Triangles Of Neck Inc Carotid Sheath

Question 1

Describe the origin and insertion of the sternocleidomastoid.

Answer 1

ORIGIN - medial part of the clavicle and the sternums superior and lateral surfaces; tendinous head at manubrium; fleshy head from medial part of clavicle
INSERTION - mastoid process of temporal bone

Question 2

Which nerves cross over the sternocleidomastoid superficially? What do these supply?

Answer 2

greater auricular nerve - supplies sensation to skin over mandible
transverse cervical nerve - supplies sensation to skin on anterior triangle of neck
(both derived from C2 and C3 nerve fibres)

Question 3

What are the borders of the anterior triangle of the neck?

Answer 3

From the midline to the sternum to the sternocleidomastoid

Question 4

What small muscle lies superficial to the brachial plexus? What nerve runs superficial to this muscle?

Answer 4

Scalenus anterior muscle
Phrenic nerve (C3,C4,C5)

Question 5

What other nerve can be seen in the posterior triangle, which comes from deep within the sternoclediomastoid? What two muscles does it innervate?

Answer 5

Accessory nerve
Supplies sternocleidomastoid and trapezius
Shrugs shoulders

Question 6

Two arteries run superficial to the anterior scalenus muscle. What are these?

Answer 6

Transverse cervical artery

Suprascapular artery

Question 7

What are the contents of the carotid sheath?

HINT: I See 10 CCs in the IV

Answer 7

Internal carotid artery
Vagus nerve
Common carotid
Internal jugular vein
Ansa cervicalis 
Deep cervical lymph nodes

Question 8

What does the ansa cervicalis supply?

Answer 8

All infrahyoid strap muscles except the thyrohyoid

Question 9

What is the name of the internal carotid bulging at the bifurcation? What is the importance of this structure?

Answer 9

Carotid sinus
Baroreceptors are present within arterial wall to detect gas changes in blood - protects brain from any change in gas levels as brain is highly sensitive

Question 10

Which cranial nerve crosses superficial to the internal carotid?

Answer 10

Hypoglossal nerve

Question 11

Which vein crosses superficial at the level just above the carotid sinus?

Answer 11

Facial vein

Question 12

Which nerves innervate the infrahyoid strap muscles?

Answer 12

Ansa cervicalis innervates sternothyroid, omohyoid, sternohyoid
hypoglossal nerve innervates thyrohyoid

Question 13

What is the valsalva manoeuvre?

Answer 13

Rise of pressure when holding breath may cause external jugular v. to stand out