These regions called as the association
areas are responsible for complex functions
like intercessory associations, memory and
communication.
III.Basal Ganglia:
- The basal ganglia (or basal nuclei) is a group
of subcortical nuclei, of varied origin, in the
brains of vertebrates. - The basal ganglia form a fundamental
component of the cerebrum. In contrast to
the cortical layer that lines the surface of the
forebrain, the basal ganglia are a collection
of distinct masses of grey matter lying deep
in the brain not far from the junction of the
thalamus. - Basal ganglia nuclei are strongly interconnected
with the cerebral cortex, thalamus, and
brainstem, as well as several other brain areas. - The basal ganglia are associated with a variety
of functions including: control of voluntary
motor movements, procedural learning,
routine behaviours or “habits” such as teeth
grinding, eye movements, cognition and
emotion.
IV. The Limbic System: - The inner parts of cerebral hemispheres and
a group of associated deep structures like
amygdala and hippocampus to form a complex
structure called the limbic lobe or limbic
system. - It is a part, which connects cerebrum and the
brain stem. It sends signals to brain and body
parts to regulate our behaviour.
a. Amygdala: It is located above the
hypothalamus and influences behaviour and
activities so that they are appropriate for
meeting the body’s internal needs. These
include feeding, sexual interest, and emotional
reactions such as anger. Hence it is responsible
for controlling our moods.
b. Hippocampus: It is the swollen lower lip of
the limbic fork. It involves with learning, the
recognition and memory. It also converts short
term memory to long term memory; hence it
plays a vital role in learning.
3. Septum: It is a part of hypothalamus has
centre for sexual arousal.
V. The Diencephalon: consists of three major
parts:- Thalamus: contains many different nuclei,
each one dedicated to sensory information of
a particular type. Incoming information from
all the senses is sorted out in the thalamus and
sent on to the appropriate higher brain centres
for further interpretation and indignation. It
also receives input from the cerebrum and
from parts of the brain that regulate emotion
and arousal, making it an important station for
controlling access to the cerebrum. - The hypothalamus: lies below the thalamus
and regulates functions, such as body
temperature, sexual drive, carbohydrate
metabolism, hunger, and thirst. (Hypothalamus
is the source of two sets of hormones, posterior
pituitary hormones and releasing hormones of
the anterior pituitary). Part of hypothalamus
called suprachiasmatic nucleus, functions as
our biological clock. - The epithalamus: small resign present
superior and anterior to the thalamus. Consists
of pineal gland-secreting melatonin, and
habernular nuclei- olfaction especially
emotional responses to odour.
Mid Brain:
The midbrain contains 4 little lobes called
Corpora Quadrigemina. It has a pair of
Superior colliculi controls visual reflexes
(to fix and focus on an object) and a pair of
Inferior colliculi controls auditory reflexes
(locates and detects the source of a sound).
Hind Brain:
I. Cerebellum: - Called the second cerebrum, contributes to
10% of the brain weight and about 50% of the
total neurons. - The cerebellum plays an important role in
motor control, and it may also be involved
in some cognitive functions such as attention
and language as well as in regulating fear and
pleasure responses, but its movement-related
functions are the most solidly established.
- Thalamus: contains many different nuclei,