AP Biology Blood Cells & Regulation in the Circulatory System

AP Biology Blood & blood cells  Blood is a tissue of cells in a fluid  plasma = fluid (55% of volume)  ions (electrolytes), plasma proteins, nutrients, waste products, gases, hormones  cells (45% of volume)  RBC = erythrocytes  transport O 2  WBC = leukocytes  defense  platelets  blood clotting

AP Biology Components of Blood tissue

AP Biology Plasma proteins  Synthesized in liver & lymph system  fibrinogen  clotting factor  blood plasma with clotting factors removed = serum  albumins  buffer against pH changes, help maintain osmotic balance & blood’s viscosity  globulins  immunoglobins = antibodies  immune response to combat foreign invaders

AP Biology  Stem cells  pluripotent cells  in bone marrow  produce all types of blood cells  cells differentiate in bone marrow & lymph tissue Blood cell production

AP Biology Red blood cells  Function  O 2 transport  Structure  small biconcave disks  large surface area  lack nuclei & mitochondria  more space for hemoglobin  iron-containing protein that transports O 2  generate ATP by anaerobic respiration  only last 3-4 months (120 days)  ingested by phagocytic cells in liver & spleen  ~3 million RBC destroyed each second  produce ~3 million RBC every second to replace 5 liters of blood in body = 25 trillion RBC

AP Biology Hemoglobin  Protein with 4° structure  O 2 carrier molecule 250,000 molecules hemoglobin/RBC  each Hb molecule carries 4 O 2  each RBC carries 1 million O 2

AP Biology Control of heart  Evolution of system to control heart beat  timely delivery of O 2 to cells is critical  cells of cardiac muscle are “self-excitatory”  contract without any signal from nervous system  each cell has its own contraction rhythm, so have to coordinate them  cells synchronized by sinoatrial (SA) node  “pacemaker”  cells in wall of right atrium  sets rate & timing of cardiac cell contraction

AP Biology SA node & Electrical signals  Pacemaker generates electrical impulses across heart  signal also transmitted to skin = EKG or ECG allows atria to empty completely before ventricles contract stimulates ventricles to contract from bottom to top, driving blood into arteries

AP Biology Regulation of heart rate  Physiological cues affect heart rate  nervous system  speed up pacemaker  slow down pacemaker  heart rate is compromise regulated by opposing actions of these 2 sets of nerves  hormones  epinephrine from adrenal glands increases heart rate  body temperature  activity  exercise, etc.

AP Biology Regulation of blood volume / pressure  Hormone regulation  ADH (antidiuretic hormone)  from pituitary  causes kidneys to reabsorb more water  aldosterone  from adrenal gland  causes kidneys to reabsorb Na + & water  atrial natriuretic hormone  from heart (right atrium)  promotes excretion of Na + in urine  nitric oxide  from blood vessel cells  dilates blood vessels  nitroglycerin & Viagra release nitric oxide  BP   

AP Biology Blood clotting Powerful evolutionary adaptation  emergency repair prevents excessive blood loss Cascade reaction Prothrombin FibrinogenFibrin Thrombin fibrin protein fibers build clot platelets seal the hole chemical emergency signals Ooooooh! Zymogen!

AP Biology Cardiovascular disease  Leading cause of death in U.S.  plaques develop in inner wall of arteries  narrowing channel  stroke, heart attack, atherosclerosis, arteriosclerosis, hypertension (high blood pressure)  tendency inherited, but other risk factors: smoking, lack of exercise, obesity, diet rich in fat

AP Biology Cardiovascular health (U.S. 2001) Heart Disease 696,947 Cancer 557,271 Stroke 162,672 Chronic lower respiratory diseases 124,816 Accidents (unintentional injuries) 106,742 Diabetes 73,249 Influenza/Pneumonia 65,681 Alzheimer's disease 58,866 Nephritis, nephrotic syndrome & nephrosis 40,974 Septicemia 33,865

AP Biology Heart Disease Heart disease death rates Adults ages 35 and older

AP Biology Women & Heart Disease  Heart disease is 3rd leading cause of death among women aged 25–44 years & 2nd leading cause of death among women aged 45–64 years. Risk factors  Smoking  Lack of exercise  High fat diet  Overweight Death rates for heart disease per 100,000 women, 2002

AP Biology Thermoregulation Vasoconstriction Vasodilation  Vasodilation & vasoconstriction  adjusts blood flow  evaporative cooling

AP Biology Temperature management Cold blood Capillary bed Veins 5˚C environmental temperature 36˚C core body temperature Artery blood from arteries warms blood in veins Counter-current exchange system! Warm blood

AP Biology My feet are cold standing around waiting… Ask some questions, already!

AP Biology nephron low Blood Osmolarity blood osmolarity blood pressure ADH increased water reabsorption increase thirst renin increased water & salt reabsorption high pituitary angiotensinogen angiotensin nephron adrenal gland aldosterone JuxtaGlomerular Apparatus (JGA) Ooooooh! Zymogen!

AP Biology Stomach  Functions  food storage  can stretch to fit ~2L food  disinfect food  HCl = pH 2  kills bacteria  breaks apart cells  chemical digestion  pepsin  enzyme breaks down proteins  secreted as pepsinogen activated by HCl Ooooooh! Zymogen!

AP Biology Pancreas  Digestive enzymes  peptidases  trypsin  trypsinogen  chymotrypsin  chimotrypsinogen  carboxypeptidase  procarboxypeptidase Explain how this is a molecular example of structure-function theme. Ooooooh! Zymogen! What stops pancreas from digesting itself small intestines

AP Biology Blood clotting Powerful evolutionary adaptation  emergency repair prevents excessive blood loss Cascade reaction Prothrombin FibrinogenFibrin Thrombin fibrin protein fibers build clot platelets seal the hole chemical emergency signals Ooooooh! Zymogen!