EXAM 2 - Reproduction

Question 1

What are Gametes

Answer 1

Sex cells: Sperm and ova

Question 2

Sex organs (gonads)

Answer 2

Testes and Ovaries

Question 3

3 x accessory reproductive organs

Answer 3

Ducts
Glands
External genitalia

Question 4

Anatomy: PENIS (Location, Structure, Function)

Answer 4

Location: External
Structure: Richly supplied with nerve endings
FUNCTION:
- urination
- release of semen

Question 5

Anatomy: SCROTUM (Location, Structure, Function)

Answer 5

Location: External
Structure: Encloses 2 x testes and epididymis
FUNCTION:
- maintains testes at a suitable temp for sperm production

Question 6

Anatomy: TESTES (Location, Structure, Function)

Answer 6

Location: Internal / inside scrotum
Structure:
Function:
- produce sperm
- produce / secrete testosterone
- Seminiferous tubules in Testes = where meiosis occurs

Question 7

Anatomy: Epididymis (Location, Structure, Function)

Answer 7

Location: Internal / inside scrotum
Structure:
Function:
- stores maturing sperm, until sperm released into vas deferens for ejaculation
- if not, then until sperm are disintegrated / reabsorbed

Question 8

Anatomy: VAS DEFERENS (Location, Structure, Function)

Answer 8

Location: Internal
FUNCTION:
- Carries sperm FROM epididymis TO ejaculatory duct

Question 9

Anatomy: SEMINAL VESICLES(Location, Structure, Function)

(Fluid producing glands)

Answer 9

Location: internal, next to bladder
FUNCTION:
- Secretes fluid to nourish sperm
- fluid also helps stimulate muscle contractions in female

Question 10

Anatomy: PROSTATE GLAND (Location, Structure, Function)

(Fluid producing glands)

Answer 10

LOCATION: internal, under bladder
FUNCTION:
- secretes fluid to nourish sperm
- AND (fluid) initiates movement of sperm

Question 11

Anatomy: COWPER’S (BULBOURETHRAL) GLANDS (Location, Structure, Function)

(Fluid producing glands)

Answer 11

LOCATION: internal, inferior to prostate
FUNCTION:
- secretes fluid that neutralizes the acidity of any urine in urethra prior to the passage of semen

Question 12

Spermatogenesis

Answer 12

DEFINITION: Production of Sperm in seminiferous tubules (in testes)

Diploid chromosomal number (2n) = Two sets (23 pairs) of chromosomes

GAMETES: Haploid chromosomal number: (n) - only 1 x set of 23

Question 13

Spermatogenesis

Answer 13

DEFINITION: Production of Sperm in seminiferous tubules (in testes)

Diploid chromosomal number (2n) = Two sets (23 pairs) of chromosomes

GAMETES: Haploid chromosomal number: (n) - only 1 x set of 23

Question 14

Meiosis v. Mitosis

Answer 14

Meosis:
- Involves 2 x consecutive cell divisions (so 4 daughter cells instead of 2)
-BUT only 1 x round of DNA replication

Functions of Meiosis:
- # of chromosomes cut in half (23 instead of 46)
- to introduce genetic diversity

Question 15

The Hypothalamic-Pituitary-Gonadal (HPG) Axis

Answer 15

1. Hypothalamus releases GnRH
2. This causes anterior pituitary to release FSH + LH

3a) FSH = causes sperm to be produced (follicle stimulating hormone)
3b) LH = causes testosterone to be produced (Lutenizing Hormone)

4) NEGATIVE FEEDBACK = Inhibin released & testosterone levels stop spermatogenesis when sperm count is high

Question 16

Anatomy: OVARY (location, structure, function)

Answer 16

• Produces and stores eggs
• Produces estrogen and progesterone

Question 17

Anatomy: FIMBRAE (location, structure, function)

Answer 17

Have cilia that sweep egg into the oviduct/fallopian tubes

Question 18

Anatomy: UTERINE TUBE (location, structure, function)

Answer 18

aka fallopian tubes
- conducts the egg into the uterus
- site of fertilisation

Question 19

Anatomy: UTERUS (location, structure, function)

Answer 19

muscular chamber where the embryo develops

Question 20

Anatomy: CERVIX (location, structure, function)

Answer 20

Opening of uterus/neck of vagina
- NEARLY closes off outer end of uterus
- Supports developing embryo during pregnancy

Question 21

Anatomy: VAGINA (location, structure, function)

Answer 21

Receptable for semen,; birth canal

Question 22

Oogenesis

Answer 22

Production of female gametes (eggs)

Question 23

Oogenesis v. Spermatogenesis

Answer 23

1. NUMBER OF FUNCTIONAL GAMETES DIFFER:
   - Oogensis: 1 viable ovum
   - unequal divisions = ensures oocyte has nutirnets to survive 6-7 day journey to uterus
   - Spermatogenesis: 4 viable sperm
2. ERROR Rates:
   - Oogenesis: 20%
   - Spermatogenesis: 3-4%

Question 24

Ovarian Cycle (2 x phases)

Answer 24

Follicular phase (days 1-14)
Luteal phase (days 15-28)

Follicular phase = period of vesicular follicle growth (growth of egg)
Luteal phase = period of corpus luteum activity

OVULATION (release of egg) = mid cycle

Follicular phase: time can sometimes vary (not always 14 days)
Luteal phase: always 14 days

Question 25

Regulation of Ovarian Cycle**

Answer 25

BEFORE puberty: small amount of estrogen (from ovaries) INHIBITS hypothalamic release of GnRH

2. (if leptin levels are adequate), hypothalamus becomes less estrogen-sensitive and releases GnRH. (step 1 of the males one)
3. This causes the anterior pituitary to release FSH and LH (step 2 of males one)
4. POSITIVE FEEDBACK: Events continue until an adult cyclic pattern is achieved, and menarche occurs

Question 26

Menstrual Cycle (3 x phases)

Answer 26

• Menstrual Phase (day 1-5)
• Proliferative Phase (day 6-14)
• Secretory Phase (day 15-28)

Question 27

Menstrual Cycle: Menstrual Phase

Answer 27

• Days 1-5
• Uterine lining is shed
• Ovarian hormones at their lowest
• END OF PHASE: Ovarian follicles start to produce more estrogen

Question 28

Menstrual Cycle: Proliferative Phase

Answer 28

• Days 6-14
• Functional layer of endometrium is rebuilt
• Estrogen levels rise / peak end of cycle
• FSH & LH peaks end of cycle
• Progesterone starts to rise