Human Reproduction

Question 1

Give the function of the seminiferous tubules

Answer 1

Spermatogenesis

Question 2

Give the function of the epididymis

Answer 2

Sperm collect and mature here

Question 3

Give the function of the vas deferens

Answer 3

The tube that takes sperm from testis to urethra during ejaculation

Question 4

Give the function of the seminal vesicle

Answer 4

Releases nutrients which sperm can use for respiration to swim

Question 5

Give the function of the prostate gland

Answer 5

Releases alkaline fluid to neutralise acidic urine

Question 6

Give the steps of spermatogenesis in order

Answer 6

Germinal epithelium (mitosis)->, spermatogonia (mitosis and growth)-> primary spermatocytes (meiosis 1)->secondary spermatocytes (meiosis 2), spermatids (differentiation)-> spermatozoa

Question 7

Which cells nourish and protect developing sperm in the seminiferous tubules?

Answer 7

Sertoli cells (nurse cells)

Question 8

Which cells in the testes release testosterone?

Answer 8

Leydig cells (also called interstitial cells)

Question 9

What is the name for the lysosome found in the head of a sperm cell, and what is its function?

Answer 9

Acrosome. Releases digestive enzymes during the acrosome reaction to hydrolyse the zona pellucida

Question 10

What are the terms for the inner lining of the uterus that sheds, and the muscular layer below?

Answer 10

Endometrium (lining) and myometrium (muscle layer)

Question 11

What are the first haploid cells produced in spermatogenesis?

Answer 11

The secondary spermatocytes

Question 12

What are the terms for the inner lining of the uterus that sheds, and the muscular layer below?

Answer 12

Endometrium (lining) and myometrium (muscle layer)

Question 13

What is the name of the muscular ring at the neck of the uterus?

Answer 13

Cervix. This dilates during labour

Question 14

What steps of oogenesis occur before birth?

Answer 14

Germinal epithelium (mitosis)->,oogonia (mitosis and growth)-> primary oocytes (begin meiosis 1 but stop at prophase 1). The primary oocytes are found in primary follicles

Question 15

What steps of oogenesis occur each month after puberty?

Answer 15

Each month FSH is released from the pituitary gland and causes some primary oocytes to finish meiosis 1, forming secondary oocytes and 1st polar bodies in secondary follicles. One of these fully develops to a Graafian follicle and bursts (ovulation), releasing the secondary oocyte from the ovary

Question 16

What steps of oogenesis occur after fertilisation?

Answer 16

When the sperm fuses with the secondary oocyte it finishes meiosis 2, forming an ovum and a second polar body. When the nucleus of the sperm fuses with the nucleus of the ovum it is a diploid zygote

Question 17

What is the name of the single fully developed follicle that forms in an ovary each cycle, and the name of the fluid filled space within it

Answer 17

Graafian follicle, fluid filled antrum

Question 18

Name the layer of glycoproteins that surrounds a secondary oocyte and the layer of cells on the outside of this that sperm must pass through

Answer 18

Zona pellucida (glycoprotein layer) and corona radiata (cells)

Question 19

What does FSH stand for and where is it released from?

Answer 19

Follicle stimulating hormone, the anterior pituitary gland

Question 20

What does LH stand for and where is it released from?

Answer 20

Luteinising hormone, the anterior pituitary gland

Question 21

What is the function of FSH?

Answer 21

It stimulates primary follicles to begin developing into secondary follicles and stimulates thecal cells in the Graafian follicle to release oestrogen

Question 22

What does oestrogen do in the first half of the menstrual cycle (follicular phase)

Answer 22

Causes the rebuilding of the endometrium, inhibits FSH secretion and stimulates LH secretion

Question 23

Give two functions of LH

Answer 23

Causes ovulation, causes the burst Graafian follicle to become the corpus luteum

Question 24

Which hormones are produced by the corpus luteum?

Answer 24

Oestrogen and progesterone

Question 25

What is the function of progesterone in the menstrual cycle?

Answer 25

Maintains the endometrium to prevent shedding, thickens it further, inhibits release of FSH and LH

Question 26

What causes the endometrium to shed in the menstrual cycle?

Answer 26

After 14 days, if there is no implantation, low LH and FSH cause the corpus luteum to breakdown, reducing its release of progesterone. This allows the endometrium to shed

Question 27

Where does fertilisation occur?

Answer 27

The beginning of the fallopian tubes

Question 28

What process happens to sperm as it swims through the fluid of the uterus?

Answer 28

Capacitation. The membrane covering the acrosome becomes more fluid and influx of Ca2+ increases motility

Question 29

How does the secondary oocyte prevent polyspermy?

Answer 29

The cortical reaction. Enzymes released by exocytosis from cortical granules harden the zona pellucida to prevent further sperm entering

Question 30

Name the hollow ball of cells formed by mitosis of the diploid zygote

Answer 30

The blastocyst. Division of cells to form this is called cleavage

Question 31

Which hormone is released from the blastocyst and what is its function?

Answer 31

Human Chorionic Gonadotropin (HCG). This is detected in a pregnancy test. It prevents the corpus luteum breaking down, so it continues to release oestrogen and progesterone

Question 32

Where do oestrogen and progesterone come from after the second month of pregnancy?

Answer 32

They are released by the placenta

Question 33

List five functions of the placenta

Answer 33

Production of progesterone and oestrogen (replacing the corpus luteum), Exchange of O2 / CO2, nutrients / wastes, A barrier to high blood pressure, bloodborne pathogens and toxins in maternal blood, Allows maternal antibodies to protect the foetus, Prevents antibodies attacking the foetus

Question 34

Which blood vessels carry deoxygenated blood away from the foetus?

Answer 34

The foetal arteries

Question 35

Which blood vessel carries oxygenated blood towards the foetus?

Answer 35

The foetal vein

Question 36

Why is maternal blood in the placenta in lacunae?

Answer 36

It can bathe the foetal capillaries, shortening the diffusion distance as oxygen does not have to pass through maternal capillary walls

Question 37

Give the functions of the amniotic fluid in the amniotic sac

Answer 37

Maintaining temperature, Providing lubrication, Contributing to lung development, Allowing movement, Acting as a shock absorber

Question 38

What does oestrogen do during pregnancy?

Answer 38

Inhibits release of FSH, stimulates the growth of the uterus to accommodate the foetus and causes growth and development of the mammary glands

Question 39

What does progesterone do during pregnancy?

Answer 39

Inhibits release of FSH and LH, suppresses uterine contractions

Question 40

Where is oxytocin secreted from and what is its function?

Answer 40

Oxytocin is secreted by the posterior pituitary gland and causes contractions of the myometrium. After birth it causes contractions of milk ducts in lactation

Question 41

Where is prolactin secreted from and what is its function?

Answer 41

Prolactin is secreted by the anterior pituitary gland and stimulates the mammary glands to synthesise milk.