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Urogenital, Reproductive, Genetics, Endocrine > Reproductive & Genetics > Flashcards

Reproductive & Genetics Flashcards

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Biology 101 flashcards
1
Q

The single gene responsible for sexual determination is:

A

SRY

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2
Q

The main cell responsible for the sexual differentiation of the internal genital tract is the:

A

Sertoli cell

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3
Q

Main hormone responsible for differentiation of the internal genital tract is:

A

Anti Mullerian Hormone - AMH

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4
Q

Main hormone responsible for differentiation of the external genitalia is:

A

Testosterone

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5
Q

Development of ___________ induces the development of the kidney

A

the ureter

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6
Q

Every individual goes through an __________ state of sexual differentiation with coexistence of both _____________ tracts

A

undifferentiated

male/female

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7
Q

What is hypospadias?

A

Birth defect in boys in which opening of urethra is not located at the tip of the penis

1 / 300

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8
Q

Name some side effects of DES - Diethylstillbestrol

A

Given in 1940-1970s, synthetic oestrogen to prevent miscarriage

DES daughters -Prenatal/ in utero exposure linked to clear cell adenocarcinoma - cervix/vagina cancer

Appears to be no known effects to DES sons

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9
Q
A
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10
Q

Most breast cancers derive from what tissue:

A

Lobular or Ductal

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11
Q

What is the % spread of invasive carcinomas of the breast?

A

75% Ductal

10% Lobular

Other rarer ones exist

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12
Q

4 molecular Subtypes of breast cancer and some features

(include rough survival %) -

A
  • Luminal A
    • ER/ PgR +ve
    • HER2 -ve
    • Ki 67 low (mitotic factor)
  • Luminal B
    • ER/ PgR +ve
    • HER2 -ve or +ve (2 subtypes)
    • Ki 67 hige (mitotic factor)
  • Erb-B2 overexpression
    • ER + PgR absent
    • HER2 +ve
  • Basal Like
    • ER + PgR Absent
    • HER2 -ve
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13
Q

What are the layers of endometrial “zona functionalis”

A

Zona compacta

Zona spongiosum

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14
Q

what are the 3 stages of implantation

A
  1. Apposition
  2. Adhesion
  3. Invasion
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15
Q

What are the 2 phases of the menstrual cycle?

A

Follicular phase → Day 0-14

Luteal Phase → Day 14-28

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16
Q

Where does Gonadotropin Releasing Hormone come from, and what does it stimulate?

A

GnRH (Gonadotropin Releasing Hormone) is released from the hypothalamus, and stimulates release of:

  • Luteinising hormone (LH) and
  • Follicle stimulating hormone (FSH)

Both from the anterior pituitary

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17
Q

Combined oral contraceptive pills (cocp) work by:

A
  • Include oestrogen and progestogen → inhibit FSH and LH release, thus inhibiting follicular development and ovulation

Also:

  • Progestogen increases cervical mucus to inhibit sperm access to uterus
  • Decreases ability for implantation of fertilised ovum due to atrophic endometrium
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18
Q

Risk factors for breast cancer

A
  • BRCA1 and BRCA2 mutations → 5-10% breast factors
    • If you have these genes ~ 80% risk of developing
  • Age > 40y
  • F:M 100:1
  • FHx
  • Past Hx
  • Hormonal influences
    • age 1st pregnancy <30 reduces risk
    • # pregnancies
    • Diet/Etoh
    • Obesity → inc risk post menopause, red risk pre menopause
    • Exogenous hormones
      • HRT - long term inc
      • Oral contraceptives - slight inc breast, red risk others
      • Tamoxifen → red risk breast, inc risk others
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19
Q

Steps of breast cancer development

A
  • Normal ductal lumen
  • Benign proliferative changes
  • Atypical hyperplasia
  • Ductal cancer in situ
  • Invasive carcinoma
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20
Q

Most common metastases from breast cancer are:

A

Brain

Bones

Lungs

Liver

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21
Q

Define breast cancer in situ vs invasive carcinoma

A

In situ - The proliferation of ductal epithelial cells with all the morphologic features of malignancy but without evidence of basement membrane penetration or stromal invasion.

