Block 2,2 midterm

Anatomy of the Female Reproductive System

• The female reproductive system comprises internal organs (ovaries, fallopian tubes, uterus, vagina) and external genitalia (vulva).
• Its functions include gamete production, hormonal regulation, fertilization, pregnancy, and childbirth.

Ovaries

• Overview: Paired oval structures in the pelvic cavity, one on each side of the uterus.
• Anchored by:
  • Ovarian ligament (attaches to the uterus).
  • Suspensory ligament (attaches to the lateral pelvic wall).
  • Mesovarium (part of the broad ligament).
• Structure:
  • Cortex: Contains developing follicles.
  • Medulla: Rich in blood vessels, lymphatics, and nerves.
  • Surface: Covered by germinal epithelium and tunica albuginea (fibrous capsule).
• Functions:
  • Oogenesis: Production and release of oocytes during the menstrual cycle.
  • Hormone Secretion:
    • Estrogen: Develops secondary sexual characteristics.
    • Progesterone: Prepares the endometrium for implantation.
• Blood Supply:
  • Ovarian arteries (branching from the abdominal aorta).
  • Venous drainage via the ovarian veins.

Fallopian Tubes

• Overview: Also called uterine tubes or oviducts; about 10-12 cm long.
• Connect the ovaries to the uterus.
• Segments:
  • Infundibulum: Funnel-shaped opening near the ovary; fimbriae sweep the oocyte into the tube.
  • Ampulla: Longest section; common site of fertilization.
  • Isthmus: Narrow portion connecting to the uterus.
  • Intramural (Interstitial): Passes through the uterine wall.
• Functions:
  • Capture and transport oocytes to the uterus.
  • Fertilization occurs in the ampulla.
  • Provides nutrients for the zygote during transit.
• Histology:
  • Mucosa: Ciliated columnar epithelium aids in oocyte transport.
  • Muscularis: Smooth muscle for peristalsis.
  • Serosa: Outer protective layer.
• Blood Supply: Tubal branches of the uterine and ovarian arteries.

Uterus

• Overview: A hollow, muscular organ in the pelvic cavity (7-9 cm in length when not pregnant).
• Anchored by ligaments (broad, round, uterosacral).
• Regions:
  • Fundus: Dome-shaped top.
  • Body (Corpus): Largest part; contains the uterine cavity.
  • Cervix: Narrow lower segment connecting to the vagina.
• Layers:
  • Endometrium: Inner mucosal layer; functional layer sheds during menstruation; basal layer regenerates.
  • Myometrium: Thick layer of smooth muscle for uterine contractions.
  • Perimetrium: Outer serous layer (continuous with the peritoneum).
• Functions:
  • Menstruation: Sheds the endometrium if no fertilization occurs.
  • Implantation: Provides a site for embryo attachment.
  • Labor: Contracts to expel the fetus during childbirth.
• Blood Supply: Uterine arteries (branching from the internal iliac artery).

Vagina

• Overview: A fibromuscular canal (8-10 cm) connecting the cervix to the external genitalia.
• Positioned posterior to the bladder and anterior to the rectum.
• Structure: Elastic walls with rugae (folds) allowing for expansion during intercourse and childbirth.
• Functions:
  • Passageway for menstrual flow.
  • Birth canal during labor.
  • Facilitates sexual intercourse.
• Histology:
  • Lined with stratified squamous epithelium for friction resistance.
  • Maintains an acidic pH due to lactobacilli metabolism of glycogen.

Vulva

• Overview: External genitalia protecting internal reproductive organs and contributing to sexual arousal.
• Components:
  • Mons Pubis: Fatty pad over the pubic bone.
  • Labia Majora: Outer, hairy folds of skin.
  • Labia Minora: Inner, hairless folds encloses the vestibule.
  • Clitoris: Erectile tissue homologous to the male penis.
  • Vestibule: Opening for vagina, urethra, and Bartholin’s glands.
  • Perineum: Area between vaginal opening and anus.

