The Reproductive System Lesson Overview The Reproductive System

Sperm Structure A mature sperm cell consists of a head, which contains a highly condensed nucleus; a midpiece, which is packed with energy-releasing mitochondria; and a tail, or flagellum, which propels the cell forward. At the tip of the head is a small cap containing enzymes vital to fertilization.

The Male Reproductive System This figure shows the structures of the male reproductive system.

The Male Reproductive System Vas deferens: extends upward from the scrotum into the abdominal cavity and eventually merges with the urethra Function: tube that carries sperm from the epididymis to the urethra

The Male Reproductive System Penis: tube outside of the body that is considered the male sex organ Function: is used for urination and during sexual functions

The Male Reproductive System Urethra: tube outside of the body that is considered the male sex organ Function: tube through which urine leaves the body

The Male Reproductive System Seminal vesicle: located behind the bladder, above the prostate gland Function: holds the liquid that mixes with sperm to form semen

The Male Reproductive System Prostate gland: walnut-sized gland located between the bladder and the penis Function: secretes fluid that nourishes and protects sperm

The Male Reproductive System Epididymis: long, coiled tube connecting the testes to the vas deferens Function: stores sperm and transports it from the testis

The Male Reproductive System Testes— the primary male reproductive organs Function: produces sperm The temperature in the scrotum is a few degrees lower than the normal temperature of the body. The lower temperature is important for sperm development.

The Male Reproductive System Scrotum: thin sac of skin that is located externally Function: hold the testis and is the body’s way of controlling the climate of the testis

Female Reproductive Structures About 400 eggs are released in a woman’s lifetime. The figure shows the other structures of the female reproductive system.

Female Reproductive Structures Oviduct (Fallopian tube): is a narrow tube about 10 cm long and is located at top of the ovary Function: passageway to the uterus

Female Reproductive Structures Ovary: primary female productive organ Function: produces egg

Female Reproductive Structures Uterus: is a hollow, muscular organ with thick walls, roughly the size and shape of a pear Function: to contain and protect the developing baby – where the developing fetus is implanted

Female Reproductive Structures Cervix: neck of the uterus Function: to connect the uterus to the vagina

Female Reproductive Structures Vagina: flexible, thin-walled organ about 9 cm long Function: used during sexual functions, birth canal through which the baby exits during birth, and a passageway for menstrual flow

Early Development Ovulation: releasing of the egg into the ovary and is drawn up into the Fallopian tubes Fertilization: the fusion of the sperm and egg in the oviduct or Fallopian tubes Implantation: attaching of the blastocyst into the uterus wall Gastrulation: production of the 3 cell layers of the embryo

Early Development 5. Neurulation: formation of the nervous system

Development of the Fetus Placenta: is the connection between the mother and embryo that acts as the embryo’s organ of respiration, nourishment, and excretion Umbilical cord: connects the embryo to the placenta Amniotic sac: the thin membrane that cushions and protects the developing embryo. Amniotic fluid: fluid inside of amniotic sac

Development of the Fetus