The Human Reproductive System

Reproduction

• Not required for the survival of an individual• Reproduction is necessary to ensure the survival of a

species• Individual species produce more of the same species• Endocrine glands (testes – male; ovaries – female)

ensures the sexual maturation of each individual• Testes produces sperm (male gamete/ sex cell)• Ovaries produce egg (female gamete/ sex cell)• All cells in the human body (except gametes) have 46

chromosomes• Each gamete contains 23• Result of fertilization is a zygote with 46 chromosomes

Comparison of the Female andMale Reproductive Systems

• Primary reproductive organs called gonads– ovaries in females – produce oocytes (eggs)– testes in males – produce sperm

• Produce gametes which unite to form a new individual• Reproductive organs produce large amounts of

hormones which affect maturation, development, and changes in the body

• Ovaries produce– Estrogen– progesterone

• Testes produce:– testosterone

Comparison of the Female andMale Reproductive Systems

• Both have accessory reproductive organs, including duct systems to carry gametes away from the gonads toward the site of fertilization (in females) or to the outside of the body (in males).

• Fertilization occurs when male and female gametes meet– A zygote is formed

Comparison of the Female andMale Reproductive Systems

• Primarily nonfunctional and “dormant” until puberty.

• At puberty, external sex characteristics become more prominent

• reproductive organs become fully functional• gametes mature• gonads secrete sex hormones• Both reproductive systems produce gametes• Female typically produces and releases a single

oocyte (egg) monthly• Male produces 100,000,000’s of (sperm) daily.

• Fertilization

• Fertilization and Fetal Development

Female Reproductive System

Pathway of the Egg Cell

• Fallopian tubes (oviducts) are passageways for eggs to travel from the ovary to the uterus

• Each month one of the ovaries releases a mature egg which enters the fallopian tube

• Fertilization usually occurs in the fallopian tube• Egg moves to the uterus

– If fertilized, becomes attached to uterine wall– If not fertilized, the egg breaks down along with the

lining of the uterus and passes out of the body through the vagina in a process call menstruation

Male Reproductive System

Pathway of a Sperm

• Male reproductive system is specialized to produce sperm and testosterone

• Major structures are the testes, scrotum and penis• Sperm cells form in the testes which also produce the

hormone testosterone• Testes located in an external pouch of skin called the

scrotum• During passage through other structures sperm mix with

fluids produced by nearby glands• Mixture of sperm cells and fluids is called semen• Semen contains about 5-10 million sperm per drop• Semen contains nutrients that provide energy to the

moving sperm and a fluid environment in which to swim• Semen leaves the body through the urethra, a tube

located within the penis, urine also leaves the body through the urethra