Lecture 44 Branchial Arches

Question 1

what are the four components of the branchial “apparatus”?

Answer 1

branchial (pharyngeal) arches; pharyngeal pouches, branchial grooves (clefts), and branchial membranes

Question 2

what are the four components of each branchial (pharyngeal) arch?

Answer 2

nerve, muscle, skeletal/cartilage, and aortic arch

Question 3

Nerves associated with the branchial arches are referred to as what kind of nerves?

Answer 3

branchiomeric nerves

Question 4

Name the five “branchiomeric” nerves.

Answer 4

CN V, CN VII, CN IX, CN X, and CN XI

Question 5

The muscle group related to branchial arch 1 is _____ mm and the muscle group related to branchial arch 2 is ______ mm.

Answer 5

masticatory, facial

Question 6

Which pharyngeal pouch is related to the pharyngotympanic tube?

Answer 6

First

Question 7

The thymus and parathyroids are related to which pharyngeal pouch(es)?

Answer 7

Third and Fourth

Question 8

The first branchial membrane is related to what derivative in adults?

Answer 8

Tympanic membrane

Question 9

How many branchial arches are said to exist in humans?

Answer 9

Six, though the existence of the fifth remains unclear and is usually considered together with the sixth or the fourth

Question 10

On the lateral aspect of the head region of the embryo, how many branchial arches can be visualized?

Answer 10

Four

Question 11

The second branchial arch is sometimes referred to as the ________ arch.

Answer 11

Hyoid

Question 12

By the _____ week, all branchial swellings (4) are visible.

Answer 12

4th week (~28 +/- 1 day)

Question 13

Muscles derived from the branchial (pharyngeal) arches come from two species. Describe them.

Answer 13

Those that form in the mesenchyme of the branchial arch, receiving cues from neural crest cells
Muscles that migrate into the head and neck region that come from myotomes (myotomal portion of somites)

Question 14

What structures migrate into the branchial (pharyngeal) aches to assist in forming their derivatives?

Answer 14

neural crest cells

Question 15

What skeletal element is related to the first branchial (pharyngeal) arch? What about the second branchial (pharyngeal) arch?

Answer 15

Meckel’s cartilage

Reichert’s cartilage

Question 16

What nerve is related to the sixth aortic arch, the derivative being the ligamentum arteriosum?

Answer 16

L recurrent laryngeal nerve

Question 17

What is the first endocrine gland to appear during development at approximately 24 days?

Answer 17

Thyroid gland

Question 18

Developmentally, the thyroid chisels through the _____ and ends up at the _____ aspect of the throat, sitting in front of the _____.

Answer 18

Tongue
Anterior
Larynx

Question 19

Name three variations or malformations that can result from incorrect descent of the thyroid.

Answer 19

Pyramidal lobes/persistent thyroglossal duct
Thyroglossal duct cysts and sinuses
Ectopic thyroid gland

Question 20

What temporary structure appears where the branchial groove and pharyngeal pouch approach one another?

Answer 20

Branchial membrane

Question 21

What syndrome results due to damage of Meckel’s cartilage, resulting in micrognathia (shortened mandible)?

Answer 21

Pierre Robin Sequence

Question 22

The 2nd-4th branchial grooves (pharyngeal clefts) temporarily exist as ______, which usually disappears.

Answer 22

Common cervical sinus

Question 23

The first branchial arch is also known as the ______ arch.

Answer 23

Mandibular

Question 24

Which branchial arch forms the upper portion of the malleus and incus?

Answer 24

1st branchial arch

Question 25

Which branchial arch forms the lower portion of the malleus, incus, and stapes, styloid process of the skull, and portions of the hyoid?

Answer 25

3rd branchial arch

Question 26

Which branchial arch forms the thyroid cartilage of the larynx?

Answer 26

4th branchial arch

Question 27

Which arch(es) form the cricoid, arytenoid, corniculate, and cuneiform cartilages of the larynx?

Answer 27

5th and 6th branchial arches

Question 28

Trigeminal (CN V) is to the ______ arch.

Answer 28

First

Question 29

Glossopharyngeal (CN IX) is to the _______ arch.

Answer 29

Third

Question 30

Vagus (CN X), specifically the superior laryngeal nerve, is to the ______ arch.

Answer 30

Fourth

Question 31

Cranial root of the Spinal Accessory (CN XI) fibers carried in the recurrent laryngeal nerve (of the Vagus) is to the _______ arch(es).

Answer 31

Fifth and Sixth

Question 32

The first branchial arch is related to what artery derivatives?

Answer 32

1st pair of aortic arches and maxillary artery

Question 33

The second branchial arch is related to what artery derivatives?

Answer 33

2nd pair of aortic arches and stapedial artery

Question 34

The third branchial arch is related to what artery derivatives?

Answer 34

3rd pair of aortic arches, proximal parts form common carotid, distal parts form portions of internal carotid

Question 35

The fourth branchial arch is related to what artery derivatives?

Answer 35

4th pair of aortic arches, L arch forms part of the aortic arch, R arch forms part of the R subclavian

Question 36

The fifth-sixth branchial arches are related to what artery derivatives?

Answer 36

6th pair of aortic arches, proximal part of the L arch forms the proximal pulmonary arteries, distal part of the L arch forms the ductus arteriosus

Question 37

What branchial arch is associated with all muscles of mastication, the anterior belly of digastric, mylhoid, and tensors?

Answer 37

First branchial arch

Question 38

What single muscle is associated with the 3rd branchial arch?

Answer 38

Stylopharyngeus

Question 39

What branchial arch is associated with the cricothyroid muscle?

Answer 39

Fourth branchial arch

Question 40

Which branchial arch is associated with all intrinsic muscles of the larynx except the cricothyroid?

Answer 40

Fifth-sixth branchial arches

Question 41

The Facial Nerve (CN VII) is to the _______ arch.

Answer 41

Second