Reproductive cycle - human development, Biology

Assignment Help:

Reproductive Cycle

The whole reproductive cycle consists of an ovarian cycle and a uterine cycle. Figure illustrates one complete reproductive cycle. You can observe in the figure the - interrelationship among the hypothalamus, pituitary, ovaries and uterus. The average reproductive cycle is spread over 28 days. It commences at puberty and generally continues throughout the reproductive years. The cycle readies the reproductive system for pregnancy. Refer to figure frequently as you read the following discussion. It will assist you to understand the close relationship between the two components of the whole reproductive cycle.

1726_reproductive cycle.png

Figure: interrelationship of the hypothalamus, pituitary, ovaries and endometrium. One complete menstrual cycle shown. Note that the cyclic activity of the ovary is intimately linked with the changes in the endometrium.

The hypothalamus synthesizes the gonadotropins releasing hormone (GnRH) which stimulates the anterior pituitary to secrete follicle stimulating hormone (FSH) and luteinizing hormone (LH). The ovarian cycle starts with the phase of follicular growth in the ovary after the end of preceding, menstrual cycle and lasts for about 14 days. In the first half of this period FSH stimulates the growth of 5-12 primary follicles out of that usually only one matures at a time. The maturing follicle secretes estrogen that exerts a feedback control on anterior pituitary inhibiting further FSH production therefore preventing maturation or more follicles. The follicular phase comes to an end along with the maturation of one follicle and its release from the ovary leading to ovulation, on day 14. At the time of ovulation the ovum is in the secondary oocyte stage surrounded by the non-cellular zona pellucida and follicle cells which make the zona radiata (or corona radiata). Following ovulation, from day 15 to 28 production of LH from anterior pituitary stimulates the formation of corpus luteum from the follicle cells left at the back in the ovary. The corpus luteum secretes the hormone progesterone which makes the endometrium for implantation of embryo and later maintenance of pregnancy during early stages. If the ovum is not fertilized, the corpus luteum degenerates and menstruation starts again.

 

 


Related Discussions:- Reproductive cycle - human development

Define absorption of calcium from dietary calcium supplement, Define Absorp...

Define Absorption of Calcium from dietary calcium supplements? Absorption from dietary calcium supplements is important to know, since they are almost universally recommended f

Meal planning and nutrient needs of fast-growing infants, Define meal plann...

Define meal planning and nutrient needs of fast-growing infants? We just got to know the meal planning and nutrient needs of fast-growing infants and preschoolers in the previo

Define the term epimerism, Define the Term Epimerism? In addition to D ...

Define the Term Epimerism? In addition to D and L isomerism sugars also exhibit epimerism. Hexoses that differ from each other as a result of variation of H and OH on carbons 2

Parturition , P ARTURITIO N - Gestation period is of 280 days (in rab...

P ARTURITIO N - Gestation period is of 280 days (in rabbit 28 days). Parturition is the expelling of fully mature young ones from the mother's uterus. Oxytocin stimulates

Influence of diabetes mellitus, Influence of Diabetes Mellitus :  Diabetes...

Influence of Diabetes Mellitus :  Diabetes causes micro vascular obstructive disease in heart, kidney, retina and peripheral nerves. Scrupulous rather than casual control of diabe

Define the indications for root-end resection apicoectomy, Define the Indic...

Define the Indications for Root-End Resection Apicoectomy a) Persistent..... "Exactly the SAME of Curettage except the biopsy. b) When the apical portion of the root canal s

Define effect of nutrition on the immune system, Define Effect of Nutrition...

Define Effect of Nutrition on the Immune System? Nutrition has a strong influence on the immune system of the elderly. Ageing induces dysregulation of the immune system, mainly

Infectious coryza, I nfectious coryza A highly infectious bacterial di...

I nfectious coryza A highly infectious bacterial disease of chickens caused by Hemop hilus paragallinarum, is characterized by catarrhal inflammation of the upper respirator

What is cytogenetics, What is Cytogenetics? Before the advent of modern...

What is Cytogenetics? Before the advent of modern technology, the American biologists Thomas Hunt Morgan, G.W. Beadle, H. Sturtevant, Barbara McClintock, and others contributed

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd