Presentation on theme: "Aim: How can hormones influence the reproductive cycles in humans?"— Presentation transcript:
Aim: How can hormones influence the reproductive cycles in humans?
Who am I? Our bodies change. You grow taller & bigger. Our sexual organs mature. Hair appears where there was no hair before. You may begin to feel attracted to another individual. An Adolescent Going Through Puberty
Control of Reproductive Systems The Hypothalamus & Pituitary Gland (in the brain) produce hormones that stimulate the gonads to produce sex hormones
What is a hormone? Hormones are chemical messengers There are many different hormones that have unique and specific functions
What is a target cell? The cell that a particular hormone will communicate its message to
How do hormones travel to their target cells? The Circulatory System!!
How do hormones recognize their target cells? Cells must bear a perfectly shaped RECEPTOR for the hormone in order to respond to them.
Hormonal Control of the Female Reproductive System: Beginning at puberty, female reproductive organs undergo a cycle of changes that prepare the body for the possibility of pregnancy. The hypothalamus, the pituitary gland, and the ovaries produce hormones that control this cycle of change. What is this cycle of change called? Menstrual Cycle
How does a woman get ready to get pregnant? An egg is produced & the lining of the uterus thickens to receive the embryo
Menstrual Cycle Stages 1)Follicular Stage: Follicle Stimulating Hormone (FSH) stimulates the ovary to produce estrogen and egg maturation Estrogen causes the lining of uterus to begin to thicken Duration: days
2) Ovulation Increased levels of Leutinizing Hormone (LH) causes the release of an egg into the oviduct Around day 14
3) Corpus Luteum Phase Ovaries continue to secrete estrogen & progesterone to further thicken the lining of the uterus Duration days
What is MENSTRUATION? Hormone levels decrease Shedding of the uterine lining and unfertilized egg Duration: 3-7 days
What happens if fertilization does occur? The levels of progesterone will remain elevated in order to maintain the thickness of the uterine lining Nicknamed the “pregnancy hormone”
Hormones & the menstrual cycle Which hormones peak before ovulation? Which hormone peaks after ovulation? ws/wld/graphics/menstrual _cycle_dw.htm
Girls Secondary Sex Characteristics Hips widen Pubic Hair Breasts enlarge Due to the hormones estrogen and progesterone.
Hormonal Regulation of the Testes: Beginning at puberty, the pituitary gland secretes FSH & LH. These hormones stimulate the testes to produce testosterone. Testosterone stimulates the production of sperm and other male sex characteristics.
Boys Secondary Sex Characteristics Voice Deepens Facial Hair Muscular Development Pubic Hair Sperm Production Due to the hormone Testosterone.