Reproductive System Anatomy and Physiology

Male Reproductive System

• Key goal: Read the presentation, and then try to do quizzes.
• Important Male Reproductive functions/organs needing attention.
• Location to be noted
• Important Male organs and functions to be noted.

Sexual Reproduction

• Involves two parents creating genetically unique offspring.
• Gametes include:
  • Sperm (small, motile, primarily DNA)
  • Egg (large, nutrient-rich)
• Humans are classified by chromosomes (XY for males, XX for females).

Reproductive System Overview

• The female system produces eggs, receives sperm, supports fertilization, and harbors the fetus.
• The male system produces sperm and delivers them.
• The process takes 128 days.
• Kidneys, after puberty, constantly generate sperms.
• The locations of the female reproductive organs are:
  • Fallopian tubes
  • Ovaries
  • Uterus
  • Cervix
• The locations of the male reproductive organs are:
  • Testes
  • Epididymis
  • Vas deferens
  • Seminal vesicles
  • Prostate gland
  • Urethra
  • Penis

Reproductive System Overview (continued)

• The male and female reproductive systems work together.
• The male reproductive system produces sperm, which are delivered to the female reproductive system.
• The female reproductive system receives and supports the development of a fertilized egg.
• This process results in a new human being.

Reproductive System Overview (continued)

• Main organs, their functions, passage, Generates eggs and sperm
• The male system produces and delivers sperm.
• The female system produces eggs and receives sperm.

Egg Cell Larger Than Sperm

• Female egg cells are larger than male sperm cells.

Male Genital Organs

• The bladder is connected to the urethra through the prostate.
• The urethra carries urine to the outside and is also part of the reproductive system.

Male Perineum

• Details about the male perineum, including anatomical regions and surface topography.

Scrotum

• The scrotum houses the testes
• It is divided into two compartments by an internal septum, marked externally by the perineal raphe.
• Cremaster and dartos muscles regulate temperature.
• Pampiniform plexus also cools arterial blood.

Scrotum (continued)

• The cord passes through the inguinal canal into the pelvic cavity.

Scrotum (continued)

• The scrotum regulates testicular temperature to 35°C.
• Mechanisms include cremaster muscle, dartos muscle, and pampiniform plexus.

Testis

• Oval organs (measuring 4 cm x 3 cm x 2.5 cm).
• Covered by the tunica vaginalis and albuginea capsule.
• Internally, connective tissue septa divide into lobules containing seminiferous tubules.

Testis (continued)

• The location where sperm are produced and partially mature
• The testes develop near the kidneys during the abdominal phase.
• During the inguinal phase, the testes move through the inguinal canal into the scrotum.
• They are typically in the scrotum by birth.

Testis (continued)

• Seminiferous tubules are lined with germinal epithelium and sustentacular cells (Sertoli).
• Sustentacular cells nourish sperm, form the blood-testis barrier, and secrete inhibin/androgens.
• Interstitial cells (Leydig) secrete testosterone.
• Rete testis is a network for sperm transport.

Testis (continued)

• Arterial supply from the testicular artery (low blood flow, low oxygen).
• Venous drainage by the pampiniform plexus which cools arterial blood.
• Veins drain into the inferior vena cava (right) and left renal vein (left).

Ducts

• Efferent ductules, duct of the epididymis, ductus deferens (vas deferens) and ejaculatory duct.
• These tubes are important for sperm transport, maturation, and delivery.
• Unused sperm are resorbed
• The sperm takes 40-60 days to mature.

Ducts (continued)

• Ejaculatory duct: Formed from the union of the ductus deferens and seminal vesicle duct.
• Empties into the urethra.
• Urethra: Shared by urinary and reproductive systems (prostatic, membranous, spongy).
• During ejaculation, the internal urethral sphincter prevents urine and semen mixing.

Accessory Glands

• Seminal vesicles, prostate gland, and bulbourethral (Cowper's) glands provide fluids nourishing sperm during ejaculation.

Penis

• Deposits semen into the vagina.
• The penis is composed of erectile tissues (corpus spongiosum, corpora cavernosa).
• Erection is due to increased blood flow into the erectile tissues.

Penis (continued)

• The shaft and glans are external parts, and the root and erectile tissues are internal.
• Blood supply through internal pudendal arteries, via dorsal and deep arteries.
• Deep arteries dilate, filling lacunae, causing swelling and elongation (parasympathetic activation).

