part of MAXillary artery  (branch of external carotid)

"1st arch to the MAX"

Stapedial and hyoid arteries

"Second = Stapedial"

Common Carotid arteries and proximal part of Internal Carotid arteries

"C is the 3rd letter of the alphabet and stands for Carotids"

R: proximal part of R subclavian artery

L: aortic arch (part of it)

proximal part of pulmonary arteries

***left arch also forms the ductus arteriosus

Branchial apparatus origins:

• Clefts?
• Arches?
• Pouches?
  

• Clefts - ectoderm
• Arches - mesoderm (mm & aa) & neural crest (bones & cartilage)
• Pouches - endoderm

"CAP covers outside to inside"

Ventral wings: thymus

Dorsal wings: inferior parathyroids

Ventral wings: ultimobranchial body (→ C cells of thyroid, which have neural crest origin)

Dorsal Wings: superior parathyroids

1st Branchial Arch derivatives

(and assoc. CN)

NC: Meckel's cartilage, Mandible, Malleus, incus, sphenoMandibular ligament

Mesoderm: Muscles of Mastication (temporalis, Masseter, lateral and Medial pterygoids), Mylohyoid, ant. belly of digastric, Tensor Tympani, Tensor veli palatini, ant. 2/3 of tongue

CN: V₂ and V₃  (Max and Mandib of Trigem)

*also assoc. w/ Maxillary artery

*remember "M's and T's"

2nd Branchial arch derivatives

(and assoc. CN)

NC: Reichert's cartilage (Stapes, Styloid process, less horn of hyoid, Stylohyoid ligament)

Mesoderm: muscles of facial expression, Stapedius, Stylohyoid, post. belly of digastric

CN: VII

*also assoc. w/ Stapedial artery

*think "S's"  - CN seven, second arch, S's above

3rd Branchial arch derivatives

(and assoc. CN)

NC: greater horn of hyoid bone

Mesoderm: stylopharyngeus

CN: IX- glossopharyngeal

*think "pharyngeal"

NC: thyroid, cricoid, arytenoids, corniculate, cuneiform cartilages

Mesoderm: 4th arch - most pharyngeal constrictors, cricothyroid, levator veli palatini; 6th - all intrinsic mm of larynx (except cricothyroid)

CN: X

4th arch: superior laryngeal branch - swallowing

6th: recurrent laryngeal branch - speaking

*think "soft palate, voice (larynx), and swallowing (pharynx)"

Level: midbrain

Medial

Lesion: lateral strabismus (down & out), fixed dilated pupil, ptosis

Arterial supply: PCA

Level: lower pons

Medial

Lesion: medial strabismus

arterial supply: Paramedian

Level: upper medulla

Medial

lesion: tongue deviation to side of lesion

arterial supply: ASA (ant. spinal artery)

Level: upper pons

Lateral

Lesion: mandibular deviation to side of lesion (due to intact lateral pterygoid)

arterial supply: Superior cerebellar artery

Level: lower pons

Lateral

lesion: paralysis of facial muscle (LMN lesion affects above and below eyebrow)

Arterial supply: AICA

*note: an UMN lesion would result in only lower facial muscle deficits contralaterally

CN IX & X Nucleus Ambiguus location

(motor nucleus)

Level: upper medulla

Lateral

Lesion: dysphasia, hoarseness, & uvula deviation away from side of lesion

arterial supply: PICA

Genital Tubercle

male and female homologues

Male: 1)glans penis; 2)corpus cavernosum & spongiosum

Female: 1)glans clitoris; 2)vestibular bulbs

Urogenital sinus

male and femal homologues

Male: 1)bulbourethral glands (of Cowper); 2)prostate gland

Female: 1)greater vestibular glands (of Bartholin); 2) urethral and paraurethral glands (of Skene)

Urogenital Folds

male and female homologues

Male: ventral shaft of penis (penile urethra)

Female: labia minora

Labioscrotal swelling

male and female homologues

Male: scrotum

Female: labia majora