sexual reproduction in humans (male ver.) Flashcards
what is a haploid set of chromosomes?
23 chromosomes (gamete—egg cell, sperm cell)
what is a diploid set of chromosomes?
46 chromosomes (zygote—egg cell + sperm cell)
what are the parts of the male reproductive system?
- testis
- epididymis
- scrotum
- sperm duct
- seminal vesicle
- prostate gland
- cowper’s gland
- urethra
- penis
functions of testis (singular) + location?
- produce sperms
- produce male sex hormones: testosterone
- located in scrotum, connected to epididymis
example + function of male sex hormone?
- testosterone
- responsible for the development and maintenance of secondary sexual characteristics in males
functions of scrotum?
- pouch-like sacs in between thighs where testes are located
- outside the main body cavity so it is lower temp than body. sperms can only develop at a temp lower than that of the body
functions of sperm duct?
- loops over ureter and opens into urethra (for pee to come out)
- sperms from testes travel through the sperm duct to be ejaculated out of the urethra
functions of seminal vesicle (gland)?
- opens into sperm duct (sperm duct then seminal vesicle)
- stores sperms temporarily before they are released though the urethra
what are the 4 glands in the male reproductive system?
- seminal vesicle
- prostate gland
- cowper’s gland
location of prostate gland + cowper’s gland?
- below urinary bladder where the two sperm ducts join the urethra
- beneath the prostate gland is the cowper’s gland
functions of all 3 glands?
- secrete a slippery fluid which mixes with the sperms
- fluid contains enzymes and nutrients which nourish the sperms and activate them (stimulate them to swim actively)
- fluid + sperms = semen
what is semen?
a slippery fluid containing nutrients and enzymes mixed with sperms
95%—fluid
5%—sperms
what do the seminal vesicles produce?
- slightly alkaline mucoid secretions which contain large amounts of fructose + small amounts of vitamins and amino acids (help to nourish and protect the sperm)
what does the prostate gland secrete?
- a thin milky alkaline fluid that helps neutralise the acidic secretions in the vagina
- raises conditions in vagina from pH3.5–pH6, sperm becomes increasingly mobile
what does the cowper’s gland secrete?
- alkaline secretions
- neutralise any traces of acidic urine in the urethra (male) and serves as lubricant for penis
functions of urethra?
- tube that passes from urinary bladder to penis
- both semen and pee pass through the urethra but NOT at the same time due to the sphincter muscle
- sphincter muscle can be controlled to prevent urine from coming out of the bladder during ejaculation
functions of penis?
- tissue in penis has numerous spaces that can be filled with blood to become erect and hard
- and erectile organ (contains erectile tissue)
what is the sperm made out of?
- acrosome
- cytoplasm
- nucleus
- cell surface membrane
- mitochondria
head of sperm?
- 2.5μm wide
- contains: large nucleus and small amount of cytoplasm
- nucleus carries haploid set of chromosomes (23)
- acrosome: contains enzymes that break down part of the egg membranes so that the sperm can penetrate the egg during fertilisation
middle piece of sperm?
- contains numerous mitochondria
- mitochondria provides energy for the sperm to swim to the egg
tail of sperm?
- beating movement of tail enables sperm to swim towards the egg
- sperm is motile because it can move on its own
