Flashcards
Module: Sexual Reproduction in Humans
Q: Function of epididymis:
Stores spermatozoa after being produced on the seminiferous tubules. The sperm
become mobile.
Q: Function of the scrotum:
External skin sac that holds the testicles.
Q: Function of the vas deferens:
Long, muscular tube that carries spermatozoa to the urethra.
Q: Function of the prostate gland:
Secretes fluid which contains zinc
Q: Function of the seminal vesicles:
Release mucus containing fructose into vas deferens.
Fructose is used for respiration in sperm.
Q: Function of the urethra:
Tube through which urine and semen are moved out of the penis.
Q: Function of the ovaries:
Site of oogenesis, as well as site of oestrogen and progesterone production.
Q: Function of the fallopian tube:
Carries egg to the uterus for fertilisation to take place.
Q: Function of the cervix:
Ring of muscle that opens and closes to allow birth of baby and maintains
pregnancy.
Q: Function of the Vagina?
Receives penis during sexual intercourse.
Q: Function of the endometrium:
The lining of the uterus, which is released each month during pregnancy.
Q: What is Gametogenesis:
The production of gametes in male or female sex organs.
Spermatogenesis occurs in the seminiferous tubules.
Oogenesis occurs in the uterus.
, Q: What effect does interstitial cells (Cells of Leydig) have on the process of
spermatogenesis?
Secrete testerone which is involved in stimulating the process of spermatogenesis.
Q: What effect does Sertoli cells have on spermatogenesis?
Provide nourishment for cells, as well as, protecting cells in this process.
Q: Describe the process of spermatogenesis to produce mature spermatozoa:
Takes place in the seminiferous tubules.
Cells of the germinal epithelium (Diploid) divide by mitosis to form diploid
spermatogonia and more germinal epithelium.
The spermatogonia divide many times by mitosis and enlarge, making diploid
primary spermatocytes and more spermatogonia.
Primary spermatocytes undergo meiosis 1, making secondary spermatocytes, which
are haploid.
Secondary spermatocytes undergo meiosis 2, making haploid spermatids.
Spermatids mature into spermatozoa.
Q: Describe the structure of a sperm?
The head contains a haploid nucleus, covered at the anterior by a lysosome called
the acrosome, which contains enzymes used at fertilisation.
The middle piece is packed with mitochondria, which provides ATP for movement.
They spiral around the microtubules which extend from the centriole into the axial
filament in the tail.
The tail or flagellum makes lashing movements that move the sperm, although
sperm are not motile until they have been modified in the epididymis.
Q: Describe the process of Oogenesis?
Before birth, in the developing foetus, cells of the germinal epithelium of the ovary,
which are diploid, divide by mitosis to make diploid oogonia, and more germinal
epithelium cells.
The oogonia divide many times by mitosis and enlarge, making diploid primary
oocytes and more oogonia.
The primary oocytes begin meiosis 1 but stop at prophase 1, until puberty occurs.
Germinal epithelium cells divide to form diploid follicle cells, which surround the
primary oocytes, making primary follicles.
From puberty onwards, hormones stimulate the primary follicles to develop further.
Just before ovulation, a primary oocyte completes meiosis 1, making a secondary
oocyte, which contains most of the cytoplasm. The other product of meiosis 1 is a
much smaller cells, called the first polar body. The secondary oocyte and polar body
are haploid.
The primary follicle develops into a secondary follicle, which is called a Graafian
follicle when its mature. It migrates to the surface of the ovary where it bursts and
releases the secondary oocyte, in a process called ovulation. Each month several
primary follicles start to develop but normally, only one matures into a fully
developed Graafian follicle.
