Physiology and Pathophysiology Flashcards
(150 cards)
1
Q
Major Functions of the HPO Axis
Hypothalamic-Pituitary-Ovarian Axis
A
- Development of sexual characteristics
- Coordinating regular periodic body changes
- Ovarian Cycle
- Uterine Cycle - Plays a role in cervix, vagina, breast function
- Maintenance of pregnancy
2
Q
where is Gonadotropin Releasing Hormone (GnRH)
made?
A
Hypothalamus
3
Q
Pathophys of the HPO axis
A
- Hypothalamus
- Makes and releases GnRH in pulses
- GnRH binds to anterior pituitary gland - Pituitary
- Gonadotrope cells - synthesize and release: Follicle Stimulating Hormone (FSH) & Luteinizing Hormone (LH)
- FSH and LH travel to ovary - Ovary
- FSH and LH
— theca and granulosa cells = folliculogenesis
4
Q
Besides folliculogenesis, FSH and LH also stimulate ovarian production of:
A
- steroid hormones
- estrogens, progesterone, androgens - gonadal peptides
- activins, inhibins, follistatins - growth factors
5
Q
Role/effect of estrogen
A
- Induces surge of LH = oocyte release
- Encourages proliferation of endometrium, myometrium
-
secondary sex characteristics
- breast enlargement and areolar pigmentation
- mature female body shape
- increased scalp hair, less body hair - Assist with libido
- Thickens vaginal wall and increases vaginal lubrication
- Other effects:
- Reduced acne formation
- Reduced cholesterol, atherosclerosis
6
Q
Role/effect of progesterones
A
- Major in maintenance of pregnancy
- Decreases uterine contractility
- Promotes breast development and differentiation
- Falling progesterone levels trigger menses
- Falling progesterone levels after pregnancy signal lactation
7
Q
What hormone of the HPO axis:
- Stimulate FSH secretion
- Involved in WBC production, embryo development
A
Activins
8
Q
Which hormone of the HPO axis inhibit FSH secretion
A
Inhibins
9
Q
which hormone of the HPO axis
Help regulate gonadotropin secretion
Binds to and inhibits activins
A
Follistatins
10
Q
which hormone of the HPO axis
Relaxes pubic symphysis, other pelvic joints in pregnancy
Inhibits uterine contractions
May help mammary gland and follicular
development and ovulation
A
Relaxin
11
Q
what is the normal HPO axis positive feedback?
A
- Estrogen (high levels) → increased GnRH and LH
- Activin → promotes gondadotropic cell function
12
Q
what is the normal HPO axis negative feedback
A
- Progesterone → inhibits GnRH and LH
- Inhibin → inhibits FSH secretion
- Follistatin → inhibits FSH secretion
- Lactation → hyperprolactinemia causes increased dopamine and altered release of GnRH
- Estrogen (prolonged moderate levels) → decreases LH
- Estrogen → decreases FSH
13
Q
What may affect Pathologic HPO Axis Feedback
A
- Hypogonadism
- Polycystic ovarian syndrome (PCOS)
- Hyperprolactinemia
- Medications - Steroids, Hormones, Opioids
- Weight status
14
Q
puberty starts at what age?
A
ages 8-13 F, 9-14 M
15
Q
Factors that influence onset of puberty
A
- Weight and nutritional status
- Genetic factors
- Abnormal hormone levels
16
Q
what is Adrenarche
A
increase in secretion of adrenal androgens, DHEA - prior to or at onset of puberty
17
Q
what is Thelarche
A
breast development
First event of puberty in females
18
Q
what hormones play a part of thelarche?
A
- Estradiol (estrogen) - duct growth
- Progesterone - lobule and alveoli growth
19
Q
what is Pubarche
A
development of pubic and axillary hair
Second event of puberty in females
20
Q
what is menarche?
A
first menstrual cycle
Typically anovulatory for first 12-18 monhs
21
Q
Normal Menstrual Cycle lasts how long?
A
Lasts roughly 28 days (+/- 7 days)
Flow - about 3-5 days
22
Q
Day 1 of the menstrual cycle is considered when?
A
1st day of menstruation
not signs of PMS!
