Histo - Male Flashcards
What are the 4 major parts of the Male Genital System?
-
Testes
- produces spermatozoa
- synthesizes & secretes androgens
-
Duct system
- carries sperm to the exterior
- epididymis, vas deferens, ejaculatory duct, urethra
-
Secretory glands
- provide fluid & nutrients to support & nourish sperm
- seminal vesicles, prostate gland, bulbourethral glands of Cowper
- provide fluid & nutrients to support & nourish sperm
-
Penis
- capable of erection
- urination
- sperm/semen ejaculation
What is this?
Testes
Basics:
- In scrotum
- develop retroperitoneally
- descend into scrotal sac at ends of the spermatic cords
- surrounded by tunica vaginalis
- serous sac from peritoneum
- 2-3 degrees below body temp
Structure:
- Epididymis attached POSTERIORLY
- Enclosed by CT = tunica albuginea
- thickens posteriorly –> mediastinum testis
- CT from here delineates testicular lobes
What is this?
Rete Testis
Mediastinum of testes:
- contains rete testes
- has septa that divide the testes into lobules
- each lobule = 1-4 seminiferous tubules
- bound by BL
- surrounded by loose CT w/ blood vessels, lymph vessels, nerves, Leydig cells
- each lobule = 1-4 seminiferous tubules
- continuous w/ tunica albuginea
Structure:
- Terminal part of testes = consists of straight tubules
- enter the rete testes
- Both straight tubules & rete testes lined w/ simple cuboidal –> low columnar w/ microvilli
- Cels have flagellum
Note:
- Rete testes fuse to form multiple efferent ductules
What is this?

Seminiferous Tubules
Basics:
- Coiled, nonbranching loop
- w/ both ends opening into rete testes
Composed of:
- Central lumen (open space)
- Germinal or spermatogenic epithelium
- Sertoli cells (sustentacular cells)
- support & create blood.testes barrier
- BL
- outside of germ layer
- Fibrous CT
- Fibroblasts
- Myoid cells
- Leydig cells
- Blood vessels, nerves, lymphatics
Cells of the Testis (Seminiferous Tubules)
W/in the Seminiferous Tubules - Germinal Epithelium
- Spermatogonia
- up against BL
- Primary spermatocytes
- meiosis I
- have condensed chromosomes
- Secondary spermatocyte
- meiosis II
-
Spermatids
- after mitosis is complete
- spermiogenesis - closer to lumen
- Immature sperm
- tails toward lumen; head embedded
-
Sertoli cells
- supporting cells
Outside the BL of Seminiferous Tubules:
- Myoid cells
- contractile cells around tubules
- Fibroblasts
- Make ECM
- Cells of blood vessels
-
Leydig cells
- Make testosterone
What is the Blood‐testis Barrier? What are the 2 compartments?
-
Basal Compartment
- Mitosis
- Spermatogonia
- Type A
- stem cells
- progenitor cells
- heterochromatic (condensed)
- Type B
- euchromatic (less condensed)
- Type A
-
Adluminal Compartment
- Meiosis
- Spermatocytes
- Primary (1st meiotic division)
- Secondary (2nd meiotic division)
- Spermatids
- Spermatozoa
Note:
- Compartments = formed by tight junctions of Sertoli Cells
What is the importance of Sertoli Cells?
Basics:
- Large, oval & euchromatic nucleus
- Prominent mucleolus
- Tight & gap junctions btw cells
- Form basal lumen vs. adluminal compartments
- DONT DIVIDE
- Survive adverse conditions
- infection, malnutrition, irradiation
Functions:
- Formation of blood-testis barrier
- Support
- Nutrition, transport of waste, protection from immune system
- Phagocytosis
- cytoplasm by spermatids
- Spermiation
- faciliates release of sperm
- Secretory
What are the Secretions of Sertoli Cells?
During weeks 8-9 of fetal development:
- Mullerian inhibitory hormone (MIH)
- causes Mullerian ducts to regress
- leads to MALE development
- No MIH = FEMALES
Mature Testes:
- Androgen binding protein (ABP)
- allows testosterone to concentrate in tubule
- Inhibin
- negative feedback to hypothalamus & pituitary to inhibit FSH
What is this?

Cryotorchidism
-
No Spermatogenesis!
- happens when testes dont decend into the scrotum
- NO SPERM BEING MADE due to high temp
What is this?

Leydig Cell Tumor
Basics of Leydig cells:
- in CT btw seminiferous tubules
- steroid secreting cell
- appears foamy
Function:
- Synthesizes & secretes testosterone
- LH
- stimulate testosterone
- Prolactin
- stimulates expression of LH receptor
Crystals of Reinke
- pink (eiosinophilic)
- tumor in Leydig cells

What are the 2 cell types?
Interstitial (Leydig) Cells & Sertoli cells
- Green image = antibody to a glycoprotein in sertoli cells
How does the Formation of Sperm occur?
Basics:
- Germinal epithelium produces male gametes
- Takes ~64 days
- Asynchronous
Sequence:
-
Spermatogenesis (dev of spermatid)
- Mitosis & Meiosis
- spermatogonia –>
- primary –>
- secondary –>
- spermatocytes –>
- spermatids
- Mitosis & Meiosis
-
Spermiogenesis (spermatid –> sperm)
- formation of acrosome
- flagellum
- nuclear flattening
- cytoplasmic shedding

