Human Reproduction

Question 1

Describe scrotum function

Answer 1

A sac of skin that holds the testes outside the body so spermatozoa develop at a lower temperature (temperature regulation)

Question 2

Describe testes function

Answer 2

Spermatogenesis and testosterone production

Question 3

Describe epididymis function

Answer 3

Coiled tube pressed against testes. Sperm gain motility and increase in concentration

Question 4

Describe vas deferens function

Answer 4

Carries sperm to urethra, stores spermatazoa

Question 5

Describe seminal vesicle function

Answer 5

Secretes mucus and watery alkali fluid containing nutrients (e.g. fructose for resp)

Question 6

Describe prostate gland function

Answer 6

Secretes mucus and alkaline fluid that helps neutralise acidity of the vagina and urine making spermatazoa more active

Question 7

Describe urethra function

Answer 7

Carries sperm and urine through the penis

Question 8

Describe seminiferous tubules function

Answer 8

Coiled tubes inside the testes. Site of spermatogenesis

Question 9

Describe interstitial cells function

Answer 9

Cells between seminiferous tubules that produce testosterone

Question 10

Describe Germinal epithelium function (testes)

Answer 10

Layer of cells surrounding the seminiferous tubules

Question 11

Describe Sertoli cells function

Answer 11

Secretes fluid that provides oxygen and nutrients (and removes waste) for developing sperm cells

Question 12

Describe ovary function (animals)

Answer 12

Site of oogenesis. Secretes oestrogen and progesterone

Question 13

Describe fallopian tube/oviduct function

Answer 13

Carry oocytes from ovaries to uterus. Lined with cilliated epithelium

Question 14

Describe uterus function

Answer 14

Behind bladder. Where implantation occurs. Grows during pregnancy

Question 15

Describe endometrium function

Answer 15

Inner most layer of the uterus. Built up and shed every month unless an oocyte is fertilised where it is then maintained

Question 16

Describe cervix function

Answer 16

Narrow entrance to the uterus from the vagina. Normally blocked by a plug of mucus and a ring of muscle which can close it

Question 17

Describe vagina function

Answer 17

Muscular tube that stretches during pregnancy and sex

Question 18

Describe penis function

Answer 18

Contains erectile tissue. When excited, the tissue fills with blood and becomes errect. Ejaculation

Question 19

Describe Germinal epithelium function (ovaries)

Answer 19

Layer of cells on the outer border of the ovary

Question 20

Describe primary follicles

Answer 20

Found close to the outside of the ovary and appear as a cluster of follicular cells with a larger primary oocyte in the middle

Question 21

Describe what a secondary oocyte is surrounded by

Answer 21

Surrounded by cumulus cells which compose the Corona radiata

Question 22

Describe the antrum

Answer 22

Fluid filled and opaque

Question 23

Describe a Graafian follicle

Answer 23

Found towards the centre of the ovary with a large antrum

Question 24

Describe the zona pellucida

Answer 24

A dark staining region around the outside of the oocyte

Question 25

Name the three stages for fertilisation

Answer 25

Capacitation, acrosome reaction, cortical reaction

Question 26

Describe capacitation

Answer 26

Sperm head is changed to make it capable of fertilisation: cholesterol and glycoproteins are removed from the cell membrane over the acrosome making it more fluid and permeable to calcium ions. This occurs in the uterus

Question 27

Describe acrosome reaction

Answer 27

Acrosome and membrane of the sperm cell rupture and release hydrolytic enzymes that digest the cells of the Corona radiata and zona Pellucida. The cell membrane of the sperm also becomes capable of fusing with the cell membrane of the secondary oocyte

Question 28

Describe cortical reaction

Answer 28

Cortical granules fuse with the cell membrane of the secondary oocyte releasing their enzymes causing the zona Pellucida to harden making a fertilisation membrane. It prevents further entry of sperm and hence polyspermy

Question 29

Define cleavage

Answer 29

Mitotic divisions of the zygote to ultimately form a ball of cells called the blastocyst. The cells get smaller and smaller as this continues

Question 30

Define blastocyst

Answer 30

A fluid filled ball of cells (called blastomeres) formed by the repeated cell division (cleavage) of a zygote. It's formed 3-4 days after fertilisation (in humans)

Question 31

Define trophoblast

Answer 31

Cells forming the outer layer of the blastocyst which will become the chorion and the placenta

Question 32

Define inner cell mass of a blstocyst

Answer 32

Collection of cells on one side of the blastocyst which will give rise to the embryo

Question 33

Define blastocoel

Answer 33

Fluid filled central cavity in the blastocyst

Question 34

Define implantation

Answer 34

The sinking of the blastocyst into the endometrium of the uterus

Question 35

Describe the role of the amniotic fluid

Answer 35

1) maintain foetal temperature 2) provide lubrication 3) shock absorber protecting the foetus from injury from outside the uterus