23
Q
when can menstrual cycles be irregular?
A
- ~ 1-2 years after menarche
- ~ 2-3 years preceding menopause
24
Q
What are the two major physiologic changes of the menstrual cycle?
A
- Ovarian Cycle: Follicular Phase → Ovulation → Luteal Phase
- Uterine Cycle: Proliferative Phase → Secretory Phase → Menses
25
Describe the preovulatory phase
varying length
1. Early in cycle - rise in FSH > rise in LH
- Several follicles begin to enlarge
- FSH causes production of inhibin B
--- inhibin B decreases release of FSH later in follicular phase
26
what happens during the Midfollicular phase
about day 6
1 follicle grows very rapidly, becoming dominant follicle
Other follicles regress to become atretic follicles
27
What happens during the follicular phase?
1. preovulatory phase
2. midfollocular phase
3. As dominant follicle matures…
- Develops LH receptors
- Releases estrogens
4. Rising estrogen levels → increased GnRH pulses → LH surge → ovulation
28
what happens during ovulation during the ovarian cycle?
1. Midcycle - approximately day 14
- Mature follicle ruptures
- Ovum → extruded in abdominal cavity → transported into oviduct
2. Corpus hemorrhagicum - ruptured follicle fills with blood
3. Mittelschmerz may occur
29
What happens during the luteal phase of the ovarian cycle?
1. Postovulatory - 14 days
2. Corpus Luteum - granulosa and theca cells of follicle lining proliferate to form yellowish, lipid-rich luteal cells
- Reacts to LH by making progesterone and estrogen
- Rising levels of estrogen and progesterone → negative feedback → decline in FSH and LH
3. If pregnancy does not occur → decline in FSH and LH → atrophy of corpus luteum 3-4 days before menses
- Eventually becomes atrophic Corpus Albicans
4. Declining levels of progesterone → shedding of endometrial lining (menses)
30
what happens during the proliferative phase of the uterine cycle
1. Preovulatory - varying length
- At end of menses, all but the deep layer of the endometrium has sloughed - stratum basale
2. Days 5-16
- Estrogen from developing follicles → endometrium regenerates from deep layer
- Forms the stratum functionale (outer ⅔)
- Uterine glands lengthen but do not become convoluted or secrete anything
31
What happens during the sectoary phase of the uterine cycle
1. Postovulatory - 14 days
2. Estrogen and progesterone from corpus luteum → **endometrium becomes more vascularized, edematous**
- Glands become coiled, tortuous and secrete clear fluid
3. **Corpus luteum regresses** → estrogen and progesterone decline → vascular spasms → **endometrial ischemia**
- Breakdown of extracellular matrix of strata functionalis and necrosis of endometrium and supplying arterial walls
- **Causes hemorrhage which coalesces into menstrual flow**
32
The 3 phases of the ovarian cycle
1. follicular phase
2. ovulation
3. luteal phase
33
2 Phases of the uterine cycle
1. proliferative phase
2. secretory phase
34
what are the cervical changes during the menstrual cycle?
1. Cervix responds differently from uterine body
- No cyclic shedding of lining
- Cervical mucus undergoes cyclic changes
2. Estrogen → mucus is thinner, more alkaline
- Enhances survival and transport of sperm
- Dries in a fern-like pattern when spread on a slide
3. Progesterone → mucus is more thick, tenacious, cellular
- NO fern pattern
4. Cervical Ectopy - Columnar epithelium extends from endocervix to ectocervix
5. As estrogen levels rise in puberty, cervical os opens exposing endocervical columnar epithelium
- Squamous metaplasia gradually replaces in 20s-30s due to acidic environment of vagina
35
When is the cervical mucus its thinnest during the menstrual cycle?
Thinnest at time of ovulation
36
when is the cervical mucus its thickest during the menstrual cycle?
thickest after ovulation and during pregnancy
37
What can cause persistence or
reappearance of cervical ectopy
OCP
38
What may accelerate squamous metaplasia
| cervical ectopy
Smoking
39
Cervical ectopy can mimic what other condition?
infectious endocervicitis
40
Cervical ectopy may increase the susceptibility to what other diseases?
STIs
41
What hormones affect the fallopian tubes and what do they do?
