1. Organ systems and Homeostasis
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 Nervous tissue Connective 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
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 envir and 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.