229 - Histology of the Male Reproductive System Flashcards
Where are mitochondria found in sperm cells?
Middle piece of the tail
What is the embryonic origin of spermatogonia?
Hindgut
Spermatogonia = immature sperm cells; they undergo mitotic expansion until it’s time to start making sperm
What is the function of prostatic gland secretions in semen?
Liquifies the semen
List the stages in sperm development and the relevant changes at each step
- Spermatogonia - under go mitosis
- Primary spermatocytes - Meiosis I
- Secondary spermatocytes - Meiosis II
- Spermatids - Acquire acrosome, mitochondria, shed cytoplasm
-
Spermatosoa - Released into seminiferous tubule lumen
- In epididimis: gains motility - sperm are mature, but do not yet have capacity to fertilize (this happens in female tract)
- Stored in the tail of the epididymis until ejaculation
Which cells in the testes perform phagocytosis?
Sertoli cells
Help get rid of sperms that die or are very abnormal
Beginning with the testes, list the sequence of structures that sperm travel through to get to the outside world
- In testes:
- Seminiferous tubules
- Rete testis
- Efferent ductules of the testis
- Epididymis
- Ductus deferens
- Ejaculatory duct (in prostate gland)
- Prostatic urethra
- Membranous urrethra
- Penile urethra
Describe the key histological features of the prostate
Prostatic concretions = Hyaloid material that may be calcified
Also look for:
- Pseudostratified columnar epithelium in glands
- Fibromuscular tissue septa between glands
What is spermiation?
Release of mature sperm inot the lumen of the efferent ductules of the testes
What are the functions of Leydig and Sertoli cells?
- Leydig cells
- Produce testosterone
- Sertoli cells = epithelium proper
- Blood-testes barrier
- Secrete androgen binding protein, AMH
- Phagocytosis
Where do sperm acquire motility?
When do they become capable of fertilization?
Motility acquired in the epididymis (as spermatozoa)
Capacitation (the ability to fertilize an ovum) occurs in the female reproductive tract
What is the embryonic origin of sertoli cells?
Leydig cells?
Sertolic cells arise from primary sex cords
Leydig cells arise from mesenchyme
How long does spermatogenesis take?
74 days from spermatogonia -> spermiation
+ 12 days to swim through the epididymis
=> up to 3 months to see if an infertility tx works
Describe the process of sperm capacitation
Capacitation make sperm able to fertilize an ovum
- Sperm bind to the zona pellucida surrounding an egg
- -> Acrosome reaction: proteases and hyaluronidase from the sperm degrade the zona pellucida
- This allows fusion of sperm and egg cell membranes
- -> Sperm can now fertilize the egg
Triggers a cortical reaction in the egg: Granules released to provide cross-linding of molecules in the zona pellucida, depolarizes membrane
List 2 mechanisms that prevent more than 1 sperm from fertilizing an egg
As soon as 1 sperm enters:
- Fast block: Depolarization of the ovum cell membrane
- Slow block: hardening of the zona pellucida
Where in the prostate do most benign tumors occur?
Transition zone
Ex: BPH, urinary symptoms
Which zone of the prostate is considered “cancer resistant”?
Central zone
Where in the prostate do most malignant tumors occur?
Peripheral zone
What kind of epithelium makes up the efferent ductules and the duct of the epididymis?
Pseudostratified columnar epithelium
True for most of the male system
