Reproduction

Question 1

Testes

Answer 1

The male gonads, which produce spermatozoa.

Question 2

Bulbourethral Gland

Answer 2

Secrete a clear mucus. It acts as a lubricant and much of it precedes the emission of the semen, with only a small amount in the semen.

Question 3

Labia Majora

Answer 3

Cover and protects the inner structure of the vulva i.e. Collective name for the external genitalia.

Question 4

Scrotum

Answer 4

Climate-control system for sperm production. Muscles of scrotum relax and contract to cool down the testis and warm up the testis respectively.

Question 5

Seminiferous Tubules

Answer 5

Sperm cells mature from spermatogonia within the tubules due to the interstitial cells secreting testosterone.

Question 6

Vas Deferens

Answer 6

Transports sperm from the epididymis to the urethra.

Question 7

Urethra (in men)

Answer 7

This serves a dual function in males. It transports urine and semen to the exterior.

Question 8

Semen

Answer 8

Created from the seminal vesicle, prostate gland, and bulbourethral gland. Aids with nourishment and development.

Question 9

Seminal Vesicle

Answer 9

Secrete a thin fluid, rich in sugars and makes up 60% of the volume of semen.

Question 10

Prostate Gland

Answer 10

Secretes a thin, milky, alkaline fluid.

Question 11

Penis

Answer 11

The erectile tissue fills with blood during sexual arousal. This causes the penis to become erect. Transports sperm to the vagina.

Question 12

Ovaries

Answer 12

Produce ova (eggs).

Question 13

Uterine Tube

Answer 13

Funnel in which cilia and smooth muscle move egg to uterus.

Question 14

Uterus

Answer 14

Protects and nourishes developing fetus.

Question 15

Cervix

Answer 15

Connects uterus to the vagina/forms the birth canal with the uterus and vagina.

Question 16

Vagina

Answer 16

Receives the penis during intercourse and with it, the sperm also.

Question 17

Fimbriae

Answer 17

Passage of ovum from ovary to uterine tubes.

Question 18

Labia Minora

Answer 18

Primarily protective of the inner structures of the vulva, also produces oily secretions for protections and lubrication.

Question 19

Clitoris

Answer 19

Pleasure.

Question 20

Urethra (in women)

Answer 20

Passageway for urine excretion.

Question 21

Spermatogenesis

Answer 21

+ Seminiferous tubules lined with spermatogonia - divide by mitosis to make more.
+ Some spermatogonia move towards the centre of the tubule - become primary spermatocyte (at puberty).
+ Undergoes Meiosis I and produces two secondary spermatocytes.
+ Undergoes Meiosis II and produces 4 spermatids (haploid).
+ Then mature into spermatozoa (sperm).
+ Takes 72 days.

Question 22

Oogenesis

Answer 22

+ Millions of oogonia (immature diploid cells) in ovaries from birth.
+ At birth they are in early Prophase I.
+ Surrounded by layer of follicular cells, referred to as a primary follicle.
+ At puberty, it completes Meiosis I - producing 2 cells. + - Secondary Oocytes (half DNA, nearly all cytoplasm).
+ - Polar Body (half DNA, nearly no cytoplasm).
+ Meiosis II begins - pauses at metaphase II (lining up at the middle, from pole to pole.)
+ It is expelled from the ovary in ovulation - the follicle ruptures.
+ Enters uterine tubes in ovulation - the follicle ruptures.
+ Enters uterine tube - if penetrated by sperm, it quickly completes meiosis II becomes ovum. Other becomes second polar body - that then disintegrates.

Question 23

Hormones

Answer 23

Chemical messengers that are released by endocrine glands and travel throughout the blood.

Question 24

Follicle-stimulating hormone (FSH)

Answer 24

+ Stimulates the development and maturation of the ovarian follicle in women. During development, the ovarian follicle releases its own hormone, oestrogen. FSH secretion is limited as the level of oestrogen increases in the blood.
+ FSH stimulates the epithelial tissue of the seminiferous tubules in the testes to produce sperm.

Question 25

Luteinising hormone

Answer 25

+ Promotes the final maturation of the ovarian follicle, ovulation, and the formation of the corpus luteum. The corpus luteum, (a temporary endocrine structure involved in ovulation and early pregnancy), secretes another ovarian hormone, progesterone, as well as oestrogen. There is a gradual reduction in LH production as the level of progesterone in the blood increases. + LH stimulates cells in the testes to secrete testosterone.

Question 26

Oestrogen

Answer 26

+ Secreted by the developing follicle in the ovary, and the corpus luteum in the follicle. + Placenta also secretes oestrogen. + Development of the reproductive system and secondary sexual characteristics. Important in the initial development of the lining of the uterus.

Question 27

Progesterone

Answer 27

+ Produced by the corpus luteum. + Produced by the placenta. + Primary roles is to develop and maintain the lining of the uterus (called the endometrium), development and maintenance of the placenta, and development of milk-secreting glands in the breast.

Question 28

Human Chorionic Gonadotropin (HCG)

Answer 28

+ Made by the placenta. Maintains the corpus luteum so it can keep making hormones.

Question 29

Testosterone

Answer 29

+ Maintenance of reproductive organs, maturation of sperm, development of secondary sexual characteristics.

Question 30

Ovarian Cycle

Answer 30

+ Includes the maturation of an egg and its release into a uterine tube, followed by the changes that occur immediately after in the ovary. + Roughly 28 day cycle. + Egg is released from one ovary at the mid-point of each cycle. + Maturation of the follicle and the formation of the corpus luteum are key stages in OC. + Oogenesis is occurring alongside the maturation of the follicle that surrounds each egg. + At ovulation, the egg is a secondary oocyte, paused at Metaphase II. + As the egg travels down the uterine tubes it remains paused at Metaphase II. + If fertilised, Meiosis II completes and a zygote is formed. + The ruptured follicle forms the Corpus Luteum.

Question 31

Menstruation Cycle

Answer 31

+ While the ovarian cycle is occurring, changes are also occurring in the uterus called the menstrual cycle. + These changes occur in the lining of the uterus called the endometrium. + These changes are in preparation for a developing embryo to implant. + While the follicle is developing (the follicular phase) the endometrium is proliferating, becoming softer and thicker and filling with capillaries and glands. + After ovulation the lining continues to thicken and the glands produce a watery mucus rich in glycogen (the luteal phase). + If the egg is not fertilised then the corpus luteum breaks down (as no HCG from placenta to keep it going), reducing the amount of progesterone and leading to menstruation - the loss of blood, mucous, and cell debris through the vagina. + This is roughly 14 days after ovulation. + Menstruation is taken as day 1 of the cycle.