The Male Reproductive System Key Concept: Humans reproduce sexually. They have specialized organs that are responsible for reproduction. Objective: I will learn the structures and function of the male reproductive system.
Human Reproduction Purposes: Keep species in existence Create differences (variation) in the population
The function of the male reproductive system is to make and deliver sperm to the female reproductive system.
Overview The male sex glands are known as the testes. Males have two testicles that are located outside of the body and are protected by a skin covered sac known as the scrotum. The testes produce the male sex hormone known as testosterone.
Testosterone Regulates sperm production and the development of male characteristics. Plays a key role in muscle, bone mass, and hair growth. Males produce 10 times more than females. It is necessary for normal sperm development. Steroids
The Scrotum The scrotum is a pouch of skin that houses the testicles. Because the scrotum is outside of the body, the testicles temperature is about 6 degrees cooler than body temperature. The job of the scrotum is to regulate testicle temperature.
The Testes (Testicles) The testes produce sperm cells by a process known as spermatogenesis, or meiosis. Animation: Spermatogenesis Sperm cells are formed in the Seminiferous tubules of the testes. From here, the sperm cells move to the Rete Testis, and then through the Efferent Ducts. Sperm cells ultimately reach their final destination, the Epididymis. Sperm are stored here until ejaculation. Efferent Ducts Rete Testis
Ejaculation When the male ejaculates, sperm cells and secretions from three other glands are released from the penis.
The pathway of a sperm cell continued… During ejaculation, the sperm cells exit the epididymus and travel through the vas deferens (ductus deferens). The two vas deferens merge into the single urethral opening. The urethra runs the length of the penis and further up into the body cavity, attaching to the bladder. The sperm cells exit the body through the urethra – this is ejaculation
Some sperm may exit the penis before ejaculation without the male’s awareness. Sexual activity that releases any sperm--even a few--can lead to fertilization and pregnancy. Fertilization occurs when a sperm penetrates an egg.
Glandular Secretions Sperm cells are not the only substance that is released during ejaculation. Sperm cells need a fluid medium to swim in. Releases of fluids from these organs provides the fluid environment: Seminal Vesicles – seminal fluid Prostate Gland – prostate fluid Bulbourethral gland – neutralizing fluid These, plus sperm make-up semen
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Nocturnal Emissions A release of semen while sleeping is a nocturnal emission or a wet dream. This condition is normal in young men and occurs due to more semen being produced than can be stored.
Circumcision This is the removal of the foreskin of the penis. This simple surgical procedure is usually done a few days after birth. Many cultures and religions do this to comply with customs. Medically, it is encouraged to help prevent bacterial infections.
Testicular Cancer Cancer of the testicles usually occurs in younger men rather than older men. Men should be familiar with the way the testicles feel so that any abnormal growth can be detected manually.
Review The male sex hormone is _______. The release of sperm from the male body is called ______. The ____ is the tube through which urine and sperm exit the human male. Sperm are produced in the ____.