Human physiology 6.2 Transport System 6.4 Gas Exchange 6.1 Digestion 6.3 Defense against infectious diseases HL 11.1 Defense against infectious diseases

6.2 Transport System Average resting heart rate: 60 – 100 beats/min

2.6 Your Blood Erythrocytes : carries oxygen via hemoglobin Leucocytes: part of immune system Plasma: carries all other components of blood Platelets: clotting of blood following damage Materials transported by blood: Oxygen, nutrients, hormones, antibodies, heat, carbon dioxide, urea

Lung and heart Deoxygenated blood from body  heart  lungs Oxygenated blood from lungs  heart  body

6.2.1 The Heart

6.2.3 Action of the heart Collection of blood: Pumping of blood: deoxygenated blood enters the right atrium from the inferior and superior vena cava oxygenated blood enters the left atrium from the pulmonary vein Pumping of blood: contraction of the atria (right and left) pumps the blood into the ventricles (right and left) contraction of ventricles (right and left) pumps the blood into the pulmonary artery (right) and aorta (left)

6.2.3 Action of the heart opening and closing of valves: as a function of pressure differences, one-way valves prevent backflow of blood atrioventricular valves prevent backflow from ventricles into atria semilunar valves prevent backflow of blood from pulmonary artery into right ventricle and from aorta into left ventricle Relaxation: The "lub" is the sound of the tricuspid and mitral valves closing. Contraction: The "DUB" is the sound of the aortic and pulmonary valves closing. http://www.nhlbi.nih.gov/health//dci/Diseases/hhw/hhw_pumping.html How a heart attack occurs: http://www.hhmi.org/biointeractive/obesity/heart_attack.html

Vinnie Jone’s hard and fast CPR http://www.youtube.com/watch?feature=player_embedded&v=ILxjxfB4zNk Learn CPR in three steps: http://depts.washington.edu/learncpr/quickcpr.html

6.2 Transport system Submit Cells Quiz Announcement: Learning Log (6.1, 6.2, 6.4), Lab TED: Growing organs

6.2.4 Beating of the heart is not a conscious process Myogenic muscle contraction Certain cells of vertebrate cardiac muscle (myocyte) are self excitable, meaning they contract without signal from the nervous system Pace-maker myocyte: sino-atrial node (SAN) located on the right atrium impulses spread throughout both atria  atria contract impulse spread to ventricles only at the atrio-ventricular node (AVN) with a delay of about 0.1 seconds  ventricles contract http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter22/animation__conducting_system_of_the_heart.html

Electrocardigram (ECG or EKG) Impulses that travel through cardiac muscle produces electrical currents http://www.practicalclinicalskills.com/reading-ekg.aspx

6.2.4 Speeding up/down heart rate Exercise. More CO2 present in blood when exercising. Detected by receptors in medulla oblongata Nerve stimulation: sympathetic nerves from brain release epinephrine, increasing heart rate parasympathetic nerves from brain via vagus nerve decrease heart rate Hormone stimulation: Adrenalin increases heart rate during fight-or-flight response

2.5 Arteries & Veins Artery Vein Thick walls of smooth muscle with elastic fiber Small lumen Valves prevent backflow of blood Thin walls of smooth muscle with thin elastic fiber Large lumen Valves maintain one-way flow of blood Carry blood away from heart under very high pressure and high speed Return blood to heart with less pressure under low pressure and low speed

2.5 Capillaries Function Structure Diffusion of dissolved materials between blood & tissue Low pressure and speed Structure No muscular wall One cell thick No valves

Blood pressure (arterial pressure) Systolic pressure Pressure created on arteries when heart beats (contraction of ventricle) Normal range: 108 – 140 mm Hg Diastolic pressure Pressure in arteries when heart rests Normal range: 60 – 90 mm Hg Hypertension = blood pressure greater than 140/90 mm Hg