The penis is a man’s reproductive and sex organ. It is formed of three columns of spongy tissue — the corpus spongiosum and two corpora cavernosa — that fill with blood during sexual excitement, causing an erection (“hard on”). The penis extends from the lower portion of the belly. It is made up of a shaft and a glans (also known as the head) and is very sensitive to the touch. A man’s urethra is enclosed in his penis. It carries urine, pre-ejaculate, and semen out of his body.
The shaft looks like a tube. The shaft of the penis is about 1–3 inches long when soft. During an erection, the shaft expands to generally reach 4–6 inches.
The glans is the soft and highly sensitive part of the penis, located at its tip.
- Opening of the Urethra
The opening of the urethra is located at the tip of the penis. This is where pre-ejaculate, semen, and urine leave the body.
The foreskin is a retractable tube of skin that covers and protects the head (glans). Some men have had their foreskin removed by circumcision during infancy. Some choose or need to be circumcised later in life.
The frenulum is where the foreskin attaches to the underside of the penis just below the glans. Usually, a portion of it remains after circumcision.
The scrotum is a sack of skin divided into two parts, enclosing the internal reproductive organs — the testicles.
Testicles have 2 main functions:
– They make male hormones (androgen’s) such as testosterone.
– They make sperm, the male cells needed to fertilize a female egg cell to start a pregnancy.
During ejaculation, sperm cells are carried from the epididymis through the vas deferens to seminal vesicles, where they mix with fluids made by the vesicles, prostate gland, and other glands to form semen. This fluid then enters the urethra, the tube in the center of the penis through which both urine and semen leave the body.
Sperm cells are made in long, thread-like tubes inside the testicles called seminiferous tubules. They are then stored in a small coiled tube behind each testicle called the epididymis, where they mature.
The information above has been adapted from:
Why do Men Have Nipples
Essentially, men have nipples because nipples are part of the basic human design option at conception. While modern societies may view nipples as secondary sexual organs, in reality a foetus of either sex develops nipples within a few weeks of conception. The human foetus actually develops several sets of nipples, much like other mammals, but only one set will fully mature in the womb. At this point in a foetus’ development, there is no genetic difference between male or female. All foetuses develop nipples, chest muscles and milk glands.