Clinical Relevance

• Ovarian Disorders: PCOS, ovarian cysts, or ovarian cancer.
• Fallopian Tube Disorders: Ectopic pregnancy, salpingitis.
• Uterine Disorders: Endometriosis, fibroids, uterine prolapse.
• Vaginal Infections: Candidiasis, bacterial vaginosis, vulvodynia, Bartholin's cyst.

Male Reproductive System

• Overview: Specialized for sperm production, storage, and delivery, and male sex hormone (testosterone) secretion.

Testis and Components

• Location: Scrotum, outside the abdominal cavity, to maintain optimal temperature for spermatogenesis.
• Structure: Lobules containing seminiferous tubules where sperm production occurs.
• Microscopic Features:
  • Seminiferous tubules: Site of spermatogenesis.
  • Interstitial (Leydig) cells: Produce testosterone.
  • Sertoli cells: Provide nourishment and support for developing sperm.
• Blood Supply: Pampiniform plexus aids in temperature regulation.

Spermatic Pathway

• Epididymis: Long coiled duct where sperm mature and gain motility.
• Ductus (Vas) Deferens: Transports sperm from epididymis to ejaculatory ducts.
• Ejaculatory Duct: Formed by the union of vas deferens and seminal vesicle duct, emptying into the urethra.

Accessory Glands

• Prostate: Produces prostatic fluid contributing to semen volume and sperm motility.
• Seminal Vesicles: Secrete fructose-rich fluid to provide energy for sperm.
• Bulbourethral Glands: Produce mucus-like secretion to lubricate the urethra and neutralize acidity.

External Genitalia

• Penis: Comprised of erectile bodies (corpus cavernosum and corpus spongiosum).
• Scrotum: Protective sac that houses the testes and regulates temperature.

Disorders of the Testis

• Cryptorchidism: Failure of the testes to descend, increased infertility risk.
• Testicular torsion: Twisting of the spermatic cord, causing ischemia.
• Testicular cancer: Often presents as a painless lump.

Prostate Disorders

• Benign Prostatic Hyperplasia (BPH): Enlarged prostate causing urinary symptoms.
• Prostate cancer: Common malignancy in older men.

Infertility

• Can result from abnormal sperm production, hormone imbalance, or obstructed pathways.

Preconception Care and Genetic Counseling

• Preconception care focuses on education, medical care, and counseling to optimize maternal and fetal health outcomes.
• Preconception consultations involve identifying and addressing medical, behavioral, or environmental risks to reproductive health and educating couples.
• Components of the consultation include clinical history, vaccinations, nutritional supplements, screening and laboratory tests, and lifestyle assessment, and genetic counseling.
• Objectives: Understanding genetic contributions, assessing risk and inheritance patterns, guiding decisions related to genetic testing, and reproductive choices.

Genetic Diseases

• Mendelian Diseases: Caused by single gene defects (e.g. Huntington's disease, cystic fibrosis).
• Multifactorial/Polygenic Diseases: Involve interactions between genetic and environmental factors (e.g. diabetes, heart disease).
• Mitochondrial Diseases: Inherited from the mother (e.g. Leber's hereditary optic neuropathy).
• Chromosomal Diseases: Abnormalities in chromosome structure or number (e.g. Down syndrome).
• Expansion Repeat Diseases: Disorders due to trinucleotide repeat expansions (e.g. Fragile X syndrome).

Clinical Cases

• Cystic Fibrosis: Autosomal recessive inheritance; mutations in the CFTR gene; thick mucus in lungs leads to infection and bronchiectasis.
• Fragile X Syndrome: X-linked inheritance; caused by CGG trinucleotide repeat expansions in the FMR1 gene; intellectual impairment and physical features like large ears.
• Consanguinity: Higher likelihood of autosomal recessive disorders due to shared genes.

Reproductive Choices

• Accept the risk and proceed with pregnancy.
• Spontaneous pregnancy with prenatal testing.
• PGT via in-vitro fertilization (IVF).
• Opt for donor eggs/sperm or adoption.
• Decide against biological children.

