Reproductive Flashcards Preview

USMLE Step 1 > Reproductive > Flashcards

Flashcards in Reproductive Deck (180):
1

Sonic hedgehog gene

Produced at base of limbs in zone of polarizing activity.
Involved in patterning along anterior-posterior axis. Involved in CNS development

2

Mutations in Sonic hedgehog gene

Can cause holoproscencephaly

3

Wnt-7 gene

Produced at apical ectodermal ridge (thickened ectoderm at distal end of each developing limb).
Necessary for proper organization along dorsal-ventral axis

4

FGF gene

Produced at apical ectodermal ridge. Stimulates mitosis of underlying mesoderm, providing for lengthening of limbs.

5

Homeobox (Hox) genes

Involved in segmental organization of embryo in craniocaudal direction.

6

Hox mutations result in..

appendages in wrong locations

7

Day 0 of fetal development

Fertilization by sperm forming zygote, initiating embryogenesis

8

Within week 1 of fertilization

hCG secretion begins after implantation of blastocyst

*pregnancy test can detect hCG levels within 7-11 days of fertilization

9

Within week 2 of fertilization

Bilaminar disc (epiblast, hypoblast)

2 weeks = 2 layers

10

Within week 3 of fertilization

Trilaminar disc. 3 weeks = 3 layers (ectoderm, mesoderm, endoderm)
Gastrulation
Primitive streak, notochord, mesoderm, and its organization and neural plate begin to form

11

Within weeks 3 - 8 of fertilization (embryonic period)

Neural tube formed by neuroectoderm and closes by week 4
Organogenesis
*Extremely susceptible to teratogens*

12

Within week 4 of fertilization

Heart begins to beat
Upper and lower limb buds begins to form
"4 weeks = 4 limbs"

13

Within week 8 (start of fetal period)

Fetal movement, fetus looks like a baby

14

Within 10 weeks of fertilization

Genitalia have male/female characteristics

15

Gastrulation

Process that forms the trilaminar embryonic disc. Establishes the ectoderm, mesoderm, and endoderm germ layers.
Starts with the epiblast invagination to form the primitive streak.

16

Three layers of ectoderm

Surface ectoderm
Neuroectoderm
Neural crest

17

Surface ectoderm derivatives

Adenohypophysis (from Rathke's pouch);
lens of eye;
epithelial linings of oral cavity;
sensory organs of ear
olfactory epithelium;
epidermis;
anal canal BELOW the pectinate line
Parotid, sweat, and mammary glands

18

Derivatives of neuroectoderm

Brain (neurohypophysis)
CNS neurons
Oligodendrocytes
Astrocytes
Ependymal cells
Pineal glands
Retina and optic nerve
Spinal cord

19

Neural crest derivatives

PNS (dorsal root ganglia, cranial nerves, celiac ganglion, Schwann cells, ANS)
Melanocytes
Chromafiin cells of adrenal medulla
Parafollicular ("C") cells of thyroid
Pia and arachnoid
Bones of skull
Odontoblasts
Aorticopulmonary septum

20

Craniopharyngioma

benign Rathke's pouch tumor with cholesterol crystals, calcifications
commonly seen in young children

21

Mesoderm derivatives

Muscle, bone, connective tissue
Seroud linings of body cavities (e.g. peritoneum)
Spleen (derived from foregut mesentary)
CV structures, lymphatics, blood
Wall of gut tube, wall of bladder, urethra, vagina, kidneys, adrenal cortex, dermis, testes, ovaries

22

Notochord induces ectoderm to form what structure?

Neuroectoderm (neural plate)

23

Postnatal derivative of the notochord

Nucleus pulposus of the intervertebral disc

24

Endoderm derivatives

Gut tube epithelium (including anal canal ABOVE the pectinate line) and luminal epithelial derivatives (e.g. lungs, liver, gallbladder, pancreas, eustachian tube, thymus, parathyroud, thyroid follicullar cells)

25

Mesodermal defects

VACTERL
V-ertebral defects
A-nal atresia
C-ardiac defects
T-racheo-Esophageal fistula
R-enal defects
L-imb defects (bone and muscle)

26

Endoderm

Agenesis

27

Agenesis

absent organ due to absent primordial tissue

28

Aplasia

Absent organ despite present primordial tissue

29

Deformation

extrinsic disruption; occurs AFTER the embryonic period

30

Hypoplasia

Incomplete organ development; primordial tissue present

31

Malformation

Intrinsic disruption; occurs DURING the embryonic period (weeks 3-8)

32

Teratogens most susceptible during which period?

