1. Respiration, Circulation, & Execretion

2. Respiratory System Organs Include: 2 lungs and a series of passageways (nasal, throat, windpipe, & bronchial tubes) Respiration = process of gas exchange (O2 in and CO2 out) Alveoli = small sacs in lungs where oxygen and carbon dioxide exchange by diffusion between air and blood

3. Mechanics of Breathing Diaphragm is relaxed and ribs are contracted when exhaling Diaphragm is contracted and ribs are expanded during inhaling

5. Control of Respiration Breathing is involuntary process Controlled by blood chemistry and medulla (brain stem)

6. Circulatory System

7. Blood Cells & Functions Blood is a tissue composed of fluid, cells, & fragments of cells Red blood cells: transport oxygen & carbon dioxide, lack nucleus, contain hemoglobin White Blood cells: large, several types, all contain nuclei, defend body against diseases Platelets: used for clotting Plasma: contains proteins, transports of blood cells, nutrients, enzymes, hormones, gases, and inorganic salts throughout body.

8. Organs of Circulatory System Arteries: large, thick-walled muscular, elastic blood vessels that carry blood away from the heart Capillaries: microscopic blood vessels with walls that are only one cell thick Veins: large blood vessels that carry blood towards the heart; equipped with valves to force blood against gravity, usually thinner and have lesser pressure on them

9. Structures

10. The Heart Aria: upper two chambers Ventricles: lower two chambers Blood enters in the left aria then is pumped to the left ventricle, the blood then travels to the lungs and then back to the heart where it enters the right aria then is pumped to the right ventricle, then to the rest of the body

11. Heart Structures to Know Atriums Ventricles Vena Cava Aorta Which are veins and arteries on picture?

12. Blood Pressure and Pulse Pulse: surge of blood through an artery; measured in beats per minute; average is between 60-80 bpm Heart rate is set by the pacemaker: bundle of nerve cells located at the top of right atrium ECG: electrocardiogram measures electrical signals Blood pressure: force blood exerts on blood vessels; normal blood pressure is 120/80 –Systolic pressure: top number, when ventricles are contracted –Diastolic pressure: bottom number, when ventricles are relaxed right before they contract

13. Urinary System Includes the following organs: kidneys, ureter, urinary bladder, and urethra Function: to maintain homeostasis by regulating sodium levels in the body, controls osmotic pressure, gets rid of nitrogenous waste, regulates blood pH levels, and it also filters out excess glucose in the blood