HUMAN BODYREPRODUCTIVE SYSTEM

MALE REPRODUCTIVE SYSTEM Testes - Also called gonads 2 of them Suspended in a sac called the scrotum Produce sperm Located outside the body where the temperature is lower and won’t kill the sperm Produces testosterone the male hormone Testosterone is responsible for secondary sex characteristics such as deeper voice, facial hair, larger muscles, and body hair

EPIDIDYMIS Sperm leave the testes and enter the epididymis Tightly coiled tube, 20 feet long Located in the scrotum, just above the testes Function  Store sperm until it matures  Produce fluid which becomes part of semen

VAS DEFERENS Function  Receives sperm from the epididymis  Temporarily stores sperm Extends from the epididymis into the abdominal cavity Tube that is cut during a vasectomy, the procedure to produce sterility in males

URETHRA Tube that extends from the bladder, through the penis, to the outside of the body Carries semen and urine 5-7 inches long in male

PENIS External male reproductive organ Enlarged structure on the end of the penis – glands penis This is covered by the foreskin The foreskin is removed in a procedure called circumcision

FEMALE REPRODUCTIVE SYSTEM Ovaries - Female gonads 2 small almond-shaped glands, located in the abdominal cavity, attached to the uterus by ligaments Contains thousands of small sacs called follicles Each follicle contains an immature egg or ovum Produce the hormones estrogen and progesterone Responsible for the secondary sex characteristics – breasts, hips widen, body hair

OVULATION The maturing and release of an egg Occurs every 28 days If egg is not fertilized, the body sheds the lining of the uterus and menstruation occurs

FALLOPIAN TUBES 2 of them 5 inches in length Attached to the upper part of the uterus Function  Move the ovum from the ovary to the uterus  Cilia and peristalsis keep the ovum moving  Site of fertilization, the union of the egg and sperm

UTERUS Hollow, muscular, pear-shaped organ Function  Organ of menstruation  Allows for the development and growth of the fetus  Contracts during birth to aid in the expulsion of the fetus Layers - endometrial - If fertilization does not occur, this lining deteriorate, resulting in menstruation

VAGINA Muscular tube that connects the cervix to the outside of the body Function  Passageway for menstrual flow  Receives sperm and semen from the male  Female organ of copulation  Birth canal during delivery of the infant

CONCEPTION  After ejaculation into the vagina, sperm swim to meet an egg  Sperm live 5-7 days (need cervical mucus)  Eggs live about hours, so conception only occurs during this short window  Fertilization occurs in the fallopian tube

Cleavage occurs over several days following fertilization. The zygote divides as it travels through the oviduct(day 1-4). By the time the cilia of the oviduct deliver the embryo to the uterus, the embryo is a ball of cells called a blastocyst. The blastocyst implants in the endometrium. CLEAVAGE

Nutrients and waste products are exchanged between the fetus and the mother within the placenta. The umbilical vein (red) carries oxygen-rich blood and nutrients to the fetus. The umbilical arteries are blue, indicating that they carry oxygen- depleted blood and waste products away from the fetus. NUTRIENT EXCHANGE

STAGES OF LIFE AT 5 WEEKS (EMBRYO), 14 AND 20 WEEKS (FETUS)

GROWTH AND DEVELOPMENT Zygote – 1 st day of conception through the 4 th day Embryo – 4 th day until 8 th Week Fetus – 8 th Week - birth Birth - around 9 th or 10 th month Infancy – birth until 1 year of age Toddler – 1-3 years of age Childhood – 3-13 years of age Puberty – age years of ae Early Adulthood – years of age Middle Adulthood – years of age Late Adulthood – 65+ years

CHILDBIRTH During childbirth: 1)Amniotic sac breaks inside the mother’s uterus 2)Estrogen induces oxytocin receptors on the uterus which stimulates the uterus to contract 3) These contractions push the baby out of the uterus and out of the body 4) Umbilical cord is cut

STAGES OF LIFE Embryologically, males and females start out “sexually indifferent”  Gonads, ducts and externally identical structures  At 5 weeks gestation changes start to take place Puberty: reproductive organs grow to adult size and reproduction becomes possible  Between 10 and 15  Influence of rising levels of gonadal hormones  Testosterone in males  Estrogen in females Female menopause (between 46 and 54):  Loss of ovulation and fertility