Reproductive System Histology Flashcards
Describe the functions of the reproductive system. What are the roles for the male? What are the roles for the female?
Reproductive Systems
- Goal is to make next generation so species can survive
Men
- Goal is production of sperm for delivery of female
Women
- Production of eggs
- Provide location for fertilization
- Provide location/support for embryonic development
Discuss the role of the male gonads – include a description of the endocrine and exocrine functions of the male gonads. What are the male gonads and gamete? Why are the male gonads found in the scrotum?
Male gonads:
- Testes,
Male Gametes
- sperm
Endocrine portion:
- Steroidgenesis
- produce testosterone ii.
Exocrine Portion:
- Spermatogenesis
- production of sperm
Testes are located in the scrotum because they must be kept at 34* C for optimal sperm production, lower than 37*C of rest of body
Describe and identify the gross and histological features of the testes.
Tunica Vaginalis
- Outer layer of testes/spermatic cord
Tunica Albuginea
- white covering of testes
Seminiferous Tubules:
- Produce sperm cells
Rete Testes
- Straight lines from seminiferous tubules → epididymis
Epidiymis
- Head, body, tail →ductus deferens
- Discuss and histologically identify the cells of the testes. Be sure to discuss spermatogenesis and spermiogenesis
Leydig Cells:
- outside seminiferous tubules, are supporting cells
- Endocrine portion
- lots of smooth ER, produce testosterone
Inside Seminiferous Tubules
- Sertoli Cells: supporting cells, attached to basal lamina and extend throughout all cells
- Spermatogenic cells
- Spermatogonia
* Type A (dark/light), and
* Type B b. Primary spermatocytes
* Secondary Spermatocytes
* Spermatids
- Spermatogonia
- c. Spermatogenesis:
- Type A Spermatagonia: undergo a lot of mitosis, ii.
- Type B Spermatagonia: continue to undergo mitosis, grow to become: iii.
- Primary spermatocytes:
- Meiosis I to become
- Secondary Spermatocytes:
- Meiosis II to become Spermatids
- Secondary Spermatocytes:
- Meiosis I to become
- Primary spermatocytes:
- Spermiogenesis
- Spermatids, then differentiate into mature spermatozoa, leaving behind some residual bodies
Trace, locate, histologically identify, and discuss the intratesticular and excretory genital ducts of the male.
a. Intratesticular Ducts;
- Straight Tubules: lined with only sertoli cells ii. →
- Rete Testis: network of channels lined w/ cuboidal epithelium iii. →
- Efferent Ductules: psudedostratified columnar epithelium
Excretory Genital Ducts
- Epididymis: highly coiled, stereocilia, maturation of sperm occurs here
- Ductus deferens:
- Narrow lumen
- Thick muscular wall (3 layers)
- Ampulla
- Ejaculatory duct: seminal vescicles + ductus deferens → prostatic urethra
- Urethra
- Prostatic: urothelium
- Membranous: pseudostratified/stratified columnar epithelium
- Spongey: pseudostratified/stratified columnar → stratified sqamous epithelium
Locate, histologically identify, and discuss the male accessory reproductive glands
- Seminal Vesicle:
- very torutuous glands with 1 lumen
- empties into ejaculatory duct
- Prostate:
- empties into prostatic urethra
- Has notable concretions.
- Bulbourethral Glands (cowper’s glands)
- Empty into proximal part of spongey urethra
Discuss and identify the anatomy, histology, and function of the male copulatory organ (i.e. the penis).
Function:
- deliver sperm to female reproductive tract ii.
Structure:
- 3 cylinders of erectile tissue – fill with blood
- dorsal paired cylinders
- corposa cavernosium
- 1 ventral cylinder
- corpus spongiosum
- surrounds spongey urethra
- corpus spongiosum
- dorsal paired cylinders
Discuss the role of the female gonads. What are female gonads and gamete?
The female gonads: ovaries
two functions:
- Endocrine function
- produce estrogens and progestogens; steroidogenesis.
