Where is foramen lacerum? What goes through it?

Where is foramen lacerum? What goes through it?

Answer:

Petrous temporal bone.
Upper end transmits ICA with sympathetic nerves.
Lower end is covered with connective tissue.

What is the position of the superior orbital fissure?

What is the position of the superior orbital fissure?

Answer: Between the greater and lesser wings of sphenoid.

What goes through foramen ovale?

What goes through foramen ovale?

Answer:

CN V3 (mandibular nerve)
Accessory meningeal artery

What goes through foramen rotundum?

What goes through foramen rotundum?

Answer:

CN V2 (maxillary nerve).
Small veins from cavernous sinus.

Where does each maxillary sinus drain?

Where does each maxillary sinus drain?

Answer: Into the middle meatus

Where does the sphenoid sinus drain?

Where does the sphenoid sinus drain?

Answer: Into the superior meatus

What important structure lies laterally on either side of the sphenoidal sinus?

What important structure lies laterally on either side of the sphenoidal sinus?

Answer: Cavernous sinus

What important structures lie above the sphenoidal sinus? (2)

What important structures lie above the sphenoidal sinus? (2)

Answer:

1) Pituitary fossa housing pituitary gland.
2) Optic chiasma and nerves

What is the pattern of drainage of the ethmoidal air cells?

What is the pattern of drainage of the ethmoidal air cells?

Answer:

Anterior - open into hiatus semilunaris (in middle meatus)
Middle - open into bulla ethmoidalis (in middle meatus)
Posterior - open into superior meatus

Where does each frontal sinus open?

Where does each frontal sinus open?

Answer: Middle meatus of the nasal cavity, either through ethmoidal infundibulum or directly via frontonasal duct.

What are the two main functions of the aqueous humour?

What are the two main functions of the aqueous humour?

Answer:

1) It provides and removes necessary metabolites to/from the lens, cornea and iris.
2) Hydromechanical function - maintains IOP

What is the average aqueous humour production rate?

What is the average aqueous humour production rate?

Answer: 2-4 microlitres a minute.

What is the average volume of the AC

What is the average volume of the AC

Answer: 250 microlitres

What is the average central AC depth?

What is the average central AC depth?

Answer: 3mm

What are zonules made of?

What are zonules made of?

Answer: A unique fibrous non-collagenous protein similar to elastin. The microfibrils contain fibrillin.

Where do the zonules arise from?

Where do the zonules arise from?

Answer: From the pars plana of the ciliary body.

How are superficial lens fibres (elongated lens cells) different from deeper fibres?

How are superficial lens fibres (elongated lens cells) different from deeper fibres?

Answer:

1. The deeper lens fibres are anucleate.
2. The more superficial fibres are rich in ribosomes, polysomes and RER - they actively synthesise lens crystallins.

Where is the maximal mitotic activity of the lens epithelium?

Where is the maximal mitotic activity of the lens epithelium?

Answer: Pre-equatorially and equatorially, at the germinative zone.

How do the lens epithelial cells change going from centre to equator?

How do the lens epithelial cells change going from centre to equator?

Answer: They become more columnar and elongate, and form lens fibres.

Where is the lens epithelium found?

Where is the lens epithelium found?

Answer: On the anterior surface only.

What type of epithelium is the lens epithelium?

What type of epithelium is the lens epithelium?

Answer: Simple cuboidal epithelium.

What is the lens capsule made of?

What is the lens capsule made of?

Answer: It is a thickened smooth basement membrane produced by the lens epithelium. It consists of glycoproteins, type IV collagen, and GAGs.

What are the three parts of the lens?

What are the three parts of the lens?

Answer:

1. Capsule
2. Lens epithelium
3. Lens fibres

What are 1) the average lens diameter and 2) the lens axial length in the adult?

What are 1) the average lens diameter and 2) the lens axial length in the adult?

Answer:

1) 10mm
2) 4mm