PENIS:-
This is the main male organ for coitus. This is considered the core symbol of masculinity. It is made of three bodies & covered with skin This varies in size from man to man in flaccid state.The largest organ was 14 cm (5.5 inches) in the flaccid state. It belonged to a slim man who was 5' 7" tall (170 cm).The smallest penis measured 6cm (2.25 inches). It belonged to a fairly heavily built man of 5' 11" (180cm).
GLANS:-
The tip of the penis is known as glans. It is an expansion of the corpus spongiosum. The base of the glans projects out from the main body of the penis and this projecting margin is called corona.
PROSTATE:-
This gland appears to be a sexual organ. In animals which have seasonal sexuality, it is noticed, that the prostate enlarges during a mating season & then shrinks until the next. In the grown up human male, it is about 4 cms across at its base and is the size of a chestnut. The prostate is composed of muscular and glandular tissue. Its secretions pass down about 20 small ducts which lead to the section of the urethra that pierces the prostate gland, but their purpose is not yet fully understood.
SEMEN:-
This is a mixture of secretion from the prostate seminal fluids & spermatozoa from the testes. When a man reaches climax in sexual play, semen starts coming out of the penis with pressure. Each time in two days about 2 to 6 ml of semen comes out when man reaches orgasm.
SMEGMA:-
In clinical terms it is- sebaceous secretion about the penisor labia. Smegma is a mixture of dead skin cells & skin grease and looks like soap as it hides under the foreskin of the penis. In women it is found near clitoris. The presence of it denoted the poor standard of person's hygiene, and it can contribute in transmitting diseases.
SPERM:-
This is the protozoa in semen. This is a male cell, which is capable of penetrating the ovum. Each sperm has an oval shaped head, a centre portion & A long tail. They are generated by testes and once shot into female reproductive tract, they live only a few hours. Many sperm hit the ovum before one pierces the exterior by means of enzyme action & penetrates it. Once one sperm enters the ovum,another sperm cannot enter in it 
TESTES:-
Testes are fairly uniform in size about 4-5 cms in length, 2-5 cms in breadth & 3 cms in width. They are situated below penis. It's main function is to produce sperms. Inside the testes there are about 250 glandular lobes. Tiny tubes collect the spermatozoa & eventually they enter the epididymis where a maturing process usually occurs.