The male reproductive system consists of the following organs:  1. Testes,  2. Vas deferens,  3. Seminal vesicle,  4. Urethra.  1. Testes: The male reproductive organs consist of two tests, lying in a special pouch of skin called scrotum sac, outside the body between the two legs. They are specialised for the production of spermatozoa. Each testis is made of the number of coiled tubes called seminiferous opens in the collecting duct, called the epididymis. The sperms are produced by cells of the epithelium layer of the seminiferous tubules and are stored in the epididymis. Each sperm consists of three parts- the anterior end of the sperm is called ahead. The nucleus containing chromosomes is located in the head. Behind the head is the middle portion. The third part is the tail, which helps in its movement.  2. Vas deferens: From each epididymis arises a duct called vas deferens, which opens in the broad structure called seminal vesicles.  3. Seminal vesicle: It is situated on the anterior part of the urethra. From seminal vesicle arises a tube called ejaculatory duct. Before ejection, the sperms are stored in this duct.  4. Urethra: The ejaculatory duct opens in a duct called the urethra, which passes through a long and muscular path, present in the penis. This long path opens outside the body through a small opening. The urine and sperms pass out through this opening hence, it is called the urinogenital aperture.  The female reproductive organs are as follows:  (1) a pair of ovaries  (2) a pair of oviducts or fallopian tubes  (3) Uterus  1. Ovaries: The female reproductive system consists of two ovaries, located in the abdominal cavity, just below the kidney. The ovaries are white or cream-coloured. They are of an oval shape. The inner layer is made up of germinal epithelium cells, which by the process of oogenesis produces eggs. In front of each, there is a funnel-shaped structure called ostium.  2. Oviducts or Fallopian tubes: The posterior end of the ostium is in the form of a duct called oviduct. The Female reproductive organ's walls of the ovary are muscular and made up of ciliated epithelium. The action of cilia and the peristaltic act of the duct walls, help the egg to move towards the uterus.  3. Uterus: The posterior part of the oviduct opens into a hollow sac-like structure called the uterus. The walls of the uterus expand according to need, during the development of an embryo. The anterior tubular part of the uterus is called the vagina and the posterior part is called the vulva.