Male and Female Reproductive System And Fertilization and Development

Sexual Development At first male and female human embryos are identical in appearance. During the ________________________, the reproductive systems of male and female embryos begin to develop. The male pattern of development is triggered by the production of testosterone in the gonads (makes gametes) of the embryo.

Sexual Development Testosterone and Estrogens have powerful effects on the body. Effects of hormones: Growth of facial hair Increased muscular development _______________________________ Breast development _____________________________

Sexual Development Puberty Period of rapid growth and sexual _________________ When reproductive system becomes fully functional Begins in the ______ when hypothalamus signals the ____________ to produce 2 hormones that affect the gonads. Between ages of 9 and 15 Females begin 1 year earlier than males

Holds urine Sperm pathway Make fluid for semen Skin sac that holds testicles And vessels Produces sperm & male hormone Sperm mature & travel through

Sexual Development What are the main functions of the male reproduce system? When puberty is complete, the reproductive system is fully functional, Meaning the male can produce and release ___________ ____________.

Female Reproductive System Ovaries: primary reproductive organs Main function: __________________, or ova (singular-ovum) Prepares the body to nourish a developing embryo

Pathway for egg: fertilization occurs Fetus grows inside Produces egg & female hormones Dilates in labor Allows for flow of menstrual blood & sexual intercourse

Female Reproductive Structures At puberty, each ovary has as many as 400,000 primary follicles that surround a single egg. The function of a follicle is to help an egg mature for release and fertilized by a sperm.

Female Reproductive Structures Other structures: Fallopian tubes ________ Cervix

Menstrual Cycle One ovary produces and releases one mature ovum every 28 days or so. Menstrual Cycle: Process of egg formation and release Regulated by hormones made by the hypothalamus, pituitary, and ovaries Cramps caused by Painful cramping is caused by clots or bloody tissues pass through the cervix.

Menstrual Cycle pg. 991 During the menstrual cycle; An egg develops within a follicle and is released from an ovary. Uterus is prepared to receive the fertilized egg. Embryonic development begins and the cycle stops.

Pregnancy Menstrual cycle also stops when a woman is ______________. If a sperm fertilizes an egg, it completes meiosis and undergoes mitosis. A ball of cells will form an implant itself in the lining of the uterus. After implantation, the embryo grows and prevents the menstrual cycle to begin again.

Fertilization and Development What takes place during fertilization and the early stages of human development? The fusion of a sperm and egg cell is called __________________.

Fertilization 1. During sexual intercourse, sperm are released when semen enters the vagina. 2. The egg is surrounded by a protective layer with binding sites for sperm to attach. 3.

Fertilization 4. The haploid (N) sperm nucleus enters the haploid egg, and chromosomes of sperm and egg join together. 5. The 2 haploid nuclei fuse and a single diploid (2N) is formed with a single set of chromosomes from each parent cell. 6. ___________: fertilized egg. At this point the developing human is called an embryo.

Later Development What important events occur during the later stages of human development?

First Trimester: Second Trimester: Third Trimester:

Months 4-6 The tissues of the fetus become more complex and specialized, and begin to function. The fetal heart becomes large enough so that it can be heard with a ___________________. Bone replaces cartilage that forms the ____________ ______________. Layer of soft hair grow. Mother feels the fetus moving.

Months 7-9 The organ systems of the fetus mature. Fetus grows in size and mass. Regulate __________________. 8 months= premature