3rd - 8 weeks (organogenesis) of pregnancy

33

Effects of teratogen on pregnancy before week 3 of pregnancy

All or none effects

34

Teratogen effects after 8th weeks of pregnancy

Growth and function affected

35

ACE inhibitor effects on fetus

renal damage

36

Alkylating agents effects on fetus

Absence of digits, multiple anomalies

37

Aminoglycosides effect on fetus

CN VIII toxicity

38

Carbamazepine effects on fetus

Neural tube defects
Craniofacial defects
Fingernail hypoplasia
Developmental delay
IUGR

39

Diethylstilbestrol effects on fetus

Vaginal clear cell adenocarcinoma, congenital Mullerian anomalies

40

Folate antagonists' effect on fetus

Neural tube defects

41

Lithium's effect on fetus

Ebstein's anomaly (atrialized right ventricle)

42

Phenytoin's effect on fetus

Fetal hydantoin syndrome
Microencephaly
Dysmorphic craniofacial features
Hypoplasit nails and distal phalanges
Cardia defects
IUGR
mental retardation

43

Tetracyclines' effect on fetus

Discolored teeth

44

Thalidomide's effects on fetus

Limb defects ("flipper" limbs)

45

Valproate's effects on fetus

Inhibition of maternal folate absorption --> neural tube defects

46

Warfarin's effect on fetus

Bone deformities, fetal hemorrhage, abortion, opthalmologic abnormalities

*Use heparin as an alternative

47

Alcohol's effect on fetus

Leading cause of birth defect and mental retardation; fetal alcohol syndrome

48

Cocaine's effect on fetus

Abnormal fetal development and fetal addiction; placental abruption

49

Smoking's effect on fetus (e.g. nicotine, CO)

Preterm labor, placental problems, IUGR, ADHD

50

Iodide (lack or excess) effect on fetus

Congenital goiter or cretinism

51

Maternal Diabetes' effect on fetus

Caudal regression syndrome (anal atresia to sirenomelia)
Congenital heart defects
Neural tube defects
Transient HYPOglycemia due to fetal islet cell hyperplasia

52

Vitamin A (excess) effects on fetus

Extremely high risk for spontaneous abortion and birth defects (cleft palate, cardiac abnormalities)

53

X-rays' effect on fetus

Microcephaly and mental retardation

54

Fetal alcohol syndrome

Leading cause of congenital malformations in the US
Increased incidence of congenital abnormalities, mental retardation, pre- and postnatal developmental retardation, microcephaly, holoproscencephaly, facial abnormalities, limb dislocation, and heart and lung fistulas

55

Dizygotic twins

arise from 2 eggs that are separately fertilized by 2 different sperm
(always 2 different zygotes) will have 2 separate amniotic sacs and 2 separate placentas

56

Monozygotic twins

arise from 1 fertilized egg (1 egg + 1 sperm) that splits into 2 zygotes early in the process

57

When does cleavage occur for most monozygotic twins?

4-8 days (after formation of morula)
- formation of monochorionic diamniotic

58

Zygote cleavage after 0-4 days occurs when

Dichorionic diamniotic (fused placenta or separate placenta)

59

Fertilized egg cleavage after 8-12 days (blastocyst stage) results in ...

monochorionic diamniotic

60

Zygotic cleavage after embryonic disc formation (>13 days) results in ...

monochorionic monoamniotic (conjoined twins)

61

Placenta

1st site of nutrient and gas exchange

62

Cytotrophoblast

inner layer of chorionic villi

63

Syncytotrophoblast

Outer blast of chorionic villi
secretes hCG (similar to LH)
stimulates corpus luteum to secrete progesterone during 1st trimester of pregnancy

64

Decidua basalis

derived from endometrium
maternal blood in lacunae

65

Umbilical arteries (2)

return deoxygenated blood from fetal internal iliac arteries to placenta

66

Umbilical VEIN - only ONE

supplies oxygenated blood from placenta to fetus; drains via ductus venosus into IVC

67

T/F. Single umbilical artery is phenotypically normal.

Single umbilical artery is associated with congenital and chromosomal arteries.

