The short but happy life of sperm Flashcards
Course of sperm
Seminuferous tubules Rete testes Efferent ductules Epididymis Vas deferens (Inguinal canal) Ejaculatory duct (seminal vesicles) Prostatic urethra Membranous urethra Penile urethra (bulbourethral glands) Outside world
2 products of the testis
spermatozoa
hormones
What is the role of FSH in sperm production?
FSH stimulates the Sertoli cells requiredfor spermatogenesis to occur
-increased secretion during puberty
What is the role of LH in sperm production?
LH stimulates Leydig cells to produce androgens required for spermatogenesis
-increased secretion during puberty
Testis anatomy
Tunica vaginalis
-Outer lining, same as peritoneum
Tunic albuginea
-White outer coating adhering to seminiferous tubules
Seminiferous tubules
Efferent ducts
Rete testis
Epididymis
Vas deferens
Compartment of testis
Production of 2 main products
-hormones and spermatozoa
Seminiferous tubules
-Spermatogenesis
Stroma with Leydig cells
- Testosterone production
- Adjacent to seminiferous tubule
- Highly vascularised
Hormone secretion of the testis
Leydig cells make testosterone
-Cholesterol and acetate
In Sertoli cells
-converts testosterone to dihydrotestosterone
Spermatogenesis pt 1
Mitosis
- Prospermatogonia reactivated at puberty
- Mitosis in basal compartment - Spermatogonia divide to form clone cells
- After final division, it forms primary spermatocyte
- Nuclei are divided but not the cytoplasm
Spermatogenesis pt 2
Primary spermatocyte enter meiosis
- Homologous chromosomes to opposite ends of the cell
- Divide to diploid cells: secondary spermatocyte
Another division - spermatid to haploid
Spermatogenesis pt 3
Packaging of spermatid
- Tail for forward propulsion
- Midpiece with mitochondria for energy
- Nucleus with packaged chromosomes
- Cap region forms for sperm-oocyte fusion
- Acrosome forms to penetrate oocyte
Unwanted material is phagocytosed by sertoli cells
The spermatogenic cycle
After spermatogenesis is originated in a locaion from a spermatogonium, it is not started for 16 more days
Spermatogonium are activated at different times in different location
The spermatogenic wave
Mature along the length of the tubule
Maturation of spermatozoa
- Wash into rete then into efferent ducts
- can twitch in rete - concentrated in epididymis
- can swim in cauda - Into vas deferens, released into semen
Capacitation of sperm
functional maturation of the spermatozoon
receptors are made available through the removal of a glycoprotein layer
changes the motility of spermatozia
Describe the path of sperm as it exists the testis
Seminiferous tubules Rete testis Efferent ducts Epididymis Vas deferens
