Ch.13 section 1

1. Ch.13 section 1 Organ systems and Homeostasis

2. Our body • Each part of the body has a specific function, or job. • The levels of organization in the human body consists of: • Cells • Tissues • Organs • Organ systems

3. Cells • Cell theory: a cell is the basic unit of structure and function of a living thing • Structure: • Membrane • Cytoplasm • Nucleus • Functions: cellular respiration, grow, reproduce, excrete waste

4. Tissues • Muscles tissue • Can contract (shorten) to move the body • Nervous tissue • Directs and controls • Carries electrical messages • Connective tissue • Provides support and connects: • bone and fat • Epithelial tissue • Skin • lining of digestive system

5. Organs and Organ Systems • 11 organ systems: • Integumentary • Skeletal • Muscular • Circulatory • Respiratory • Digestive • Excretory • Immune • Reproductive • Nervous • Endocrine

6. Integumentary system • Skin, hair, and nails make up your body’s covering • Create a barrier • Regulate your body temp • Remove waste – perspire • Works with nervous system to give info about your environm.

7. Skeletal • Bones and other connective tissues • Supports the body and gives it structure • Protects body’s organs • Produce bloods cells • Connective tissues attaches bones together

8. Muscular • Move the body by pulling on the skeleton • Involuntary muscles work by themselves • Muscles and bones: musculoskeletal system • Cells – fibers – muscle groups

9. Circulatory • Transportation network – carries food and oxygen • Collects waste • Transports blood • Powered by pumping of blood: heart • Away: arteries • To: veins • Capillaries: smallest – connect the arteries and veins- reach every cell

10. Respiratory • Lungs : takes in oxygen and disposes of carbon dioxide • Air moves into the lung then to the capillaries • Oxygen crosses into the blood • Lung expands due to the actions diaphragm.

11. Digestive • Digestion: breakdown of food into small molecules the body can use • Liver produces bile and pancreas makes enzymes which help break down the food • Water is removed in large intestine

12. Excretory • Body makes excess water and waste • Excretory system removes these waste products • Kidneys has nephrons which filters blood • Urine flows from kidney to urinary bladder

13. Immune • Protects the body from disease-causing bacteria and viruses(pathogens) • White blood cells attack and destroy viruses or make antibodies (proteins) • The immune system remembers the past pathogens and destroys them quicker the next time. (immunity)

14. reproductive • Organs that produce sex cells • Sex cells carry DNA – information • Organs can also produce chemicals that regulate the physical development

15. Nervous • Takes info from envirand body – processes this info and commands the body to respond • Some times, you control the brain, in other times, the brain decides for you (involuntary) • Brain + spinal cord + nerve cells

16. Endocrine • Helps regulate the activities of the organs by releasing hormones (chemicals that change the activity in cells) • Collection of glands (tissues that produce and release hormones) • Brain signals how much hormones to produce

17. Homeostasis (hoh-mee-oh-stay-sis) • Process by which an organism’s internal environment is kept stable in spite of changes in the external environment • Warm blooded… 37 °C – even when it’s cold or hot • Sweating… or shivering • Stress : reaction of your body to potentially threatening, challenging, or disturbing events.- body produces adrenaline to carry more oxygen to body cells.