Female Reproductive System

• Title of the lecture for the female reproductive system.

Reproductive System Overview (continued)

• The female and male have analogous organ systems.

Ovary

• Produces egg cells (ova) and sex hormones.
• Approximately 3 cm x 1.5 cm x 1 cm.
• Located in the ovarian fossa of the posterior pelvic wall.
• Has a tunica albuginea capsule.

Ovary (continued)

• Has internally connective tissue septa, into lobules containing seminiferous tubules.
• Medulla, contains fibrous tissue, with arteries and veins.
• Cortex, houses ovarian follicles, where eggs develop.

Ovary (continued)

• Ovaries are supported by ovarian ligament, suspensory ligament and mesovarium.
• The ovaries receive blood from the ovarian branch of the uterine artery and ovarian artery.

Ovary (continued)

• Oogenesis is the process of egg production in females, while spermatogenesis is the process of sperm production in males.
• Oogenesis is a rhythmic process called the ovarian cycle.
• Oogenesis produces one functional gamete from an oogonium (while other daughter cells become polar bodies and degenerate).

Ovary (continued)

• Ovulation occurs around day 14 of the menstrual cycle and lasts around 2-3 minutes
• Follicle Rupture (a stigma forms on the ovarian surface, the mature follicle releases the oocyte).
• Corpus Luteum Formation (the ruptured follicle collapses and fills with granulosa and theca interna cells).

Ovary (continued)

• If no pregnancy, the corpus luteum undergoes involution becoming a corpus albicans.
• If pregnancy occurs, the corpus luteum stays active.
• These ovarian events are synchronized with uterine changes.

Uterine Tubes

• The ovulated oocyte enters the uterine tube.
• The uterine tube has four parts: infundibulum, ampulla, isthmus , and mesosalpinx.
• The function of the uterine tube is to propel the oocyte toward the uterus.

Uterus

• The uterus is a thick, muscular chamber and is tilted forward over the bladder.
• Its primary functions are to harbor the fetus, provide nutrition via the placenta, and expel the fetus at the end of gestation.

Uterus (continued)

• There are three layers in the uterine wall: perimetrium, myometrium, and endometrium.
• The perimetrium is the outer serosa, while the myometrium is the thick middle layer of smooth muscle. The endometrium is the inner mucosa, and is divided into a functional layer (shed during menstruation) and a basal layer (regenerates the functional layer).

Uterus (continued)

• The uterus is supported by the muscular floor of the pelvic outlet and peritoneal folds (broad ligament, containing mesosalpinx and mesometrium).
• Cardinal ligaments support the cervix and upper vagina.
• Uterosacral ligaments attach the uterus to the sacrum.
• Round ligaments extend from the uterus to the labia majora via the inguinal canals.

Uterus (continued)

• The peritoneum creates two key pouches: vesicouterine and rectouterine pouches.
• The uterine blood supply is crucial for the menstrual cycle and pregnancy, coming from branches of the internal iliac artery.
• Smaller branches called arcuate arteries extend through the myometrium, forming spiral arteries.

Uterus (continued)

• The uterine histology changes throughout the average 28-day menstrual cycle.
• The cycle consists of proliferative, secretory, and premenstrual phases, where endometrial tissue is rebuilt, thickens, and eventually sheds.

Vagina

• 8-10 cm tube with roles in menstrual discharge, intercourse, and childbirth.
• Distensible wall with three layers (adventitia, muscularis, mucosa).
• Lacks glands, lubricated by transudation and cervical mucus.
• Surrounds the cervix with blind spaces (fornices).

Vagina (continued)

• Rugae: Transverse ridges that enhance stimulation during intercourse.
• Hymen: Membrane at the vaginal orifice, often ruptured during intercourse.
• Epithelium: Simple cuboidal (childhood) to stratified squamous (puberty), producing glycogen and maintaining a low pH to inhibit pathogens.

External Genitalia

• The external female genitalia or vulva includes several structures:
  • Mons pubis
  • Labia majora
  • Labia minora
  • Clitoris

Homologous Organs in Genital System

• Homologous structures arise from the same embryonic tissue and adapt to male or female functions in the reproductive system.

Test your knowledge of key concepts in reproductive system anatomy and physiology with this quiz. Questions cover arterial supply, sperm maturation, and the menstrual cycle, offering a comprehensive overview of essential functions and structures. Ideal for students of anatomy and physiology.