1. Respiratory System and Circulatory System

2. The Need for Oxygen Oxygen is used to get energy from food Nutrients that were broken down in digestion are turned into energy by the mitochondrion Single-celled organisms get oxygen from the environment by diffusion Humans require a respiratory system

3. Nasal cavity Pharynx Larynx Right lung Left lung Trachea Left bronchus Right bronchus Right bronchioles Left bronchioles Ribs Diaphragm Bronchiole Capillaries Alveoli

4. Pathway of Air 1.Air enters though the nasal cavity Tiny hairs called cilia filter dirt and other particles Dirt and other particles can also be trapped by mucus Cilia sweep the trapped particles out through the mouth 2.Pharynx and larynx (voice box) 3.Trachea: has rings of cartilage to keep it open Also has cilia and mucus

5. 4.Trachea branches off into two bronchi 5.Bronchi branch off into small bronchioles 6.Each bronchiole ends in a microscopic alveolus (air sac) Surrounded by capillaries Oxygen diffuses from the air in the alveoli to the blood in the capillaries Carbon dioxide diffuses from the blood in the capillaries into the air in the alveoli 7.Reverse the pathway for exhalation

6. Breathing The lungs have no muscles and cannot move on their own We breathe using the muscles between our ribs and a large muscle under the lungs called the diaphragm

7. Diseases Most diseases are caused by tobacco smoke Tobacco smoke paralyzes the cilia so they cannot sweep out the particles from the smoke These particles cause cancer in the lungs and other organs Bronchitis: the bronchial tubes swell and become inflamed Mucus accumulates and blocks the airway, making breathing difficult and painful

8. Asthma: the walls of the bronchi contract and narrow the airway The lungs cannot fill or empty normally Emphysema: the alveoli lose their ability to expand to take in air The lungs can no longer inflate and less air is taken in Pneumonia: the alveoli fill with liquid and breathing is difficult Caused by a bacterial or viral infection

9. A Transport System Required to move materials to every cell in the body Ex: nutrients and oxygen Wastes need to be taken away from the cells Ex: carbon dioxide Blood that contains oxygen is called oxygenated Blood that does not contain oxygen is called deoxygenated

10. Pulmonary veins Right atrium Right ventricle Left atrium Left ventricle Aorta Vena cava Pulmonary arteries

11. The Heart Four-chambered muscle Top chambers = atria Right atrium and left atrium Bottom chambers = ventricles Right ventricle and left ventricle The heart has valves between the chambers to prevent the blood from flowing backwards

12. Blood Vessels Arteries carry oxygenated blood away from the heart and to all the cells Very elastic and very thick-walled Veins carry deoxygenated blood from the cells back towards the heart Not as elastic and not as thick as arteries Capillaries are very tiny blood vessels where nutrients and gases are exchanged Only 1 cell thick

13. From the heart, blood flows from arteries  arterioles  capillaries  venules  veins The aorta is the largest artery The vena cava is the largest vein

14. Blood Most of the blood is a clear light yellow fluid called plasma Red blood cells (RBCs) carry oxygen to the cells and carry carbon dioxide away from cells The protein hemoglobin gives RBCs their red color and lets them carry oxygen Hemoglobin contains iron White blood cells (WBCs) fight diseases Platelets help blood to clot

15. Blood Pressure As blood moves through the arteries, the artery walls exerts a pressure on the blood This is your blood pressure The pressure when your heart contracts is the systolic pressure Usually 120 The pressure when your heart relaxes is the diastolic pressure Usually 80 Normal blood pressure is 120/80

16. Diseases A heart attack occurs when coronary arteries become blocked Coronary arteries supply the heart with blood Heart muscle that cannot get blood dies Atherosclerosis is the gradual build up of layers of cholesterol on the insides of arteries Shrinks the inside of the arteries and hardens them The artery can become blocked, causing a heart attack If the artery is in the brain, it can cause a stroke

17. Hypertension is high blood pressure Makes you more likely to have a heart attack or a stroke Cardiovascular disease can be prevented or reduced by eating healthy, exercising, and not smoking