas a
motor, or efferent neuron, sends neural impulses from the brain to the effectors
located in the peripheral organs such as muscles and glands.
- An interneuron conducts neural impulses from a sensory neuron to a motor nerve
cell. Interspersed among the neurons are the glial cells that serve as the structural
supportive framework of the nervous system. Some glial cells are responsible for
the formation and preservation of the myelin sheath in the brain and the spinal
cord. Others have a phagocytic function or act as scavengers for the elimination of
neural debris.
6. Myelin Sheath – a white tissue that covers a nerve fiber. It runs along the fiber, is interrupted at
fairly regular intervals called the nodes of Ranvier. The transmission of neural impulses assumes
a jumping characteristics.
Nerve Impulse Transmission
A neuron manifests irritability, or the ability to respond, to a stimulus. Once excited, the neuron
shows its irritability by generating and transmitting action potentials, or nerve impulses to and from

3. the brain. These neural impulses are electrochemical in nature. They are transmitted from one
neuron to another neuron at a junction known as the synapse.
Depolarization – when the adjacent sodium channel become stimulated, thus propagating the
depolarization wave throughout the length of the nerve fiber.
Repolarization – when the nerve fiber becomes ready to transmit another impulse. It restores the
cell membrane to its resting potential.
Exocytosis – the excitatory neurotransmitter molecules diffuse across the synaptic cleft and bind
themselves to the neuroreceptor molecules in the cell membrane of the postsynaptic neuron in a
lock-and-key fashion.
Divisions of the Nervous System
Cerebrum – left and right brain
Brain stem – is the part of the neural tube between the cerebral hemispheres and the spinal cord.
Sensory signals from the spinal cord pass through the brainstem.
Medulla – is the structure that lies just above the spinal cord. It is concerned with the regulation
of breathing and some vital bodily functions such as the beating of the heart and blood
circulation.
Pons – is the structure that lies above the medulla. It is concerned with the communication
between cerebral motor cortex and the cerebellum.
Midbrain – lies superior to the pons is the smallest and least differentiated structure of the brain
stem. Some neurons of the midbrain contain the melanin pigments, while other
synthesize dopamine.
Interbrain – is the uppermost part of the brain stem. It has two subdivision, thalamus and the
hypothalamus.
Thalamus – serve as the last relay center for all incoming sensory impulses to the cerebral cortex,
with the exception of the olfactory sense. It sends projection to the cortical centers

4. transmitting the neural signal for the proper cortical mechanisms of sensations and
perceptions.
Hypothalamus – contains group of nuclei that are involve in eating, drinking, emotion, and sexual
behaviors. It also plays a significant role in the regulation of stress responses, the
mechanism of which lead to the secretion by the adrenal cortex of the stress hormone
(cortisol) that will give the necessary energy for fight or flight reactions.
Reticular System – a mixture of gray and white matter that extend from the lower brainstem up to the
thalamus. It plays a significant role in controlling the organism’s state of arousal. It also
act as a filter allowing for some sensory messages to reach the cerebrum while
preventing other messages from reaching the cerebral cortex. In this way, it enables an
individual to focus his attention to a particular stimuli.
Limbic System – it is the structures surrounding the thalamus. This system is closely interconnected with
the hypothalamus. It appears to exert additional control over some of the instinctive
behaviors already under regulation of the hypothalamus and the brainstem.
Hippocampus, amygdale, and hypothalamus are part of this system.
Hippocampus – lies between the thalamus and the cortex, plays crucial role in memory. It is associate
with the temporal lobes.
Amygdala – located at the base of the temporal lobe is concerned with the control of appetitive,
sexual, and aggressive behavior. It is also concerned with emotional memories.
Cerebellum – located dorsally, or at the back of the pons and medulla, it is concerned with the
coordination of somatic motor activities, or voluntary movements, the regulation of
muscle tone, and mechanisms that influence and maintain equilibrium.
Cerebrum – is the uppermost and most expanded structure of the neural tube. Its outer layer is an area
of gray matter called the cerebral cortex, beneath which is an area of white matter
composed of mostly myelinated fibers.
Corpus Callosum – the fiber that joins the two cerebral hemisphere of the brain and spinal cord.
Gyri (or Gyrus) – is the numerous folds or convolutions in the surface of the cerebral hemisphere.
Sulcus or fissure – a canal or groove between two gyri.
Different Lobe of the cerebral hemisphere
1. Frontal lobe – is involved in organization and planning, judgment, or decision making, the ability
to adapt to situations, and personality. It also governs the ability to perform a series of tasks in
the proper sequence and to stop doing them at the proper time. It is also associated to have a