- Estrogens – promote the growth and maturation of internal and external sex organs; promote cyclic changes in uterine mucosa; development of the secondary female sex characteristics; promote breast development.
- Progestogens – prepare internal sex organs (primarily uterus) for pregnancy by promoting changes in endometrium; prepare mammary glands for lactation.
- produce estrogens and progestogens; steroidogenesis.
- Exocrine function, as the ovaries produce the female gamete (i.e. ovum); gametogenesis;
- ovaries produce and ovulate a secondary oocyte.
The ovaries & testes have the same embryological origin.
Theca Folliculi or Follicular Theca
Theca folliculi or the follicular theca
- sheath of CT cells
- develop from stromal cells surrounding the developing follicle.
- External to the basal lamina
- Differentiates into two parts:
- Theca interna
- cuboidal secretory cells;
- in response to LH,
- synthesize and secrete androgens (i.e. precursors of estrogen);
- endocrine function:
- also fibroblasts, collagen bundles, and lots of blood vessels.
- Theca externa
- fibrous outer portion
- smooth muscle cells, fibroblast, and bundles of collagen
- Theca interna
Discuss the process of follicular growth and ovulation, as well as histologically identify the different components involved.
autocrine/paracrine system
Essential Organs of the Reproductive System:
Gonads
- produce germ cells or gametes;
- gametes have only half the normal chromosome number as other body cells;
- 23 chromosomes (n number or haploid) vs. 46 chromosomes (2n or diploid).
- Of Males: Testes
- Of Females: Ovaries
Ovarian follicles
- found within the cortex of the ovaries.
- composed of an oocyte surrounded by one or more layers of epithelial cells.
- follicles are of various sizes
- size indicates the developmental state of the oocyte.
- Three basic types of ovarian follicles:
- Primordial follicles
- Growing follicles
- Primary follicles
- Secondary (Antral) follicles
- Mature or Graafian follicles
- Primordial Germ Cells → Oogonia → Primary Oocyte
Five million ovarian follicles in fetus; reduced to 600,000 to 800,000 at birth; reduced to 300,000 at beginning of puberty; only ~ 400 ovulated; most lost via atresia.
Corpus Luteum
Two Cells of the Corpus Luteum:
- Granulosa lutein cells
- undergo hypertrophy; 30 μm in diameter;
- centrally located cells derived from the granulosa cells
- begin to produce progesterone.
- Theca lutein cells
- only increase slightly in size; 15μm in diameter;
- peripherally located cells
- derived from cells of the theca internal;
- are slightly darker-staining than the granulosa lutein cells;
- continue to produce estrogens.
Uterine Tubes (a.k.a. Fallopian Tubes or Oviducts)
- Paired muscular tubes, 12 cm in length
- Where fertilization takes place
- Wall is folded mucosa with simple columnar epithelium, a thick muscularis (interwoven layers of smooth muscle), and serosa
- Two types of cells:
- Ciliated cells
- cilia to help move oocyte towards uterus
- Secretory cells (a.k.a. peg cells)
- darker staining; apical end budges into lumen; produce nutritive fluid covering epithelium
- Ciliated cells
the Uterus
Three Layer of the Uterus:
- Perimetrium
- outer connective tissue layer; either adventitia or serosa.
- Myometrium
- middle layer and thickest layer; bundles of smooth muscle separated by connective tissue containing many blood vessels; four poorly defined layers of smooth muscle.
- Endometrium
- inner layer; simple columnar epithelium with both ciliated and secretory cells with an underlying lamina propria; contains uterine glands.
Two parts:
- Basal Layer
- deeper layer
- Functional Layer
- superficial layer; thickness of functional layer changes influenced by the shifting levels of ovarian hormones and majority can be sloughed away monthly as the menstrual flow.
Vagina (a.k.a. Vaginal Canal)
- Wall has a mucosa, a muscular layer, and an adventitia.
- Mucosa consists of nonkeratinized stratified squamous epithelium
- Muscular layer has two indistinct layers of smooth muscle; inner circular and outer longitudinal
