Antomy of Thalamus and hypothalamus

this presentation summaries the basic anatomy of thalamus and hypothalamus with respect to their position, nuclei and their functions.

1. Thalamus and
Hypothalamus
To MBBS 2
nd
year
03-03-2017
By Dr. Laxman Khanal
Assistant professor, department of anatomy
BPKIHS, Dharan

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, metathalamusand epithalamus.
•Pars ventralisconsists of hypothalamus and subthalamus.

3. T
3
rd
ventricle
Thalamus–2innumber(rightandleft)
Hypothalamus-singlewithrightand
lefthalf.
Epithalamus
•Habenularnuclei
•Pineal body

4. Interventricular foramen
Hypothalamic sulcus
T
HT

5. Where does thalamus lie in
horizontal section ?

6. Coveredonitssuperiorsurface
byathinlayerofwhitematter,
calledthestratumzonale.
•Coveredonitslateralsurfacebyanother
layer,theexternalmedullarylamina.
•Reticularnucleusliesoutsideofit.
Thegraymatterofthethalamusis
dividedbyaverticalsheetofwhite
matter,theinternalmedullarylamina
intoanterior,medialandlateralparts.

7. •Medial geniculate body
•Lateral geniculate body
•Subthalamus

8. Ventral part Dorsal part
•Dorsal tire nucleus
•Ventral tire nucleus
•Anterior thalamus
•Medial thalamus
•Lateral thalamus
Intra-laminar nuclei
Q. What are the nuclei of thalamus ?
Reticular nuclei
Intralaminarnuclei
Nucleus of-
1.Anterior thalamus
2.Medial thalamus
3.Lateral thalamus
•Dorsal tire nuclei
•Ventral tire nuclei

9. Anterior nucleus of thalamus
•Adjust your mood with recent memory.
•Have connection with limbic system
•Component of Papezcircuit
Cingulate gyrus
Mamillothalamictract
Hippocampus

10. Prefrontal cortex
Concerned with thought and behavior.
Dorsomedialnucleus
Adjustbehaviorand physicaland
psychologicalstateaccordingtoyourmood.

11. Intra-laminar nuclei
Trigeminal lemniscus
Spinothalamic pathway
Reticular formation
Intra-laminar nuclei act as a switch for Cerebral arousal by
reticular formation.
Cauterizationofthesenuclei
hasbeenshowntorelieve
severeandintractablepain
associatedwithterminal
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.
Thalamichand
Wristispronatedandflexed,MP
jointsareflexedandIPjointsare
extendedwithverylittle
movements.

14. Hypothalamus
•It forms the floor and lateral wall of anterior part of 3
rd
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

17. Ant-Post division
1.Preoptic region
2.Supraopticregion
3.Tuberalregion
4.Mammillary region

18. Preoptic region
1.Preoptic nucleus
Supra-optic region
1.Anterior nucleus
2.Supra optic nucleus
3.Suprachiasmaticnucleus
4.Paraventricular nucleus
Tuberalregion
1.Dorsomedial nucleus
2.Ventromedial nucleus
3.Arcuate nucleus
Mammillary region
1.Posterior nucleus
2.Mammillary nucleus

19. Preoptic region
1.Preoptic nucleus
GnRH
FSH
LH

20. Supra-optic region
1.Supra-chiasmaticnucleus
2.Anterior nucleus
3.Supra-optic nucleus
4.Paraventricular nucleus
Functions
1.Circadian rhythm
2.AC (cooling mechanism)
3.ADH & oxytocin hormone
HHT-hypothalamo-hypophysealtract

21. Tuberalregion
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 papezcircuit
2.
•Heating center
•Sympathetic center

23. Afferent connection
•Visual afferent
•Corticohypothalmic
•Fornix
•Striaterminalis
•Thalamohypothalamic
tract
•Tegmental fibers

24. Efferent connection
•Descending hypothalamic
tract
•Mammillothalamictract
•Mammillotegmentaltract
•HHT

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 3
rd
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 !!!!!!!!!