2. Introduction
• The diencephalon is the part of brain between the cerebrum and the
brainstem. The cavity within it is termed third ventricle.
• Hypothalamic sulcus divides the diencephalon into pars dorsalis and
pars ventralis.
• Pars dorsalis consists of thalamus, metathalamus and epithalamus.
• Pars ventralis consists of hypothalamus and subthalamus.
3. T
3rd ventricle
Thalamus – 2 in number (right and left)
Hypothalamus- single with right and
left half.
Epithalamus
• Habenular nuclei
• Pineal body
6. Covered on its superior surface
by a thin layer of white matter,
called the stratum zonale.
• Covered on its lateral surface by another
layer, the external medullary lamina.
• Reticular nucleus lies outside of it.
The gray matter of the thalamus is
divided by a vertical sheet of white
matter, the internal medullary lamina
into anterior, medial and lateral parts.
9. Anterior nucleus of thalamus
• Adjust your mood with recent memory.
• Have connection with limbic system
• Component of Papez circuit
Cingulate gyrus
Mamillothalamic tract
Hippocampus
10. Prefrontal cortex
Concerned with thought and behavior.
Dorsomedial nucleus
Adjust behavior and physical and
psychological state according to your mood.
11. Intra-laminar nuclei
Trigeminal lemniscus
Spinothalamic pathway
Reticular formation
Intra-laminar nuclei act as a switch for Cerebral arousal by
reticular formation.
Cauterization of these nuclei
has been shown to relieve
severe and intractable pain
associated with terminal
cancer.
12. LD
LP
Pulvinar
1. Anterior thalamus
Anterior nucleus of thalamus
2. Medial thalamus
Dorsomedial nucleus
3. Lateral thalamus
A. Dorsal tire
Lateral dorsal
Lateral posterior
Pulvinar
B. Ventral tire
Ventral anterior
Ventral lateral
Ventral posterior
VPM
VPL
VP
VPL
VPM
Trigeminal lemniscus
Gustatory pathway
Long ascending tracts
Motor function
13. Thalamic syndrome
Thalamic pain
• Occurs as the patient is recovering from a
thalamic infarct.
• The painful sensation may be aroused by
light touch or by cold.
• May fail to respond to powerful analgesic
drugs.
• Excessive pain might be due to overreaction
of thalamus.
Thalamic hand
Wrist is pronated and flexed, MP
joints are flexed and IP joints are
extended with very little
movements.
14. Hypothalamus
• It forms the floor and lateral wall of anterior part of 3rd ventricle.
• It controls 3 system
1. Autonomic nervous system
2. Endocrine system
3. Limbic system (emotional brain)
• Basically it has major role in maintaining homeostasis.
15. • Tuber cinerium
• Median eminence• Mammillary bodies
Medial zone
Lateral zone
16. Lateral zone is mainly occupied by long lateral nucleus (Hunger center)
4 regions
1. Pre optic
2. Supra-optic
3. Tuberal
4. Mammillary
21. Tuberal region
1. Arcuate nucleus
2. Ventromedial nucleus
3. Dorsomedial nucleus
Functions
1. Releasing factors
2. Satiety & reward center
3. Savage behavior
22. Mammillary region
1. Mammillary nucleus
2. Posterior nucleus
Functions
1.
• Behavior
• Part of papez circuit
2.
• Heating center
• Sympathetic center
25. Conclusion
• Thalamus acts as relay and integrative station for all the sensory
information except smell.
• Hypothalamus lies anterior to and inferior to the thalamus. It is center
of integration of autonomic and endocrine function.
• Both thalamus and hypothalamus makes the boundaries of 3rd
ventricle.
• Both thalamus and hypothalamus also play a role in memory and
emotion.
There are many nuclei and it is very hard to remember…
But not impossible !!!!!!!!!