Preimplantation Genetic Testing (PGT)

• An IVF-based process to select embryos free of specific genetic mutations.
• Indication: High risk of transmitting genetic conditions.
• Process: Embryos created via IVF; biopsy and genetic testing before implantation.
• Outcomes: 20% chance of pregnancy per treatment cycle; smoking, obesity, and advanced maternal age reduce success rates.

Ethical Issues

• Non-directive Counseling: Respect for patient autonomy.
• Informed Consent: Explicit, voluntary consent with adequate information; ethical considerations vary by country.

Screening in Population Health

• Screening is identifying individuals at high risk of developing conditions within an apparently healthy population, serving as a tool for prevention, early detection, and intervention.
• Types: Population (e.g. mammograms), individual (e.g. genetic testing), and occupational (e.g. lung function tests).
• Key components of screening programs: eligibility based on scientific evidence, accuracy, intervals, and confirmation.

Balancing Benefits and Risks of Screening

• Benefits: Early detection for better outcomes, reduced disability, and cost savings.
• Risks: False positives/negatives, overdiagnosis, and complications of testing procedures.

Screening Programs

• Key components: Eligibility, accuracy, intervals, and confirmation.
• Steps in a screening pathway: test application, risk identification, diagnostic confirmation, treatment/intervention, and validity of screening tests.

Validity of Screening Tests

• Sensitivity: Ability to correctly identify those with the condition.
• Specificity: Ability to correctly identify those without the condition.
• Positive Predictive Value (PPV): Likelihood that a positive result indicates actual disease.
• Negative Predictive Value (NPV): Likelihood that a negative result indicates absence of disease.

Screening vs. Diagnostic Testing

• Screening: Identifies risk in asymptomatic populations; less resource-intensive; used for initial identification.
• Diagnostic testing: Confirms conditions identified by screening; higher resource-intensive; essential for definitive diagnosis.

Evaluation of Screening Programs

• Evaluation assesses effectiveness in reducing morbidity and mortality, ensuring resource efficiency, and monitoring unintended consequences.
• Metrics: Coverage (proportion of eligible population screened), outcome measures (reduction in disease), and cost-effectiveness.

Case Studies - Tuberculosis Screening and Intellectual Disability (Fragile X Syndrome)

• Tuberculosis screening in prisons aims to reduce its high incidence via automated chest X-rays.
• Fragile X syndrome is an X-linked condition, involving intellectual impairment and physical features (e.g., large ears, flat feet) due to CGG trinucleotide repeat expansions in the FMR1 gene (Xq27.3).
• Genetic basis and risk factors in both conditions were summarized with case detail.

Neural Tube Defects (NTDs)

• NTDs are congenital malformations resulting from incomplete neural tube closure during embryonic development, leading to several types like spina bifida, anencephaly, encephalocele, and craniorachischisis.
• Key aspects include types, epidemiology, pathophysiology, risk factors, diagnosis, and prevention.

Prenatal Diagnosis

• Maternal serum screening (e.g., elevated AFP).
• Ultrasound (detects structural abnormalities).
• Amniocentesis (evaluates AFP and acetylcholinesterase levels).

Prevention

• Key strategies for NTD prevention include proper folate supplements.
• Other steps like lifestyle modifications and genetic counselling for individuals at risk are recommended.

Complications of Miscarriage

• Types of miscarriage include threatened, inevitable, incomplete, complete, and missed.
• Causes of miscarriage include fetal chromosomal abnormalities or maternal factors (infections, autoimmune diseases) or environmental causes (exposure to teratogens) that may increase the risk.
• Clinical presentations and management of each miscarriage type.

Management of Miscarriage

• Expectant management (allowing natural passage of pregnancy tissue).
• Medical management (using medications like misoprostol or mifepristone).
• Surgical management (dilation and curettage [D&C] or manual vacuum aspiration [MVA]).
• Complications include hemorrhage, infection, Asherman syndrome, and emotional distress.

Test your knowledge about preconception care, its importance, and the various health factors involved before conception. This quiz covers nutritional supplements, health screenings, and neural tube defects related to reproductive health. Assess your understanding of essential practices that can impact pregnancy outcomes.