Human Reproduction

Question 1

What is the function of the scrotum?

Answer 1

• temperature regulator = formation of fertile sperm

- houses and protects testes

Question 2

Testes

Answer 2

• produce sperm

- produce testosterone

Question 3

Epididymis

Answer 3

• immature sperm enter here and become mature & stored for several months

Question 4

Sperm duct

Answer 4

Pushes mature sperm forward - epididymis to urethra - ejaculation

Question 5

Urethra

Answer 5

Transports semen and urine out the body

Question 6

Prostate glad

Answer 6

• Secretes a fluid that aids the transport of sperm

- contains enzymes that makes sperm more active

Question 7

Cowper’s gland

Answer 7

Produce an alkaline mucous-like fluid when sexually aroused

• neutralizes acidic urine
• lubricates urethra = protects sperm

Question 8

Ovaries

Answer 8

• form and release eggs

- produce oestrogen & progesterone

Question 9

Fallopian tubes / oviducts

Answer 9

• pathway between uterus and ovary
• site of fertilization & initial cell division of zygote
• enable egg/zygote to move towards uterus

Question 10

Uterus

Answer 10

• blastocyst implants, develops and grows

- contraction of myometrium = pushes baby out

Question 11

Vagina

Answer 11

• place where sperm is deposited

- birth canal

Question 12

What is puberty?

Answer 12

Process of physical and physiological changes

• development of secondary sex characteristics
• a child becomes capable of reproduction

Question 13

How does puberty start? (4)

Answer 13

• 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)

Question 14

What is gametogenesis?

Answer 14

Formation of mature gametes by the reproductive glands (gonads)
- involves meiosis (46 - 23 chromosomes)

Question 15

What is spermatogenesis?

Answer 15

Sequence of events where mature, haploid sperm are produced

- begins at puberty

Question 16

What is oogenesis?

Answer 16

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

Question 17

What is the menstrual cycle?

Answer 17

• average length of 28 days
• uterine and ovarian cycles - controlled by the endocrine system
• occurs from puberty until menopause

Question 18

Ovarian cycle

Answer 18

1. DEVELOPMENT OF THE GRAAFIAN FOLLICLE
   - primary follicles mature & prepare to release egg
   - stimulated by FSH
   - develops into GF
2. OVULATION
   - GF contains ovum
   - matures, enlarges, moves to ovary surface
   - mid cycle : LH released = GF ruptures = ovum released
3. FORMATION OF THE CORPUS LUTEUM
   - GF remains = glandular tissue
   - produces progesterone

Question 19

Uterine cycle

Answer 19

1. CHANGES IN ENDOMETRIUM
   - oestrogen - starts the repair of endometrium
   - corpus luteum = endometrium thickens = more glandular and vascular
   - suitable for implantation of fertilized egg
2. 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

Question 20

What is copulation?

Answer 20

Transfer of sperm into vagina when the penis is inserted and sperm are deposited near the cervix

Question 21

What is fertilization?

Answer 21

Fusion of sperm nucleus with the egg nucleus to form a zygote

Question 22

What is gestation?

Answer 22

The time between conception and birth

- 280 days (40 weeks)

Question 23

What are the functions of the placenta? (5)

Answer 23

• 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