[Biology Class Notes] on Androgen Pdf

Testes are present in human males. They are present in a pair. They are formed from the mesoderm of the endoderm. They are located in the scrotal sac and this sac is present outside the abdominal cavity. This scrotal sac is known as the scrotum. This scrotum is responsible for the production of sperms because sperms require 2-3 degree celsius less temperature than the body. These testes are developed in the abdomen but in the foetal stage, they get transferred to the scrotum. The hormones that are produced by them are called the androgen hormone. It is not necessary that only testes will produce hormones and they are present only in males, some amount of testosterone is even present in the female and that is responsible for giving some male-like characteristics. Dihydrotestosterone or testosterone is the major androgen. In this article, we will learn about what androgen means in detail.

Sertoli Cells

Sertoli cells are present in the testis. They help in the secretion of dihydrotestosterone. The function of Sertoli cells are:

• The parts that are absorbed by the spermatozoa are absorbed by these Sertoli cells. 

• They release anti-mullerian factors. These factors prevent oviduct development in males.

• The blood-testis barrier is formed by the androgen. 

• Androgen-binding protein is released by these Sertoli cells. 

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Testes and Their Hormones

The testes are the primary sex organs and they also act as endocrine glands. As they function like endocrine glands, they can be called adrenal androgens. Seminiferous tubules are present in the testes. Interstitial and stromal tissues are also present in the testes. The process of formation of sperms is achieved by the seminiferous tubules. This helps in fulfilling the function of primary sex organs. Inside the seminiferous tubules, we have the Leydig cells and interstitial cells and these are present inside the spaces of seminiferous tubules. Androgen is steroid hormones that are produced by these Leydig cells and interstitial cells. Dihydrotestosterone is one of the major androgens. The luteinizing hormone influences the Leydig cells to secrete testosterone. 

The Functions of the Androgen Hormone Are:

• Muscular growth is stimulated by the androgens. 

• It helps in the male pattern of the external genitalia. 

• These androgens act on the androgens and they help in influencing male sexual behaviour. 

• Spermatogenesis is the process by which sperms are formed and these androgens help in stimulating that process. 

• The male accessory sex organs are developed with the help of these androgens. 

• Acne on the face is known as androgen acne. 

Testosterone Functions

Testosterone is the strongest androgen and estrogen is a natural anti androgen. 

• The testes are descended with the help of testosterone.

• It helps in the male pattern of development.

• It helps in developing male sexual characteristics.

• It helps in the maintenance of male sexual characteristics. 

• The process of spermatogenesis is stimulated by testosterone

• They help in a growth spurt. 

Disorders of Testosterone

The ovaries produce estrogen. It can function as an anti androgen hormone. When the androgens or the testosterone is not present in sufficient quantities, then we face some issues. 

They are:

• Eunuchoidism: This condition is seen when there is no testes secretion. When this condition occurs, then secondary sex organs such as the penis and testes remain small and dysfunctional. The sperms are also produced. Some secondary sexual characteristics such as beard and moustaches are also not present in these types of males. 

• Gynaecomastia: When breast tissues are developed in males then this condition is known as gynecomastia. This condition is developed when the androgen and estrogen hormones are not present in proper ratios as they are required by the body. Sometimes when there is a decrease in the amount of testosterone even then this condition can occur. The removal of testis from the males can also result in this condition. Dheas PCOS (dehydro epi androsterone)hormone is present in the ovary of the females. Estrogen is one of the strongest natural anti androgens. 

Spermatogenesis

It Occurs in Four Stages:

• Spermatocytogenesis: The spermatogonia present on the wall of the seminiferous tubules multiply by mitotic division and increase in numbers. Each spermatogonium is a diploid containing 46 chromosomes.

• Meiosis-I: A primary spermatocyte is diploid with 44+ XY chromosomes. It completes the primary meiotic division resulting in the formation of two equal, haploid cells called secondary spermatocytes which have 23 chromosomes.

• Meiosis-II: In this stage, the spermatids are reduced to 23 in number. 

• Spermiogenesis: By the end of spermiogenesis, 4 haploid sperms are produced.