Human Reproduction Flashcards
What is the function of the scrotum?
- temperature regulator = formation of fertile sperm
- houses and protects testes
Testes
- produce sperm
- produce testosterone
Epididymis
- immature sperm enter here and become mature & stored for several months
Sperm duct
Pushes mature sperm forward - epididymis to urethra - ejaculation
Urethra
Transports semen and urine out the body
Prostate glad
- Secretes a fluid that aids the transport of sperm
- contains enzymes that makes sperm more active
Cowper’s gland
Produce an alkaline mucous-like fluid when sexually aroused
- neutralizes acidic urine
- lubricates urethra = protects sperm
Ovaries
- form and release eggs
- produce oestrogen & progesterone
Fallopian tubes / oviducts
- pathway between uterus and ovary
- site of fertilization & initial cell division of zygote
- enable egg/zygote to move towards uterus
Uterus
- blastocyst implants, develops and grows
- contraction of myometrium = pushes baby out
Vagina
- place where sperm is deposited
- birth canal
What is puberty?
Process of physical and physiological changes
- development of secondary sex characteristics
- a child becomes capable of reproduction
How does puberty start? (4)
- pituitary gland releases gonadotropins = initiate puberty
- males: interstitial-cell-stimulating hormone (ICSH) - stimulates testes = testosterone
- females: FSH - stimulates ovaries = oestrogen
- hormones initiate changes (primary and secondary sexual characteristics)
What is gametogenesis?
Formation of mature gametes by the reproductive glands (gonads)
- involves meiosis (46 - 23 chromosomes)
What is spermatogenesis?
Sequence of events where mature, haploid sperm are produced
- begins at puberty
What is oogenesis?
Production of mature, haploid eggs in follicles of ovaries
- number of eggs determined before birth
- mature eggs are not formed continuously throughout life - stops at menopause
- occurs in menstrual cycle
What is the menstrual cycle?
- average length of 28 days
- uterine and ovarian cycles - controlled by the endocrine system
- occurs from puberty until menopause
Ovarian cycle
- DEVELOPMENT OF THE GRAAFIAN FOLLICLE
- primary follicles mature & prepare to release egg
- stimulated by FSH
- develops into GF - OVULATION
- GF contains ovum
- matures, enlarges, moves to ovary surface
- mid cycle : LH released = GF ruptures = ovum released - FORMATION OF THE CORPUS LUTEUM
- GF remains = glandular tissue
- produces progesterone
Uterine cycle
- CHANGES IN ENDOMETRIUM
- oestrogen - starts the repair of endometrium
- corpus luteum = endometrium thickens = more glandular and vascular
- suitable for implantation of fertilized egg - MENSTRUATION
- high levels of oestrogen and progesterone = negative feedback = LH & FSH release
- no hormone = endometrium lining breaks down & sheds
- detached tissue and blood pass out vagina as menstrual flow
What is copulation?
Transfer of sperm into vagina when the penis is inserted and sperm are deposited near the cervix
What is fertilization?
Fusion of sperm nucleus with the egg nucleus to form a zygote
What is gestation?
The time between conception and birth
- 280 days (40 weeks)
What are the functions of the placenta? (5)
- oxygen & dissolved food substances pass from mom to foetus = respiration & nutrition
- urea & CO2 passed into maternal blood system for excretion
- maternal anti-bodies pass to foetus = temporary immunity
- prevents pathogenic micro-organisms from entering foetus
- endocrine function
