Male reproductive system Flashcards
What are the main functions of the male reproductive system?
-formation of sperm
-produce hormones
-aid in production of gametes
-regulate sexual maturation and development of secondary sex characteristics
-transmission of sperm to female
How tall are the testes?
4cm
Describe the structure of the scrotum
-a sac of skin and superficial fascia that hangs outside of the abdominopelvic cavity at the root of the penis contains the testes
-when warm the scrotal skin is flaccid and loose to lower the testes and increase cooling
-these changes maintain a fairly constant temp and reflect the activity of 2 sets of muscles, dartos, cremaster
Describe the function of the scrotum
-viable sperm cant be produced at body temp
What is the function of the penis?
-deliver sperm into the female reproductive tract
What is the structure of the penis?
-root- inside the body that runs into the shaft (external)
-tip is called the glans
-skin covering the penis is loose and forms a cuff over the glans called the prepuce
-urethra runs down the centre
Describe the erectile tissue of the penis
-three cylinders running length wise
-each made of a sponge like network of connective tissue and smooth muscle seperated by vascular spaces
Describe the structure of the corpus spongiosum
surrounded by urethra, located in the middle along the ventral side
Describe the structure of the corpora cavernosa
paired structure that run side by side along the dorsal surface
What is the ductus vas deferens?
-sperm storage and transport organ
-connects the epididymis to the urethra
What parts make up the ductal system?
-ductus vas deferns
-urethra
-epididymis
describe the structure of the urethra
comes from the bladder, meets to vas deferens at the penis base, runs through the penis, opens to the outside at the end of the penis
Describe the route of sperm during ejaculation
-testes
-epididymis
-vas deferens
-ejaculatory duct and urethra
-expelled out of the penis
describe the structure of the epididymis
-4cm long
-lies on the lateral side of the testes
-long coiled tube where sperm matures- can take up to 20 days
Describe the function of the epididymis
-sperm can be stored for months in the epididymis and eventually phagocytized by its epithelial cells
-sperm stored near tail portion and in the vas deferens until they are ejaculated
-during ejaculation smooth muscle walls of the epididymis contract strongly and move sperm to the vas deferens
describe the structure of the ductus vas deferens
-45cm long
-runs up through the spermatic cord into pelvic cavity, loop medially and descend along the posterior bladder wall
-at its termus, forms the ampulla to lead to the ejaculatory duct
What is the function of the ductus vas deferens?
propel sperm using strong peristaltic waves from the epididymis during ejaculation
How is an ejaculatory duct formed?
the ampulla of the vas deferens joins with the duct of the seminal vesicle to form a short duct.
Describe the function of the urethra
-carries both urine and semen
-mucosa lining contains scattered urethral glands which secrete mucous into the lumen just before ejaculation
-prostatic urethra-surrounded prostate gland
membranous urethra-in the urogenital diaphragm
spongy penile urethra-runs through the penis to the external urethral orifice
Whats the general structure of the accessory glands-seminal vesicles?
-behind bladder
5-7cm
-70% of semen volume
-duct of each vesicle joins the ductus deferens on the side to form the ejaculatory duct
describe the function of seminal fluid
-transport medium for sperm
-nutrition for sperm
-enhances motility-relaxin hormones and enzymes
-causes semn to coaggulate so it will stick to walls of vagina
-decreases the viscocity of cervival mucus
-neutralises acidic conditions of vagina
-induces contractions in the fallopian tubes to move sperm towards the ova- reverse peristalsis
Descirbe the structure of the prostate accessory glands
-base of bladder
-surrounds the proximal segment of the urethra
-prostate gland secretions enter the prostatic urethra via several ducts when prostatic smooth muscle contracts during ejaculation
Describe the function of prostate secretion
-milky slightly acidic-30% semen volume
-contains citrate(nutritiion) enzymes such as fibrinolysin-liquifies sticky semen after depositied in vagina to allow sperm to swim
-Prostate specific antigen-activates sperm
Describe the structure and function of the Cowpers gland-accessory gland
-known as bulbourethral gland
-below prostate
-produces thick clear mucus that runs into the urethra
-secretions of this fluid prior to ejaculation neutralises acidic urine remaining in urethra
What is the passage of semen assisted by?
-ejacualtion propels sperm at speed up to 500cm/s
-accessory gland secretions-transport medium,provides nutrients, protects sperm,activates sperm,facilitates movement
-female orgasm
-chemical signals directing sperm toward oocyte
