male reproductive system Flashcards
(55 cards)
the male reproductive system produces what cells
sperm cells
which can be transferred to female
in what way is the male reproductive system different to females
anatomically
as Some hormones are same, but act in very different ways
what is the scrotum and what compartments is it divided into
Pouch containing testes
- L lower than R to avoid compression between thighs
Divided into R & L compartments
- by internal median septum
- Externally marked by seam
(perineal raphe)
what temp is required for sperm production
<37oC
name the 3 mechanisms for regulating testes temperature
cremaster muscle
dartos muscle
pampiniform complex
how does the cremaster muscle regulate testes temp
strips of internal abdominal oblique muscle, contracts when cold to draw testes nearer body
how does the dartos muscle regulate testes temp
subcutaneous layer of smooth muscle, contracts when cold, so taut & wrinkled
how does the pampiniform complex regulate testes temp
extensive vein network, cools blood [by 2oC] & testis [so sperm formed] by acting as a ‘countercurrent heat exchanger’.
explain the Countercurrent Heat Exchanger
blood flowing towards testis is leaving body at body temperature (37oC) but since the vessels (arteries) are close to the cooler blood from the testis entering the body, heat is lost (exchanged) and so blood enters the testis at the cooler temperature of 35oC, required for sperm production.
The cooler blood coming from the testis then gains heat from nearby vessels containing blood flowing in the opposite direction, so enters the body at a warmer temperature.
explain testes shape
Each testis is oval (4x2.5cm)
what glands do testes have
Both exocrine (sperm) & endocrine (testosterone ) glands
whats the outer cover of the testes called
tunica vaginalis
whats the White fibrous capsule of the testes called
tunica albuginea
what doe the Connective tissue septa divide testes organ into
300 cone/wedge-shaped lobules
each testes lobule conatins how many seminiferous tubules
1-3
what are seminiferous tubules
slender ducts [70cm long] where sperm produced
what between the Between sem.tub. (seminiferous tubules) in testes
clusters of interstitial cells [cells of Leydig], producing testosterone
what are sem.tub. (seminiferous tubules) lined by
several layers of germ cells (in process of becoming sperm) & fewer tall sustentacular [Sertoli] cells
- provide nutrients, waste removal, growth factors; secrete inhibin –> which regulate rate of sperm production
Spermatogenesis occurs where
in the seminiferous tubules
how does spermatogenesis start and what happens
it starts at the outer edge of the tubule (at the top of the diagram) and sperm matures towards the lumen of the tubule (at the base of the diagram), to become a spermatozoon.
what forms the blood-testies barrier (BTB)
Tight junctions between adjacent Sertoli cells
what does the blood testes barrier prevent and whys this important
proteins & other large molecules from getting to germ cells, i.e., prevent attack from immune system
- Important because germ cells are genetically different from other cells of body
what occurs when Blood testes barrier fails to form adequately in adolescence
sterility
- immune system produces autoantibodies against the germ cells.
name the components of the Germinal epithelium of testis
1.Basal lamina
2.Spermatogonia
3.Spermatocyte 1st order
4.Spermatocyte 2nd order
5.Spermatid
6.Mature spermatid
7.Sertoli cell
8.tight junction (BTB)
1 starts at bottom of layer, cells 2 -6 go all the way up to 6 which is top of layer
8 is where the 2 sertoli cells(7) join, which is just above cell 2
number 7 are the big cells which the rest surround
