Reproductive System

What is reproduction?

Reproduction Definition The production of offspring by a sexual or asexual process

Sexual Reproduction Male –Sperm Female- Egg (Ovum) Gonads -Reproductive organs Copyright Pearson Prentice Hall

Fertilization Internal Fertilization Sperm is delivered inside of female Environment must be moist Why?

Development External In water: eggs are soft-shelled and nutrients/wastes can pass through shell by diffusion On land: eggs are hard shelled (to protect growing baby); yolk provides nutrition for growing baby

Internal fertilization Almost all Mammals Most insects, reptiles, amphibians Copyright Pearson Prentice Hall

External Fertilization Copyright Pearson Prentice Hall

The Male Reproductive System Urinary bladder Vas deferens Pubic bone Copyright Pearson Prentice Hall Seminal vesicle Urethra Rectum The main structures of the male reproductive system produce and deliver sperm. The main organs of the male reproductive system are the testes. The testes are located in an external sac called the scrotum. The scrotum is located outside the body cavity, where it is between 1 and 3 degrees cooler than normal body temperature. The lower temperature helps sperm development. The testes are located in an external sac called the scrotum. Within each testis are clusters of hundreds of tiny tubules called seminiferous tubules. The seminiferous tubules are tightly coiled and twisted together. Sperm are produced in the seminiferous tubules. Sperm produced in the seminiferous tubules move into the epididymis, where they mature and are stored. From there, sperm move into a tube called the vas deferens, which extends up from the scrotum into the abdominal cavity. This merges with the urethra, the tube that leads to the outside of the body through the penis. Glands lining the reproductive tract produce seminal fluid. Seminal fluid nourishes sperm and protects them from the acidity of the female reproductive tract. The combination of sperm and seminal fluid is called semen. Penis Prostate gland Epididymis Bulbourethral gland Testis Scrotum

The testes are located in an external sac called the scrotum. The scrotum is located outside the body cavity, where it is between 1 and 3 degrees cooler than normal body temperature. The lower temperature helps sperm development. Copyright Pearson Prentice Hall

Sperm Formation MEIOSIS forms sperm Sperm forms in testes Scrotum keeps cooler than rest Semen is sperm plus protecting fluid Semen leaves testes through the vas deferens (sperm ducts) to the urethra before it exits.

The Male Reproductive System A sperm cell consists of: a head, which contains the nucleus a midpiece, which contains energy-releasing mitochondria a tail, which propels the cell forward Head Nucleus Midpiece Mitochondria The sperm is the male gamete, or sex cell. Tail

Testes Within each testis are clusters of hundreds of tiny tubules called seminiferous tubules. The seminiferous tubules are tightly coiled and twisted together. Sperm are produced in the seminiferous tubules. Sperm produced in the seminiferous tubules move into the epididymis, where they mature and are stored. Copyright Pearson Prentice Hall

Path of Sperm Travel From the epididymus, sperm move into a tube called the vas deferens, which extends up from the scrotum into the abdominal cavity. This merges with the urethra, the tube that leads to the outside of the body through the penis. Copyright Pearson Prentice Hall

Accessory Glands The seminal vesicles, prostate gland, and bulbourethral gland Glands lining the reproductive tract produce seminal fluid. Seminal fluid nourishes sperm and protects them from the acidity of the female reproductive tract. The combination of sperm and seminal fluid is called semen.

Secondary Sexual Characteristics - Male Produced by testosterone Deeper voice Chest and facial hair Lengthen bones Increased size of testes for sperm production https://www.youtube.com/watch?v=-XQcnO4iX_U

Sperm Production (Spermatogenesis) Video Copyright Pearson Prentice Hall