* Progesterone - reduces ciliary beat frequency (CBF)
* Estrogen - increases ciliary beat frequency (CBF)
42
what ovarian hormones affect muscles and what do they do?
* Progesterone - reduces spasms, relaxes smooth muscle, and antagonizes effects of insulin on glucose metabolism
* Estrogen - improves skeletal muscle contractility
* Both estrogen and progesterone may help regulate
* protein metabolism
43
how do ovarian hormones affect skin?
* Maintains skin collagen and skin moisture
* Increased cutaneous wound healing and hair growth
* Increases skin pigmentation
44
How do ovarian hormones affect fat deposition?
* Increase fat deposition - “pear shape”
* Progesterone - mediator of fat gain in pregnancy
45
how do ovarian hormones affect sodium/water balance?
* Estrogen - sodium and water retention
* Progesterone - sodium and water excretion
46
what are the anatomic CV changes seen in matneral changes?
1. PMI shifts laterally
2. Heart size increases 12%
- Increase in myocardial mass and
intracardiac volume
47
what is Supine Hypotensive Syndrome and how to tx?
* hypotension, bradycardia, syncope
* Compression of the vena cava
* Tx - R or L recumbent position
48
how do maternal changes affect stroke volume?
increases
sensitive to maternal position
increases even more with multiple gestation
49
how do maternal changes affect HR?
increases
1. progressively increases over the course of gestation
1. ~ 15 bpm more at term than nonpregnant rate
- still affected by factors like exercise, stress, heat, meds
- increases more in multiple gestation
50
how do maternal changes affect CO?
increases
* due to hormonal changes, shunt of uteroplacental circulation
* also transiently increases during L&D
51
how do maternal changes affect BP?
1. Arterial pressure declines slightly
- Returns to prepregnancy levels ~36 wks
- Widened pulse pressure
2. LE venous pressure progressively increases
- Can cause edema and varicosities
52
how do maternal changes affect peripheral vasular resistance?
1. Decreases due to enhanced vasodilators
2. At delivery - 40% decrease in vascular resistance
- Offset by rise in CO
53
how do maternal changes affect blood flow distribution
1. Increased to uterus, kidneys, breasts and skin
- Uterus - 4x of normal
2. Strenuous exercise - may divert blood
54
how do maternal changes affect Heart Sounds and Murmurs
1. Systolic murmurs in up to **90%**
1. May see split S1 or loud S3
1. Murmurs or bruits at left sternal edge
- internal thoracic (mammary) artery
55
how do maternal changes affect heart rhythm
1. Decreased threshold for reentrant SVT
1. May see sinus tachy, sinus brady, isolated PAC/PVCs
56
how do maternal changes affect EKG?
May see L axis shift, ST depression, T-wave flattening
57
how do maternal changes affect respiratory anatomy?
1. Capillary dilation - engorged nasopharynx, larynx, trachea, bronchi
- May see prominent pulmonary vascular
markings on CXR
2. Rib cage is increasingly displaced upward
- Elevated diaphragm
- Increased thoracic circumference
58
how do maternal changes affect lung volumes and capacities?
**Net Effect** - less overall lung space, but less “dead space” and increased tidal volume
59
how do maternal changes affect respiration?
* More diaphragm-dependent
* Little effect on respiratory rate
* 50% increase in minute ventilation
* Increased arterial O2 and O2 consumption
* Mild **respiratory alkalosis**
60
how do maternal changes affect renal anatomy?
1. Increased renal size
1. Dilated renal calyces and pelves
1. Dilated and tortuous ureters
1. Bladder - displaced upward,
1. flattened, decreased tone - Capacity increased up to 1500 mL
61
how do maternal changes affect renal pathophys?
| plasma flow, GFR, etc
1. **Plasma flow increases** 50-85%
- Decreased renal vascular resistance
2. **GFR increases** significantly
3. **CrCL increases** with GFR
- _Lower_ serum Cr and BUN
- Saturation of tubular reabsorption capacity
--- glucosuria in >50% during pregnancy
--- Urinary protein loss
4. Renin activity increases
- Gravidas very resistant to pressor effects
62
how do maternal changes affect GI anatomy?
stomach pushed upward
bowels pushed up and laterally
63
how do maternal changes affect the oral cavity
increased salivation
gum hypertrophy and hyperemia
no increase in tooth decay or loss of calcium from teeth
64
how do maternal changes affect the intestines?
