Embryo

Front 1

What is the gene that is expressed at the base of limbs in a zone of polarizing activity?

Back 1

Sonic hedgehog gene

Front 2

The sonic hedgehog gene regulates patterning along the _____ (anterior-posterior or cranial-caudal) axis.

Back 2

anterior-posterior

Front 3

Name 2 genes expressed at the apical ectodermal ridge (the thickened ectoderm at the distal end of each developing limb).

Back 3

Wnt-7 and FGF

Front 4

What is the gene responsible for proper organization along the dorsal-ventral axis?

Back 4

Wnt-7

Front 5

What gene is responsible for the lengthening of limbs?

Back 5

FGF

Front 6

Which embryonic layer responds to products of the FGF gene?

Back 6

The mesoderm

Front 7

How does the FGF gene cause limbs to lengthen?

Back 7

It stimulates mitosis of the underlying mesoderm

Front 8

What phenotype would be seen if there was a mutation in the homeobox gene?

Back 8

There would be defects in segmental organization

Front 9

What are common abnormalities seen in a neonate with defects in embryogenesis involving the mesodermal germ layer?

Back 9

VACTERL: Vertebral defects, Anal atresia, Cardiac defects, Tracheo-Esophageal fistula, Renal defects, Limb defects

Front 10

Chorion

Back 10

Composed of Cytotrophoblast and Syncytiotrophoblast. Invades endometrium to allow transfer of nutrients.

Front 11

Cytotrophoblast

Back 11

Inner layer of chorionic villi; Cyto makes Cells

Front 12

Syncytiotrophoblast

Back 12

Outer layer of chorionic villi; secretes hCG (structurally similar to LH; stimulates corpus luteum to secrete progesterone during first trimester).

Front 13

Amnion

Back 13

Surrounds and protects the embryo. Forms around day 8. Twinning after this stage results in conjoined twins

Front 14

Decidua basalis

Back 14

Derived from endometrium. Transfers maternal blood to chorion.

Front 15

What is the term for a fistula between the umbilicus and terminal ileum?

Back 15

Vitelline fistula

Front 16

What is the term for a fistula between the umbilicus and the bladder?

Back 16

Urachal fistula

Front 17

Umbilical arteries and veins are derived from what?

Back 17

Allantois

Front 18

Bulbus cordis

Back 18

Gives rise smooth parts (outflow tract) of left and right ventricle

Front 19

Primitive ventricle

Back 19

Gives rise to trabeculated part of ventricles

Front 20

Primitive atria

Back 20

Gives rise to trabeculated left and right atrium

Front 21

Left horn of sinus venosus

Back 21

Gives rise to coronary sinus

Front 22

Right horn of sinus venosus

Back 22

Gives rise to smooth part of right atrium

Front 23

Right common cardinal vein and right anterior cardinal vein

Back 23

Gives rise to Superior Vena Cava

Front 24

What is the opening called in the early muscular ventricular septum?

Back 24

The interventricular foramen

Front 25

_____ divides the truncus arteriosus into the aortic and pulmonary trunks.

Back 25

The aorticopulmonary septum

Front 26

The aorticopulmonary septum meets and fuses with the muscular ventricular septum to form the _____.

Back 26

membranous interventricular septum

Front 27

______ forms to close the interventricular foramen and separate the two ventricles.

Back 27

The membranous interventricular septum

Front 28

What two components make up the interventricular septum?

Back 28

The muscular septum and the membranous septum

Front 29

Near the end of fetal heart development, the remaining portion of the septum primum is called the valve of the ______.

Back 29

Foramen ovale

Front 30

What is the order in which organs become the primary site of fetal erythropoiesis?

Back 30

The Yolk sac (3-8 wk), Liver (6-30 wk), Spleen (9-28 wk), Bone marrow (28 wk) (remember: Young Liver Synthesizes Blood)

Front 31

The umbilical vein in the fetus becomes what structure in the adult?

Back 31

The ligamentum teres hepatis (round ligament of liver)

Front 32

The ligamentum teres hepatis is contained in what structure in the adult?

Back 32

The falciform ligament

Front 33

The foramen ovale in the fetus becomes what structure in the adult?

