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USMLE Step 1 > Reproductive > Flashcards

Reproductive Flashcards

1
Q

Sonic hedgehog gene

A

Produced at base of limbs in zone of polarizing activity.

Involved in patterning along anterior-posterior axis. Involved in CNS development

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2
Q

Mutations in Sonic hedgehog gene

A

Can cause holoproscencephaly

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3
Q

Wnt-7 gene

A

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

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4
Q

FGF gene

A

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

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5
Q

Homeobox (Hox) genes

A

Involved in segmental organization of embryo in craniocaudal direction.

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6
Q

Hox mutations result in..

A

appendages in wrong locations

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7
Q

Day 0 of fetal development

A

Fertilization by sperm forming zygote, initiating embryogenesis

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8
Q

Within week 1 of fertilization

A

hCG secretion begins after implantation of blastocyst

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

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9
Q

Within week 2 of fertilization

A

Bilaminar disc (epiblast, hypoblast)

2 weeks = 2 layers

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10
Q

Within week 3 of fertilization

A

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

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11
Q

Within weeks 3 - 8 of fertilization (embryonic period)

A

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

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12
Q

Within week 4 of fertilization

A

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

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13
Q

Within week 8 (start of fetal period)

A

Fetal movement, fetus looks like a baby

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14
Q

Within 10 weeks of fertilization

A

Genitalia have male/female characteristics

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15
Q

Gastrulation

A

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.

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16
Q

Three layers of ectoderm

A

Surface ectoderm
Neuroectoderm
Neural crest

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17
Q

Surface ectoderm derivatives

A 
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
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18
Q

Derivatives of neuroectoderm

A 
Brain (neurohypophysis)
CNS neurons
Oligodendrocytes
Astrocytes
Ependymal cells
Pineal glands
Retina and optic nerve
Spinal cord
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19
Q

Neural crest derivatives

A 
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
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20
Q

Craniopharyngioma

A

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

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21
Q

Mesoderm derivatives

A

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

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22
Q

Notochord induces ectoderm to form what structure?

A

Neuroectoderm (neural plate)

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23
Q

Postnatal derivative of the notochord

A

Nucleus pulposus of the intervertebral disc

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24
Q

Endoderm derivatives

A

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)

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25
Q

Mesodermal defects

A 
VACTERL
V-ertebral defects
A-nal atresia
C-ardiac defects
T-racheo-Esophageal fistula
R-enal defects
L-imb defects (bone and muscle)
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26
Q

Endoderm

A

Agenesis

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27
Q

Agenesis

A

absent organ due to absent primordial tissue

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28
Q

Aplasia

A

Absent organ despite present primordial tissue

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29
Q

Deformation

A

extrinsic disruption; occurs AFTER the embryonic period

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30
Q

Hypoplasia

A

Incomplete organ development; primordial tissue present

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31
Q

Malformation

A

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

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32
Q

Teratogens most susceptible during which period?

A

3rd - 8 weeks (organogenesis) of pregnancy

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33
Q

Effects of teratogen on pregnancy before week 3 of pregnancy

A

All or none effects

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34
Q

Teratogen effects after 8th weeks of pregnancy

A

Growth and function affected

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35
Q

ACE inhibitor effects on fetus

A

renal damage

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36
Q

Alkylating agents effects on fetus

A

Absence of digits, multiple anomalies

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37
Q

Aminoglycosides effect on fetus

A

CN VIII toxicity

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38
Q

Carbamazepine effects on fetus

A 
Neural tube defects
Craniofacial defects
Fingernail hypoplasia
Developmental delay
IUGR
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39
Q

Diethylstilbestrol effects on fetus

A

Vaginal clear cell adenocarcinoma, congenital Mullerian anomalies

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40
Q

Folate antagonists’ effect on fetus

A

Neural tube defects

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41
Q

Lithium’s effect on fetus

A

Ebstein’s anomaly (atrialized right ventricle)

