Board Review-Embryology-Day 2

Front 1

What are the Branchial Arch 2 Derivatives?

Back 1

Reichert's Cartilage: Stapes, Styloid process, Stylohyoid Ligament, lesser horn of hyoid
Muscles: of facial expression, Stapedius, Stylohyoid, post. belly of Digastric
Nerve: CN VII

Front 2

Derivatives of Branchial Arch 3?

Back 2

Cartilage: greater horn of hyoid
Muscle: Stylopharyngeus
Nerve: IX

Front 3

What happens if the cleft and pouch of 3 persist?

Back 3

Congenital Pharyngocutaneous Fistula = between tonsilar area and lateral neck

Front 4

Derivatives of Branchial Arches 4-6?

Back 4

Cartilage: Thyroid, Cricoid, Arytenoids, Corniculate, Cuneiform
Muscles (4th): Most pharyngeal constrictors, Cricothyroid, levator veli palatini
Muscles (6th): all intrinsic ones of larynx Except Cricothyroid
Nerves (4th) CN X (sup. laryngeal branch=swallowing)
Nerves (6th): CN X (recurrent laryngeal branch = speaking)

Front 5

1st cleft derivatives?

Back 5

External Auditory Meatus

Front 6

2nd-4th cleft derivatives?

Back 6

Temporary cervical sinuses
Obliterated by prolif of 2nd arch mesenchyme

Front 7

What happens if one of the temporary cervical sinuses doesn't go away?

Back 7

Branchial Cleft Cyst w/in lateral neck

Front 8

1st pouch derivatives?

Back 8

Middle Ear Cavity
Eustachian Tube
Mastoid Air Cells

contributes to endoderm

Front 9

2nd pouch derivatives?

Back 9

Epithelial lining of palantine tonsil

Front 10

3rd pouch derivatives?

Back 10

Dorsal Wings: inferior parathyroids
Ventral Wings: Thymus

These structures end up below 4th pouch structures

Front 11

4th pouch derivatives?

Back 11

Superior Parathyroids

Front 12

What happens if your 3rd and 4th pouches don't develop correctly?

Back 12

DiGeorge Syndrome--->
T-cell def (thymic aplasia)
Hypocalcemia (parathyoid agenesis)

Front 13

What different structures give rise to parts of the ear?

Back 13

1st Arch (malleus/incus, tensor tympani)
2nd Arch (stapes, stapedius)
1st Cleft: External Auditory Meatus
1st Branchial Membrane: Tympanic Membrane
1st Pouch: Eustachian tube, middle ear cavity, mastoid air cells

Front 14

What gives rise to our tongue?

Back 14

1st Branchial Arch: anterior 2/3 (sensation via V3, taste via VII)
3rd and 4th Arches: posterior 1/3 (sensation and taste from IX, with extreme post. from X)
Motor Inn. from XII
Muscles of tongue from Occipital Myotomes

Front 15

Taste, Pain, and Motor Innervation of the tongue?

Back 15

Taste: VII, IX, and X (solitary nucleus)
Pain: V3, IX, X
Motor: XII

Front 16

What is a dividing marker between ant 2/3 and post 1/3 of tongue?

Back 16

Foramen Cecum

Front 17

Thyroid Dev kickers?

Back 17

Descends into neck via Thyroglossal duct which connects thyroid to tongue. Duct should disappear and leave behind foramen cecum. If it persists = pyramidal lobe of thyroid

Front 18

How does a Cleft Lip happen?

Back 18

Failure of fusion of maxillary and medial nasal processes (formation of primary palate)

Front 19

How does a Cleft Palate happen?

Back 19

failure of fusion of lateral palatine processes, the nasal septum, and/or the median palatine process (secondary palate)

Front 20

What is the Diaphragm derived from?

Back 20

1. Septum Transversum--> Central Tendon
2. Pleuroperitoneal Folds
3. Body Wall
4. Dorsal Mesentery of esophagus--> Crura

Front 21

Movement of Diaphragm during dev and significance?

Back 21

Descends, but keeps innervation from above.

Front 22

Who innervates the Diaphragm?

Back 22

C3, 4, 5 keep the diaphragm alive

Front 23

Who gives rise to the GI Tract?

