Histology of the Reproductive System - Brodsky Flashcards
What are the components of the testicular lobules?
Semineferous tubules:
-Functional unit, produces sperm (spermatogenic cells) and hormones (sertoli cells)
-Each lobule contains 1-4 (lobules separated by septa)
Majority of what is seen in a cross-section
Internstitial tissue:
-Contains Leydig cells which produce testosterone
Epididymis:
Sperm maturates and storage
Cross section of the testicle contains the mediastinum (rete testes) and surrounded by tunica albuguinea
What are the properties of sertoli cells?
Support, protect and nourish the spermatogenic cells
Secrete fluid into seminiferous tubules
Form tight junctions with adjacent Sertoli cells, dividing the lumen of the seminiferous tubles into basal and adluminal compartment.
Blood-testis-barrier, protecting developing sperm cells from autoimmune reactions.
They synthesize androgen-binding protein (ABP) under the influence of FSH
ABP assists in testosterone production
Secrete inhibin, that inhibits FSH in pituitary
What are the three phases of spermatogenesis?
1 Spermatocytogenesis Spermatogonia proliverate (mitosis), differentiate to primary spermatocytes
2 Meiosis primary spermatocytes (diploid) differentiate into secondary spermatocytes (haploid)
3 Spermiogenesis
spermatids differentiate
into highly specialized
spermatozoa (sperm)
no cell division
Which hormones from the adenohypophysis regulate the male reproductive system? How?
Luteinizing Hormone (LH): stimulates testosterone production by Leydig cells
Follicle Stimulating Hormone (FSH):
stimulates production of sperm in conjunction with testosterone by regulating activity of Sertoli cells
What is the role of seminal vesicles?
The seminal vesicles secrete a significant proportion of the fluid that ultimately becomes semen. Lipofuscin granules from dead epithelial cells give the secretion its yellowish color.
50-70% of seminal fluid
Not the first part of the ejaculate
Alkaline pH
What is the histological composition of the prostate?
What is its role?
Secretes slightly alkaline fluid, milky or white in appearance
Constitutes 20-30% of the volume of the semen
The prostatic fluid is expelled in the first ejaculate fractions, together with most of the spermatozoa. In comparison with the few spermatozoa expelled together with mainly seminal vesicular fluid, those expelled in prostatic fluid have better motility, longer survival and better protection of the genetic material (DNA).
The prostate also contains some smooth muscles that help expel semen during ejaculation.
Composed of simple or pseudostratified columnar epithelium
30-50 tubuloalveolar glands emptying into urethra
Rich in citric acid, phosphatase, and proteolytic enzymes
What are the contents of the ovaries?
OOGONIA (7 million at 5th fetal month), undergo mitosis, big pool of precursors which reduce with time. During the cycle only a few develop and only one will beecome the oocyte and be expelled during ovulation. Differentiate into: Primary OOCYTES (1 million at birth) at birth arrested at Meiosis I
Primordial Follicles (400,000 at menarche): Oocytes surrounded by squamous (flat) cells
Corpus luteum is leftovers of ovulation (yellow body)
After ovulation stays behind to secrete hormones (contains granulosa and theca cells)
When spent, will become the corpus albicans
What are the stages in growing follicles (unilaminar to secondary follicle) and what are their properties?
Unilaminar primary follicle:
- follicular cells still unilaminar but now cuboidal (used to be squamous)
Multilaminar primary follicle:
- multilaminar follicular layer, composed of granulosa cells
- zona pellucida, composed of glycoproteins
- surrounding stromal cells differentiate into theca
Secondary (antral) follicle:
- cavities appear between granulosa cells forming an antrum
- formation of cumulus oophorus and corona radiata (together is the antrum, accompanies oocytes at ovulation)
What are the two layers of endometrium and what are their functions?
FUNCTIONAL LAYER (stratum functionalis)
- BORDERS UTERINE LUMEN
- SLOUGHED OFF AT MENSTRATION (due to ischemia of spiral arteries)
Thickens in secretory phase
(2) BASAL LAYER
(stratum basale)
- RETAINED AT MENSTRATION
- SOURCE OF CELLS FOR REGENERATION OF FUNCTIONAL LAYER
What are the types of estrogen and when are they primarily secreted?
E1, a type of estrogen, is the most active estrogen in the nonpregnant female.
E3 (estriol) is the major estrogen in the pregnant female. It is produced in the placenta.
Estrogen controls the growth of the lining of the uterus during the first part of the menstrual cycle, cause breast development in pregnancy and regulates various metabolic processes.
What are the glands of the genitals?
Lesser Vestibular (Paraurethral, Skene's) : Male Homolog = prostate located on the upper wall of the vagina, around the lower end of the urethra. They drain into the urethra and near the urethral opening Function - mucus production to aid lubrication during intercourse
Greater Vestibular (Bartholin’s): Male Homolog = bulbourethral glands located slightly below and to the left and right of the opening of the vagina. They secrete mucus to provide lubrication, especially when the woman is sexually aroused