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22
Q

Name some prognostic and predictive factors for breast cancer

A

Prognostic markers – e.g., ER + good prognosis; HER2 + bad prognosis Predictive markers – e.g., ER+ responds to Hormone Therapy; HER2 + to Herceptin® Therapy

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23
Q

Name some genes involved in breast cancer progression

A
  • Oncogenes
    • KRAS
    • ERBB2 (HER2/NEU)
  • Mismatched Repair
    • MLH1
    • MLH2
    • BRACA1
    • BRACA2
  • Tumour Suppressor
    • PTEN
    • P53
    • BRACA1
    • BRACA2
  • Cell Adhesion
    • CDH1 - e cadherin
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24
Q

Foetal blood is separated from maternal blood by:

A
  • Foetal capillary endothelium
  • Mesenchyme (embryonic connective tissue undifferentiated cells) and cytotrophoblasts (inner layer of trophoblasts)
  • Thin layer of syncytiotrophoblasts (epithelial cells that cover villous tree)
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25
Q

Where does the placenta shear off after birth?

A

At the decidua basalis

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26
Q

What are the names of the foetal, and maternal portions of the placenta?

A

Foetal → villous chorion

Maternal → decidua basalis

These two are held together by anchoring villi that are anchored to the decidua basalis by the cytotrophoblastic shell

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27
Q
  1. Lactogenesis (secretion) is inhibited during pregnancy by high levels of what hormone?
  2. What triggers a sudden drop in this?
A
  1. Progesterone → has an inhibitory effect on prolactin
  2. Expulsion of the placenta

Note → “retained products” aka retention of placental tissue can result in early failure lactogenesis

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28
Q

Suckling at the breast stimulates:

A

Oxytocin release from the posterior pituitary

This leads to contraction of myoepithelial cells → milk ejection or “let down”

Also - prolactin bursts from anterior pituitary → aids milk production

This becomes a supply & demand situation → weaning must occur slowly as when done abruptly, can cause painful mastitis, and infection of the breast

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29
Q

5 D’s of endometriosis

A
  • Dolor - (chronic pelvic pain)
  • Dysmenorrhea - painful period
  • Dyspareunia - painful intercourse
  • Dysuria - painful urination
  • Dyschezia - painful defecation
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30
Q

Define & describe persistent pelvic pain (PPP)

A
  • “non-cancer pain, > 3-6months perceived in structures related to pelvis” → seems currently preferred to Chronic pelvic pain (CPP)
  • 20% wome will experience at one stage in their lift
  • Very common, assoc w poor outcomes, mental health and “suffering in silence”
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31
Q

Name some potential causes of PPP (persistent pelvic pain)

A
  • Gynaecologic → Endometriosis, Ovarian cysts
  • Urologic → Chronic UTI, Bladder dysfunction / stones
  • Gastrointestinal → IBD, IBS, Hernia
  • Musculoskeletal → Pelvic floor myalgia, Nerve entrapment, SIJ disorders
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32
Q

Rhesus (Rh) incompatibility occurs when:

A
  • Rhesus (Rh) factor is a protein found on outside of red blood cells (RBCs).
  • ~ 85% of people are Rh +ve

Problem occurs when:

  • Mother is Rh -ve
  • Pregnant with Rh +ve baby
    • Mum’s immune system reacts, creates Rh antibodies, which facilitates an immune system attack against the baby.
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33
Q

Rhesus (Rh) antibody formation can happen due to:

A

Only occurs with Negative mum, Positive bub

Antibodies form when Foetal blood enters mother’s circulation or post blood transfusion, from causes such as:

  • Injury to stomach area during pregnancy
  • Bleeding during pregnancy
  • Tests that require cells or fluids drawn from pregnant woman - ie amniocentesis, chorus villus sampling
  • Early pregnancy complications such as miscarriages, ectopic pregnancies, termination
  • Delivery of baby - vaginal or caesarian
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34
Q

