Unit 8: Body Systems

1. Unit 8: Body Systems Ms. Battaglia

2. Body Organization • The human body is highly organized • All the different parts work together • The levels of organization consist of cells, tissues, organs, & organ systems

3. Cells • Basic unit of structure & function • Specific to the function they perform • All body process are dependent on what occurs in cells • Ex: chemical reactions break down food within cells to give you energy

4. Tissues • Group of similar cells that perform the same function

5. Organs & Organ Systems • Organs are made from different types of tissues that work together to perform a certain job. • Ex: stomach, tooth, kidney, heart, etc. • Organ systems are groups of organs that work together to perform a major function. • Ex: digestive system, muscular system

6. Homeostasis & Stress • The process by which an organism’s internal enviro is kept stable in spite of changes in the external enviro • Under stress the body produces adrenaline. Over time, the body is not able to restore homeostasis. • This is why it’s important to deal with stress

7. The Skeletal System 5 major functions: • Provides shape & support • Enables movement • Protects internal organs • Produces blood cells • Stores materials until the body needs them

8. Bone Formation • All bones form from cartilage • A baby’s skeleton is made primarily of cartilage. • Most cartilage turns to bone when growth stops • You still have cartilage in some joints that acts as a cushion • Ex: knee & elbow

9. Body’s Joints • Immovable joints • Don’t move – places in your skull & your ribs • Moveable joints • Allow you to move

10. Moveable Joints • Ball & socket joint • Allows greatest amt of movement • Shoulders & hips • Hinge joint • Back & forth movement • Knee & elbow • Pivot joint • One bone rotates around another • Neck • Gliding joint • Bones glide over each other • Wrist & ankle

11. Connections • Bones connect to bones by ligaments which are present at a moveable joint. • Cartilage protects bones from rubbing against each other at joints.

12. Muscles • 2 main types: • Voluntary • We are able to control • Skeletal muscles like our legs & arms • “volunteer’ to move them • Involuntary • Not able to control • Smooth muscle (in internal organs) & cardiac muscle (in heart) • Control things like breathing & digesting food

13. Types of Muscles • Your body has 3 types of muscle tissue: • Skeletal muscle • Smooth muscle • Cardiac muscle

14. Skeletal muscle • Voluntary muscle • Tendons attach skeletal muscles to bones • Have striations (check out pic below) • Can tire quickly • Includes: biceps, triceps, abdominal, etc.

15. Smooth Muscle • Involuntary muscle • Located inside many internal organs • Stomach (to churn food), blood vessels (to circulate blood to dif parts of body) • Not striated – doesn’t tire

16. Cardiac Muscle • Only located in heart • Involuntary • Striated – but does not tire

17. Muscles at Work • Muscles cells can only contract (shorten); they can never extend (lengthen) • B/c of this, they must work in pairs • While one muscle contracts, the other muscle in the pair returns to its original length. • Contracting muscle = flexor

19. Take Care of Your Muscles! • Exercise! • This helps muscles to grow and become thicker, which makes them stronger • Stretch! • When you stretch muscles you become more flexible (reducing risk of injury) • Warm-Up! • Your muscles should be warm before you push them to their limits • Cramps =( • When the muscle contracts & stays contracted

20. Food and Energy • We must consume food to get energy • 6 kinds of nutrients necessary for human health: • Carbohydrates (Carbs) • Fats • Proteins • Vitamins • Minerals • Water

21. Food Guide Pyramid

22. The Digestive System • Functions: • Breaks down food small enough for body to use • Nutrients circulate through the body • Wastes are eliminated

23. Types of Digestion • Mechanical • Food broken down physically • Chewing • *Stomach churning • Chemical • Food broken down by very strong chemicals • In saliva • In stomach acid • Both have to occur for our body to receive the energy it needs from food

24. Parts of the Digestive Process • Mouth • Teeth • Includes salivary glands that produce saliva • Epiglottis • Blocks access to trachea • Esophagus • Squeezing motion = peristalsis • Leads to stomach • Stomach • Churns to break down food mechanically • Chem digestion w/ digestive juice

25. Final Digestion • Small intestine • Where most chemical digestion & nutrient absorption occurs • On average about 6 meters long (~20 ft) • Large intestine • Where water is absorbed • Rectum • Anus

26. Other Important Organs of Digestion • Food DOES NOT enter these organs, but they help in the digestive process • Liver • Largest & heaviest organ of the body • Produces bile • Breaks down fats into smaller droplets • Gall bladder • Stores bile produced by the liver • Pancreas • Produces enzymes that break down carbs, proteins, & fats

27. Circulation • The circulatory system, aka cardiovascular system, carries needed substances to cells & carries waste products away from cells. • Materials carried in blood • Oxygen • Carries wastes (like carbon dioxide) • Circulates disease fighting cells (white blood cells) Why is it important to take care of your heart & circulatory system?

28. The ♥ Heart ♥ • Each time the ♥ beats it pushes blood through the blood vessels of the cardiovascular system. • http://kidshealth.org/kid/htbw/htbw_main_page.html

29. Your ♥’s Structure • Heart is 2 sided (right & left) – separated by the septum • Each side has 2 chambers • Atrium – top chamber – receives blood coming into heart • Ventricle – bottom chamber – pumps blood out of heart • The chambers are separated by valves • Protects blood from flowing backward

31. How the ♥ Works • The pacemaker sends signals that make the heart muscle contract depending on the body’s oxygen needs • During exercise, the skeletal muscles need more oxygen so the pacemaker signals for the heart to beat faster & pump more blood to your body. What happens if a person’s pacemaker becomes diseased or stops working well?

32. Three Types of Blood Vessels • Blood travels through: • Arteries • Carry blood away from ♥ • Very thick smooth muscle tissue • Capillaries • Middle ground b/w arteries & veins • Single layer of cells (not thick muscle tissue) • Veins • Carry blood toward ♥ • Not very thick smooth muscle tissue Why do arteries have thick smooth muscle tissue whereas veins tissue is thinner?

33. The Path of Blood 2 loops • To lungs & back to ♥ • Vein from body right atrium  right ventricle  lungs  vein from lungs • To body & back to ♥ • Vein from lungs  left atrium  left ventricle  artery to body (aorta)

35. Pulse vs. Blood Pressure • Pulseis the expansion & relaxation of the artery wall • Counting your heartbeats (the #) • Blood pressureis when the ventricles contract & force blood out. • Measuring how forceful

36. Types of Blood Cells • Red blood cells (RBC’s) • Carries oxygen to body cells • Greatest # of cells in your body • White blood cells (WBC’s) • Find & destroy disease causing organisms • Larger than RBC’s • Platelets • Help blood clot when you cut yourself

37. Cardiovascular Diseases • Caused by inactivity and poor diet • Leading cause of death in the U.S. • 2 main types: • Arteriosclerosis • Plaque builds up in the arteries; causes ♥ attack • Hypertension • High blood pressure; makes ♥ work too hard • Stay healthy by: • Eating properly • Exercising • Avoid smoking