5. key role in thought processes that requires problem-solving behavior, organization, and
processing.
2. Parietal lobe – is concerned with the integration of complex sensorial information like
recognizing a particular stimulus perceived through the sense of touch only, or form among
groups of stimuli using the visual sense.
3. Temporal lobe – is regarded as the center for memory.
4. Occipital lobe – contains the primary visual area for the perception of basic visual information
such as the perception of something green, rough, or smooth.
Cortical Areas and Their Functions
Motor Area – located in the frontal lobe. It controls voluntary movements.
Somatosensory Area – also called as somesthetic area is located in the parietal lobe. Sensory signals
conveying touch, pressure, pain, thermal sense, and sense of body movements are brought to
this convolution for perception.
Visual Area – located in the occipital lobe. Also called the striate cortex, it receives visual signals from
the thalamus. It is responsible for visual sensations which include seeing colors, seeing lines or
something straight, rough or smooth.
Auditory Area – it lies in the temporal lobe of the brain. It receives signals from the thalamus for basic
auditory sensation.
Association Area – areas of the cerebral hemispheres that are not concerned with primary sensory and
motor processes are termed association area. The association areas occupy the bigger part of
the brain. Neural signals from the primary and secondary sensory areas are transmitted to the
association area for the meaningful interpretation of sensory experience. Gnosis refers to the
arousal of association areas, consequently triggering the cascading of memory complexes.
The Peripheral Nervous System
It is made up of the somatic nervous system and the automatic nervous system. The somatic nervous
system consists of spinal nerves and cranial nerves. They innervate the peripheral structures such as the
skin and muscles, as well as the visceral organs. On the other hand, the autonomic nervous system is
made up of the sympathetic and parasympathetic subdivisions.
Autonomic nervous system – concerned with the involuntary activities of the organism, it is made up of
the sympathetic and parasympathetic divisions. Generally, the two divisions function
antagonistically: if the sympathetic stimulate, the parasympathetic inhibits.
Endocrine system – this is made up of ductless glands that secrete hormones directly into the
bloodstream. Bothe the nervous system and endocrine system use chemical substances to
transmit messages or information. The endocrine system has hormones that affect the
specialized cells in the various organs of the body.
Pituitary gland – is one of the endocrine glands located at the base of the brain. It is referred to as the
master gland as it controls the activities of the other endocrine glands and secrets a growth
hormone that has the curial role of controlling body growth.
Tyroid gland – is located at the base of the throat near the Adam’s apple in males. It secrets hormones
the control basal metabolism.
Adrenal gland – are lodged on top of each kidney. Their inner layer secrets adrenalin, or epinephrine,
which gives extra energy very much needed during emergencies and prolonged stress. Their
outer layer secrets cortical hormones that control basic chemical mechanisms within the body.

6. Islets of Langerhans – found in the pancreas secrets insulin, which prevent the accumulation of sugar in
the blood.
Testes – male sex glands, secrete testosterone for the production of male secondary sex characteristics.
Ovaries – female sex glands, secrete estrogen for the appearance of female secondary sex
characteristics and progesterone for the thickening of the uterine wall in preparation for
pregnancy and childbirth.
Different Sense Modalities
1. Visual Sense (Sense of Sight)
2. Auditory Sense (Sense of Hearing)
3. Olfactory (Sense of Smell)
4. Gustatory Sense (Sense of Taste)
5. Cutaneous Sense or Somatosensation (touch, Pressure, Pain, cold and warm sensation)
EVALUATION:
Group Project:
The class will be divided into smaller groups and will be ask to prepare a presentation of slide in MS
Powerpoint presentation about the following Areas:
Group 1: Different Sense Modalities (its parts and function)
Group 2: The Peripheral Nervous System (its parts and function)
Group 3: The Central Nervous System (its parts and function)
Group 4: Different Lobe of the cerebral hemisphere, and Cortical Areas and Their Functions
Group 5: The Neuron, its parts and function