branchial arches

Question 1

first arch

Answer 1

mandibular arch
nerve- CN V- trigeminal
muscles: mastication, mylohyoid, anterior belly of digastric, tensor veli palatini
skeletal- head of malleus, upper incus, meckels cartilage
artery- 1st pair of aortic arches- remaining is maxillary

Question 2

second arch

Answer 2

hyoid arch
nerve- CN VII- facial
muscles: facial expression, stapedius, stylohyoid, posterior belly of digastric
skeletal: handle of malleus, lower incus, stapes, styloid process, lesser cornu of hyoid, upper body of hyoid
artery: 2nd pair of aortic arches- stems of stapedial artery

Question 3

third arch

Answer 3

nerve: CN IX- glossopharyngeal
muscles: stylopharyngeus
skeletal: greater cornu of hyoid, lower part of hyoid body
artery: 3rd pair of aortic arches, proximal part- common carotid, distal- part of internal carotid artery

Question 4

fourth arch

Answer 4

nerve: CN X: vagus
muscles: cricothyroid, levator veli palatini, pharyngeal constrictors, palatoglossus, salpingopharyngeus, palatopharyngeus
skeletal: laryngeal cartilages
artery: 4th pair aortic arches- left arch becomes part of aortic arch, right arch becomes part of right subclavian

Question 5

fifth and sixth arches

Answer 5

Nerve: cranial root of CN XI: spinal accessory
muscles: all intrinsic muscles of the larynx except cricothyroid, levator veli palatini, palatoglossus, pharyngeal constrictors, salpingopharyngeus, palatopharyngeus
skeletal: laryngeal cartilages
artery: 5th pair of aortic arches– rudimentary or doesnt develop
6th pair of aortic arch- L and R proximal– proximal pulmonary a
L distal– ductus arteriosus
R distal- degenerates