Major risk factors for postnatal depression

A
  • PHx Dep/Anx
  • Antenatal Dep/Anx
  • FHx Dep/MI
  • Lack of social, practical, financial or emotional support
  • Life stresses & adverse life events
  • Stressful or complicated pregnancy
  • Previous miscarriage/stillbirth
  • Young maternal age
  • Unwell/ unsetteld bub
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35
Q

Rx postnatal depression can include:

A
  • Social support
  • Psychological therapy
  • Pharmacotherapy
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36
Q

General principles of Dep/Anx Rx in pregnancy

A
  • Planned pregnancy allows time to discuss Rx options, and to switch if necessary to a med that appears safer in pregnancy
  • Whenever possible, psychotherapy & psychosocial measures take precedence over pharmacotherapy or electroconvulsive therapy
  • Pharmacotherapy goal → not max control of symptoms, but reduction of those that jeopardise mum or pregnancy
  • All Rx recommendations discussed w patient, partner and obstetrician
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37
Q

Differentiation between stillbirth and miscarriage

A

“Expulsion from mother, embryo or fetus:”

Miscarriage

  • < 20 weeks
  • < 400g (NSW), <500g (WHO→ median wt @ 20w)

Stillbirth after these times/weights

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38
Q

Sperm had 3 major roles in fertilisation

A
  • Induce change in zonal pellucida which prevents polyspermy
  • Stimulate second meiotic division of ovum → generating a second polar body which then dies
  • Deliver paretnal gene compliment to ovum
    • haploid → diploid - which forms the zygote
    • determine the gender of the zygote
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39
Q

What is the terminology of developing foetus

A

First 2 weeks:

  • zygote → morula → blastocyst

2-8 weeks

  • Embryo

9-40 weeks

  • Foetus
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40
Q

3 stages of implantation

A
  1. Apposition
  2. Adhesion
  3. Invasion
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41
Q

Steps in Follicle development

A
  • Female born with many many diploid (2N) Oogonium
  • Pre puberty, these develop into Primordial Follicles (still 2N) → frozen in prophase 1 of Meiosis
  • Primary Follicles : Local androgens at puberty (not FSH or LH) convert some of the primordial follicles into primary follicles
    • Primary Follicle → primary oocyte, still frozen in prophase 1, with single layer of cuboidal or columnar follicle cells
  • Early 2ndary Follicle: Secretion of FSH by the anterior pituitary stimulates development of primary follicle to early 2ndary
    • Early 2ndary Follicle → has many layers of cuboidal follicle cells surrounding primary oocyte
    • Has Zona Pellucida (glycoprotein membrane) surrounding oocyte
    • FSH stimulates follicle now to begin production of oestrogen
  • Late 2ndary Follicle (still a primary oocyte → ie hasn’t finished meiosis 1) → develops via FSH & LH stimulation
    • Production of pockets of follicular fluid → rich in hyaluronic acid
    • More follicular cells
  • Graffian / Vecicular / Tertiary (3ry) Follicle
    • 2ndary oocyte → 2 x (n), ie 2 haploid daughter cells - has finished meiosis I
    • Frozen in metaphase II
    • Pockets of follicular fluid merge to become antrum
    • Releases Inhibin B → inhibits FSH production
  • Proteolytic enzymes cut “stigma” to pop 2ndary oocyte out of Graffian follicle → Ovulation!! (~day 14)
  • Corpus Luteum → LH surge promotes Graffian follicle to ovulate.
    • LH stimulates Corpus Luteum to produce Progesterone
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42
Q

How do follicles produce oestrogen?

A
  • Thecal cells surrounding granulosa cells of the follicle are stimulated by LH
    • Theca cells: in presence of LH Cholesterol → Androgens (such as androstenedione)
  • Granulosa cells in presence of FSH
    • Androgens → Oestrogen
43
Q

High Oestrogen levels towards the end of Follicular phase stimulate:

A
  • Hypothalamus to release GnRH
  • Anterior pituitary to produce tonnes of LH (LH surge)
    • Note, Inhibin B inhibits production of FSH
44
Q

2 layers of endometrium are?

