Review of 4 Weeks in 20 Minutes or Less Blood o Components: plasma, red blood cells, white blood cells, platelets o RBC have hemoglobin that carry O2 o WBC fight invaders o Platelets form clots so we don’t bleed to death o Plasma carries it all, and has nutrients, hormones Blood Types o Antigens on RBC o Antibodies in the Plasma o Matching antibodies and antigens results in agglutination o Type: A, B, AB, or O o Rh factor=antigen, if present +, absent – o Rh negative will produce antibodies for Rh+ after exposed once to it For problems, we’re going to assume that the Rh (-) people have Rh antibodies

Blood Vessels o Arteries flow into capillaries, which flow into veins o Arteries take blood away from heart, veins take blood to heart o Gas exchange occurs in the capillaries Heart o 4 chambers, 4 valves o Labeled “opposite” for left and right on paper, due to perspective of drawing (teacher’s right hand looks like your left) o AV valves between atria and ventricles, semilunar valves between arteries and ventricles o Pulmonary circuit goes to lungs. Systemic to body Cardiac Cycle o Consists of systole and diastole o Systole: Isovolumetric Contractions and Ejection o Diastole: Isovolumetric Relaxation and Rapid Inflow and Atrial Systole Which valve close at which stage and where is the blood at that moment

Blood Pressure o Consists of systolic/diastolic o Normal is 120/80 o Heart pumping creates pressure on the arteries – systolic # o pressure in the arteries when the heart rests between beats – diastolic # ECG o Electrocardiogram o Measures heart’s electrical activity o P Wave" represents the electrical activity of the SA Node and contraction of atrium o QRS Interval" represents the electrical activity of the ventricle o T Wave" represents the ventricle relaxing ready for the next electrical impulse - known as repolarization

Nervous control of heart beat o SA node is pacemaker o Activates atria, which then activate the AV node, which contracts the ventricles Nerve impulse o Parasympathetic slows it down o Sympathetic speeds it up Chemical control of the heart beat o Acetylcholine slows it down o Epinephrine speeds it up Respiratory system o Air in the trachea to bronchi to bronchioles to alveoli o Gas exchange occurs in alveoli o External respiration is breathing outside air in o Internal respiration is process of getting gases to cells o Cellular respiration is process of getting energy from sugars and oxygen

Homeostasis: refers to same state o Involves negative feedback cycles o Body senses something is wrong and immediately initiates a corrective mechanism Breathing increased when blood pH is lowered (due to dissolved CO2) Heart rate is slowed when cardiac output is too high because aorta stretches more than it should, and this sends signal to slow heart rate Lifestyle choices can prevent heart disease Diseases and disorders range from asthma to narrowing of the vessels causing heart disease or attacks