a&p2 final (new content)

What are the primary sex organs?

Gonads (testes and ovaries). Produce gametes

What are the secondary sex organs

Ducts, glands, and structures that support reproduction

What are the major functions of the reproductive system?

Gamete production, fertilization, fetal development, birth, nourishment of offspring

Why is scrotal thermoregulation essential?

Spermatogenesis requires temperatures ~2–3°C below core body temp

How does the cremaster muscle regulate temperature?

Contracts to elevate testes (warm), relaxes to lower them (cool)

How does dartos fascia regulate temperature?

Changes scrotal surface area (wrinkling vs relaxing skin)

What is the function of the pampiniform plexus?

Countercurrent heat exchange that cools arterial blood entering testes

What is the role of seminiferous tubules?

Site of spermatogenesis

What are the functions of Sertoli (nurse) cells?

Support sperm, secrete ABP (androgen-binding protein), inhibin, maintain blood-testis barrier

What do Leydig (interstitial) cells do?

Produce testosterone in response to LH (luteinizing hormone)

What is inhibin and its function?

Hormone that inhibits FSH (follicle-stimulating hormone) to regulate sperm production

What is spermatogenesis?

Process of producing haploid sperm from germ cells

Where do sperm mature and gain motility?

Epididymis

Pathway of sperm

Seminiferous tubules → efferent ductules → epididymis → ductus deferens → ejaculatory duct → urethra

What is the function of the ductus deferens?

Transports sperm to ejaculatory duct via peristalsis

What is the composition and function of seminal vesicle fluid?

Fructose-rich, alkaline fluid that nourishes sperm (~60% semen)

What is the function of prostate secretions?

Activate sperm and enhance motility (~30% semen)

What is the role of bulbourethral glands?

Secrete mucus to lubricate and neutralize urethral acidity

Mechanism of erection

Parasympathetic → NO release → vasodilation → blood fills erectile tissue

Why does the corpus spongiosum not expand as much?

Prevents compression of urethra

Emission in ejaculation

Semen enters urethra

Expulsion in ejaculation

Semen exits body via muscular contractions

What prevents urine mixing with semen?

Internal urethral sphincter contraction

What is a vasectomy and its effect?

Cutting ductus deferens; sperm still produced but not ejaculated

What is benign prostatic hyperplasia (BPH)?

Enlarged prostate compresses urethra → urinary difficulty

What are the two main regions of the ovary?

Cortex (follicles), medulla (blood vessels)

What is oogenesis?

Formation of haploid ova from germ cells

What is ovulation?

Release of secondary oocyte from follicle

What is the function of fimbriae?

Sweep ovulated egg into uterine tube

How is the egg transported in the uterine tube?

Cilia + smooth muscle contractions

Where does fertilization occur?

Uterine tube

What are the three layers of the uterus?

Perimetrium, myometrium, endometrium

What is the function of the myometrium?

Produces contractions during menstruation and labor

Functional layer of endometrium

Sheds

Basal layer of endometrium

Regenerates

How does cervical mucus change during ovulation?

Becomes thin to allow sperm passage

What is the function of the vaginal low pH?

Prevents pathogen growth

What is the function of the ovarian ligament?

Anchors ovary to uterus

What is the round ligament homologous to?

Gubernaculum

What arteries supply the uterus?

Uterine arteries → arcuate arteries → spiral arteries

HPG (Hypothalamic-Pituitary Gland) axis

Hypothalamus (GnRH - gonadotropin-releasing hormone) → pituitary (FSH - follicle-stimulating hormone, LH-luteinizing hormone) → gonads → sex hormones

What is negative feedback in the HPG axis?

Sex hormones inhibit GnRH (gonadotropin-releasing hormone), FSH (follicle-stimulating hormone), LH (luteinizing hormone) release

What stimulates testosterone production?

LH (luteinizing hormone)

What stimulates spermatogenesis?

FSH (gonadotropin-releasing hormone) and testosterone

What triggers ovulation?

LH (luteinizing hormone) surge

What is the role of estrogen?

Endometrial growth, secondary sex characteristics

What is the role of progesterone?

Maintains uterine lining, prepares for implantation

What initiates puberty?

Increased GnRH (gonadotropin-releasing hormone) secretion

What is leptin’s role in female puberty?

Signals sufficient body fat to initiate GnRH (gonadotropin-releasing hormone) release

What are the phases of the ovarian cycle?

Follicular → ovulation → luteal

What happens during the luteal phase?

Corpus luteum secretes progesterone

What causes menstruation?

Drop in estrogen and progesterone

How is gestation measured?

From first day of last menstrual period (~40 weeks)

What is the function of hCG (human chorionic gonadotropin)?

Maintains corpus luteum early in pregnancy

What happens to the corpus luteum later in pregnancy?

Degenerates as placenta takes over hormone production

What does estrogen do in pregnancy?

Promotes tissue growth and uterine enlargement

What does progesterone do in pregnancy?

Prevents contractions and maintains endometrium

What does relaxin do?

Relaxes pelvic ligaments

How does blood volume change in pregnancy?

Increases ~30–40%

Why does urination increase in pregnancy?

Uterus compresses bladder

What is implantation?

Embryo embedding into endometrium

What is the placenta composed of?

Maternal endometrium + fetal tissue

What is the placental barrier?

Semipermeable membrane for exchange of gases/nutrients

What major development occurs by week 8?

All major organ systems present

When can fetal movement be felt?

Around weeks 17–20

What is the function of the foramen ovale?

Shunts blood from right atrium to left atrium

What is the function of the ductus arteriosus?

Shunts blood from pulmonary trunk to aorta

Why is fetal circulation different?

Lungs are not functional yet

What is an ectopic pregnancy?

Implantation outside uterus (usually tube)

Why is ectopic pregnancy dangerous?

Risk of rupture → internal bleeding/shock

What causes gestational diabetes?

Hormonal changes affecting insulin sensitivity