Week 6: Repro Histology Flashcards
tunica albuginea
tough CT covering over each testis
lobules of testis
- fibrous sept divide it into 250-300 lobules
* each lobule has 1-4 seminiferous tubules
rete testis
•network of channels that collects products of seminiferous epithelium
seminiferous tubules produce
sperm, secretory proteins, and ions
space between seminiferous tubules filled with
abundant blood vessels and aggregates of andogen producing Leydig cells
Leydig cells respond to ___ and produce___
LH; testosterone
2 distinct cell populations in seminiferous epithelium
- somatic Sertoli cells
2. spermatogenic cells
Sertoli cells
- columnar epithelium containing light staining nutrients with a prominent nucleus
- connected by tight junctions to form basal and adluminal compartment within the tubule
“blood-testis barrier”
- tight junctions between Sertoli cells are components
* protects developing spermatogenic cells within adluminal compartment from autoimmune reactions
other functions of sertoli cells
- phagocytose residual germ cell cytoplasm
- regulate release of mature spermatozoa
- secrete andogen binding protein (ABP) in response to FSH stimulation
Andogen binding protein (ABP)
functions to concentrate testosterone produced by the leydig cells in the seminiferous tubules to stimulate spermatogenesis
Spermatogenic cells include
spermatogonia, spermatocytes, and spermatids
spermatagonia
- diploid stem cells of the testis
- small dense oval nuclei and are closely associated with seminiferous tubular wall
- divide by mitosis to generate 2 daughter cells
spermatogonia that enter the spermatogenesis cell sequence
divide and give rise to primary speramtocytes (also diploid)
secondary spermatocytes
•haploid cells
•primary spermatocytes enter meiosis I to give rise to these
they differentiate into haploid spermatids during meiosis II
primary and secondary spermatocytes in H and E sections
- indistinguishable from one another
- will be located far from tubular wall within adluminal compartment
- have large nuclei containing dark-staining chromatin
spermatids in H and E sections
- even closer to the lumen of the tubule
* identified by small dense dark staining nuclei that dan appear round in early spermatids and oblong in late spermatids
spermatogenesis
- process of sperm cell development
* seminiferous epithelial cells undergo successive mitotic and meiotic divisions to produce spermatozoa
spermiogenesis
- last step of spermatogenesis
* spermatids undergo dramatic change in form to become the streamline spermatozoa adapted for fertilization
changes to spermatids in spermiogenesis
- nuclear condensation
- formation of acrosomal cap
- development of tail
sperm are nonmotile until
they mature in the epididymis where they acquire forward motility
epididymis consists of
- highly elongated coiled tubules where sperm mature and are stored
- classically divided into head, body, and tail
epithelium of epididymis
•pseudostratified columnar with long and branched stereocilia
•two major cell types:
1. columnar principle cells from lumen to basal lamina; their apical domain display branched stereocilia
2. basal cells associated with basal lamina regarded as the precursors of the principle cells (stem cells)
smooth muscle of epididymis
- head surrounded by smooth circular muscle
* body and tail have an increased thickness of smooth circular plus an outer longitudinal smooth muscle layer
vas deferens
- continuous with epididymis
- lined by pseudostratified columnar with stereocilia and supported by CT lamina propria with elastic fibers
- muscular wall has inner and outer longitudinal muscle separated by a middle circular layer
- external layer has loose CT and adipose cells
ampulla of vas deferens
leads directly into the prostate gland and fused with the duct of the seminal vesicle, forming the ejaculatory ducts that empty into the prostatic urethra
prostate
- largest accessory reproductive gland
* 30-50 branched tubuloalveolar glands that empty contents into prostatic urethra
glands of prostate are surrounded by smooth muscle cells and CT and are arranged into 3 specific zones
- transition zone closes to and surrounding the prostatic urethra
- central zone
- a peripheral zone
prostate glands are lined with
- combination of simple and pseudostratified columnar epithelium
- lumen of glands often contain concretions (corpora amylacea) rich in glycoproteins that are sometimes a site of calcium deposition
glands of prostate produce
zinc-rich alkaline fluid that neutralizes the acidity of the vagina, provides nutrients, transports sperm, and liquefies semen
benign prostate hyperplasia (BPH)
- condition that occurs with aging
- enlargement of prostate that can restrict flow of urine through prostatic urethra
- the cells and stroma of the periurethral central and transitional zones are involved