Important Notes on Human Reproduction for NEET Biology

Important Notes for NEET Biology - Human Reproduction

Human Reproduction is an avital chapter for the NEET exam preparation as per the NEET biology syllabus. This article is going to fulfill all your understanding, and it would be helpful for the NEET aspirants and as well as for the other exams. These important notes of biology for human productions for NEET will cover all the significant concepts and topics for the exam. Check and refer this article for gaining the utmost knowledge and do not let your preparation go futile and quickly start preparation with important notes of biology for human production to crack NEET within the first attempt.


Human Reproduction - Introduction:

  • Reproduction is a process of producing progenies, and the reproductive system is a system of organs that partakes in this reproduction process.

  • Humans are viviparous, and they are sexually reproducing their offspring. The rate of reproduction is always logier in sexual reproduction.

  • The human’s reproductive system consists of three distinguishable sex organs; these are:

  • Primary Sex Organs: Primary sex organs are also considered as gonads that form gametes like ovary in females and testis in males.

  • Secondary Sex Organs: Glands and ducts are essential for sexual reproduction and do not produce gametes that are considered secondary sex organs.

  • Accessory/External Sex Characters: These are the criteria which do not possess a direct role in reproduction but significantly provide definite structures to both male and female. 


The Male Reproductive System: 

The male reproductive system is situated in the pelvis region and includes a paired duct system such as vasa efferentia, urethra, epididymis, vas deferens, ejaculatory duct, and a pair of the testis.


Testes:

  • Testes are located within a pouch of the outside of an abdominal cavity called scrotum.

  • In the scrotum, sperms are generated at the 2-2.5C lower temperature than the body temperature. They are being produced in the seminiferous lobules, which are the coiled section of testicular lobules.

  • The testes are connected to the scrotum by gubernaculum testis, and the inguinal canal is the medium by which scrotum communicates with the abdominal cavity.

  • There are also two types of cells present: Male-germ cells and Sertoli cells.

  • Germ cells produce spermatozoa by undergoing spermatogenesis, and Sertoli cells are identified as nurse cells for distinguishing spermatozoa. 


Secondary Sex Organs:

  • Through rete testis, the seminiferous tubules open into the vasa efferentia, and thereafter it leaves the testes and opens into the epididymis.

  • The epididymis is differentiated into three parts: Anterior caput epididymis, middle corpus epididymis, and posterior cauda epididymis. 

  • Ejaculation takes place due to the robust contraction of the urethra, and the duct system operates the semen to the exterior. 

  • Ejaculatory ducts assist in the emission of seminal fluid.

  • The urethra is present from the bladder through the prostate glands and finally into the penis. It consists of four parts: Prostatic, urinary, membranous, and penile. 

  • The penis is the concourse organ, and the glans penis is highly sensitive to stimulation. 


Hormonal Control of Male Reproductive System:

Leydig’s cells of testis secrete the testosterone hormone, which helps to maintain the growth and functions of the secondary sex organs. Well, the Follicular Stimulating Hormone (FSH) and Interstitial Cells Stimulating Hormone (ICSH) control the Leydig’s cells of the testis and seminiferous tubules.   

(Image to be added soon)


The Female Reproductive System: 

The Female Reproductive System includes a pair of oviducts, ovaries, a uterus, a vagina, a pair of mammary glands, and external genitalia. 

(Image to be added soon)


What is the Menstrual Cycle?

  • This is the cyclic change in the reproductive propagation of females.

  • The first menstruation begins at puberty, and it happens every month when the lining of the womb sheds and red blood like material comes out from the vagina.

  • Menstruation signals indicate that women are releasing eggs that can be fertilized.

  • The duration of the menstrual cycle differs from one woman to another, and the average time period is 28 days. This remains to stop in the time of pregnancy and may be inhibited during lactation and totally stops at menopause.


Fertilization and Implantation: 

  • The process of fertilization is known as the fusion of sperm with an ovum which forms a diploid.

  • This process activates the secondary oocyte cell to overpast the division.

  • This usually happens when sperm and egg interact with ampulla.

(Image to be added soon)

  • During the process of fertilization, a sperm gets in touch with an ovum, and the changes in the membrane restrict the entry of additional sperms. 

  • The secretions of the acrosome aid the sperm to enter into the cytoplasm of ovum, and thus the meiotic division of the secondary oocyte induces the completion process. Soon the ovum and the haploid nucleus are combined together to make a diploid zygote.

  • Cleavage happens expeditiously in the active cytoplasm, and it is the mitotic division of the zygote, which forms blastomeres.

  • After 5th cleavage and 31 cell division, Morula forms, and it significantly changes to blastula due to the blastomeres rearrangements.

  • Blastulation is a process of blastula formation, and a mammalian blastula with a huge blastocoel is known as a blastocyst.

  • The blastomeres are arrayed significantly into an outer layer known as trophoblast, and the attachment of inner cells to trophoblast is known as inner cell mass.

  • The formation of the endometrium happens when the trophoblast layer gets associated with it, and the inner cell mass formed as the embryo.

  • After this procedure, the uterine cells divide expeditiously and cover up the blastocyst. Thus, blastocyst gets inlaid to the endometrium. This leads to pregnancy.  

  • The implantation occurs in between 6th to 9th day after fertilization

(Image to be added soon)

FAQ (Frequently Asked Questions)

1. What is The Size of The Ovum?

The size varies in animals and generally, it varies from 10 microns to a few centimeters.

2. What is Spermatogenesis?

This is a biological process where the haploid spermatozoa produce the germ cells.

3. What is The Timing of The Gestation Period Animals?

The gestation period varies from one animal to another. For cats and dogs, it takes 60-65 days and for elephants, it takes 22 months.

4. What is The Reason Behind Menopause?

It generally occurs between the age of 45 to 55 and the reason is the cessation of the female reproductive system. Another reason is: ovaries gradually curtail the secretion of estrogen.

5. How Does The Foetal Ejection Reflex in Human Females Induce?

The Foetal ejection reflex in human females induced by the completely developed placenta and foetus.