A
  • Stratum Functionalis
    • Innermost layer
    • Spiral & Coiled arteries
    • Regenerates (proliferative phase) and is shed every cycle → regenerates in response to oestrogen
  • Stratum Basalis
    • Outermost
    • Straight arteries - branches of uterine arteries
    • Remains
45
Q

Define “Ectopic Pregnancy”

A
  • Non-intrauterine pregnancy → potentially life threatening
  • May occur in:
    • ovaries
    • cervix
    • intra abdominally
    • but most common is uterine (fallopian) tubes
      • 55% ampulla
      • 25% isthmus
      • remainder in fimbriae or uterine part
46
Q

Describe the parts of the uterine (fallopian) tubes

A

FIAI

47
Q

Risk factors for ectopic pregnancy

A
  • Previous ectopic pregnancy
  • Previous surgery → eg tubal ligation
  • Pelvic infection
  • Endometriosis
  • In vitro fertilization (IVF)
  • However, 50% of ectopic pregnancies occur in women with no predisposing risk factors
48
Q

Clinical presentation of ectopic pregnancy

A

Range from no symptoms, to:

  • Lower abdo pain → L, R or bilateral depending on location
  • Vaginal bleeding
  • Intra-abdominal haemorrhage
  • Collapse
49
Q

Describe Ectopic pregnancy:

  • Confirmation of Dx
  • Rx
A

Dx:

  • hCG test (Human chorionic gonadotropin) → still usually raised despite implantation outside uterus
  • Ultrasound of uterus

Rx:

  • When occurring in uterine (fallopian) tubes
    • Laparascopic salpingostomy (incision into tube)
    • Salpingectomy (removal of tube)
50
Q

Pre-eclampsia is defined as:

A

Pregnancy induced hypertension (PIH),

Oedema, and

Proteinuria

Relatively common, occurring in ~10% of pregnancies

51
Q

Pregnancy induced hypertension (PIH) is heterogenous in manifestation but areas affected include:

A
  • Liver damage
  • Kidney dysfunction
  • Hypertension itself may be dominant feature
52
Q

A number of factors predisposing a woman to developing (PIH) pregnancy induced hypertension include:

A
  • FHx
  • First pregnancy
  • Extremes of maternal age
  • Medical Hx (pre-existing htn, diabetes mellitus)
  • Obstetric Hx (multiple pregnancy, hydatitdiform mole)
53
Q

Common complaints of symptomatic menopause include:

A

Most common (effectively relieved by HRT)

  • Hot flushes
  • Night sweats
  • Vaginal dryness

Less commonly (may improve with HRT)

  • Mood swings
  • Sleep disturbance
  • Sexual dysfunction
  • Myalgia
54
Q

One “bonus” of HRT is:

A

Reduction of osteoporosis assoc with menopause, and associated #s

55
Q

The anaerobic bacterium Treponema Pallidum causes:

A

Syphillis

Microbiologically classified as a spirochete (sp-eye-roh-keet) - (rhymes with parakeet)

56
Q

Describe Stages of meiosis (I & II)

→ what we have at the start and end of each

A
57
Q

What are the 2 major cells in the testes, and what do they do?

A

Sertoli cells

  • Spermatogenesis

Leydig cells

  • Testosterone
58
Q

As well as producing sperm, what do the Sertoli cells do?

A
  • Form the “blood testes barrier”
  • Segregating the basal lamina to lumen
  • This avoids blood contact with the gametes, and avoids any 2ndary immune response that may occur because of this
59
Q

Where and how do the 2 major endocrine hormones react with cells in the testes?

