Spermatogenesis Flashcards
Where are sperm made and stored?
β In the testes
β stored in the epididymis
What contracts during ejaculation?
β The vas deferens
Where do the sperm travel to after the vas deferens?
β Seminal vesicle which contribute seminal fluid
β move to the prostate which also contribute secretions
Where does the vas deferens meet the urethra?
β In the prostatic gland
What is responsible for erections?
β Hydrostatic pressure
Where are the testes located?
β in the scrotum outside the body cavity
Why are the testes located outside the body?
β Optimum temperature for sperm production
β overheating reduces sperm count
What is the normal volume of the testes and how is this measured?
β 15-25ml
β orchidometer
What do the tubules lead to?
β Rete on one side
What does the rete lead to?
β Epididymis and vas deferens
What is 90% of the testis made up of?
β seminiferous tubules
Where is the site of spermatogenesis?
β Seminiferous tubules
How long does it take for sperm to go from the basal side to the lumen?
β 74 days
What are sertoli cells held together by?
β Tight junctions
What are tight junctions for?
β preventing an immune response against sperm cells
Describe the formation of spermatozoa
β The sperm start as spermatogonia which are diploid
β they replicate by mitosis and form 2 types of cell
β type A and type B
β type A is used as the template and replicates again
β type B moves into the adluminal compartment and becomes a primary spermatocyte
β the primary spermatocyte undergoes meiosis I and become secondary spermatocyted
β 2ndary spermatocytes divide to form 4 daughter cells (meiosis II)
β these are spermatids
What are the walls of the seminiferous tubules made from?
β Tall columnar endothelial cells which are Sertoli cells
What are spaces between the seminiferous tubules filled with?
β blood
β lymphatic vessels
β Leydig cells
How long does the cycle of spermatogenesis take?
β 74 days