Anatomy of the Pituitary Gland

Question 1

What makes up the diencephalon and what is it’s purpose?

Answer 1

The thalamus and hypothalmus

Central core of the cerebrum with connections to the right and left cerebral hemispheres and the midbrain

Question 2

What are the 3 parts of the brainstem?

Answer 2

Midbrain
Pons
Medulla oblongata

Question 3

What is the inferior continuation of the brainstem called?

Answer 3

Spinal cord

Question 4

What connects the pituitary gland to the hypothalamus?

Answer 4

infundibulum

Question 5

Where exactly does the pituitary gland sit?

Answer 5

Midline structure in the pituitary fossa of the sphenoid bone which sits in the sella turcica

Question 6

Briefly describe what happens when light rays come from the nasal side of the right visual field.

Answer 6

• They are absorbed by the temporal retina
• Posterior to the retina is the optic nerve (ight changes to AP here)
• This AP goes posteriorly and crosses at the optic chiasm
• Now known as the optic tracts, they leave and synapse in the thalamus
• continue posteriorly as the optic radiation to the left vvisual cortex in the left occipital lobe

Question 7

What is the clinical outcome of a pituitary tumour?

Answer 7

Bilateral hemianopia - loss of vision on the temporal side of visual field bilaterally

Question 8

Give 3 options for gaining surgical access to the pituitary fossa.

Answer 8

Subfrontal
Transsphenoidal
le-Fort 1 down fracture

Question 9

Which bones are involved in the nasal cavities?

Answer 9

Cribiform plate of ethmoid bone - roof
Perpendicular plate of ethmoid bone - superior part
Vomer - inferior part

Question 10

What are the names of the 3 nasal conchae and which bones do they come from?

Answer 10

Superior nasal concha of ethmoid bone
Middle nasal concha of ethmoid bone
Inferior nasal concha (separate bone)

Question 11

What are the nasal concha and paranasal sinuses lined by?

Answer 11

Mucous secreting respiratory mucosa

Question 12

Name the 4 sets of paranasal sinuses.

Answer 12

Frontal sinuses
Maxillary sinuses
Ethmoidal air cells
Sphenoid sinuses

Question 13

Where is dura mater and what is its function?

Answer 13

Adherent to the iternal aspects of ALL bones in the cranial vault
Functions to protect structures of the cranial cavity

Question 14

What is tentorium cerebelli?

Answer 14

A tough sheet of dura mater “tenting” over the cerebellum within the posterior cranial fossa
It has a central gap which allows the brainste to pass through

Question 15

What is the diaphragm sellae and where is it?

Answer 15

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

Question 16

What do dural venous sinuses drain?

Answer 16

Drains most of the venous blood from the cranial cavity (including the brain) into the internal jugular veina at the jugular formainae in the floor of the posterior cranial fossa

Question 17

What is the pituitary gland surrounded by?

Answer 17

Cavernous ad intercavernous sinuses

Question 18

What does the anterior intercavernous sinus connect?

Answer 18

The right and left cavernous sinuses anteroir to the pituitary gland

Question 19

Where does the ophthalmic artery come from and what does it supply?

Answer 19

Branches off the internal carotid artery to supply the eye

Question 20

What branches from the ophthalmic artery?

Answer 20

The central artery of the retina (end artery)

Question 21

Give some potential functions of the paranasal sinuses.

Answer 21

Make mucous anddrain it into the nasal cavities via ostia
reduce the weight of the skull
Add resonance to the voice
Increase bouyancy in aquatic mammals

Question 22

What do the left and right vertebral arteries become when they join?

Answer 22

Basilar artery (crossing anterior surface of Pons)