Transit times decrease in 2nd and 3rd trimesters
65
how do maternal changes affect the gallbladder?
emptying slowed and often incomplete
66
how do maternal changes affect esophagus/stomach?
1. Reflux/heartburn in 30-80% of gravidas
- Greater production of gastrin
- Decreased esophageal peristalsis
- Hormone-mediated relaxation of LES
2. Decreased gastric emptying
67
how do maternal changes affect the liver?
1. Mild decrease in protein, esp. albumin
- Calcium also decreases with albumin
2. Increased serum alkaline phosphatase
- Due to alk phos isoenzymes from placenta
68
How do maternal changes affect blood volume?
1. 50% elevation in plasma volume
- increased estrogen → stimulates RAAS → increased aldosterone → Na+ reabsorption → water retention
69
Functions of maternal hypervolemia
1. Helps meet increased metabolic demands for mother, fetus, and placenta
1. Protects mother and fetus from effects of impaired venous return with postural changes
1. Compensates for maternal blood loss at delivery
70
how do maternal changes affect RBC?
_increase_ by 33%
- **Anemia** - plasma volume increase > RBC increase
- enhanced erythropoiesis → need iron supplement
71
how do maternal changes affect WBC?
overall increase
72
how do maternal changes affect platelets
increase in production and consumption
Net effect - overall _decrease_ as pregnancy progresses
73
how do maternal changes affect coagluation?
* Increase in several clotting factors
* Decrease in protein S, fibrinolytic activity
* **Overall net effect - procoagulant**
74
how do maternal changes affect immunologic function?
Overall slightly _decreased_ - predisposes to infections
75
how do maternal changes affect the pititary gland?
1. Enlarges during normal pregnancy
2. Growth Hormone - increased
3. Prolactin - at term 10x > nonpregnant
- prepares breasts to secrete milk
- decrease after delivery even in breastfeeding women
76
how do maternal changes affect the thyroid?
1. 40-100% increase in thyroid hormone production
- Normally no significant thyromegaly
2. Fetus dependent on maternal thyroid in 1st trimester
3. hCG structurally similar to TSH - TSH naturally drops
- May be mistaken for subclinical hyperthyroidism
- Low TSH can mask hypothyroidism in pregnancy
77
how do maternal changes affect the parathyroid?
1. PTH - ↓ 1st trimester, ↑ 2nd and 3rd
2. Calcium - decreased
- Due to ↑ plasma volume, ↑ GFR, fetal transfer, lower albumin
3. Vitamin D - increased
78
how do maternal changes affect the adrenal glands
1. ACTH and free cortisol - increased
- May help maintain homeostasis with elevated plasma volume
2. Aldosterone - increased
- RAAS activity, can help protect against natriuresis
79
how do maternal changes affect the eyes?
1. Intraocular Pressure - decreased
2. Cornea
- Decreased sensitivity, increased thickness
- Krukenberg spindles - brownish-red opacity on posterior cornea
3. May see transient loss of accommodation
4. Visual function essentially normal
overall not many/drastic changes
80
how do maternal changes affect skin?
| 8 findings
1. Hyperpigmentation
1. striae gravidarum
1. Spider angiomas
1. Palmar erythema
1. Cutis marmorata
1. Varicosities - dilated veins in legs, anus (hemorrhoids), vulva
1. Nails - brittle; horizontal grooves (Beau’s lines)
1. Hair - thickened and increased growth
81
what hyperpigmentation can you see during maternal changes?
1. Linea nigra on abdomen
2. Melasma - “mask of pregnancy”
- uneven darkening in centrofacial - malar area
- exacerbated by sun exposure
- up to 70-90% of pregnancies
3. Also seen in women on oral contraceptives (OCPs)
82
Thick, hyperemic skin caused by decreased collagen adhesiveness and increased ground substance formation
**Striae gravidarum - “stretch marks”**
Abdomen (48%), breasts, thighs, buttocks
Begin to appear in 2nd trimester
83
RF for striae gravidarum?
