Diencephalon

Question 1

What are the 4 components of the diencephalon?

Answer 1

1. Thalamus
2. Subthalamus
3. Epithalamus
4. Hypothalamus

Question 2

Answer 2

Question 3

What is the relationship between the diencephalon and the 3rd ventricle

Answer 3

the 3rd ventricle is in the middle of the diencephalon. The thalamus, epithalamus and hypothalamus form the walls and floor of the 3rd ventricle

Question 4

Describe the Thalamus

Answer 4

• major relay station
• divided into different nuclei ie ventrolateral nucleus, medial geniculate nucleus
• has lamina - internal lamina and external lamina

Question 5

Describe the Thalamus

Answer 5

• major relay station
• divided into different nuclei ie ventrolateral nucleus, medial geniculate nucleus
• has lamina - internal lamina and external lamina

Question 6

Describe the subthalamus

Answer 6

• includes subthalamic nuclei, substantia nigra, cerebellothalamic fibres

Question 7

Describe the epithalamus

Answer 7

• consists of habenular nuclei, pineal gland
• pineal gland aka epiphysis

Question 8

Describe the epithalamus

Answer 8

• consists of habenular nuclei, pineal gland
• pineal gland aka epiphysis

Question 9

Describe the function of the pineal gland

Answer 9

• organised like endocrine,
• antigonadotrophic action.
• primary secretion = melatonin (influenced by ambient light)

Question 10

Describe the hypothalamus

Answer 10

• occupies the region between 3rd ventricle and subthalamus
• integrates and control ANS activity

Important structures of hypothalamus:
* mamillary bodies
* tubercinereum
* pituitary stalk/infundibulum (arises from median eminence)
* OVLT (mechanism of fever & appetite for salt)
* pre-optic area
* columns of fornix

Anterior hypothalamis mediate parasympathetic. Posterior/lateral hypothalamis mediate sympathetic.

Question 11

What are the major divisions of the pituitary gland?

Answer 11

Anterior - true endocrine gland, connected to hypothalamus by hypophyseal portal system
Posterior - projection of hypothalamus, neurons from median eminence/paraventricular nucleus/supraoptic nucleus project down here

Question 12

What are the posterior & anterior pituitary hormones and their functions

Answer 12

Posterior
* ADH - increases resorbtion of water in kidneys
* oxytocin - role in parturition and milk letdown

Anterior
* FSH - stimulates ovarian follicles and sperm production
* LH - increase progesterone and testosterone
* TSH - stimulates T4 & t3 release fromt hyroid
* ACTH - stimulates adrenal gland to release cortisol & steroids
* Prolactin - stimulates mammary gland/lactation development in women
* growth hormone - growth in bones, muscles & organs