1. Emotion and Motivation
Parts of brain important in control of emotional stress are:
Hypothalamus – in diencephalon
Limbic system – composed of nuclei and fiber tracts:
- Cingulate gyrus - Septal nuclei
- Amygdala - Hippocampus

2. Emotion and Motivation
Hypothalamus and limbic system are involved in control of:
Aggression = stimulation of certain areas of amygdala/hypothalamus
causes aggression.
Fear = electrical stimulation of other parts of hypothalamus and amygdala
causes fear. Removal of limbic system = absence of fear
(e.g monkey & snake)
Feeding = feeding center and satiety center in hypothalamus;
stimulation of feeding center = overeating
stimulation of satiety center = stop eating
Sex = sexual behavior and drive are regulated by hypothalamus and limbic
system, but the cerebrum is also important in this control .
Goal-directed behavior = stimulation area between frontal cortex and
hypothalamus gives feeling of relief from tension, stimulating a site close to
that causes feeling of being punished.

3. Frontal Cortex Damage
An accident caused penetration of a thick long iron into Phineas Gage’s skull.
he survived, but his personality changed, he became less responsible and lost
his social inhibitions, used gross profanity.

4. Memory Medial temporal lope Memory = storage of learned information.
Working memory – a limited capacity short-term memory that lasts only
seconds to minutes. It is operated in frontal lobes of cerebral cortex.
Dopamine is one of the most important neurotransmitters in the operation of
Working memory.
Long-term memory – storage of information which can last for hours, days or
Years. The process of transferring memory from short-term to long-term is
called consolidation of memory.
GABA decreases memory consolidation, whereas glutamate, ACh and NE
stimulate it.
Medial temporal lope
- Two types of long term memory:
1- Procedural memory = remember how to do something e.g ride a bike or swim
2- Declarative memory = remembering facts, e.g names.

5. Diencephalon (Thalamus, Hypothalamus & Pituitary Gland)

6. Diencephalon 1- Thalamus:
- Gray matter forming most of the wall of 3rd ventricle.
- Relay center for passage of sensory information to cerebrum.
- Contains choroid plexus = source of CSF secretion.
2- Hypothalamus:
- Located below the thalamus.
- Forms floor of the 3rd ventricle.
- Contains neural centers for:
hunger, thirst and regulates:
- body temperature
- hormone secretion from pituitary glands
- sleep and wakefulness
- anger and fear
- pain and pleasure

7. Diencephalon 3- Pituitary Gland:
- Located inferior to the hypothalamus.
- Connected to the hypothalamus by a tract of neurons (Stalk).
- The tract is called hypothalamo-hypophyseal tract.
- Hormones secreted by hypothalamus (ADH + Oxytocin)
- ADH and oxytocin travel down the tract to pituitary and stored prior secretion.
- Oxytocin = contraction of
uterus during delivery
(child-birth).
- ADH = reabsorption of
water by kidney.
- Hypothalamic neurons also
secret: releasing hormones
and inhibiting hormones.

8. Mesencephalon (Midbrain)
Located between diencephalon and pons.
Composed of:
1- Corpora quadrigemina : four rounded bodies in the dorsal part of midbrain
involved in visual and auditory functions:
- superior colliculi = visual reflexes
- inferior colliculi = auditory information
2- Cerebral peduncles = composed of ascending and descending fiber tracts.
3- Red nucleus = gray matter area in midbrain which maintains connections
between cerebrum and cerebellum (motor co-ordination).
4- Substantia nigra = connections with basal neuclei (motor co-ordination).

9. Rhombencephalon (Hindbrain)
Composed of 2 regions :
1- Metencephalon (pons and cerebellum):
a) Pons ; located between midbrain and medulla.
contains several nuclei
contains respiratory control centers: apneustic and pneumotaxic.
b) Cerebellum: 2nd largest structure of the brain.
- outer gray and inner white matter.
- Connected with pons, medulla, and spinal cord through fibers.
- co-ordinates body movements.
2- Myelencephalon (medulla oblongata):
- located between pons and spinal cord (3 cm)
- all fiber tracts that provide communication between spinal cord
and brain must pass through medulla.
- contains important nuclei
- contains vital centers = breathing and cardiovascular.

10. Respiratory Control Centers

11. Spinal Cord
Extends from level of foramen of magnum to 1st lumbar vertebra.
- Arrangment of gray and white matters is opposite to the brain. Gray matter is
surrounded by white matter.
The gray matter is arranged in the
form of H.
The white matter is composed of
ascending (sensory) and descending
(motor) tracts.
Examples of such tracts:
Spinothalamic tract = carriers sensory
touch to thalamus.
Corticospinal tract = carries motor
fibers from cortex down spinal cord.

12. Spinal Cord Tracts
1- Ascending tracts: convey sensory information from:
- cutaneous receptors (skin),
- proprioceptors (muscle and joint senses)
- visceral receptors (internal body organs)
*senses from right
side of the body are
connected to the left
brain and senses from
left side of the body
are connected to
right brain.

13. Spinal Cord Tracts 2- Descending tracts:
convey motor signals from brain
to the periphery.
There are two major groups:
1- Corticospial (pyramidal) tracts
2- Extrapyramidal tracts

14. Spinal Nerves 8 Cervical 12 Thoracic 5 Lumbar 1 Coccygeal 5 Sacral
31 pairs of spinal nerves :
8 Cervical
12 Thoracic
5 Lumbar
1 Coccygeal
5 Sacral

15. Spinal Reflex
- Reflex = an unconscious motor response to a sensory stimulus.