[Biology Class Notes] on Human Reproductive System Pdf for EXAM

Reproduction can be defined as the biological process of producing a new individual or an offspring. This process ensures the increase in the number of individuals of a species when conditions are favourable. It is one of the fundamental characteristics of living things and an essential life process.

Types of Reproduction

There are mainly two types of reproduction – 

• Sexual Reproduction – This process of reproduction is very complex and involves the formation and transfer of gametes, followed by fertilization, the formation of the zygote, and embryogenesis.

• Asexual Reproduction – This process of reproduction involves only one parent and the new offspring produced is genetically similar to the parent.

Reproduction in Human Beings

All human beings undergo a sexual mode of reproduction wherein, two parents are involved in producing a new individual. Offspring are produced by the fusion of gametes (sex cells) from each parent. Hence, the newly formed individual will be different from parents, both genetically and physically. In human beings, both males and females have different reproductive systems; hence, they are known to exhibit sexual dimorphism. Males have testes- also called testicles, while the females have a pair of ovaries

Human Reproductive System

The reproduction in human beings involves the fusion of male and female gametes produced in their reproductive system. The male reproductive system is different from the female reproductive system, both in structure and in function.

Male Reproductive System

The male gametes, i.e., sperms are produced within the male reproductive system. Sperms are small unicellular structures with a head, middle piece, and a tail.

The male reproductive system consists of :

A pair of oval-shaped organs masked in a pouch called scrotum which is responsible for the production of sperms and the male hormone testosterone.

It is a sac-like organ that hangs below the penis and behind it. It is the house of the testicles, or testes, and maintains an appropriate temperature required for the production of sperms.

It is a closely coiled tube that lies along the inner side of each testis. It is mainly responsible for storing the sperms and nourishing them. 

They are formed by the union of a vas deferens and duct from the seminal vesicle. These ducts are mainly responsible for carrying sperms and secreting seminal vesicles. 

The sperms produced in the testes are stored in a tube called the epididymis. Here the sperms get matured and pass to the urethra through the muscular tube called vas deferens.

This includes three glands, namely seminal vesicles, prostate gland, and Cowper’s gland or bulbourethral gland. 

i. Seminal Vesicle – These are a pair of sac-like structures present near the base of the bladder. The secretion of this gland is alkaline and forms almost 60 % of the volume of the semen. The pH of the seminal fluid is 7.4 and it plays an important role in neutralising the acidic environment of the male urethra.

ii. Prostate gland – This gland surrounds the urethra and the secretion of this gland serves the purpose of nourishment and activates the spermatozoa to swim.

iii. Cowper’s gland – These glands are present on either side of the urethra and the secretion of these glands is alkaline. This alkaline secretion neutralises the acids present in the urine.

Penis is a cylindrical tube-like structure that serves as both a reproductive organ as well as an excretory organ. It helps to put sperms into the vagina during sexual intercourse.

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Functions of the male reproductive system

The functions of the male reproductive system are summarised below:

• Occurrence of spermatogenesis by which sperms are produced.

• Male sex hormones are released by Leydig’s cells.

• At the time of copulation, copulatory organs (penis) transfers the sperms to the female reproductive system.

Female Reproductive System

The female reproductive system is active before, during, and after fertilisation as well. It consists of the following parts:

Ovaries are paired structure and they are the primary sex organs in females.  Ovum is produced and stored in Ovaries. Ovaries are also responsible for producing female sex hormones.

They are the site of fertilisation. They connect ovaries with the uterus. Each Fallopian tube consists of the following parts-

i. The infundibulum

ii. The ampulla

iii. The isthmus

iv. The uterine part

Uterus is the site of development for the embryo.

It is the part that connects the cervix to the external female body parts. It also forms the route for the penis during coitus as well as a foetus during delivery.

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Functions of the Female Reproductive System

The functions of the female reproductive system are given below:

During puberty, eggs in the ovaries start to mature. One of the ovaries releases the mature ovum every 28 to 30 days and the process is called ovulation.

Reproduction Process in Human Beings

The process in which zygote is produced by the fusion of sperm with egg is called Fertilisation. It is a crucial stage of reproduction in human beings. The fertilised egg is called the zygote. Zygote starts to divide into many cells and develops into an embryo. Embryo moves into the uterus and gets attached to its walls. This process is referred to as implantation, and the implanted embryo eventually develops into a foetus.