What is Spermatogenesis?
Spermatogonia
- Type A dark stem cells
- Type A pale (mature into type B)
- Type B
- mitose & differentiate –> primary spermatocytes
Primary spermatocytes (4N)
- Meiosis I
- produce secondary spermatocytes
Secondary spermatocytes (2N)
- Meiosis II
- produce spermatids (1N)
Spermatids
- undergo spermiogenesis

What are the 4 phases of Spermiogenesis?
-
Golgi phase
- begin to form acrosome (hydrolytic enzymes)
- centrioles/microtubules –> flagellum
-
Cap phase
- acrosomal cap THICKENS & FLATTENS
- nucleus condenses
-
Acrosome phase
- nuclei elongate; protamines replace histones
- head still embedded in Sertoli cells
-
Maturation phase
- cytoplasm = lost (forms residual body)
- released to lumen

What is the basic Anatomy of Sperm?
-
Head
- Acrosome
- Nucleus
-
Tail
- Midpiece
- helically arranged mitochondrial sheath
- Prinicpal piece
- End piece
- Midpiece

What is the purpose of Intratesticular Ducts?
Basics:
- Allow for the movement/migration of sperm
Consists of :
- seminiferous tubules
- straight tubules (tubuli recti)
- sertoli cells = proximal part
- simple cuboidal = distal part
- rete testis
- simple cuboidal cells w/ microvilli + 1 cillium
- efferent ductules
- connects rete testis to epididymis
What is this?

Rete Testis & Efferent Ductules
-
Rete testes
- absorb fluid
- move sperm via cilia
-
Efferent ductules
- tall simple ciliated columnar cells
- simple cuboidal cells w/ no cilia
- scalloped appearance
- convoluted
- absorb fluid from semiferous tubules
- SM around ductules to aid in motility
- SM in epididymis = helps move sperm –> epididymis

What are the components of the Excretory Genital Ducts?
- Epididymis
- Vas deferens
-
Urethra
- all 3 transport sperm from ST –> penile urethra for ejaculation
What is this?
Ductus Epididymis
Basics:
- Connects efferent ductules to vas deferens
Structure:
- Pseudostratified columnar epithelium w/ stereocilia
- NOT scalloped
- Principal cells = have stereocilia
- absorb water, residual bodies & debris
- SM around to aid sperm motility
Function:
- Sperm maturation
- Acrosome maturation
- Fluid prevents acrosomal reactions
- decapacitation factors
What is this?
Vas Deferens (Ductus deferens)
Basics:
- Thick SM wall
- inner = longitudinal
- middle = circular
- outer = longitudinal
- Helps propel sperm
Structure:
- Small stellate lumen
- Pseudostratified columnar epithelium
- w/ stereocilia
- Enlarges over urinary bladder
- more folded epithelium

What is this?

Ampulla of the Vas Deferens
Basics:
- Vas deferens dilate to form ampulla
- Mucosa = more highly folded
Final part of ampulla:
- seminal vesicle joins the duct
- forms the ejaculatory duct
- opens to the prostatic urethra
- forms the ejaculatory duct
What is this?
Ejaculatory Duct
- Open to the posterior wall of the prostatic urethra
- Walls of ED = folded + lined w/ simple columnar epithelium
- surrounded by CT + SM
What are the 3 Accessory Glands?
- Seminal vesicles
- Prostate
- Bulbourethral glands

What is this?
Seminal Vesicles
Basics:
- Folded tubes/mucosa
- Epithelium = simple columnar –> pseudostratified
- Sperm not usually in lumen
- Thin muscle layer
- Inner = circular
- Outer = longitudinal
Secretions:
-
Fructose (eosinophiilic)
- energy for sperm
-
Prostaglandins
- stimulate part of female reproductive tract
- Citrate
- Inositol
-
Fibrinogen
- helps semen coagulate
What is this?
Prostate Gland
Basics:
- Tubuloacinar glands
- open into urethra
- Capsule forms lobes
- subdivide:
- lobes = anatomy
- zones = pathology
- subdivide:
- Enlarges at age 45+
Structure:
- Simple or pseudostratified columnar
- lower if NO testosterone
Prostatic Concretions (aka corpora amylacea)
- glycoproteins in lumen
- increase w/ age
- can calcify
Prostatic Fluid
- Expulsion fluid during ejaculation
- Contains glycoproteins, enzymes, etc
Note:
- Clinically important = Prostate-specific antigen
- no longer considered a useful marker for prostatic cancer
What are the 3 Histologic Prostate Gland Zones?
-
Transition Zone
- periurethral mucosal glands
- main site of BENIGN PROSTATIC HYPERTOPHY (BPH)
- contains ANTERIOR lobe
-
Central Zone
- periurethral submucosal glands
- contains MEDIAN lobe
- periurethral submucosal glands
-
Peripheral Zone
- main glands
- main site of PROSTATE CANCER
- contains POSTERIOR lobe
Note:
- Right & left lateral lobes = found in ALL zones

What is the importance of the Bulbourethral Glands of Cowper?
Basics:
- In the urogenital diaphragm
- Drain into PENILE urethra
Structure & Function:
- Tubuloacinar glands w/ SM around
- Simple columnar epithelium
- secretes mucous + lubricates
What is this?
Penile Urethra & Erectile Tissue
What is this?

Penis
Basics:
- 3 regions of erectile tissue
- venous cavernous spaces w/ CT + SM
Dorsal = 2 corpora cavernosa
- blood vessels w/in
- surrounded by tunica albuginea
Ventral = 1 corpus spongiosum
- penile urethra w/in
- lined by multiple types of epithelium
- uretral glands (glands of Littre) along urethra
- secrete mucous