Back 33

The fossa ovalis

Front 34

The allantois (urachus) in the fetus becomes what structure in the adult?

Back 34

The mediaN umbilical ligament comes from the allaNtois

Front 35

first aortic arch

Back 35

The MAXillary artery (remember: the 1st arch is MAXimal)

Front 36

second aortic arch

Back 36

The stapedial artery and the hyoid artery (remember: Second = Stapedial)

Front 37

third aortic arch

Back 37

The common Carotid and proximal internal Carotid (remember: C is the third letter of the alphabet)

Front 38

fourth aortic arch on the left

Back 38

The aortic arch (remember: 4th arch [4 limbs] = systemic circulation)

Front 39

fourth aortic arch on the right

Back 39

The subclavian artery (remember: 4th arch [4 limbs] = systemic circulation)

Front 40

fifth aortic arch

Back 40

Nothing

Front 41

sixth aortic arch

Back 41

The pulmonary artery and the ductus arteriosus

Front 42

Prosenencephalon

Back 42

Telencephalon and Diencephalon

Front 43

telencephalon

Back 43

The cerebral hemispheres and lateral ventricles

Front 44

diencephalon

Back 44

The thalami and third ventricle

Front 45

mesencephalon

Back 45

Midbrain

Front 46

Rhombencephalon

Back 46

Metencephalon, Myelencephalon

Front 47

metencephalon

Back 47

The pons and the cerebellum

Front 48

myelencephalon

Back 48

The medulla

Front 49

mesencephalon cavity

Back 49

The aqueduct

Front 50

metencephalon and myelencephalon cavity

Back 50

4th ventricle

Front 51

3 Neural Tube Defects

Back 51

Spina bifida occulta, Meningocele, Myelomeningocele

Front 52

Holoprosencephaly

Back 52

Decreased separation of hemispheres across midline; results in cyclopia; associated with Patau's syndrome, severe fetal alcohol syndrome, and cleft lip/palate. Associated with Sonic Hedgehog gene.

Front 53

Lissencephaly

Back 53

Congenital absence of gyri

Front 54

Chiari II malformation

Back 54

Cerebellar tonsillar herniation through foramen magnum with aqueductal stenosis and hydrocephaly. Often presents with synringomyelia, thoracolumbar myelomeningocele

Front 55

Dandy-Walker malformation

Back 55

Large posterior fossa; absent cerebellar vermis with cystic enlargement of 4th ventricle. Can lead to hydrocephalus and spina bifida.

Front 56

Syringomyelia

Back 56

Enlargement of central canal of spinal cord -> damaged crossing fibers of spinothalamic tract -> Bilateral loss of pain and temperature sensation in upper extremeties with preservation of touch sensation. Associated with Chiari II.

Front 57

Branchial Apparatus parts

Back 57

CAP from outside to inside. Clefts = Ectoderm. Arches = mesoderm. Pouches = endoderm.

Front 58

1st cleft development

Back 58

External auditory meatus

Front 59

2nd through 4th cleft development

Back 59

Temporary cervical sinuses which are obliterated

Front 60

Persistent cervical sinus

Back 60

Leads to branchial cleft cyst within lateral neck

Front 61

Branchial Arch 1 Innervation

Back 61

Cranial nerve V2 and V3. Maxillary and Mandibular.

Front 62

Branchial Arch 1 Cartilage

Back 62

Meckel's Cartilage: Mandible, Malleus, incus, sphenoMandibular ligament

Front 63

Branchial Arch 1 Muscles

Back 63

Muscles of Mastication (temporalis, Masseter, lateral and Medial pterygoids), Mylohyoid, anterior belly of digastri, tensor tympani, tensor veli palatini, anterior 2/3 of tongue

Front 64

Treacher Collins syndrome

Back 64

1st-arch neural crest fails to migrate -> mandibular hypoplasia, facial abnormalities

Front 65

Branchial Arch 2 Cartilage

Back 65

Reichert's cartilage: Stapes, Styloid process, lesser horn of hyoid, Stylohyoid ligament

