Anatomy W5 - Cranial Cavity part 2

Question 1

What is the vault of the skull rich in?

Answer 1

Red bone marrow

Question 2

What is the boundary between the anterior cranial fossa and the middle cranial fossa?

Answer 2

The lesser wing of the sphenoid bone

Question 3

What structure does the pituitary reside in (middle cranial fossa) ?

Answer 3

Sella tursica /The hypophyseal fossa

Question 4

What is the boundary between the middle cranial fossa and the posterior cranial fossa?

Answer 4

The superior border of the petrous part of the temporal bone and the dorsum sellae

Question 5

On what part of the sphenoid bone does the brainstem lie?

Answer 5

The clivus

Question 6

What is the foramen lacera?

Answer 6

A hole in the floor of the cranial cavity where a cartilage precursor persists unossified.

Question 7

What veins drain into the superior sagittal sinus?

Answer 7

The superior cerebral veins

Question 8

In what direction does blood flow in the dural venous sinuses?

Answer 8

From front to back

Question 9

What does the vein of Galen/the great cerebral vein drain?

Answer 9

The midline of the forebrain (thalamus and the hypothalamus)

Question 10

What growth plate is present near the clivus on the floor of the cranial cavity?

Answer 10

The spheno-occipital growth plate

Question 11

When does The spheno-occipital growth plate start to fuse?

Answer 11

12 years and onwards (until age of 25)

Question 12

Where is the foramen magnum located?

Answer 12

On the baslar part of the occipital bone

Question 13

Where are nerves that supply muscles formed from pharyngeal arches situated in relation to the midline of the brain?

Answer 13

Further from the midline

Question 14

Where are nerves that supply muscles formed from somites situated in relation to the midline of the brain?

Answer 14

Closer to the midline

Question 15

What Cranial nerves comes off the brainstem as rootlets (instead of bundles)?

Answer 15

CN 9, 10, 11 & 12

Question 16

Rootlets of what cranial nerve(s) come from the RETRO olivary sulcus in the in the medulla oblongata of the brainstem?

Answer 16

CN 9, 10 & 11

Question 17

Rootlets of what cranial nerve(s) come from the PRE olivary sulcus in the medulla oblongata of the brainstem?

Answer 17

CN 12

Question 18

What are the signs of damage to the Oculomotor nerve CN 3?

Answer 18

Levator palpebrae superioris not being innervated = Eye lid droops/cant open

Eye drifts to the side since the medial rectus is not pulling the eye towards the centre (adducts).

Question 19

How can you assess if the pupils are symmetrical?

Answer 19

Look for the highlight on the pupils - are they in the same place?

Look at the amount of sclera on each side of the pupil - is it the same?

Question 20

What muscle is used in the light reflex?

What is the nerve supply to this muscle?

Answer 20

The constrictor papillae muscle.

Parasympathetic fibres from the oculomotor nerve.

Question 21

What nerve supplies the angle of the mandible?

Answer 21

The C2 & C3 spinal nerves - not a cranial nerve

Question 22

Define dermatome.

Answer 22

An area of skin supplied by any particular cranial or spinal nerve

Question 23

When is facial paralysis given the name Bells Palsy?

Answer 23

When the cause is unknown

Question 24

What is the risk of a patient getting a schwannoma of CN 8 removed?

Answer 24

Since CN 7&8 run close together through the internal acoustic meatus there is a risk that there could be damage to the facial nerve = facial palsy that affects the whole side of her face.

Question 25

What nerve innervates the larynx?

Answer 25

The vagus

Question 26

What is Horner’s syndrome?

Answer 26

Damage to the sympathetic NS

Question 27

What can cause Horner’s syndrome?

Answer 27

Congenital defects

Malignancy

Stroke

Trauma to neck

Question 28

What are the symptoms of Horner’s syndrome?

Answer 28

Constriction of the pupil on that side - dilator is under sympathetic control.

Lack of sweat on that side - controlled by sympathetic NS

Drooping eyelid (ptosis) - mix of skeletal muscle from CN 3 and smooth muscle - smooth muscle is under sympathetic control.

Question 29

Where is the superior cervical ganglion located?

Answer 29

Behind the bifurcation of the carotid artery

Question 30

What structures in the ventricles of the brain produce CSF?

Answer 30

Choroid plexus

Question 31

Describe the constant turn over of CSF.

Answer 31

Choroid plexus in the ventricles produce CSF, CSF fills the subarachnoid space.
The arachnoid villi extend from the subarachnoid space into the superior sagittal sinus and allow CSF to enter into the venous circulation.

Question 32

What do you call the large collection of CSF near the brainstem?

Answer 32

The systerna magna