68

Umbilical arteries and veins are derived from....

Allantois

69

Urachal duct

formed in 3rd week
Yolk sac forms allantois, which extends into urogenital sinus. Allantois becomes urachus, a duct between bladder and yolk sac

70

Patent urachus

results in urine discharge from the umbilicus

71

Failure of urachus to obliterate:

Vesicourachal diverticulum -- outpouching of the bladder

72

Vitelline duct

formed in 7th week - obliteration of vitelline duct (omphalo-mesenteric duct), which connects yolk sac to midgut lumen

73

Failure of vitteline duct to close results in these 2 conditions

Vitelline fistula
Meckel's diverticulum

74

Vitelline fistula

results from vitelline duct failing to close:
meconium discharge from umbilicus

75

Meckel's diverticulum

results from failure of vitelline duct to close
partial closure, with patent portion attached to ileum. May have ectopic gastric mucosa --> melena, periumbilical pain and ulcer

76

Aortic derivatives

6 of them. which develop in to the arterial system

77

1st aortic arch derivative

1st - part of maxillary artery (branch of external carotid)

"1st arch is MAXimal"

78

Second aortic arch

Stapedial artery and hyoid artery
"Second" = "S"tapedial

79

Third aortic arch derivative

Common carotid artery and proximal part of internal carotid artery

80

Fourth aortic arch

On left, aortic arch
On right - proximal part of internal Carotid artery

81

Sixth aortic arch

Proximal part of pulmonary arteries and (on left only) ductus arteriosus

6 arch = pulmonary and the pulmonary to systemic shunt (ductus arteriosus)

82

Branchial apparatus

Also called pharyngeal apparatus.
Composed of "CAP"
= clefts, arches, pouches

83

Brachial clefts derived from

ectoderm. Also called brachial grooves

84

Branchial arches derived from ...

Mesoderm (muscles, arteries) and neural crest (bones, cartilage)

85

Branchial pouches derived from ...

endoderm

86

1st branchial cleft derivative

external auditory meatus

87

2nd through 4th branchial cleft form....

temporary cervical sinuses, which are obliterated by proloferation of 2nd arch mesenchyme

88

Persistent cervical sinus leads too...

branchial cleft cyst within lateral neck

89

1st branch arch derivatives

Meckel's cartilage (Mandible, Malleus, incus, sphenomandibular ligament)
Muscles of Mastication (Temporalis, Medial pterygoids, Masseter), Mylohyoid, anterior belly of digastric, tensor tympani, tensor veil palantini
Nerves: CN V2 and V3

90

Treacher Collins syndrome

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

91

Second Branchial Arch: Cartilage

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

92

2nd branchial arch muscle derivatives

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

93

Second Branchial Arch: Nerve Derivatives

CN VII (facial expression)

94

Third Branchial Arch: Cartilage

Greater horn of hyoid

95

Third Branchial Arch Muscles

Stylopharngeaus (think stylopharyngeus innervated by glossopharyngeal nerve)

96

Third Branchial Arch Nerve Nerve Derivative

CN IX

97

Congenital pharyngocutaneous fistula

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

98

4th and 4th arches: cartilage

Cartilage: thyroid, cricoid, arytenoids, corniculate, cuneiform

99

4th branchial arch muscles

most pharyngeal constrictors, cricothyroid, levator veli palantinin

100

6th arch muscle derivatives

all instrinsic muscles of larynx excpt cricothyroid

101

4th branchial arch nerve

CN X (superior laryngeal branch)

102

6th branchial arch nerves

CN X (recurrent laryngeal branch)

103

Arches 3 and 4 form

posterior 1/3 of tongue

104

Branchial arch 5 makes what developmental contributions

None

105

1st branchial pouch derivative

develops into middle ear cavity, eustachian tube, mastoid air cells

*1st pouch contributes to endoderm-lined structures of ear

106

2nd branchial pouch

develops into epithelial lining of palantine tonsil

107

3rd branchial pouch

dorsal wings - develops into inferior parathyroids
ventral wings - develops into thymus

108

3rd pouch contributes to which 3 structures?