Front 66

Branchial Arch 2 Muscles

Back 66

Muscles of facial expression, Stapedius, Stylohyoid, posterior belly of digastric

Front 67

Branchial Arch 2 Nerves

Back 67

CN VII

Front 68

Branchial Arch 3 Cartilage

Back 68

Greater horn of hyoid

Front 69

Branchial Arch 3 Muscles

Back 69

Stylopharyngeus (innervated by glossopharyngeal)

Front 70

Branchial Arch 3 Nerves

Back 70

CN IX (stylopharyngeous)

Front 71

Congenital Pharyngocutaneous fistula

Back 71

Persistence of cleft and pouch -> fistula between tonsillar area, cleft of lateral neck.

Front 72

Branchial Arch 4-6 Cartilage

Back 72

Thyroid, crycoid, arytenoids, corniculate, cuneiform

Front 73

Branchial Arch 4-6 Muscles

Back 73

4th arch: most pharyngeal constrictors, cricothyroid, levator veli palatini. 6th arch: all intrinsic muscles of larynx except cricothyroid.

Front 74

Branchial Arch 4-6 Nerves

Back 74

4th Arch: CN X (superior laryngeal branch - swallowing). 6th Arch: CN X (recurrent laryngeal branch - speaking)

Front 75

Tongue Arch Derivative

Back 75

Branchial arches 3 and 4 form posterior 1/3 of tongue.

Front 76

1st pouch

Back 76

Middle ear cavity, eustachian tube, mastoid air cells.

Front 77

2nd pouch

Back 77

Epithelial lining of palatine tonsil

Front 78

3rd pouch (Dorsal wings)

Back 78

left and right inferior parathyroids

Front 79

3rd pouch (Ventral wings)

Back 79

Thymus

Front 80

4th pouch

Back 80

Superior parathyroids. 3rd pouch structures end up below 4th-pouch structures

Front 81

DiGeorge Syndrome

Back 81

Aberrant development of 3rd and 4th pouches -> T cell deficiency (thymic aplasia) and hypocalcemia (failure of parathyroid development)

Front 82

Thyroglossal duct

Back 82

Normally disappears but may persist as pyramidal lobe of thyroid. Foramen cecum is normal remnant of thyroglossal duct

Front 83

What happens to a thyroglossal duct cyst with swallowing?

Back 83

It will move with swallowing, unlike a branchial cleft cyst

Front 84

A persistent cervical sinus, leading to a branchial cyst, is commonly found and felt where?

Back 84

In the lateral neck

Front 85

Cleft lip results from the failure of which structures to fuse?

Back 85

Maxillary nasal process and medial nasal process (formation of primary palate)

Front 86

Cleft palate results from failure of which structures to fuse?

Back 86

The lateral palatine process, the nasal septum and the median palatine process (formation of secondary palate)

Front 87

Cleft lip is a defect in the formation of the _____ (primary/secondary) palate, and cleft palate is a defect in the formation of the _____ (primary/secondary) palate.

Back 87

Primary; secondary

Front 88

Gastroschisis

Back 88

Extrusion of abdominal contents through abdominal folds; not covered by peritoneum.

Front 89

Omphalocele

Back 89

Persistence of herniation of abdominal contents into umbilical cord, covered by peritoneum.

Front 90

Midgut development timeline

Back 90

Week 6: herniation of midgut through umbilical ring. Week 10: return to abdominal cavity + rotate around SMA

Front 91

The head of the pancreas is derived from the _____ (ventral/dorsal) pancreatic bud, the body is derived from the _____ (ventral/dorsal) pancreatic bud, and the tail is derived from the _____ (ventral/dorsal) pancreatic bud.

Back 91

Ventral; dorsal; dorsal

Front 92

A patient has a congenital malformation of the pancreas in which the ventral bud abnormally encircles the second part of the duodenum and forms a ring of tissue; what is the name of this abnormality?

Back 92

Annular pancreas

Front 93

Pronephros

Back 93

Week 4, then degenerates

Front 94

Mesonephros

Back 94

interim kidney for 1st trimester; later contributes to male genital system. Think "meSONephros -> male genital"

Front 95

Metanephros

Back 95

Permanent; beginnings first appear during 5th week of gestation. Nephrogenesis continues through 32-36 weeks of gestation.