Back 23

Foregut: pharynx to duodenum
Midgut: duodenum to transverse colon
Hindgut: Distal transverse to rectum

Front 24

What is the difference between Gastroschisis and Omphalocele?

Back 24

Gastroschisis: Failure of lateral body folds to fuse--->extrusion of abdominal contents

Omphalocele = persistence of herniation of abdomical contents into umbilical cord

Front 25

Most common type of Tracheoesophageal fistula?

Back 25

Blind upper esophagus
Lower esophagus connected to trachea

Presents w/ cyanosis, choking, vomiting w/ feeding, air bubble on CXR, and polyhydramnios

Front 26

Cause, Sx's, Rx, and Prevalence of Congenital Pyloric Stenosis?

Back 26

Hypertrophy of pylorus
Palpable "olive" in epigastric region and Nonbilious projectil vomiting at ~2 wks
Surgical Incision
1/600 live births, often w/ 1st born male

Front 27

Pancreas Embryology?

Back 27

From foregut
Ventral pancreatic bud-->head, uncinate process, and main pancreatic duct
Dorsal bud--->everything else (body, tail, isthmus, acc. duct)

Front 28

What is an annular pancreas?

Back 28

When ventral bud encircles 2nd part of duodenum-->ring of pancreatic tissue around duodenum possibly leading to duod narrowing

Front 29

Spleen embryology?

Back 29

From dorsal mesentery (mesoderm) but is supplied by artery of foregut (celiac a)

Front 30

5 Main components of Embryonic Kidney?

Back 30

Pronephros (week 4, then degenerates)
Mesonephros (kidney for 1st tri-->male genital system)
Metanephros: permanent. kidney from glomerulus to DCT
Urogenital Sinus--->bladder, urethra, allantois
Ureteric Bud: from mesonephros--->collecting duct, calyces, pelvises, and ureter

Front 31

What is Potter's Syndrome?

Back 31

Bilateral Renal Agenesis-->oligohydramnios-->limb deformities, facial deformities, lung hypoplasia

Malformed ureteric bud

Front 32

What's up with horseshoe kidneys?

Back 32

Inferior poles fuse
As they ascend they get caught on Inf. Mesenteric Artery and thus remain low
Fxn normally

Front 33

Default genital dev?

Back 33

FEMALE
Mesonephric Duct degenerates and paramesonephric duct develops

Front 34

What needs to happen for a Male to happen?

Back 34

SRY gene on Y Chromosome codes for testis-determining factor
Mullerian inhibiting substance is made by testes (sertoli's) and stops paramesonephric duct from dev.
Inc Androgens (leydig's)-->dev of mesonephric ducts

Front 35

Who is the Wolffian duct and what does it become?

Back 35

That'd be the mesonephric duct
Develops into male internal structures: Seminal Vesicles, Epididymis, Ejaculatory Duct, and Ductus Deferens (not prostate)

Front 36

Who is the Mullerian Duct and what does it become?

Back 36

Mullerian = Paramesonephric
Develops into Fallopian Tube, Uterus, and Upper 1/3 of Vagina (lower 2/3 from urogenital sinus)

Front 37

What the crap is a Bircornuate Uterus?

Back 37

From incomplete fusion of paramesonephric ducts--->2 headed uterus
Associated w/ UT abnormalities and infertility

Front 38

4 Embryonic Structures for external male/female genitalia?

Back 38

Genital Tubercle
Urogenital Sinus
Urogenital Folds
Labioscrotal Swelling

Front 39

What do each one of these structures become?

Back 39

Genital Tubercle---> Glans penis/glans clitoris, corpus spongiosum/vestibular bulbs
Urogenital Sinus-->Bulbourethral Glands/Greater vestibular glands (bartholin), Prostate Gland/urethral/paraurethral glands
Urogenital Folds--->Ventral Shaft (penile urethra)/Labia Minora
Labioscrotal Swelling--->Scrotum/Labia Majora

Front 40

What are hypospadias and epispadias?

Back 40

Hypo: abnormal ventral urethral opening due to failure of urethral folds to close

Epi: Dorsal blow hole due to faulty positioning of genital tubercle

Front 41

Epispadias association?

Back 41

Exstrophy of bladder