Genetic predisposition
also risk with wt gain, young maternal age, + FHx
84
spider angiomas and palmar erthyema is more common in what demographic?
white women > black women
85
mottled appearance of skin
secondary to vasomotor instability
cutis marmorata
86
how do maternal changes affect general metabolism?
1. Desire to rest - increased
1. Appetite/Thirst - increased (along with food intake)
- Also increased by breastfeeding
3. Weight - increased, average 12.5 kg (27.5 lbs)
- Greater weight loss in breastfeeding women
87
how do maternal changes affect fat metabolism?
Total body fat increases during pregnancy
Plasma lipids increase
88
how do maternal changes affect water metabolism
increased water retention
often demonstrable pitting edema in LE
89
how do maternal changes affect carbohydrate metabolism
* Mild fasting hypoglycemia
* Postprandial hyperglycemia
* **Hyperinsulinemia and insulin resistance**
* Typically disappears after delivery
90
how do maternal changes affect protein metabolism
1. Protein → 1 kg of weight gain
- 500 g - fetus and placenta
- 500 g - uterine contractile protein, breast
glandular tissue, plasma protein, hemoglobin
91
how do maternal changes affect electrolyte and mineral metabolism
1. Sodium and potassium - slightly decreased
- Increased retention of sodium and potassium
- Diluted due to increased plasma volume
2. Calcium and magnesium - decreased
3. Phosphate - little change
4. Iron - decreased
- _Need supplemental iron_ for normal pregnancy
- Fetal RBC production not impaired
92
why is supplemental iron need for a pregnant woman and how does it help?
iron is decreased
fetus/placenta
support increase in RBC volume
lost through various normal excretory routes (GI)
93
what is the wt goal for a pregnant woman?
**Recommended Weight Gain**
- 25-35 lb (11.5-16 kg) for pt with normal BMI
- Balanced diet
- Special need for iron, folic acid, Ca and zinc
94
how many calories are needed during pregnancy?
Avg. 58 kg (127 lb) woman - 2300 kcal/d
- additional **300 kcal/d** during pregnancy
- additional **500 kcal/d** during lactation
95
protein recommendations during pregnancy?
1. 1 g/kg/day, plus 20 g/d in 2nd half of pregnancy
- 60-80 g/d in the average woman
2. Crucial for embryonic development
3. Lean animal, low-fat dairy, vegetable protein
96
calcium recommendations during pregnancy
1200 mg/d during pregnancy and lactation
< 600 mg/d - maternal skeleton demineralization
97
iron recommendations during pregnancy
* Adequate intake of iron-rich foods
* Supplement 30-60 mg/day during 2nd/3rd trimester
* **Iron-deficiency anemia** - 60-120 mg/day
98
folic acid recommendations during pregnancy
1. Reduces risk of **neural tube defects**
2. At least **0.4 mg/d** for 1 month prior to conception and through 1st 3 months of pregnancy
- **1 mg/d** - insulin-dependent DM or taking valproic
acid or carbamazepine - incr risk for NTD (1%)
- **4 mg/d** - if + hx of NTD; 70% reduced recurrence
99
if a pregnant woman is vegetarian or hx megaloblastic anemia, what supplement should they get?
B12
100
if a pregnant woman is at risk for inadequate nutrition, what supplement should they get?
B6
101
what supplement combo may help with N/V of pregnancy?
B6 and doxylamine
102
what vitamin is sufficient and typically can get through diet?
