Anatomy of the pituitary gland

Question 1

What are the main endocrine glands in the body?

Hint think:

• In the cranial cavity
• Neck
• Abdomen
• Pelvis
• Perineum

Answer 1

Cranial cavity:

• Hypothalamus and pituitary gland

Neck:

• 4 Parathyroids and throid gland

Abdomen:

• 2 adrenal glands
• Pancreas

Pelvis (female):

• 2 ovaries

Perineum (male):

• 2 testes

Question 2

Label the main parts of the brain

Answer 2

Question 3

What is the dinecephalon ?

Answer 3

• It is the Thalamus + the Hypothalamus
• It forms the central core of the cerebrum

Question 4

Label the parts of the brain stem and the dinecephalon

Answer 4

Question 5

What conencts the hypothalamus to the pituitary gland ?

Answer 5

The infundibulum

Question 6

Where is the pituitary gland located in the cranial cavity ?

Answer 6

Located in the pituitary fossa which lies within the sella turcica

Question 7

What structure does the pituitary gland lie immediately inferior too ?

Answer 7

The optic chiasm

Question 8

What forms the optic chaism ?

Answer 8

The right and left optic nerves (CN II)

Question 9

After the optic chaism describe the pathway of the optic tracts

Answer 9

• The right and left optic tracts pass posteriorly from the chiasm
• After synapsing in the thalamus the next axons in the chain pass via the optic radiation to the visual cortex in the occipital lobe

(The second point refers to the black dot on the pathway to the end of the pathway)

Question 10

How can a pituitary tumour affect somones sight ?

Answer 10

It can compress on the optic chaism - resulting in a bitemportal hemianopia

(it results in a bitemporal hemianopia because the nasal retinae are the nerve fibres which cross over and swap which side of the optic pathway they are on at the optic chaism, and since in terms of seeing in the eye the nasal retinae produce sight in the temporal field (in the eyes its light opposites for nerves and what you see))

Question 11

What are the 2 main surgical approaches which can be taken to reach the pituitary gland ?

Answer 11

• Transcranial approach (subfrontal – under the frontal lobe)
• Transsphenoidal approach (via nasal cavities & sphenoid sinus)

Blue line - transsphenoidal

Red line - transcranial

Question 12

Go over this pic of the osteology of the nasal cavity

Question 13

Go over the anatomy of the lateral wall of the nasal cavity

Answer 13

Question 14

What are the paranasal sinuses ?

Answer 14

Air-filled spaces within the bones surrounding the nasal cavities (no. refer to the pic)

1. Frontal sinuses
2. Sphenoid sinuses
3. Ethmodial sinuses
4. Maxillary sinuses

Question 15

Label the fractures shown

Answer 15

Question 16

For learning the crianl nerves, there function and foramen then exist use the rafi ahmed brainscape and the table ive printed off.

Answer 16

Use them

Question 17

What is the dura mater ?

Answer 17

The dura mater is the outermost layer of the meninges, lying directly underneath the bones of the skull and vertebral column. It is thick, tough and inextensible.

Question 18

What is the diaphragm sellae ?

Answer 18

A tough sheet of dura mater forming a roof (diaphragm) over the pituitary fossa

Question 19

What is the tentorium cerebelli ?

Answer 19

A tough sheet of dura mater “tenting” over the cerebellum within the posterior cranial fossa but with a central gap to permit the brainstem to pass through)

Question 20

What foramens do the vertebral arteries and the internal carotid arteries enter the cranial cavity in ?

Answer 20

• Vertebral arteries - formane magnum
• Internal cartotid arteries - carotid canal

Question 21

Go over this pic

Answer 21

Question 22

What is the dural venous sinus ?

Answer 22

Venous channels within the dura mater that drain most of the venous blood from the cranial cavity (including the brain) into the internal jugular veins

Question 23

What is the pituitary gland surrounded by ?

Answer 23

Surrounded by the cavernous and intercavernous sinuses