Thymus, left and right inferior parathyroids

* 3rd pouch structures end up BELOW 4th pouch structures

109

Mneumonic for branchial pouch derivatives

"Ear, tonsils, bottom-to-top"
1-ear
2-tonsils
3-dorsal ("bottom" for inferior parathyroids)
3- ventral ("to "= thymus)
4- "top" = superior parathyroids

110

DiGeorge Syndrome

aberrant development of 3rd and 4th pouches --> T-cell deficiency (thymic aplasia) and hypocalcemia (failure of parathyroid development)
- deletion of chr 22 at q 11.2

111

MEN2A

Mutation germline RET (neural crest cells)
- Adrenal medulla (pheochromocytoma)
- Parathyroid (tumor): 3rd/4th pharyngeal pouch
- Parafollicular cells (medullary thyroid cancer): derived from neural crest cells; associated with 4th / 5th pharyngeal pouches

112

Cleft lip

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

113

Cleft palate

failure of fusion of the LATERAL palantine processes, the nasal septum and/or MEDIAN palantine process (formation of secondary palate)

* Cleft lip and cleft palate have two distinct etiologies, but often occur together

114

Female genital development

Default development. Mesonephrine duct degenerates and paramesonephric duct develops

115

Male genital development

SRY gene on Y chromosome - produces testis-determining factor (testes development)

Sertoli cells secrete Mullerian inhibitory factor (MID) that suppresses development of paramesonephric ducts

Leydig cells secrete androgens that stimulate the development of mesonephric ducts

116

Paramesoneprhic duct

develops into FEMALE internal structures - fallopian tubes, uterus, and upper portion of vagina (lower portion from urogenitl sinus)
Mullerian duct abnormalities result in anatomical defects that may present as primary amenorrhea in females with full developed secondary sexual characteristics (indicator of functional ovaries)

117

Mesonephric (Wolfian) duct

Develops into male internal structures (except prostate) - Seminal vesiscles, Epididymis, Ejaculatory duct, and Ductus deferens (SEED)

118

Result of no Sertoli cells or lack of MIF

Develop both male and female internal genitalia and male external genitalia

119

5-alpha reductase deficiency

Male internal genitalia, ambiguous external genitalia until puberty

120

Wolfian duct makes...

male internal genitalia EXCEPT prostate

121

Genital tubercle, urogenital sinus makes...

male external genitalia, prostate

122

Genital tubercle induced by dihydrotestosterone

Glans penis
Corpus cavernosum and spongiosum

123

Genital tubercle induced by estrogen

Glans clitoris, vestibular bulbs

124

Urogenital sinus induced by dihyrdotestosterone

Bulbourethral glands (of Cowper)
Prostate gland

125

Urogenital sinus induced by estrogen

Greater vestibular glands (of Bartholin)
Urethral and paraurethral glands of Skene

126

Urogenital folds induced by dihydrotestosterone

Ventral shaft of penis (penile urethra)

127

Urogenital folds induced by estrogen

Labia minora

128

Labioscrotal swelling induced by dihydrotestosterone

Scrotum

129

Labioscrotal swelling induced by estrogen

Labia majora

130

Hypospadias

abnormal opening of penile urethra on inferior (ventral) side of penis due to failure of urethral folds to close

131

More common: hypospadias or epispadias?

Hypospadias. Must be fixed to prevent UTIs.

"Hypo" is below

132

Epispdias

abnormal opening on penile urethra on superior (dorsal) side of penis due to faulty positioning of genital tubercle

133

Extrophy of bladder is associated with what congenital penile abnormality?

Epispadas

"When you have Episadas, you hit your Eye when you pEE"

134

Gubernaculum (band of fibrous tissue)

in men: anchors testes within scrotum
in women: ovarian ligament + round ligament of uterus

135

Processus vaginalis (evagination) of peritoneum)

in women: forms tunica vaginalis
in men: obliterated

136

Gonadal venous drainage

left ovary/testis --> left gonadal vein --> left renal vein --> IVC
right ovary/testis --> right gonadal vein --> IVC

* similar to left adrenal vein drains to left renal vein before IVC

137

Gonadal lymphatic drainage

Ovaries/testes --> para-aortic lymph nodes

Distal 1/3 of vagina/vulva/scrotum --> superficial inguinal nodes
Proximal 2/3 of vagina/uterus --> obturator, external ilia and hypograstric nodes

138

Discuss difference in flow between left spermatic vein drainage and right spermatic draining.