A
  • Luteinizing Hormone (LH) → Leydig Cells
    • → Testosterone
  • Follicular Stimulating Hormone (FSH) → Sertoli Cells
    • → Sperm development
    • “Androgen binding protein” → keeps some testosterone intertesticular(as testosterone is hydrophobic)
60
Q

Steps of sperm production:

A
  1. Spermatogonia → 46n, XY → (base cell)
  2. Primary spermatocytes → 46n, XY → (via Meiosis I)
  3. Secondary Spermatocytes → 23nn, X or Y → (via Meiosis II)
  4. Spermatids → 23n, X or Y → (end of Meiosis II → gametes)
  5. Spermatozoa (via spermiogenesis → ie, change to nucleus, cytoplasm. Now functional sperm)
61
Q

Key features of sperm for travelling

A
  • Acrosome → contains hydrolyric enzymes, required to penetrate ovum
  • Nuclear condensation → “getting lean”, less cytoplasm
  • Mitochondrial spiral → ATP
  • Flagellum → movement
62
Q

Describe the function of the epididymus

A
  • 400 - 600 seminiferous tubules join to form this
  • Single, long coiled duct → continuous with “Ductus Deferens”
  • Sperm maturation occurs here → ~ 12 days
  • Aquire motility, protein secretions
  • Sperm can be stored here for months
63
Q

Function of seminal vesicles

A
  • Add most of volume of semen ~ 70%
  • Thick, alkaline fluid
  • Fructose & citrate for nourishment
  • Prostaglandins for motility → kind of works like coagulant, stick together stay safe
64
Q

Penis erectile tissue includes:

A
  • 2 Corpora cavernosa
  • 1 Corpus spongiosum (with urethra)
65
Q

What creates Dihydrotestosterone?

A
66
Q

Describe female hormone levels as they fluctuate throughout the menstrual cycle

A
67
Q

Define pleitrophy

A

One genetic mutation has multiple effects in the same organism

eg → marfan syndrome

  • unusually tall
  • thin fingers & toes
  • disloc lens of eye
  • cardiac problems → rupture aorta
68
Q

In males, what cells are responsible mainly for testosterone production

A

LH → Leydig cells

69
Q

In females, what cells are mainly responsible for androstenedione and progesterone

A

LH → Theca cells

70
Q

Gender split of central precocious puberty

A

~90% females idiopathic

~75% males have CNS lesion

71
Q

Pathological causes for delayed puberty

A
  • Tumor
  • Trauma
  • Treatment
72
Q

Describe HDN → Haemolytic Disease of the Newborn

A
  • Happens with Rh (Rhesus) -ve mother, +ve child
  • Generally does not happen with first pregnancy
  • Occurs after a sensitising event such as:
    • Miscarriage >12w
    • Abdominal trauma
    • Birth of previous bub
  • When Rhesus +ve red blood cells come into contact with mum’s B cells, they identify it as foreign and start creating anti rhesus antibodies
  • These are small enough to cross the placental barrier, and can cause haemolytic anaemia of the next child → hyperbilirubinaemia
  • Complications include:
    • Jaundice, brain damage, long term learning difficulties
73
Q

Prevention of HDN (haemolytic disease of the newborn) involves?

A

Injecting mum with anti-d antibodies if there is a fear of any new sensitising event (with -ve mum and +ve bub)

This “destroys” +ve blood cells in mum before she can become sensitised and launch her own immune response

Give -ve mum anti D injection at any risk of sensitising event

74
Q

3 types of chromosomal abnormalities

A
  • Numerical abnormalities
  • Structural abnormalities
  • Mosaicism → either numerical or structural abnormalities can be mosaic
75
Q

Describe 4 common subtypes of chromosomal structural changes

Give an eg of each

A

DDIT

  • Deletions
    • Deleting part of genetic material from a chromosome
    • Often results in miscarriage (unless micro deletion)
      • Cystic Fibrosis
  • Duplications
    • Have duplication of genetic material
      • Huntington’s Disease
  • Inversions
    • Info from area of a chromosome has moved - but still on the same chromosome
      • Haemophilia
  • Translocations
    • Genetic info has moved from one chromosome to another
    • Ie no genetic material is gained or lost → no problem in somatic cell, but in Gamete can cause problems
      • Robertsonian translocation → other cause of Trisomy vs non-disjunction in Meiosis I
76
Q

