The Male Reproductive System
Structure and function Composed of both internal and external organs. Internal organs - store, nourish, and transport the sperm cells once they are produced. External organs - produce, store, and release the sperm. Once released, a sperm cell unites with an egg from a female in order for reproduction to occur. This process is called fertilization.
Testes 2 major functions ◦1. The production of male hormone testosterone ◦2. The production of sperm Hang outside the body within a sac of skin called the scrotum. Scrotum – protects the sperm by keeping the temperature of the testes slightly lower than body temperature. Sperm need lower temperature in order to form and survive
Epididymis A J-shaped tube located on the back of each testis. Within the epididymis, sperm mature and gain the ability to move then are stored for several weeks.
Penis The penis is the external sexual organ through which sperm leave the body. The tip of the penis, also called the head, is covered with loose skin. (foreskin) In some males the foreskin is removed shortly after birth. This procedure is called a circumcision. Over the years circumcision has been performed for both religious and health reasons.
Circumcision Some physicians think removing the foreskin helps to keep the penis clean and free from possible infection. Others think that regular daily cleanliness will prevent any possible problems.
Other Glands and Ducts Vas Deferens – an 18 inch tube that receives sperm from the epididymis. Urethra – A tube that passes through the penis to the outside of the body. The urethra carries urine and sperm but not at the same time. A valve in the urethra prevents the two from mixing.
Sperm Production Once a male reaches puberty, millions of sperm are produces in his body each day. For most men, sperm continues to produce throughout adult life unless the reproductive system is altered in some way. Sperm productions occurs when the hypothalamus signals the pituitary gland to release FSH and LH which in turn stimulates the cells of the testes to produce testosterone.
Sperm Production The fluids from the seminal vesicle, Cowper's gland and prostate gland form the composition of semen. 60% from seminal vesicle 5% from Cowper’s Glands 35% from Prostate Gland
Ejaculation The ejection of semen from the penis Ejaculation occurs when muscles at the base of the bladder, prostate, and seminal vesicles contract, forcing semen through the vas deferens and urethra. In a normal state, the penis is soft, and hangs from the front of the body. Ejaculation can occur when the penis is in an erect state. Erection – A condition in which the penis becomes larger and stiffer as blood chambers in the penis become filled with blood.
Erections Can be causes by different factors ◦Sexual excitement ◦Tight clothing ◦Or no reason at all (puberty) Nocturnal emission (wet dream) ◦ An erection and ejaculation during sleep
Follicle Stimulating Hormone (FSH) FSH regulates the development, growth, pubertal maturation, and reproductive processes of the human body. Released from Anterior Pituitary Gland Stimulates the production of sperm
Luteinizing Hormone (LH) Stimulates the production of testosterone
Scrotum Protects the sperm by keeping the temperature of the testes slightly lower than body temperature. Sperm need lower temperature in order to form and survive
Testes 2 major functions ◦1. The production of male hormone testosterone ◦2. The production of sperm The testes hang outside the body within a sac of skin called the scrotum.
Eididymus A J-shaped tube located on the back of each testis. This is where sperm mature are stored for several weeks.
Penis The penis is the external sexual organ through which sperm leave the body.
Urethra A tube that passes through the penis to the outside of the body. The urethra carries urine and sperm but not at the same time. A valve in the urethra prevents the two from mixing.