nervous system

To start off , you need to know where the thalamus and hypothalamus
reside and how they are related.

In our brain we have a part called Diencephalon which is located between
2 -

the
2-
cerebrum and the brain stem. It links the nervous system with the
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endocrine system and gives rise to four distinct components: the thalamus,
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subthalamus, hypothalamus, and epithalamus.
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Hypothalamus is located under the thalamus, and the thalamus is a well-
defined area while the hypothalamus is not (it has many scattered areas
of neurons that are relayed to one centerso they have a certain kind of
center).

-Thalamus:

*the thalamus is mainly a gray matter structure, composed of several
nuclei (about 30-40), and it is divided into two parts: right thalamus, and
left thalamus.

Everything that goes to the cerebral cortex must pass through the
thalamus (where processing might occur). All sensations pass through it
except for smell which goes from the receptors of smell directly to the
cerebral cortex. So the thalamus is said to be a relay station for sensory
impulses going to the cerebral cortex (Impulses of similar function are Retrograde:
sorted out, edited, and relayed as a group).The thalamus acts as a inability to
secretory to the cerebral cortex. recall past
memories.
*It is concerned with past memory, so if we destroy the thalamus; the
Anterograde:
kind of memory that will be lost is the past one - a condition called
inability to
retrograde amnesia- ,moving from short-term memory to long-term
create new
memory according to the strength of damage. memories




-The thalamus plays a key role in mediating sensation, motor activities,
cortical arousal, learning, and memory.

:*?
Note the difference: aan
*Learning: is the ability to acquire new information or skills
through instructions or experiences.

*Memory: is the process by which information acquired
refined:& -
o
.




through learning is stored and retrieved.

, *Cortical arousal: increases wakefulness, muscle tone, heart rate, and
ventilation.

The thalamus is concerned with state of sleep and arousal because the
RAS(reticular activating system (attention center in brain)) activates the
cerebral cortex and it must pass through the thalamus as well.

-Hypothalamus:
Note: we have a
*the hypothalamus is responsible for controlling vegetative functions center called
(functions that are ), like: hunger and
satiety center
Eating by hunger center which makes you feel hungry. located in the
hypothalamus
Satiety by satiety center which makes you feel satisfied . which controls
eating
Drinking
processes
-Since the hypothalamus controls the drinking center, then this means that it regulates
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fluids in our bodies.
mm

*The hypothalamus controls the autonomic nervous system (ANS) Recall that ANS is
,which - - -
divided into:
and has a neuroendocrine function(it links the nervous system to the
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sympathetic and
endocrine system via the pituitary gland). parasympathetic
nervous system.

*Signals from the hypothalamus travel to the pituitary gland; a gland
=
located at the base of the hypothalamus and = is connected to it through
the pituitary stalk (infundibulum).The pituitary gland has discrete
2-
posterior and anterior parts which perform different functions. The

o
- -


posterior pituitary gland is an extension of the hypothalamus and

hypothalamus to be released in response to nerve impulses transmitted
by the hypothalamus).In contrast, the anterior pituitary gland secretes Hypothalamus= H.T
its own hormones in response to hormones from the hypothalamus (the Anterior pituitary=A.P
hypothalamus regulates the anterior pituitary hormones by releasing Posterior pituitary= P.P
inhibiting or releasing hormones that control their release ).
H.T A.P
P.P A.P H.T
P.P H.T