Question

1. List the stages of development that occur (in order) from ovulation to implantation

2. What is the function of the penile corpora in the male?

3. What hormones from the pituitary gland regulate meiosis (gametogenesis)?

Answer 1

1. Ovulation - Release of ovum from the female gonad 'Ovary'
2. Fertilization - Penetration of the sperm across zona pellucida
3. Formation of zygote - Fertilized egg - Day 1
4. Cleavage - Division of the zygote to form 2,4,8, and 16 cell mass progressively by the mitosis
5. Morula - 16 cell mass - Day 4
6. Blastocyst - A collection of 32 or more embryonic cells
7. Implantation in the uterine wall - Blastocyst implantation into the growing uterine wall - Day 7

2.The Male external genital organ have two types of muscles that helps in the erection(Becoming harder).

1. Corpus Spongiosum (surrounding the urethra) - on the ventral aspect of the external genitalia
2. Corpora cavernosa (2 big cylinder along the length of the external genitalia)

3. FSH.In male reproductive sysytem, spermatogenesis is controlled by the pituitary hormone FSH.

The anterior pituitary has blood vessels connecting the hypothalams. The hypothalamus secretes the Gonadotropin releasing hormone, (GnRH) which travels to the anterior pituitary through the blood vessels. The anterior pituitary secrete two important hormones:

1. Follicle stimulating Hormone (FSH)
2. Lutenizing Hormone (LH)

The FSH travels to male testis by the blood and reaches the seminiferous tubule. Surrounding the seminiferous tubule there is blood vessels & interstitial cells.FSH & LH are released into the interstitial space between the seminiferous tubule and the blood vessels. Within the interstitial cells, there are many cells known as Leydig cells. Within the seminiferous tubule, there are Sertloi cells /Nurse cells.Spermatogonia(Male germ cell) is found in the seminiferous tubule matrix.LH enters to the interstitial space and targets the leydig cells to release the testosterone(Male hormone). The FSH targets sertoli cells stimulating ABP release by the sertoli cells.(Androgen Binding Protein).ABP stimulate the synthesise of the spermatozoa.(spermatogenesis)