Week 4 - A - Pituitary gland anatomy

Question 1

What is the other name of the pituitary gland?

Answer 1

The hypophyisis

Question 2

What are the 3 parts of the brainstem? (superior to inferior) What does the brainstem continue to form? What foramen does this continuation pass through?

Answer 2

Midbrain

Pons

Medulla

Continues to form the spinal cord passing through the foramen magnum

Question 3

What structures form the diencephalon?

Answer 3

diencephalon = thalamus (T) + hypothalamus (H)

the diencephalon forms the central core of the cerebrum with connections to the right and left cerebral hemispheres & the midbrain

Question 4

The pituitary gland lies in the pituitary fossa in what depression of which bone?

Answer 4

Lies in the depression called the sella turcica (turkish saddle)

It is in the sphenoid bone

Question 5

What structure does the pituitary gland lie immediately inferior to? What forms this structure?

Answer 5

Lies immediately inferior to the optic chiasm formed by the right and left optic nerves

Question 6

What are the two types of photoreceptors found in the the eye? Which part of the eye are these two photoreceptors found in?

Answer 6

Rods & Cones

Found in the retina of the eye (temporal and nasal)

Question 7

Are rods or cones more responsible for vision at low levels of light? Which is more sensitive?

Answer 7

Rods are responsible for visions at low levels of light and are more sensitive than the cones and do not mediate colour

Question 8

If damage is cause to the optic chiasm (eg via a pituitary adenoma causing a midline compression), what visual defect most commonly arises?

Answer 8

A bitemporal hemianopia

Question 9

The temporal side of the visual field refers to the periphery of the eye, does this refer to the inner or outer part of the actual eye itself? How does bitemporal hemaniopia occur?

Answer 9

Refers to the inner part of eye

Due to the fact the axons cross over at the optic chiasm, a midline compression will disrupt the transmission causing no sight in the temporal visual field

Question 10

What are the two types of surgery carried out to approach the pituitary gland? Which is more commonly carried out?

Answer 10

transcranial approach (subfrontal – under the frontal lobe)

transsphenoidal approach (via nasal cavities & sphenoid sinus) - this is the more commonly carried out approach

Question 11

What are the structures of the nasal cavities, that increase the surface area of these cavities, thus providing for rapid warming and humidification of air as it passes to the lungs? (they are also known as turbinates)

Answer 11

The nasal concha

Question 12

What are the nasal concha parts? Which are part of the ethmoid bone?

Answer 12

The superior nasal concha (of the ethmoid bone)

The middle nasal concha (of the ethmoid bone)

The inferior nasal concha

Question 13

A Le Fort fracture of the skull is a classic transfacial fracture of the midface, involving the maxillary bone and surrounding structures in either a horizontal, pyramidal or transverse direction What type of fracture allows best access to the nasal cavities in more complicated cases?

Answer 13

Le Fort 1 down fractures (speak no evil) allow best access to the nasal cavities

Le Fort 1 (speak no evil) - horizontal maxillary fractures

Le Fort 2 (see no evil) - pryamidal maxillary fractures

Le Fort 3 (hear no evil) - transverse maxiallary fractures

Question 14

Blood supply to nasal cavities? (3 arteries, names of the cranial nerves)

Answer 14

* facial artery

* ophthalmic artery

* maxillary artery

Question 15

What are the 12 cranial nerves in order? Which are sensory and which are motor?

Answer 15

• Olfactory (sensory),
• Optic (sensory),
• Oculomotor (motor),
• Trochlear (motor),
• Trigeminal (Opthalmic, maxillary, mandibular) (sensory and motor),
• Abducent (motor),
• Facial (sensory and motor),
• Vestibulocochlear (sensory),
• Glossopharyngeal (sensory and motor),
• Vagus (sensory and motor),
• Spinal accesory (motor),
• Hypoglassal (motor)

Question 16

What are the foramen of the 12 cranial nerves?

Answer 16

• Olfactory - cribiform plate of ethmoid bone
• Optic - optic canal
• Oculomotor - superior orbital fissure
• Trochlear - superior orbital fissure
• Trigeminal (Opthalmic (superior orbital fissure), maxillary (foramen rotundum), mandibular (foramen ovale))
• Abducent (superior orbital fissure)
• Facial (internal acoustic meatus + stylomastoid foramen)
• Vestibulocochlear (internal acoustic meatus)
• Glossopharyngeal (jugular foramen)
• Vagus (jugular foramen)
• Spinal accesory (jugular foramen)
• Hypoglassal (hypoglassol canal)

Question 17

Identify the indicated blood vessel. What forms this vessel?

Answer 17

basilar artery

Formed by the right and left vertebral arteries

The basilar artery crosses along the anterior surface of the pons

Question 18

what is the thick membrane that is the outermost of the three layers of the meninges that surround the brain and spinal cord?(nb. all three meninges layers surround the brain and spinal cord) What are the three meninges layer?

Answer 18

Dura matter

The three layers are: Pia matter Arachnoid matter Dura matter

Question 19

What is the tough sheet of dura matter that tents over the posterior cranial fossa however has a gap for the brainstem to pass through?

Answer 19

The tenotrium cerebelli

Question 20

what drains most of the venous blood from the cranial cavity into the internal jugular veins?

Answer 20

The dural venous sinuses

Question 21

What nerve provides the muscle to give the eye with lateral movement?

What nerve provides the muscle to give the eye with downward and out movement?

Answer 21

The abducent nerve

The trochlear nerve

Question 22

What structures are at risk of damage in pituitary gland surgery?

Answer 22

optic chiasm

dura mater

Cavernous sinus - cranial nerves 3, 4, 5 (v1, v2), 6 &

internal carotid artery