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42
Q

Phenytoin’s effect on fetus

A 
Fetal hydantoin syndrome
Microencephaly
Dysmorphic craniofacial features
Hypoplasit nails and distal phalanges
Cardia defects
IUGR
mental retardation
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43
Q

Tetracyclines’ effect on fetus

A

Discolored teeth

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44
Q

Thalidomide’s effects on fetus

A

Limb defects (“flipper” limbs)

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45
Q

Valproate’s effects on fetus

A

Inhibition of maternal folate absorption –> neural tube defects

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46
Q

Warfarin’s effect on fetus

A

Bone deformities, fetal hemorrhage, abortion, opthalmologic abnormalities

*Use heparin as an alternative

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47
Q

Alcohol’s effect on fetus

A

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

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48
Q

Cocaine’s effect on fetus

A

Abnormal fetal development and fetal addiction; placental abruption

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49
Q

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

A

Preterm labor, placental problems, IUGR, ADHD

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50
Q

Iodide (lack or excess) effect on fetus

A

Congenital goiter or cretinism

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51
Q

Maternal Diabetes’ effect on fetus

A

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

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52
Q

Vitamin A (excess) effects on fetus

A

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

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53
Q

X-rays’ effect on fetus

A

Microcephaly and mental retardation

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54
Q

Fetal alcohol syndrome

A

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

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55
Q

Dizygotic twins

A

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

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56
Q

Monozygotic twins

A

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

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57
Q

When does cleavage occur for most monozygotic twins?

A

4-8 days (after formation of morula)

- formation of monochorionic diamniotic

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58
Q

Zygote cleavage after 0-4 days occurs when

A

Dichorionic diamniotic (fused placenta or separate placenta)

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59
Q

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

A

monochorionic diamniotic

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60
Q

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

A

monochorionic monoamniotic (conjoined twins)

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61
Q

Placenta

A

1st site of nutrient and gas exchange

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62
Q

Cytotrophoblast

A

inner layer of chorionic villi

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63
Q

Syncytotrophoblast

A

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

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64
Q

Decidua basalis

A

derived from endometrium

maternal blood in lacunae

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65
Q

Umbilical arteries (2)

A

return deoxygenated blood from fetal internal iliac arteries to placenta

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66
Q

Umbilical VEIN - only ONE

A

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

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67
Q

T/F. Single umbilical artery is phenotypically normal.

A

Single umbilical artery is associated with congenital and chromosomal arteries.

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68
Q

Umbilical arteries and veins are derived from….

A

Allantois

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69
Q

Urachal duct

A

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

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70
Q

Patent urachus

A

results in urine discharge from the umbilicus

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71
Q

Failure of urachus to obliterate:

A

Vesicourachal diverticulum – outpouching of the bladder

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72
Q

Vitelline duct

A

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

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73
Q

Failure of vitteline duct to close results in these 2 conditions

A

Vitelline fistula

Meckel’s diverticulum

74
Q

Vitelline fistula

A

results from vitelline duct failing to close:

meconium discharge from umbilicus

75
Q

Meckel’s diverticulum

A

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
Q

Aortic derivatives

A

6 of them. which develop in to the arterial system

77
Q

1st aortic arch derivative

A

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

“1st arch is MAXimal”

78
Q

Second aortic arch

A

Stapedial artery and hyoid artery

“Second” = “S”tapedial

79
Q

Third aortic arch derivative

A

Common carotid artery and proximal part of internal carotid artery

80
Q

Fourth aortic arch

A

On left, aortic arch

On right - proximal part of internal Carotid artery

81
Q

Sixth aortic arch

A

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

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

82
Q

Branchial apparatus

A

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

83
Q

Brachial clefts derived from

A

ectoderm. Also called brachial grooves

84
Q

Branchial arches derived from …

A

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

85
Q

Branchial pouches derived from …

86
Q

1st branchial cleft derivative

A

external auditory meatus

87
Q

2nd through 4th branchial cleft form….

