Respiration, Circulation, and Excretion Chapter 37 Respiration, Circulation, and Excretion

I. The Respiratory System *Respiration includes all the mechanisms involved in getting oxygen to the cells of your body.

A. Passageways and Lungs 1. Take air through mouth or nose 2. Trachea - tubelike passageway that leads to two bronchi tubes

3. Two bronchi lead into lungs 4. Nasal cavity, trachea, bronchi are lined with ciliated cells that secrete mucus.

5. Alveoli - sacs of the lungs where oxygen and carbon dioxide are exchanged by diffusion between air and blood 6. Once oxygen diffuses to blood vessels it is pumped by the heart to the body cells.

B. The Mechanics of Breathing 1. Inhale: Muscles between the ribs contract -Rib cage rises Diaphragm contracts, flattens -Moves down 2. Exhale: Muscles between the ribs relax -Rib cage drops Diaphragm relaxes -Returns to original position

C. Control of Respiration 1. Involuntary - controlled by the medulla oblongata (maintains homeostasis) How_Your_Respiratory_System_Works.asf

·Hard palate ·Soft palate ·Epiglottis ·Larynx ·Trachea ·Esophagus ·Thyroid gland ·Thymus gland ·Diaphragm ·Lungs ·Pyloric sphincter ·Small Intestine ·Caecum ·Large intestine ·Rectum ·Liver ·Gall bladder ·Pancreas ·Spleen ·Paired nares ·Sensory Papillae ·Rugae ·Heart ·Stomach

II. The Circulatory System A. Your Blood Fluid Transport 1. Plasma - fluid portion of blood

2. Red blood cells - carry oxygen to body cells (44%) a. Produced in bone marrow b. Broken down in the spleen c. Hemoglobin - iron containing protein molecule allows for binding of oxygen

3. White blood cells - play a role in protection from pathogens (1%) a. Pathogen - anything foreign to body that can harm it

4. Platelets - small cell fragments which help blood clot after injuries

B. ABO Blood Groups 1. Antigens - substances that stimulate an immune response in the body 2. Antibodies - react with matching antigen = clumped blood cells that can no longer function *A blood group does not contain antibodies for its own antigens

3. Rh factor a. Rh+ = have Rh Antigen b. Rh- = no Rh Antigen c. Pregnant woman Rh-, baby Rh+, blood comes in contact at birth, woman creates Anti-Rh+ antibodies, new Rh+ baby can be affected

C. Your Blood Vessels: Pathway of Circulation 1. Arteries - large, thick-walled, muscular elastic vessels that carry oxygenated blood away from the heart

2. Capillaries - microscopic blood vessels with walls that are only one cell thick 3. Veins - large blood vessels that carry blood from tissue back to the heart

D. Your Heart the Vital Pump 1. Atria - upper chambers of the heart 2. Ventricles - two lower chambers of the heart

3. Venae Cavae - right atrium receives non-oxygenated (from head and body) blood through these two large veins. 4. Aorta - vesicle that the left ventricle pushes oxygen rich blood through to arteries Largest blood vessel in the body

5. Pulse - surge of blood through an artery 6. Heart rate is set by the pace-maker (bundle of nerve cells) which generates an electrical impulse.

7. Blood Pressure - force that blood exerts on the blood vessel a. Systolic - high pressure (ventricles contract) b. Diastolic - lowest pressure 8. Medulla oblongata regulates rate of pacemaker

A. Kidneys: The Body's Janitor III. The Urinary System A. Kidneys: The Body's Janitor 1. Kidneys - filter the blood to remove wastes from it a. Maintain homeostasis of body fluids The_Kidneys.asf

b. Nephron - filtering unit in the kidney i. Blood enters nephron ii. Flows into glomerulus (bed of capillaries) iii. Water, glucose, vitamins, amino acids, salts...pass out of capillaries into Bowmans capsule (U-shaped) vi. Most ions and water are reabsorbed.

2. Ureter - tubes connecting kidneys to urinary bladder 3. Urinary bladder - smooth muscle bag used for storage of waste in the form of urine.

4. Urine - liquid that remains - excess water, waste molecules, excess ions 5. Urethra - tube where urine exits body

B. The Urinary System and Homeostasis 1. Major waste product = nitrogenous wastes (ammonia, urea) 2. Control sodium levels in blood = osmotic pressure Virtual Dissection