Vit C
103
T/F: there are no set recommendation levels for zinc
T
suggestions - approx. 12 mg/d - can get through diet
104
iodine recommendations during pregnancy
increased demand during pregnancy
* can get through diet - recommend iodized salt
* pregnancy 220 mcg/day; lactation 290 mcg/day
* over-supplementation may cause thyroid disease
105
Functions of the Placenta
* Release hormones and enzymes to maternal bloodstream
* Transport of all fetal nutrients and metabolic products
* Exchange of O2 and CO2 for fetal circulation
* Fetal in origin but relies on maternal blood
106
Circulatory Function of the placenta
1. 500-700 mL/min to uterus
- 85% - divisions of placenta
1. Uterine spiral arteries - become tortuous channels
1. Arterial bleeding controlled by uterine contraction
107
role of placental secretions
* Help control intrauterine growth, maturation of vital organs, and childbirth ~ 7 weeks-term
* Includes hCG, placental proteins, steroids (DHEAS and estriol)
108
describe the placental transport
* High metabolism - consumes O2 and glucose faster than fetus
* O2 and nutrients → fetus
* CO2, urea and catabolites → mother
109
describe the Placental Transport of Drugs
1. Very few substances will not cross at all
2. Large molecular size or charge - minimal transfer
- Heparin, insulin
3. Albumin-bound - higher unbound concentrations, higher placental gradient
- Warfarin, salicylates
110
process of gestations weeks 1-4
1. **Conception** - A single sperm enters the egg cell
1. Causes formation of a **zygote**
1. Zygote slowly divides → forms a small ball of cells - **morula**
- Enters uterus **3-5 days** after fertilization
1. Gradual accumulation of fluid between cells of morula = **blastocyst**
- inner cell group → embryo
- outer cell group → supportive tissues
- Day 6-7 - blastocyst implants and invades the endometrium and myometrium
- **Day 10** - blastocyst is totally encased in endometrium
1. Outer cell group - chorionic villi → becomes placenta
2. Inner cell group → becomes major cell lines that eventually give rise to distinct tissues
111
The 3 distinct tissues of the inner cell group
1. Endoderm - innermost layer
2. Mesoderm - middle layer
3. Ectoderm - outermost layer
112
Epithelial lining of multiple systems
GI, respiratory, endocrine, auditory, urinary
which major tissue/layer?
Endoderm
113
connective tissue - pericardium, peritoneum, pleura
muscle tissue, bone, most of the circulatory and GU systems
which major tissue/layer
mesoderm - middle layer
114
Skin - epidermis, sweat glands, hair, nails
tooth enamel
“outer” epithelium - lining of mouth, nostrils and anus
nervous system
which major cell/layer?
Ectoderm - outermost layer
115
at what week does the development of the brain, spinal cord, heart and GI tract start?
week 5
116
what starts developing during week 6-7?
1. eyes, ears, some bones (including vertebrae)
2. **Limb buds** and some cranial nerves
3. Brain divides into 5 areas
4. **Heart begins to beat** at regular rhythm
117
when do lungs begin to develop?
week 8
Limbs lengthen, with foot/hand areas and early digits
Brain continues to develop
118
when do all essential organs begin to form
week 9
Nipples, hair follicles, elbows, toes develop also
119
* Eyelids, external ear, facial features continue developing
* Intestines rotate and swallowing begins
* **FHT audible by doppler US**
* **End of embryonic period**
what week is this?
week 10
120
what happens/develops during weeks 11-14
1. Further refinement of face, limbs and genitals
- Ability to distinguish genitalia on US
- Fetus can make a fist with its fingers
2. RBC are produced in the liver
3. Urine produced and put into amniotic fluid
4. Centers of ossification in most fetal bones
121
1. Fine hair called lanugo develops
1. More bone and muscle tissue develop
- Active movements, including sucking
1. Meconium produced in the intestinal tract
1. Fat begins to accumulate
what week is this
week 15-18
122
1. Fetus is capable of **hearing**
1. Vernix caseosa covers body
1. Fetus moves every minute and begins to swallow
- **Mother may begin feeling “fluttering” fetal movement**
what week is this
week 19-21
123
when is the midpoint of pregnancy
| week
week 20
124
at what week can a Fetal heartbeat can be perceived
with fetoscope?
week 22
125
* Bone marrow begins to make blood cells
* Fingerprints and footprints form
* Fetus is regularly sleeping and waking
* Fetus may respond to sounds
what week is this
week 23-25
126
what is the fetal survivability based on week?
Week 23 - 20-35%
Week 25 - 50-75%
Week 26 or later - up to 90+ %
later the better
127
Fetus has **hand and startle reflex**
Alveoli form in lungs
what week is this
week 26
128
1. Rapid brain development
- Enough to control some body functions
2. Eyelids open and close
3. **Surfactant begins to be produced**
what week is this
week 27-30
129
what happens during weeks 31-42?
