Reproductive Biology (16-18) Flashcards
(11 cards)
What are the main anatomical components of the male reproductive system and their functions?
The male reproductive system includes:
Testes: Produce sperm and testosterone.
Seminiferous Tubules: Site of spermatogenesis.
Epididymis: Site of final sperm maturation and acquisition of motility.
Vas Deferens: Transports sperm from the epididymis to the urethra.
Urethra: Part of both the urinary and reproductive systems; expels semen.
Leydig Cells: Located between seminiferous tubules; secrete testosterone.
Sertoli Cells: Support sperm development inside seminiferous tubules.
What are the main anatomical components of the female reproductive system and their functions?
The female reproductive system includes:
Ovaries: Produce estrogen, progesterone, and release ova.
Uterine Tubes (Fallopian Tubes): Conduct ova from ovaries to uterus; site of fertilization.
Fimbriae: Guide ovum into the uterine tubes.
Uterus: Supports fetal development; contracts during childbirth.
Cervix: Connects uterus to vagina; passage for sperm and baby.
Vagina: Canal for intercourse, menstruation, and childbirth.
What are the roles of different cell types in the microanatomy of the reproductive systems?
Male:
Spermatogonia: Stem cells that initiate spermatogenesis.
Primary and Secondary Spermatocytes: Undergo meiosis.
Spermatids & Spermatozoa: Immature and mature sperm.
Leydig Cells: Produce testosterone.
Sertoli Cells: Nurture and support sperm development.
Female:
Granulosa Cells: Surround oocytes, produce estrogen.
Theca Cells: Collaborate with granulosa cells to produce hormones.
Corpus Luteum Cells: Produce progesterone post-ovulation.
Endometrial Gland Cells: Secrete nutrients for early embryo.
What is the hormonal regulation of reproduction via the HPG axis?
The Hypothalamic-Pituitary-Gonadal (HPG) axis involves:
Hypothalamus: Releases GnRH.
Anterior Pituitary: Releases FSH and LH in response to GnRH.
FSH: Stimulates follicle development (females) or Sertoli cells (males).
LH: Triggers ovulation (females) or stimulates Leydig cells (males).
Sex Hormones: Estrogen, progesterone, testosterone regulate feedback.
Feedback loops: Positive (e.g., estrogen → LH surge) and negative feedback regulate hormone levels.
What is PCOS and how does it affect reproductive health?
Polycystic Ovary Syndrome (PCOS) is an endocrine disorder marked by:
Hormonal imbalance, leading to high androgens.
Irregular or absent ovulation, causing infertility.
Polycystic ovaries with multiple undeveloped follicles.
Often linked to insulin resistance, obesity, and increased diabetes risk.
Symptoms: Hirsutism, acne, weight gain, irregular periods.
Treatment: Lifestyle changes (diet/exercise), hormonal therapy (birth control), insulin management (metformin), and fertility support if needed.
What is endometriosis and how does it affect reproductive health?
Endometriosis is a condition where endometrial-like tissue grows outside the uterus:
This tissue thickens and bleeds with each cycle → pain and inflammation.
Common locations: ovaries, fallopian tubes, pelvic lining, intestines.
Symptoms: Severe menstrual pain, pain during sex, fatigue, infertility.
Diagnosis: Pelvic exams, ultrasound, laparoscopy.
Treatment: NSAIDs for pain, hormonal therapy (e.g., GnRH agonists), or surgery to remove tissue.
How do oocytes develop from primordial to ovulatory stages in mono-ovular and poly-ovular species?
Primordial follicles: Present at birth; small, with flattened granulosa cells.
Primary follicles: Granulosa cells become cuboidal; zona pellucida forms.
Secondary follicles: Granulosa layers thicken; gonadotropin-independent.
Tertiary (Antral) follicles: Antrum forms; gonadotropin-dependent phase begins.
Pre-ovulatory follicles: Large antrum; ovulation triggered by LH surge.
Mono-ovular species (e.g., humans): Typically release one oocyte per cycle.
Poly-ovular species (e.g., dogs, mice): Release multiple oocytes per cycle.
How does an oocyte acquire meiotic and developmental competence for fertilisation?
Oocytes are arrested in Prophase I from fetal life.
LH surge restarts meiosis → First meiotic division → First polar body extruded.
Enters Metaphase II arrest → Awaits fertilisation.
Meiotic competence: Ability to resume and complete meiosis correctly.
Developmental competence: Ability to undergo fertilisation and support early embryo development.
Indicators: Reaching Metaphase II and responding to fertilisation signals.
What is the process of meiosis in spermatogenesis?
Spermatogonia (2N): Divide by mitosis → Some differentiate into…
Primary Spermatocytes (2N): Enter Meiosis I →
Secondary Spermatocytes (1N): Enter Meiosis II →
Spermatids (1N): Undergo morphological changes →
Spermatozoa: Mature, functional sperm cells.
The full process takes ~75 days and occurs continuously throughout life post-puberty.
What morphological changes do adult sperm undergo to prepare for fertilisation?
Spermiogenesis: Round spermatids elongate.
Tail formation: For motility.
Acrosome development: Enzyme cap forms for egg penetration.
Nuclear condensation: DNA tightly packed into the head.
Capacitation: In female tract, enhances motility and prepares sperm for acrosome reaction.
Acrosome Reaction: Enzymes released to penetrate the zona pellucida.
What causes abnormal oocyte and sperm morphology, and how does it affect reproduction?
Oocyte Abnormalities:
Aging → Increased non-disjunction → Aneuploidy (e.g., Trisomy 21).
Poor meiotic division → Chromosomal errors, developmental arrest.
Mitochondrial dysfunction → Reduced energy for fertilisation.
Sperm Abnormalities:
Head defects: Multiple heads, large/small heads.
Tail defects: Coiled, short, or multiple tails.
Causes: Genetics, environment, lifestyle, oxidative stress.
Impact: Impaired motility, failed fertilisation.
ART solutions: ICSI and IVF can bypass some morphological issues.
