Lecture 19 - SQ

Question 1

1. Where may you best feel the pulsations of the facial artery and the superficial temporal artery? Which artery are these vessels derived from?

Answer 1

1. Facial artery – over the body of the mandible at the anterior border of masseter. Superficial temporal artery – immediately anterior to the ear. These arteries are derived from the external carotid artery.

Question 2

On the drawing below, mark in the area of skin supplied by the:

a) ophthalmic nerve
b) maxillary nerve
c) mandibular nerve

Answer 2

Question 3

3. Which muscles affect the size of the: a) oral fissure b) orbital fissure.

Answer 3

3. a) Orbicularis oris is a sphincter muscle – it “purses” the lips. Levator anguli oris and zygomaticus major elevate the corner of the lip. Levator labii superioris working bilaterally “curls back” the upper lip. Depressor labii inferioris and depressor anguli oris depress the lower lip and the corner of the mouth. b) Orbicularis oculi forms a sphincter around the eye. It closes the eye.

Question 4

4. What is the function of the posterior fibres of the temporalis muscle?

Answer 4

4. Retraction of the mandible.

Question 5

5. What is the major function of the lateral pterygoid muscle?

Answer 5

5. Protraction and depression of the mandible – opens the mouth. It is also associated with lateral movements of the jaw, as in chewing, when the medial pterygoid of the same side also contracts.

Question 6

6. What sensory deficit would result from sectioning the inferior alveolar nerve as it enters the mandibular foramen?

Answer 6

6. The lower teeth would become insensitive and the skin over the chin and lower lip together with the mucous membrane on the inside of the lower lip and the adjacent gingiva would become numb (mental nerve).