1. Weeks 31-34
- Rapid increase in body fat
- Bones are fully developed, but still soft and pliable
- Fetus begins _storing_ iron, calcium and phosphorus
2. Weeks 35-38
- Lanugo begins to disappear
- Body fat continues to increase
3. Weeks 39-42
- Lanugo is gone except for upper arms and shoulders
- Small breast buds present on both sexes
130
one of the highest risk of malformation of all body systems during embryologic development
GU tract
131
what is needed for male GU tract to have proper embryolic development?
Functional Y chromosome
132
Most of the GU tract develop at what layer and at what week?
| embryologic development
1. intermediate mesoderm
1. Weeks 4-8 - formation of all major GU structures begins
- Including urogenital ridge and urogenital sinus
- Most likely to develop major anomalies at this time
133
what is the process of the reproductive embryolic development in order?
genetic → gonadal → ductal → genital
134
when/how is Genetic determined during embryologic development?
determined at fertilization by sex chromosomes
135
how/when is the gonadal embryologic development expressed?
1. genetic sex is expressed on developing gonadal tissue
- Begins about week 8
- Sex-determining region of Y chromosome encodes for testis-determining factor (**TDF**)
136
what promotes for gonad differentiation into a testis with production of antimüllerian hormone and testosterone
testis-determining factor (TDF)
137
both “male” Wolffian (mesonephric) ducts and “female” Müllerian (paramesonephric) ducts exist in embryo
until when?
until **ductal** differentiation
138
which hormone suppresses “female” Müllerian (paramesonephric) ducts
antimüllerian hormone
139
what hormone persistence and differentiation of “male” Wolffian (mesonephric) ducts
testosterone
140
how do the genitals develop during embryologic development
the Wolffian or Müllerian ducts develop into distinct sex-specific genitalia
141
types of Abnormal Gonad Development
1. Gonadal absence
- _agenesis_ - gonad did not form at all
- _agonadism_ - gonads formed initially and later degenerated
2. **Streak gonads**
- primordial gonadal formation
- no differentiation → lacks germ cells
3. release of antimüllerian hormone w/o production of testosterone - _suppresses both ducts_
4. ectopic gonadal tissue
142
what is the precursor of urogenital structures
cloaca
143
when does the urorectal septum during embryologic develop?
how is it different between males vs females?
* Weeks 5-7 - urorectal septum → divides cloaca into the urogenital sinus and the anorectal canal
* Male - becomes urinary bladder, urethra, and penis
* Female - becomes urinary bladder, urethra and vagina
144
possible findings Abnormal Vaginal Development
* Vaginal agenesis - rare - 0.025%
* Vaginal atresia - lower portion is only fibrous tissue
* Vaginal septa - transverse or longitudinal - Can have imperforate hymen
* May see rectovaginal fistula
145
**Wolffian/Mesonephric Ducts** develop into what for male sex development?
* Epididymis, ductus deferens, ejaculatory ducts
* Vestigial remnant - appendix epididymis
* requires presence of gonads (testes)
146
Müllerian/Paramesonephric Ducts develope into what for male sex development?
regress under hormonal influence
may persist as appendix testis
147
what is the relocation process for male sex development
* 28th week - testes descend through inguinal canal
* 32nd week - testes in scrotum
148
Wolffian/Mesonephric Ducts develope into what for female sex development
Mostly regress
Small portion becomes trigone of bladder
149
**Müllerian/Paramesonephric Ducts** develop into what for female sex development?
Ductal differentiation does not require ovaries
Midline fusion → uterus
Distal ducts → oviducts
150
how do External Genitalia Abnormalities (Female)
develop and what are other abnormalities that can be seen?
1. Labia Majora/Minora
- Fusion → tissue separation failure or inflammatory reaction
- May be hypertrophic or hypoplastic
2. Clitoris
- agenesis - atresia or lack of genital tubercule formation
- bifid /double - failure of fusion
- hypertrophy - in intersex disorders
3. Perineum (Male/Female)
- Imperforate anus
- Anal stenosis
- Anal agenesis with fistular ectopic anus