A

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

88
Q

Persistent cervical sinus leads too…

A

branchial cleft cyst within lateral neck

89
Q

1st branch arch derivatives

A

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
Q

Treacher Collins syndrome

A

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

91
Q

Second Branchial Arch: Cartilage

A

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

92
Q

2nd branchial arch muscle derivatives

A

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

93
Q

Second Branchial Arch: Nerve Derivatives

A

CN VII (facial expression)

94
Q

Third Branchial Arch: Cartilage

A

Greater horn of hyoid

95
Q

Third Branchial Arch Muscles

A

Stylopharngeaus (think stylopharyngeus innervated by glossopharyngeal nerve)

96
Q

Third Branchial Arch Nerve Nerve Derivative

97
Q

Congenital pharyngocutaneous fistula

A

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

98
Q

4th and 4th arches: cartilage

A

Cartilage: thyroid, cricoid, arytenoids, corniculate, cuneiform

99
Q

4th branchial arch muscles

A

most pharyngeal constrictors, cricothyroid, levator veli palantinin

100
Q

6th arch muscle derivatives

A

all instrinsic muscles of larynx excpt cricothyroid

101
Q

4th branchial arch nerve

A

CN X (superior laryngeal branch)

102
Q

6th branchial arch nerves

A

CN X (recurrent laryngeal branch)

103
Q

Arches 3 and 4 form

A

posterior 1/3 of tongue

104
Q

Branchial arch 5 makes what developmental contributions

105
Q

1st branchial pouch derivative

A

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

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

106
Q

2nd branchial pouch

A

develops into epithelial lining of palantine tonsil

107
Q

3rd branchial pouch

A

dorsal wings - develops into inferior parathyroids

ventral wings - develops into thymus

108
Q

3rd pouch contributes to which 3 structures?

A

Thymus, left and right inferior parathyroids

  • 3rd pouch structures end up BELOW 4th pouch structures
109
Q

Mneumonic for branchial pouch derivatives

A 
"Ear, tonsils, bottom-to-top"
1-ear
2-tonsils
3-dorsal ("bottom" for inferior parathyroids)
3- ventral ("to "= thymus)
4- "top" = superior parathyroids
110
Q

DiGeorge Syndrome

A

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
Q

MEN2A

A

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
Q

Cleft lip

A

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

113
Q

Cleft palate

A

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
Q

Female genital development

A

Default development. Mesonephrine duct degenerates and paramesonephric duct develops

115
Q

Male genital development

A

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
Q

Paramesoneprhic duct

A

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
Q

Mesonephric (Wolfian) duct

A

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

118
Q

Result of no Sertoli cells or lack of MIF

A

Develop both male and female internal genitalia and male external genitalia

119
Q

5-alpha reductase deficiency

A

Male internal genitalia, ambiguous external genitalia until puberty

120
Q

Wolfian duct makes…

A

male internal genitalia EXCEPT prostate

121
Q

Genital tubercle, urogenital sinus makes…

A

male external genitalia, prostate

122
Q

Genital tubercle induced by dihydrotestosterone

A

Glans penis

Corpus cavernosum and spongiosum

123
Q

Genital tubercle induced by estrogen

A

Glans clitoris, vestibular bulbs

124
Q

Urogenital sinus induced by dihyrdotestosterone

A 
Bulbourethral glands (of Cowper)
Prostate gland
125
Q

Urogenital sinus induced by estrogen

A

Greater vestibular glands (of Bartholin)

Urethral and paraurethral glands of Skene

126
Q

Urogenital folds induced by dihydrotestosterone

A

Ventral shaft of penis (penile urethra)

127
Q

Urogenital folds induced by estrogen

A

Labia minora

128
Q

Labioscrotal swelling induced by dihydrotestosterone

129
Q

Labioscrotal swelling induced by estrogen

A

Labia majora

130
Q

Hypospadias

A

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

131
Q

More common: hypospadias or epispadias?

A

Hypospadias. Must be fixed to prevent UTIs.

“Hypo” is below

132
Q

Epispdias

A

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

133
Q

Extrophy of bladder is associated with what congenital penile abnormality?