Describe paternal vs maternal imprinting

A

Happens when genes are silenced from either Father’s (paternal imprinting) or mother’s (maternal imprinting)

Different areas are silenced on from either source

Commonly occurs on Chromosome 15

77
Q

Explain Prader Wili and Angleman in terms of imprinting

Some traits of each

A

Prader-Willi →

Gene zone on chromosome 15 which is imprinted (turned off) on the maternal chromosome has its corresponding paternal gene area deleted

Issues with HPA axis in satiety, weight gain and OCD style traits, mild to moderate intellectual impairment,

Angelman Syndrome

Gene zone in chromosome 15 which is normally imprinted (turned off) on the paternal side has its corresponding maternal coding zone deleted

Development of key neurological areas in early embryological development are impaired, leading to severe intellectual disability, convulsions

78
Q

Define aneuploidy

A

Change in chromosome number

Polyploidy → too many (trisomy)

Monoploidy → too few

79
Q

Describe Trisomy 13 and Trisomy 18

A

Trisomy 13 - Patau’s syndome

Trisomy 18 - Edward’s syndrome

  • 1/5000
  • Poor prognosis - often die very young
  • Congenital heart defects
  • Positive association with maternal age incidence

As with most Trisomies, caused by Non-disjunction in meiosis most of the time, but also by Robertsonian translocation

80
Q

Describe Trisomy 21

A

Aka Down’s Syndrome

  • Non disjunction in meiosis 95% cases (~90% maternal, 5% paternal)
  • Unbalanced Robertsonian translocations 2-4%
  • 1-4% mosaic karyotype
  • 70% of trisomy 21 pregnancies miscarry
81
Q

Common impacts of Trisomy 21

A

Most

  • memory and learning difficulties
  • craniofacial alterations
  • muscle hypotonia

Some

  • congenital heart defects → AV canal defects most common
  • leukaemia
  • gut abnormalities → Duodenal atresia most common
82
Q

Describe PAR regions on sex chromosomes

A

Towards the peripheries of the sex chromosomes, these are known as Pseudo-Autosomal Regions.

Ie - They act like autosomes and we need two copies from XX or XY to code unlike the remainder of the sex chromosomes which generally just need one copy

Also → Contains SHOX gene, which codes for skeletal development (key involvement in Klinefelter’s Syndrome)

83
Q

Describe Klinefelter’s syndrome (genetics)

A

47 - XXY

1/500 → 1/1000

Extra chromosome from meiotic errors in each parent

  • Newborn boys asymptomatic
  • Dx mid childhood
  • Can be assoc with infertility

Normally in males, the Y chromosome tells the X to not turn into a Barr body

In XXY, there is “cross talk” in which the Y is telling an X to not shut down, but the 2nd X is giving mixed messages to the first, telling it to turn into a Barr body.

We end up with triple gene dosage in the PAR region

84
Q

What is a Barr Body?

A

Inactive X chromosome in a cell with more than 1 X chromosome

eg, In humans with euploidy, a genotypical female (46, XX karyotype) has one Barr body per somatic cell nucleus, while a genotypical male (46, XY) has none.

85
Q

Symptoms Klinefelter’s syndrome

A

Xxy 47

  • Language based learning difficulties
  • Testosterone deficiency and hypogonadism
  • Motor difficulties in strength and running
  • 50% have gynaecomastia and increased risk of breast cancer
  • Increase in stature, relatively long limbs
86
Q

Describe Turner’s syndrome (genetics)

A

“Monoploidy on X chromosome” → ie 45 X

  • 97% all Turner’s pregnancies are lost
  • 50% result from meiotic error
  • Can also be
    • 45 X/46 XX mosaicism
    • 46 XX with one partially deleted
  • Key is that we have lost “Parr region”
87
Q

Symptoms of Turner’s syndrome

A

45 X

Inherited features

  • Shield shaped chest
  • Low hairline
  • Wide spacing nipples
  • Infertility - oestrogen replacement therapy required to reduce osteoporosis risk

Common internal abnormalities

  • Coarction aorta 15%
  • Renal malformation 40%

Acquired Disorders

  • Short stature may be apparent (½ normal dose of Shox gene on PAR region → missing one sex chromosome which codes for height!)
  • Growth hormone can add 5-10cm
  • Chronic middle ear infections - hearing loss
  • Autoimmune disorders such as underactive thyroid and celiac disease
88
Q

Increase in basal body temp seen ~ day 14 of menstrual cycle is due to the effect of:

A

Progesterone increasing the set point temp in the hypothalamic thermoregulatory centre

89
Q

Anti mullerian hormone has what effect?

