Histology of the Male Reproductive System Flashcards
What do the lobules of the testes contain?
Seminiferus tubules
Leydig cells
What type of epitheium composes the seminiferous tubules?
Complex stratified epithelium
What is the purpose of the peritubular/myoid cells?
Surround the cells of the seminiferous tubules => create peristaltic waves to move spermatozoa through tubules
What cells make up the proximal and distal ends of the straight tubules?
Proximal: Sertoli cells
Distal: Simple cuboidal cells
What epithelium composes the Rete testis?
Simple cuboidal/low columnar
How long for sperm maturation?
2-12 days
What does the head of the epididymis contain? What epithelial cells is it made of?
Efferent ductules (connect rete testes to head)
Pseudostratified columnar
What does the body of the epididymis contain? What epithelial cells is it made of?
Duct of epididymis - contains principal cells
Pseudostratified columnar epithelium WITH STEREOCILIA to move sperm towards tail
What epithelium is the Ductus (Vas) Deferens composed of?
Pseudostratified columnar epithelium WITH STEREOCILIA
What are the layers of the muscular wall of the ductus deferens?
Inner and outer longitudinal layers
Middle circular layer
What structures come together to form the ejaculatory duct?
Distal end of ampulla of the ductus deferens
Ducts of the seminal vesicles
Type A spermatogonia will appear how? What do they do?
Appearance: Ovoid nuclei with intensely basophilic, granular chromatin
Job: Remain as reserve stem cells or differentiate into Type B
Type B spermatogonia appearance and job?
Appearance: Spherical nuclei, chromatin condensed in large clumps around central nucleolus
Job: Enter meiosis to become mature sperm
What cell division causes a primary spermatocyte to divide into 2 secondary spermatocytes?
Meiosis I
What cell division causes secondary spermatocytes to divide into spermatids?
Meiosis 2
What cell division causes a spermatogonium to divide into Type A and B spermatogonium?
Mitosis
4 phases of spermiogenesis
- Golgi
- Cap
- Acrosome
- Maturation
What is the acrosomal vesicle and when is it formed?
Membrane-bound cap filled with hydrolytic enzymes from the Golgi Apparatus, determines the anterior pole of the sperm
Golgi phase
What happens during the cap phase of spermiogenesis?
Acrosomal vesicle enlarges and spreads over anterior 1/2 of nucleus
Nuclear envelope attaches to acrosomal sac
What happens during the golgi phase of spermiogenesis?
Acrosomal vesicle formed next to the nucleus
Centrioles migrate to posterior pole to form the axoneme of sperm tail
What happens during the acrosome phase of spermiogenesis?
Spermatid orients self so head is embedded in sertoli cell and tail extends into lumen of seminiferous tubule
Manchette formed to transport protein from the head to the tail
What happens during the maturation phase of spermiogenesis?
Excess cytoplasm removed as residual bodies create mature sperm
Spermatids released from sertoli cells into the lumen
Where does the axonemal complex of the sperm begin and end?
Begins in the head, ends in the tail
What part of the sperm contains the mitochondria?
Middle piece of the tail
What is the sperm pathway?
SEVEn UP
- Seminiferous Tubule
- Straight tubule
- Rete Testis
- Efferent Ductule
- Epididymal duct
- Vas (Ductus) Deferens
- Ejaculatory duct
- Urethra
- Penis
What is the appearance of sertoli cells?
Columnar with extensive apical and lateral processes surrounding adjacent spermatogenic cells
What cells produce the blood-testis barrier?
Sertoli cells through tight jxns
What are Androgen-Binding proteins secreted from? What do they do?
Sertoli cells
Bind T and DHT with high affinity
During aging, what happens to the lamina propria in the seminiferous tubules?
Thickening causes decreased rate of sperm production and reduced size of seminiferous tubules
What cells exist within the lamina propria of the seminiferous tubules?
Myoid cells
What cells produce Crystals of Reinke?
Leydig cells
What substances does the Leydig cell produce?
T and Insulin-Like Protein 3
What is the action of INSL3 in the embryo and during puberty?
Embryo: stimulates descent of testes
Puberty: promote meiotic division in seminiferous tubules
Name the accessory sex glands
Seminal vesicles
Bulbourethral glands
Prostate
What are the layers of the seminal vesicle?
Mucosa - increased surface area
Smooth M - contraction during ejaculation
Fibrous coat
What do the seminal vesicles secrete?
White/yellow viscous fluid (75% of semen secretion)
Alkaline to protect from acidic urethra and vagina
Contains fructose, AAs, ascorbic acid, prostaglandins
What type of epithelium makes up the seminal vesicles?
Pseuodstratified columnar
What type of epithelium makes up the bulbourethral glands?
Simple columnar
What do the bulbourethral glands secrete?
Preseminal fluid
Contains galactose, sialic acid, methylpentose
Alkaline to neutralize acidic urethra
What is the largest accessory sex gland?
Prostate
What type of epithelium lines the prostate gland?
Simple columnar or pseudostratified epithelium
What are the 4 zones of the prostate?
Peripheral
Transitional
Central
Periurethral
What zone of the prostate is palpable during a DRE?
Peripheral
(means it is the location of prostatic CA)
What zone of the prostate compresses the prostatic urethra in Benign Prostatic Hyperplasia?
Transitional
What zone of the prostate surrounds the ejaculatory ducts?
Central
What are the symptoms of benign prostatic hyperplasia?
Inability to void bladder
Urinary frequency
Urgency
Nocturia
Difficulty starting/stopping stream
Excessive dribbling
Dysuria
What structures produce seminal secretions?
Testes
Epididymis
Ductus Deferens
Prostate
Seminal Vesicles
Bulbourethral glands
Prostate Specific Antigen (PSA) is used as a means of early diagnosis of what?
Prostate CA
How many sperm per ejaculate? What percentage is normal?
100 million
~50%
What are the sx of Prostate CA?
Urinary frequency
Dysuria
Hematuria
Low back pain (late)
What tissue is identified by irregular, interconnected vascular sinuses w/ fibrocollagenous stroma?
Erectile tissue
What arteries fill the vascular sinuses of erectile tissue?
Helicine arteries
What is the mechanism of action of sildenafil?
Inhibits PDE to increase cGMP => increased blood into sinusoids => maintain erection
