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USMLE Step 1 > Reproductive > Flashcards

Reproductive Flashcards

(180 cards)

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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
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

USMLE Step 1 (34 decks)

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