A

Epispadas

“When you have Episadas, you hit your Eye when you pEE”

134
Q

Gubernaculum (band of fibrous tissue)

A

in men: anchors testes within scrotum

in women: ovarian ligament + round ligament of uterus

135
Q

Processus vaginalis (evagination) of peritoneum)

A

in women: forms tunica vaginalis

in men: obliterated

136
Q

Gonadal venous drainage

A

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
Q

Gonadal lymphatic drainage

A

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
Q

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

A

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
Q

Suspensory ligament of the ovaries

A

Connect ovaries to lateral pelvic wall

contains ovarian vessels

140
Q

Structure at risk during ligation of ovarian vessels

141
Q

Cardinal ligament

A

connects cervix to sidewall of pelvis

contains uterine vessels

142
Q

Structure at risk during ligation of uterine vessels in hysterectomy

143
Q

Round ligament of the uterus

A

connects uterine fundus to labia majora

structures contained artery of Sampson

144
Q

Round ligament is derivative of ..

A

gubernaculum

145
Q

Broad ligament

A

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

146
Q

Components of broad ligament

A

Mesosalpinx, Mesometrium, and Mesovarium

147
Q

Ligament of the ovary

A

Connects medial pole of ovary to lateral uterus

148
Q

Vagina Histo

A

Stratified squamous epithelium, nonkeratinized

149
Q

Ectocervix histology

A

Stratified squamous epithelium

150
Q

Uterus histology

A

Simple columnar epithelium, pseudostratified tubular glands

151
Q

Fallopian tube histology

A

Simple columnar epithelium, cilitated

152
Q

Ovary histology

A

Simple cuboidal epithelium

153
Q

Endocervix Histology

A

Simple columnar epithelium

154
Q

Pathway of sperm during ejaculation

A 
SEVEN UP
Seminiferous tubules
Epididymis
Vas deferens
Ejaculatory ducts
Nothing
Urethra
Penis
155
Q

Erection

A

Parasympathetic nervous system (pelvic nerve)

156
Q

G protein pathway for NO

erection

A

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

157
Q

G protein pathway for NE (antierection)

A

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

158
Q

Emission

A

Sympathetic nervous system (hypogastric nerve)

159
Q

Ejaculation

A

visceral and somatic nerves (pudendal nerve)

160
Q

Mechanism of Sildenafil and Vardenafil

A

Inhibit cGMP breakdown

161
Q

Cells in seminiferous tubules

A 
Spermatagonia (germ cells)
Sertoli cells (non-germ cells)
Leydig cells (endocrine cells)
162
Q

Spermatogonia

A

maintain germ pool and produce primary spermatocytes

Line seminiferous tubules

163
Q

Sertoli cells (non-germ cells)

A

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
Q

Temperature in varicocele, cryptorchidism

A

Increased temperature

165
Q

Leydig cells (endocrine cells)

A

secrete testosterone; testosterone production unaffected by temperature

Interstitium

166
Q

Spermatogenesis

A

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
Q

Spermatogonium

A

Diploid (2N, 2C)

168
Q

Primary spermatocyte

A

Diploid (2N, 2C)

169
Q

Secondary spermatocyte

A

Haploid (1N, 2C)

170
Q

Spermatid

A

Haploid (1N, 1C)

171
Q

Mature spermatozoon

A

Haploid (N)

172
Q

LH

A

stimulates synthesis of testerone in Leydig cells

173
Q

FSH

A

stimulates Sertoli cells to produce ABP and inhibin

174
Q

Source of DHT and testosterone

175
Q

Source of androstendone

A

adrenal glands

176
Q

Testosterone

A

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
Q

Potency:

DHT, Androstenedione, testosterone

A

DHT > testosterone > androstenedione

178
Q

Converts DHT to testosterone

A

5-alpha reductase (inhibited by finasteride)

179
Q

Converts testosterone and androstenedione

A

Aromatase - converted in adipose tissue and Leydig cells

180
Q

Aromatase

A

converts testosterone and androstenedione

Converts androgens to estrogen

USMLE Step 1 (34 decks)

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