Diencephalon and Third Ventricle

Question 1

Ends of thalamus

Answer 1

Anterior: Narrow. Posterior boundary of interventricular foramen
Posteior: Pulvinar. Overhangs medial, lateral geniculate bodies, sup. colliculi

Question 2

Surfaces of thalamus

Answer 2

Sup: Lateral part forms floor of lateral ventricle. Medial part has tela choroidea of 3rd ventricle
Inf: Anterior part fused with subthalamus
Med: Lateral wall of 3rd ventricle
Lat: Medial boundary of internal capsule

Question 3

White matter of thalamus

Answer 3

External and Internal medullary lamina

Question 4

Nuclei in anterior part of thalamus

Answer 4

Anterior nucleus

Question 5

Nuclei in medial part of thalamus

Answer 5

Medial dorsal

Medial ventral

Question 6

Nuclei in lateral part of thalamus

Answer 6

Craniocaudally
Dorsal:
1. Lateral dorsal
2. Lateral posterior
3. Pulvinar
Ventral:
1. Ventroanterior
2. Vetro intermediate
3. Ventroposterior

Question 7

Connections and functions of VPM

Answer 7

Aff: Trigeminal lemniscus
Eff: Post central gyrus
Func: Relay for face, head, taste bud impulses

Question 8

Connections and functions of VPL

Answer 8

Aff: Medial lemniscus, Spinal lemniscus
Eff: Postcentral gyrus
Func: Relay for exteroceptive, proprioceptive

Question 9

Connections and functions of VA

Answer 9

Aff: from globus pallidus
Eff: Premotor cortex
Func: Relay for striatal impulses

Question 10

Connections and functions of VI

Answer 10

Aff: Dentatothalamic
Eff: Motor and premotor cortex
Func: Relay for cerebellar impulses

Question 11

Connections and functions of Medial Geniculate body

Answer 11

Aff: Auditory fib. from inf. colliculus
Eff: Primary auditory area
Func: Relay for auditory impulses

Question 12

Connections and functions of Lateral Geniculate body

Answer 12

Aff: Optic tract
Eff: Primary visual cortex
Func: Relay for visual impulses

Question 13

Connections and functions of Anterior nucleus

Answer 13

Aff: from Mamillary body
Eff: Cingulate gyrus
Func: Attention, recent memory

Question 14

Connections and functions of Medial dorsal nucleus

Answer 14

Aff: Hypothalamus
Eff: Prefrontal area
Func: Mood, Emotional balance

Question 15

Connections and functions of Lateral dorsal nucleus

Answer 15

Aff: Thalamic n.
Eff: Cingulate gyrus
Func: Integrate sensory info

Question 16

Connections and functions of pulvinar nucleus

Answer 16

Aff: Thalamic n.
Eff: Association area
Func: Coorelation of senses

Question 17

Connections and functions of reticular nucleus

Answer 17

Aff: Brainstem reticular formation
Eff: Cerebral cortex
Func: RAS

Question 18

Functions of thalamus

Answer 18

1. Integration and relay station of all impulses

2. Poor recognition of pain, temp.

Question 19

Thalamic syndrome

Answer 19

1. Pain, temp., touch treshold decreases contra.

2. Emotional instability

Question 20

External features of pineal gland

Answer 20

• occupies vertical groove b/w sup. colliculi
• has a stalk
• stalk divides into 2 laminae
• Inf. lamina contd. with posterior commissure
• Sup. lamina contd. with habenular commissure
• supplied by nervus cornii

Question 21

Structure of pineal gland

Answer 21

• contains pinealocytes and neuroglial cells
• Pinealocytes secrete melatonin
• Ca phosphates and crabonates get deposited with age to for CORPORA ARENACEA (brain sand)

Question 22

Functions of pineal gland

Answer 22

1. Neuroendocrine activity
2. Biological clock
3. Melatonin inhibits secretion of GnRH

Question 23

Unique features of pineal gland

Answer 23

No nerve cells

Only part of brain supllied by nervus conarii that arises outside brain

Question 24

Habenular nucleus

Answer 24

• lies beneath habenular triangle
• habenular triangle is above sup. colliculus medial to pulvinar of thalamus
• with its connections, forms part of limbic system

Question 25

Habenular commissure

Answer 25

- connects habenular nucleus on both sides | - crosses midline by passing thru sup. lamina of stalk of pineal gland

Question 26

Posterior commissure

Answer 26

- connects MLF, interstitial nuclei, sup. colliculus, pretectal n. of both sides - crosses midline by passing thru inf. lamina of pineal stalk

Question 27

Boundaries of hypothalamus

Answer 27

``` Ant: Lamina terminalis Post: Subthalamus Inf: Floor of 3rd ventricle Sup: Thalamus Lat: Internal capsule Med: Cavity of 3rd ventricles ```

Question 28

Hypothalamic nuclei

Answer 28

1. Preoptic 2. Supraoptic 3. Anterior 4. Arcuate 5. Ventromedial 6. Dorsomedial 7. Posterior 8. Mamillary 9. Lateral

Question 29

Functions of Preoptic n.

Answer 29

Regulates release of Gn releasing hormones

Question 30

Functions of Supraoptic n.

Answer 30

1. Produces ADH, oxytocin | 2. Regulates water balance

Question 31

Functions of Anterior n. of hypothalamus

Answer 31

1. Regulates body temp. | 2. Stimulates parasym. NS

Question 32

Functions of Arcuate n. of hypothalamus

Answer 32

Produces hypothalamic releasing factors

Question 33

Functions of Ventromedial n. of hypothalamus

Answer 33

Satiety centre

Question 34

Functions of Dorsomedial n. of hypothalamus

Answer 34

Stimulation causes obesity and savage behaviour

Question 35

Functions of Posterior n. of hypothalamus

Answer 35

1. Regulates body temp. | 2. Stimulates Symp. NS

Question 36

Functions of Mamillary n. of hypothalamus

Answer 36

Receives info from hippocampus thru fornix

Question 37

Afferent connections of hypothalamus

Answer 37

1. Fornix connects hippocampus to mamillary bodies 2. Stria terminalis: amygdala to preoptic, anterior 3. Mamillary peduncle: spinal cord to lateral 4. Thalamus 5. Corpus striatum

Question 38

Efferent connections of hypothalamus

Answer 38

``` Mamillothalamic tract Mamillotegmental tract (midbrain reticular formation) ```

Question 39

Anterior wall of 3rd ventricle

Answer 39

Up to down 1. Anterior column of fornix 2. Anterior commissure 3. Lamina terminalis

Question 40

Posterior wall of 3rd ventricle

Answer 40

Up to down 1. Pineal gland 2. Posterior commissure

Question 41

Roof of 3rd ventricle

Answer 41

Ependyma

Question 42

Floor of 3rd ventricle

Answer 42

Front to back 1. Optic chiasma 2. Tuber cinerum 3. Pituitary stalk 4. Mamillary bodies 5. Posterior perforated substance 6. Tegmentum of midbrain

Question 43

Lateral wall of 3rd ventricle

Answer 43

Hypothalamic sulcus

Question 44

Recesses of 3rd ventricle

Answer 44

From front below to back 1. Infundibular 2. Optic 3. Anterior 4. Suprapineal 5. Pineal

Question 45

Blood vessels contributing to choroidal plexus of 3rd ventrilce

Answer 45

Anterior choroidal arteries