Left spermatic vein enters the left renal vein at a 90 degress angle, flow is LESS continuous on left than on right.
--> left venous pressure > right venous pressure
--> variocele more common on left

139

Suspensory ligament of the ovaries

Connect ovaries to lateral pelvic wall
contains ovarian vessels

140

Structure at risk during ligation of ovarian vessels

Ureter

141

Cardinal ligament

connects cervix to sidewall of pelvis
contains uterine vessels

142

Structure at risk during ligation of uterine vessels in hysterectomy

Ureter

143

Round ligament of the uterus

connects uterine fundus to labia majora
structures contained artery of Sampson

144

Round ligament is derivative of ..

gubernaculum

145

Broad ligament

Connects uterine, fallopian tubes, and ovaries to pelvic side wall
Contains ovaries, fallopian tubes and round ligament of uterus

146

Components of broad ligament

Mesosalpinx, Mesometrium, and Mesovarium

147

Ligament of the ovary

Connects medial pole of ovary to lateral uterus

148

Vagina Histo

Stratified squamous epithelium, nonkeratinized

149

Ectocervix histology

Stratified squamous epithelium

150

Uterus histology

Simple columnar epithelium, pseudostratified tubular glands

151

Fallopian tube histology

Simple columnar epithelium, cilitated

152

Ovary histology

Simple cuboidal epithelium

153

Endocervix Histology

Simple columnar epithelium

154

Pathway of sperm during ejaculation

SEVEN UP
Seminiferous tubules
Epididymis
Vas deferens
Ejaculatory ducts
Nothing
Urethra
Penis

155

Erection

Parasympathetic nervous system (pelvic nerve)

156

G protein pathway for NO
(erection)

NO --> increased cGMP --> smooth muscle relaxation --> vasodilation --> proerectile

157

G protein pathway for NE (antierection)

NE --> increased Ca --> smooth muscle contraction --> vasoconstriction --> antierectile

158

Emission

Sympathetic nervous system (hypogastric nerve)

159

Ejaculation

visceral and somatic nerves (pudendal nerve)

160

Mechanism of Sildenafil and Vardenafil

Inhibit cGMP breakdown

161

Cells in seminiferous tubules

Spermatagonia (germ cells)
Sertoli cells (non-germ cells)
Leydig cells (endocrine cells)

162

Spermatogonia

maintain germ pool and produce primary spermatocytes

Line seminiferous tubules

163

Sertoli cells (non-germ cells)

Secrete inhibin
Secrete androgen-binding protein (ABP)
Tight junction between adjacent Sertoli cells from blood-testis barrier
Support and nourish developing spermatozoa
Regulate spermatogenesis
Produce anti-mullerian hormone
Temperature sensitive ( decrease sperm production and decrease inhibin with increased temperature)`

164

Temperature in varicocele, cryptorchidism

Increased temperature

165

Leydig cells (endocrine cells)

secrete testosterone; testosterone production unaffected by temperature

Interstitium

166

Spermatogenesis

Spermatogenesis begins at puberty with spermatogonia Full development takes 2 months. Occurs in seminiferous tubes. Produces spermatids that undergo spermiogenesis (loss of cytoplasm contents, gain of acrosomal cap) to form mature spermatozoan

167

Spermatogonium

Diploid (2N, 2C)

168

Primary spermatocyte

Diploid (2N, 2C)

169

Secondary spermatocyte

Haploid (1N, 2C)

170

Spermatid

Haploid (1N, 1C)

171

Mature spermatozoon

Haploid (N)

172

LH

stimulates synthesis of testerone in Leydig cells

173

FSH

stimulates Sertoli cells to produce ABP and inhibin

174

Source of DHT and testosterone

testis

175

Source of androstendone

adrenal glands

176

Testosterone

Differentiation of epididymis, vas deferns, seminal vesicles (internal genitalia except prostate)
Growth spurt (penis, seminal vesicles, sperm, muscle, RBCs)
Deepening of voice
Closing of epiphyseal plates via estrogen converted from testosterone

177

Potency:
DHT, Androstenedione, testosterone

DHT > testosterone > androstenedione

178

Converts DHT to testosterone

5-alpha reductase (inhibited by finasteride)

179

Converts testosterone and androstenedione

Aromatase - converted in adipose tissue and Leydig cells

180

Aromatase

converts testosterone and androstenedione
Converts androgens to estrogen