Male Reproductive Histology Flashcards
(75 cards)
The testes are posteriorly associated with the epididymis and both are suspended by the ______
The testes are enclosed by the _________, which thickens to form the mediastinum, where the _______ is located
Spermatic cord
Tunica albuginea; rete testis
Septa form 250-300 _____ within the testes, each with 1-4 _______ ______
Lobules; seminiferous tubules
Seminiferous tubules consist of a central lumen lined by a specialized seminiferous epithelium, composed of _______ and _______ cells
Somatic sertoli; spermatogenic
The ____ _____ is a network of spaces contained within the CT of the mediastinum
Rete testes
Epithelium of the seminiferous tubules is surrounded by a _____ _____ consisting of multilayered CT, collagen, and 3-5 layers of myoid cells
Lamina propria
________ cells are found in between the seminiferous tubules
Leydig (interstitial)
The wall of seminiferous tubules consists of peritubular _____ cells separated from the seminiferous epithelium by a basement membrane
Myoid
Seminiferous epithelium is _________ epithelium with unusual characteristics. It is made up of _____ ______ sertoli cells which interact with ______, ______, and _____
Stratified; somatic columnar; spermatogonia; spermatocytes; spermatids
Of the cells that somatic columnar sertoli cells interact with:
____ are mitotic
_____ are meiotic
_______ are haploid, and undergoing spermatogenesis
Spermatogonia
Spermatocytes
Spermatids
The seminiferous epithelium houses different structural types of nuclei:
Nuclei of ______ and _______ are closely associated with tubular wall
Nuclei of _________ cells are larger and contain clumps of chromatin
Nuclei of _______ are round and light
Nuclei of ________ are cylindrical, and condensed
Spermatogonia; sertoli cells
Spermatogonial cells (primary spermatocytes)
Early spermatids
Late spermatids
[note that early and late spermatids’ nucli lie close to the lumen]
_____ cells extend the full thickness of the seminiferous epithelium, and the nucleus is basally located with a large nucleolus
Sertoli
Sertoli cells’ apical and lateral membranes have an irregular outline - why?
To provide niches and crypts to hous developing spermatogenic cells
Functions of sertoli cells:
- support, protect, and nourish developing spermatogenic cells
- eliminate _________ via phagocytosis (discarded by spermatids during _______)
- release of mature spermatids into lumen of tubule in process called ________
Residual bodies; spermiogenesis
Spermiation
On micrographs, sertoli cells have _____ or ______ nuclei and distinct ______
Oval; pyramidal; nucleoli
At basolateral domain, sertoli cells have tight junctions creating ______ and _______ compartments (this is special to the testes as usually it is an apical specialization)
Basal; adluminal
In the basal compartment of seminiferous epithelium, spermatogonial cells are housed in ______, which allows greater access to nutrients and signaling molecules
In the adluminal compartment, tight junctions establish the _________ which protects developing spermatocytes and spermatids from autoimmune reactions as well as selects nutrients needed for spermatogenic cells
Niches
Blood-testes barrier
Spermatocytes are located above the blood-testis barrier, most of which are ______ spermatocytes
Primary
Leydig cells are present in the ______ space, close to blood vessels
They are _____-producing cells that contain lipid droplets, mitochondria with tubular cristae, and a well developed sER
They also produce 95% of the body’s ______
Intertubular
Steroid
Testosterone
Leydig cell function is regulated by the 2 hormones of the AP, _____ which stimulates testosterone production, and ______ which induces the expression of the LH receptor
LH; Prolactin
______ regulates the synthesis of steroids in Leydig cells by transporting cholesterol across the outer mitochondrial membrane. A mutation in the gene encoding this protein is detected in individuals with a defective synthesis of adrenal and gonadal steroids
StAR (steroidogenic acute regulatory protein)
In the sequence of spermatogenesis:
A spermatogonial cell arises from a _______ ___ cell which will initiate a spermatogenic cell sequence or will retain stem cell capacities via mitosis (this ensures continuous sperm production)
After division, spermatogenic cells remain interconnected by intercellular bridges and cytokinesis is incomplete
Primordial germ
T/F: each cohort of spermatogonia, spermatocytes, and spermatids complete their growth and differentiation in a timely manner, proliferating and differentiating synchronously
True
Diploid spermatogenic cells reside in a ___ of basal compartment of sertoli cells, located ______ the blood testis barrier
Niche; outside
What is the difference between type A and type B spermatogonia?
Type A: Oval, euchromatic nucleus and nucleolus attahed to nuclear envelope (subclasses dark and pale); type A clonally divide (mitosis), generating copies of itself or differentiating into type B
Type B: round nucleus, masses of heterochromatin attached to nuclear envelope and central nucleolus; divide (mitosis) and cells immediately enter meiotic prophase as primary spermatocytes (ensures 2x DNA when starting meiosis prophase I)
