Endocrine System

 Help regulate activities  Produces chemicals that control many of the body’s daily activities  Regulates long-term changes such as growth and development  Made up of glands: an organ that produces or releases chemicals  Endocrine glands: produce and release their chemicals directly into the bloodstream Endocrine System

 Chemical product of an endocrine gland  Like a chemical messenger  Regulate activities in tissues and organs  Production: nerve impulses from brain signal for endocrine glands to produce hormones  Action: hormones cause a slower, but longer lasting response than the nerve impulses  Target cells: the cells the hormones interact with, they recognize the hormone’s structure Hormones

 Each gland releases different hormones  Endocrine glands:  Hypothalamus:  links nervous and endocrine systems  Pituitary:  regulates growth, blood pressure, and water balance  Thyroid:  controls release of energy from food molecules  Parathyroid:  regulate amount of calcium in blood Functions of Endocrine Glands

 Adrenal  Adrenaline triggers response to emergencies  Salt and water balance in kidneys  Sugar in the blood  Thymus  Immune system development  Pancreas  Insulin and glucagon control glucose level in blood  Ovaries (in females)  Estrogen controls changes in female body  Trigger egg development  Testes (in males)  Testosterone controls changes in male’s body  Regulates sperm production More endocrine glands…

 Tiny part of the brain near the middle of your head  Link between nervous system and endocrine system  Sends out never messages and produces hormones  Controls pituitary gland Hypothalamus

 Just below hypothalamus  Size of a pea  Communicates with the hypothalamus to control body activities  Responds to hypothalamus by releasing hormones  Some hormones trigger other glands to produce hormones Pituitary Gland

 Process in which a system is turned off by the condition it produces  When the amount of a particular hormone in the blood reaches a certain level, the endocrine system send signals that stop the release of that hormone. Negative Feedback

The Reproductive System

 Reproduction where offspring arise from a single parent  Inherit the genes of that parent only  Offspring will be exact genetic copies of parent  Reproduction for single cell organisms  Bacteria  Protists  Many fungi Asexual Reproduction

 Involves the production of eggs by the female and sperm by the male  Egg is the female sex cell  Sperm in the male sex cell  Fertilization: process by which male and female living things produce offspring  Zygote: a fertilized egg Sexual Reproduction

 Carry information that controls inherited characteristics  Cells have 46 chromosomes  Except sex cells only have 23 chromosomes  23 chromosomes of sperm join the 23 of the egg  Zygote then contains the 46 need to produced offspring Chromosomes

 Specialized to produce sperm and testosterone  Testes  Organ that produces sperm and testosterone  Located in the scrotum  External pouch of skin  Keeps testes about 2  C to 3  C below body temp  Sperm need slightly cooler condition for development Male Reproductive System

 Composed of a head containing chromosomes and long tail  Path:  Sperm mix with fluids produced by glands  Mixture is called semen  Contains about 5-10 million sperms per drop  Fluid allows for sperm to swim  Contains nutrients that sperm use as energy  Leaves body through penis  Tube is call urethra (same tube urine travels through) Sperm

 Specialized to produce eggs and nourish a developing baby  Ovaries  Produce eggs and estrogen  Egg released about once a month  Fallopian tubes (or oviducts)  Passageway for eggs to travel from ovary to uterus  Fertilization usually occurs in fallopian tube Female Reproductive System

 Uterus  Hollow muscular organ  Fertilized egg attaches to wall  Egg not fertilized breaks down and leaves uterus through opening called cervix  Vagina (birth canal)  Muscular passageway leading to the outside of the body  Baby leaves mother’s body Female Reproductive System

 Monthly cycle of changes in female reproductive system  Egg develops in ovary while uterus prepares for arrival of an embryo  Stages of cycle:  Egg matures, uterus walls thicken  Mature egg is released (ovulation)  Unfertilized egg enters uterus to breakdown  Thickened walls break down  Extra blood and tissue of thickened walls leave through vagina (menstruation)  Last 4-6 days  New egg starts to mature Menstrual Cycle