what are the gonads and what do they do?
-testes
-produce sperm and secrete hormones
what does the system of ducts include?
-ductus epididymis
-ductus deferens
-ejaculatory duct
-urethra
what does the system of ducts do?
-transports and stores sperm, assists in their maturation, conveys them to the exterior
what do accessory sex gland include?
-seminal vesicles
-prostate gland
-bulbourethral glands
what are the supporting structures of the male reproductive system and what do they do?
-scrotum-supports testes
-penis-delivers sperm into the female reproductive tract
what is the scrotum?
-a cutaneous out pouching of the abdomen that supports the testes
what temp does normal sperm production and survival require?
-a temp 2-3*c below core body temp
what are the two halves the scrotal septum divides the scrotum into?
-cremaster muscle
-dartos muscle
what does the cremaster muscle do?
-contracts to elevate the testes on exposure to cold and moves the testes close to the pelvic cavity (skeletal muscle fibres)
what does the dartos muscle do?
-contracts and makes the scrotal skin wrinkle minimising heat loss (smooth muscle fibres)
what are the testes/testicles?
-paired oval glands that descend from the abdomen to the scrotum during the 7th month of fetal development
what is the structure of the testes/testicles?
-it is covered by a fibrous tissue called tunic albuginea
-invaginations form 200-300 compartments called lobules
-each lobule is filled with 2 or 3 seminiferous tubules (spermatogenesis)
what is the pathway for sperm transport?
-seminifrous tubule
-straight tubule
-rete testis
-epididymis (head, body,tail)
-ductas vas deferens
-exit through the spermatic cord which also contain blood vessels and nerves
what are the cells of the testes?
-leydig cells (interstitial endocrinocytes)
-large sertoli cells
what do leydig cells do?
-they are found in spaces between adjacent seminiferous tubules which secrete the male hormone testosterone
where are large Sertoli cells found?
-embedded among the spermatogenic cells in the tubules
what do large Sertoli cells do?
-form the blood testes barrier
-nourish spermatocytes
-mediate the effect of testosterone and FSH on spermatogenesis
-phagocytose excess spermtids
-secrete the hormone inhibin which helps regulate sperm production by inhibiting the production of FSH
what does spermatogenesis do?
-produces haploid sperm (one set of 23 chromosomes) from diploid spermatogonia
how many days does the process of spermatogenesis take?
74 days
what happens in meiosis one? (reduction division)
what happens in meiosis 2 (equatorial division)?
what is spermiogenesis?
-involves the development of spermatids into sperm,acrosome(head) and flagella (tail) form and the mitochondria multiply
what is spermination?
-the release from connections to sertoli cells
what is sperm morphology?
-how sperm are adapted for reaching and penetrating a secondary oocyte