Front 96

Ureteric bud

Back 96

Derived from caudal end of meSONephros. From collecting duct to ureter. Fully canalized by 10th week.

Front 97

Metanephric Mesenchyme

Back 97

From glomerulus to distal convoluted tubule

Front 98

Last portion of kidney to canalize

Back 98

Uteropelvic junction

Front 99

The _____ develops into the bladder, urethra, and allantois.

Back 99

urogenital sinus

Front 100

Mesonephric duct structures

Back 100

Wolffian duct. SEED -> Seminal vesicles, Epididymis, Ejaculatory duct, Ductus deferens

Front 101

What three structures are derived from the paramesonephric duct?

Back 101

The fallopian tubes, the uterus, and upper one-third of the vagina

Front 102

What structure becomes the lower two-thirds of the vagina?

Back 102

The urogenital sinus

Front 103

Bicorniate Uterus etiology

Back 103

Results from incomplete fusion of the paramesonephric ducts. Associated with urinary tract abnormalities and infertility.

Front 104

Testis-determining factor

Back 104

Produced by SRY gene on Y chromosome -> testis development.

Front 105

The genital tubercle forms what two structures under the influence of dihydrotestosterone?

Back 105

The glans penis, corpus cavernosum, corpus spongiosum

Front 106

The genital tubercle forms what two structures under the influence of estrogen?

Back 106

The glans clitoris and the vestibular bulbs

Front 107

The urogenital sinus forms what two structures under the influence of dihydrotestosterone in the male embryo?

Back 107

The prostate and the bulbourethral glands

Front 108

Embryologically, the urogenital sinus forms what two structures under the influence of estrogen in the female embryo?

Back 108

The greater vestibular glands (of Bartholin) and the urethral and paraurethral glands (of Skene)

Front 109

Embryologically, the urogenital folds develop into what structure under the influence of dihydrotestosterone in the male embryo?

Back 109

The ventral shaft of the penis (penile urethra)

Front 110

Embryologically, the urogenital folds develop into what structure under the influence of estrogen in the female embryo?

Back 110

The labia minora

Front 111

Embryologically, the labioscrotal swelling develops into what structure under the influence of dihydrotestosterone in the male embryo?

Back 111

The scrotum

Front 112

Embryologically, the labioscrotal swelling develops into what structure under the influence of estrogen in the female embryo?

Back 112

The labia majora

Front 113

Embryologically, the genital tubercle develops into what structure in the male and what structure in the female?

Back 113

The glans penis in the male and the glans clitoris in the female

Front 114

Embryologically, the urogenital folds develop into what structure in the male and what structure in the female?

Back 114

The ventral shaft of the penis in the male and the labia minora in the female

Front 115

Embryologically, the labioscrotal swellings develop into what structure in the male and what structure in the female

Back 115

The scrotum in the male and the labia majora in the female

Front 116

What condition results from an abnormal opening of the penile urethra on the inferior (ventral) side of the penis as a result of the failure of urethral folds to close?

Back 116

Hypospadias (remember: Hypo is below)

Front 117

What condition results from an abnormal opening of the penile urethra on the superior (dorsal) side of the penis as a result of the faulty positioning of the genital tubercle?

Back 117

Epispadias (remember: when you have Epispadias you hit your Eye when you p,EE)

Front 118

What common complication is prevented by fixing hypospadias?

Back 118

Urinary tract infections

Front 119

Which is a more common congenital penile abnormality: epispadias or hypospadias?

Back 119

Hypospadias

Front 120

Which is associated with exstrophy of the bladder: epispadias or hypospadias?

Back 120

Epispadias (remember: Exstrophy of the bladder is associated with Epispadias)

Front 121

Which congenital penile abnormality is associated with failure of the urethral folds to close?

Back 121

Hypospadias

Front 122

Which congenital penile abnormality is associated with faulty positioning of the genital tubercle?

Back 122

Epispadias

Front 123

Anchors testes within scrotum in men, and forms ovarian ligament + round ligament of uterus in women.

Back 123

Gubernaculum