TBL 24

Question 1

What nerve crosses the external carotid artery at the origin of the facial and lingual arteries?

Answer 1

Hypoglossal nerve (CN XII)

Question 2

Where does the hypoglossal nerve cross the external carotid artery?

Answer 2

At the origin of the facial and lingual arteries

Question 3

Where are the attachment sites of the two-bellied omohyoid muscle?

Answer 3

Scapula and hyoid

Question 4

What muscle extends from the scapula to the hyoid bone?

Answer 4

Omohyoid muscle

Question 5

What nerves are the strap muscles innervated by?

What is the exception?

Answer 5

Ansa cervicalis of the cervical plexus

Exception: thyrohyoid innervated by C1

Question 6

Which nerve transports C1 fibers to the thyrohyoid?

Answer 6

Hypoglossal nerve (CN XII)

Question 7

What is the name of the ganglion formed by the union of the inferior cervical sympathetic ganglion and the superior thoracic ganglion?

Answer 7

Stellate ganglion

Question 8

What is the origin of the superior thyroid artery?

Answer 8

External carotid artery

Question 9

What is the origin of the inferior thyroid artery?

Answer 9

Thyrocervical trunk emerging from the subclavian artery

Question 10

What are the branches of the external carotid artery?

Answer 10

Lingual, facial, and superior thyroid arteries

Question 11

Is the thyroglossal duct an endodermal or ectodermal bud?

Answer 11

Endodermal

Question 12

Where is the thyroglossal duct found?

Answer 12

Foramen cecum

Question 13

What are parafollicular cells of the thyroid gland derived from?

Answer 13

Neural crest cells migrating into the 4th pharyngeal pouch

Question 14

From which pharyngeal pouch do the thymus and inferior pair of parathyroid glands arise?

Answer 14

3rd pharyngeal pouch

Question 15

From which pharyngeal pouch do the superior pair of parathyroid glands arise?

Answer 15

4th pharyngeal pouch

Question 16

Are pharyngeal pouches endodermal or ectodermal?

Answer 16

Endodermal

Question 17

Are pharyngeal clefts endodermal or ectodermal?

Answer 17

Ectodermal

Question 18

How are the two lobes of the thyroid gland interconnected across the 2nd and 3rd tracheal rings?

Answer 18

By the isthmus

Question 19

What is thyroglobulin?

Answer 19

Iodinated glycoprotein precursor of thyroid hormones (triiodothyronine and tetraiodothyronine)

Question 20

What are three functions of thyroid hormones?

Answer 20

1. Increase oxygen consumption
2. Increase metabolic rate
3. Promote normal growth, maturation, and mental activity

Question 21

What do parafollicular cells secrete?

Answer 21

Calcitonin, which lowers blood calcium levels to counterbalance action of parathyroid hormone

Question 22

What does parathyroid hormone do?

Answer 22

Mobilizes calcium from bone to raise blood calcium levels

Question 23

What blood vessel crosses the sternocleidomastoid?

Answer 23

External jugular vein

Question 24

What does the external jugular vein drain?

Answer 24

Scalp superior and posterior to the ear

Question 25

What does the internal jugular vein drain?

Answer 25

Brain, face, and cervical viscera