Male Reproductive System - Vocabulary Flashcards

Vocabulary flashcards covering key structures, cells, hormones, processes, and functions of the male reproductive system as described in the lecture notes.

Gonads

Primary sex organs; in males this refers to the testes, which produce sperm and androgens.

Testes

Male gonads where spermatogenesis occurs and testosterone is produced.

Epididymis

Coiled duct on the posterior surface of the testis where sperm mature and are stored; has head, body, and tail.

Efferent ductules

Passages that transport sperm from the testis to the epididymis, aided by cilia.

Ductus deferens (vas deferens)

Muscular duct that carries sperm from the epididymis to the urethra; includes the ampulla.

Ampulla of the ductus deferens

Expanded region of the ductus deferens just before the seminal vesicle junction, where sperm begin to mix with seminal fluids.

Seminal glands (seminal vesicles)

Glands that produce most of the semen volume; fluids contain fructose, citrate, and prostaglandins.

Prostate gland

Gland that produces prostatic fluid, contributing to about a quarter of semen volume.

Bulbourethral glands (Cowper’s glands)

Glands that secrete thick, alkaline mucus to neutralize acids and lubricate the penis tip.

Semen

Fluid containing sperm and secretions from the seminal glands, prostate, nurse cells, and epididymis.

Seminiferous tubules

Tightly coiled tubes in the testes where spermatogenesis occurs; contain germ and supporting cells.

Sertoli cells (nurse cells)

Support germ cell development, form the blood-testis barrier, and secrete inhibin and ABP.

Blood-testis barrier

Tight junctions between Sertoli cells that protect developing germ cells from immune attack.

Interstitial (Leydig) cells

Cells located between seminiferous tubules that produce testosterone.

Testosterone

Male sex hormone; stimulates spermatogenesis and secondary sex characteristics; provides negative feedback to GnRH and gonadotropins.

Gonadotropin-releasing hormone (GnRH)

Hormone released by the hypothalamus that stimulates the anterior pituitary to secrete FSH and LH.

FSH (follicle-stimulating hormone)

Pituitary hormone that stimulates Sertoli cells to support spermatogenesis and ABP production.

LH (luteinizing hormone)

Pituitary hormone that stimulates Leydig cells to secrete testosterone.

Androgen-binding protein (ABP)

Protein from Sertoli cells that binds testosterone to maintain high intratubular testosterone levels.

Inhibin

Hormone from Sertoli cells that inhibits FSH secretion via negative feedback.

Spermatogonia

Diploid germ cells on the basement membrane of seminiferous tubules that divide by mitosis to form more spermatogonia and primary spermatocytes.

Primary spermatocyte

Diploid cell derived from a spermatogonium that undergoes meiosis I.

Secondary spermatocyte

Haploid cell produced after meiosis I that undergoes meiosis II to form spermatids.

Spermatid

Haploid cell produced by meiosis II that matures into a spermatozoon during spermiogenesis.

Sperm (spermatozoon)

Mature male gamete with a head (nucleus and acrosome), midpiece (mitochondria), and tail (flagellum).

Spermiogenesis

Final maturation step in which spermatids become mature spermatozoa, shedding cytoplasm and forming the tail and acrosome.

Meiosis I

First meiotic division; homologous chromosomes separate, forming two haploid secondary spermatocytes with recombined genetic material.

Meiosis II

Second meiotic division; sister chromatids separate to form four haploid spermatids.

Mitosis

Cell division that produces two genetically identical diploid daughter cells; precedes meiosis in spermatogenesis.

Capacitation

Physiological changes sperm undergo in the female reproductive tract that enable fertilization.

Erection

Parasympathetic-mediated relaxation of penile arteries and dilation of erectile tissues, leading to penile rigidity.

Emission

Sympathetic-driven peristaltic movement that moves semen into the prostatic urethra.

Ejaculation

Rhythmic contractions of pelvic floor muscles expel semen through the urethra; sphincters regulate flow.

Corpora cavernosa

Two dorsal erectile tissues that fill with blood during erection.

Corpus spongiosum

A single erectile tissue surrounding the urethra; helps keep the urethral opening open during erection.

Tunica albuginea

Dense connective tissue sheath surrounding the corpora cavernosa and forming a rigid support.

Tunica vaginalis

Serous covering of the testes with parietal and visceral layers.

Scrotum

Sac that houses the testes; composed of skin, dartos muscle, fascia, cremaster muscle, and tunica vaginalis; helps regulate temperature.

Cremaster muscle

Skeletal muscle that elevates the testes to regulate temperature; part of the spermatic cord system.

Dartos muscle

Smooth muscle that wrinkles the scrotal skin to reduce heat loss or gain.

Pampiniform plexus

Venous network surrounding testicular arteries that cools arterial blood to protect sperm viability.

Spermatic cord

Cord containing the ductus deferens, vessels, nerves, and lymphatics that travels through the inguinal canal.

Rete testis

Network of ducts that connect seminiferous tubules to efferent ductules.

Prostatic urethra

Part of the urethra that passes through the prostate; receives secretions from the prostate.

Membranous urethra

Segment of the urethra between the prostate and the penis surrounded by muscle.

Spongy (penile) urethra

Longest segment of the urethra within the penis; carries urine and semen.

Semen volume and composition

Typically 2-5 mL per ejaculation; 20-100 million sperm/mL; semen contains sperm and secretions from seminal vesicles, prostate, nurse cells, and epididymis; secretions provide energy, protection, and motility cues.

Semen fluid components (fructose, citrate, prostaglandins)

Nutrients and signaling molecules in semen that nourish sperm, stimulate motility, and facilitate transport.

Capacitation vs fertilization

Capacitation is the functional activation of sperm in the female tract, enabling fertilization capability.

Prostate cancer and BPH

Common male prostate disorders; BPH is benign enlargement; cancer is a major cancer risk in older men.