Branchial (pharyngeal) arch

During which week do branchial arches develop?

Week 4

What does each pharyngeal arch contain?

Cartilage, muscle, cranial nerve, artery

Pharyngeal clefts are derived from what?

Ectoderm

Pharyngeal pouches are derived from what?

Endoderm

What is the name of Arch 1?

Mandibular arch

What is the cranial nerve associated with Arch 1?

CN V (Trigeminal - V2/V3)

What are the skeletal derivatives of Arch 1?

Malleus, Incus, Mandible

What muscles are associated with Arch 1?

Muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini

What is the function of Arch 1?

Chewing

What is the name of Arch 2?

Hyoid arch

What is the cranial nerve associated with Arch 2?

CN VII (Facial nerve)

What are the skeletal derivatives of Arch 2?

Stapes, styloid process, lesser horn of hyoid, upper body of hyoid

What muscles are associated with Arch 2?

Muscles of facial expression, stapedius, stylohyoid, posterior belly of digastric

What is the function of Arch 2?

Facial expression

What is the cranial nerve associated with Arch 3?

CN IX (Glossopharyngeal)

What are the skeletal derivatives of Arch 3?

Greater horn of hyoid, lower body of hyoid

What muscle is associated with Arch 3?

Stylopharyngeus

What is the function of Arch 3?

Swallowing

What is the cranial nerve associated with Arch 4?

CN X (Vagus - superior laryngeal branch)

What are the skeletal derivatives of Arch 4?

Laryngeal cartilages (partial)

What muscles are associated with Arch 4?

Pharyngeal constrictors, cricothyroid, levator veli palatini

What is the function of Arch 4?

Swallowing (pharynx)

What is the cranial nerve associated with Arch 6?

CN X (Vagus - recurrent laryngeal branch)

What are the skeletal derivatives of Arch 6?

Laryngeal cartilages (remaining)

What muscles are associated with Arch 6?

Intrinsic muscles of larynx

What is the function of Arch 6?

Speech

Which arch is absent or rudimentary?

Arch 5

Which arches form ear ossicles?

Arch 1 and Arch 2

From which arch do the malleus and incus come?

Arch 1

From which arch does the stapes come?

Arch 2

The middle ear develops from which structure?

1st pharyngeal pouch

What does the 1st pharyngeal pouch form?

Tympanic cavity and auditory (Eustachian) tube

How many layers does the tympanic membrane have?

3

What is the outer layer of the tympanic membrane derived from?

Ectoderm (1st cleft)

What is the middle layer of the tympanic membrane derived from?

Mesoderm

What is the inner layer of the tympanic membrane derived from?

Endoderm (1st pouch)