Anatomy and physiology of the male reproductive system

The male reproductive system includes internal and external organs and structures that help with reproduction.

The external male sex organs are the penis, and below it, the scrotum.

Inside the scrotum, there are the two testicles, or testes - the male gonads.

Inside the body, there’s a system of ducts through which sperm travel during ejaculation, as well as the male accessory sex glands, which secrete nourishing fluids for the travelling sperm.

Now, the testes are two organs the size of small plums, that are located in a skin and muscle pouch called the scrotum.

This pouch has a line called the scrotal raphe running down the middle, which separates it in two chambers - one for each testis.

The scrotum hangs outside of the body but has several layers of muscles and fascia that keep the testis temperature about 3 degrees lower than body temperature, which is perfect for sperm production.

When it’s cold outside, the scrotal skin wrinkles and the scrotum elevates to bring the testes closer to the body to warm up.

When it’s warm outside, the scrotal skin loosens up and the scrotum lowers the testes away from the body, and heat is released through sweating.