A

Present in males, it inhibits the development of mullerian ducts into the uterus, cervix, fallopian tubes and upper vagina.

If no AMH is present, the ducts automatically develop, and wolffian ducts (aka mesonephric ducts) responsible for male reproductive development die

first 8 weeks gestation

90
Q

McArdle’s disease is?

A

Glycogen storage disease type 5

Muscle glycogen storage disease

  • Autosomal recessive
  • Deficiency of myophosphorylase → cannot breakdown muscle glycogen
  • Rhabdomyolysis, Myoglobinuria, may develop acute kidney injury or renal failure due to myoglobinuria
  • Can have “2nd wind phenomenon” after 10 minutes of low intensity exercise
91
Q

Von Gierke’s Disease is?

A

Glycogen storage disease type 1

Hepatocytes unable to breakdown glycogen

  • Deficiency in glucose-6-phosphatase (Ia) or glucose-6-phosphatase-translocase (Ib)
  • Both types lead to excessive glucose storage in liver and kidneys
  • Involves hypoglycaemia, NAFLD, hepatomegaly
92
Q

Glactosaemia is?

A

Hereditary inability to metabolise galatose

Without Rx, mortality in infants is ~75%

Symptoms include:

  • cataracts, ataxia, delayed development
93
Q

Why is exogenous testosterone associated with a reduction in spermatogenesis?

A

-ve feedback loop to hypothalamus

leading to decreased production of GnRH → less FSH & LH

Thus, less spermatogenesis and testicular testosterone

94
Q

What is enzyme A?

Where is it commonly found?

A

5α reductase.

High conc. in prostate and skin

95
Q

What is enzyme B?

Where is it commonly found?

A

Aromatase

High conc. in adipose tissue liver and some brain regions

96
Q

Where is β-HCG secreted from and when does its level peak in pregnancy?

A
  • Syncytiotrophoblastic cells
  • Placenta
  • Peaks around 10 weeks gestation
97
Q

What is the path of blood from the mother’s heart to the fetus’ heart?

A
  • Aorta → common iliac → internal iliac → uterine arteries → placenta
  • Across placenta → fetal umbilical vein → ductus venosus → IVC → heart
98
Q
A
99
Q

Describe APGAR scores (when, where, how much?)

A

ASAP after delivery

Again at 5 minutes

total/10

~98% of babies have 7 or higher at 5 minutes

100
Q

2 factors causing jaundice in newborn

A
  • Increased bilirubin production due to decreased lifespan of neonatal red blood cells
  • Decreased capacity of the neonatal liver to conjugate bilirubin.
101
Q

How are immunoglobulins in breast milk absorbed in newborn GI tract?

A

Transcytosis - a form of receptor mediated endocytosis

This allows the immunoglobulin (protein) to enter the infant’s bloodstream intact

Most maternal immunoglobulins are IgA

102
Q

7 common genes involved in breast cancer

A
  • PTEN – inhibits PI3K pathway
  • P53 – apoptosis; cell cycle regulation, check points etc
  • BRCA1 & BRCA2 – MMR in breast cancer
  • CDH1 – codes for E-cadherin, functions in cell adhesion to form organised
    tissues
  • STK11 –tumour activity involved in cell apoptosis and polarisation
  • PALB2 –tumour suppressor activity, MMR and homologous recombination
103
Q

Hormonal changes through menstrual cycle and early pregnancy

A

Urogenital, Reproductive, Genetics, Endocrine (3 decks)

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