REPRODUCTIVE SYSTEM

Testes

Contain spermatogenic stem cells that continuously divide to produce new generations of cells.

Epididymis

Responsible for storage and maturation of sperm.

Spermatogenesis

The process by which sperm are produced in the testes.

Countercurrent heat-exchange mechanism

A mechanism that maintains lower temperature in the testes by cooling arterial blood with venous blood.

Tunica albuginea

The thick connective tissue capsule that surrounds each testis.

Seminiferous tubules

Coiled tubules within the testes where spermatogenesis occurs.

Spermiogenesis

The transformation of spermatids into mature sperm cells.

Acrosome

A specialized type of lysosome that contains enzymes assisting sperm in penetrating the oocyte.

Corpus luteum

The temporary endocrine organ formed after ovulation that secretes hormones.

Luteinizing hormone (LH)

Hormone that stimulates testosterone production in Leydig cells.

Follicle-stimulating hormone (FSH)

Stimulates Sertoli cells for sperm maturation and androgen-binding protein secretion.

Blood-testis barrier

Formed by tight junctions of Sertoli cells to protect developing sperm from the immune system.

Corpus albicans

The degenerated form of the corpus luteum.

Maturation of sperm

The final stages where spermatids are transformed into sperm and released into the seminiferous tubules.

Prostate gland

Accessory gland that contributes to semen production.

Seminal vesicles

Glands that produce a fluid that nourishes and activates sperm.

Bulbourethral glands

Glands that provide lubrication for the penile urethra.

Penile urethra

The passage through which sperm and urine exit the male body.

Oocyte

An immature egg cell released from the ovaries during ovulation.

Endometrium

The inner lining of the uterus that thickens during the menstrual cycle.

Sertoli cells

Supportive cells in seminiferous tubules that nourish developing sperm.

FSH receptors

Receptors on follicular cells that respond to follicle-stimulating hormone.

Atresia

The process by which non-dominant follicles degenerate.

Hormonal regulation of menstruation

Cycles controlled by FSH and LH from the pituitary gland.

Primary oocytes

Immature egg cells arrested in the first meiotic division.

Vitamin D

Hormone mentioned as necessary for several physiological functions.

Human chorionic gonadotropin (hCG)

Hormone produced by the placenta that maintains the corpus luteum during pregnancy.

Menstrual cycle phases

The three phases of the menstrual cycle are the proliferative, secretory, and menstrual phases.

Menarche

The onset of the first menstrual cycle.

Menopause

The end of the menstrual cycles in a woman.

Functional layer of endometrium (stratum functionalis)

The layer that is shed during menstruation.

Basal layer of endometrium (stratum basalis)

The layer that remains intact during menstruation and serves as a source for regeneration.

Testes

Contain spermatogenic stem cells for sperm production.

Epididymis

Storage site for mature sperm

Ductus deferens

Tube transporting sperm from epididymis.

Penile urethra

Final passage for sperm and urine.

Accessory glands

Include prostate, seminal vesicles, bulbourethral glands.

Scrotum

External pouch housing the testes

Spermatogenesis

Process of sperm production.

Pampiniform plexus

Vein network cooling testicular arteries.

Countercurrent heat-exchange

Mechanism cooling arterial blood before testes.

Tunica albuginea

Connective tissue capsule surrounding each testis.

Mediastinum testis

Thickened tunica albuginea extending inward.

Septum

Connective tissue dividing each testis into compartments.

Testicular lobules

250 compartments containing seminiferous tubules.

Seminiferous tubule

Lined with germinal epithelium for sperm development.

Sertoli cells

Support spermatogenic cells in seminiferous tubules.

Interstitial cells

Secrete testosterone, crucial for sperm formation.

Spermatids

Cells with 23 single chromosomes from meiosis.

Spermiogenesis

Transformation of spermatids into mature sperm.

Intercellular bridges

Connect spermatogenic cells during differentiation.

Acrosome

Lysosome-like structure aiding sperm penetration.

Golgi phase

Formation of acrosomal granule in spermatid.

Acrosomal phase

Acrosome forms at spermatid's anterior tip.

Maturation phases

Development of sperm tail and mitochondria arrangement.

Final maturation phase

Shedding excess cytoplasm, releasing sperm into lumen.

Mature sperm cell

Composed of head, neck, middle piece, principal piece.

Excurrent ducts

Pathway for sperm from seminiferous tubules to urethra.

Seminiferous tubules

Site of sperm production and testosterone synthesis.

Straight tubules

Initial ducts leading from seminiferous tubules.

Rete testis

Epithelial-lined spaces in mediastinum testis.

Ductuli efferentes

Conduct sperm from rete testis to epididymis.

Ductus epididymis

Duct conducting sperm to penile urethra.

Ejaculatory ducts

Formed in prostate, carry sperm to urethra.

Spermatogonia

Stem cells that undergo mitosis to form sperm.

Testosterone

Hormone crucial for male sexual characteristics.

Meiotic divisions

Reduce chromosome number, forming spermatids.

Phagocytosis

Process by Sertoli cells to remove excess cytoplasm.

Spermiation

Release of mature sperm into seminiferous tubules.

Androgen-binding protein (ABP)

Binds testosterone, increasing its concentration in tubules.

Inhibin

Hormone that suppresses FSH release from pituitary.

Anti-Müllerian hormone

Inhibits female reproductive organ development in males.

Blood-testis barrier

Prevents autoimmune response and protects developing sperm.

Tunica vasculosa

Vascular layer of loose connective tissue in testis.

Septa

Partitions dividing testis into lobules.

Lobules

Compartmental sections of the testis.

Germinal Epithelium

Stratified epithelium lining seminiferous tubules.

Spermatogenic Cells

Cells producing sperm within seminiferous tubules.

Luteinizing Hormone (LH)

Stimulates testosterone production by Leydig cells.

Follicle-Stimulating Hormone (FSH)

Stimulates Sertoli cells to support spermatogenesis.

Fibroblasts

Cells providing structural support in testis.

Pale Type A Spermatogonia

Light-staining immature sperm cells with ovoid nuclei.

Cilia

Hair-like structures aiding movement in ductuli efferentes.

Microvilli

Small projections enhancing absorption in ductuli efferentes.

Basement Membrane

Thin layer supporting seminiferous tubules.

Type A Spermatogonia

Dark chromatin, serve as stem cells.

Type B Spermatogonia

Develop into primary spermatocytes.

Primary Spermatocytes

Largest germ cells in seminiferous tubules.

Secondary Spermatocytes

Formed from primary spermatocytes, undergo meiosis.

Pseudostratified Columnar Epithelium

Lining of ductus epididymis and ductus deferens.

Principal Cells

Tall columnar cells with stereocilia in epididymis.

Basal Cells

Small spherical cells at the base of epithelium.

Irregular Lumen

Characteristic of ductus deferens structure.

Fibromuscular Tissue

Surrounds seminiferous tubules in testes.

Meiotic Division

Process producing haploid spermatids from diploid cells.

Connective Tissue

Supports and surrounds ductuli efferentes and tubules.

Smooth Muscle Layer

Surrounds ductuli efferentes and ductus epididymis.

Stereocilia

Nonmotile microvilli on principal cells of epididymis.

Lamina Propria

Thin connective tissue layer with collagen and elastic fibers.

Muscularis

Three smooth muscle layers in ductus deferens.