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Download 1. Circulation & The Blood
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Circulation & The Blood Functions of the Circulatory System • Transport oxygen to cells • Transport nutrients from the digestive system to body cells • Transport hormones to body cells • Transport waste from body cells to excretory organs • Distribute body heat Gastrovascular Cavity of Aurelia Open Circulatory System Closed Circulatory System Ventricle Atrium Circulatory Systems in Fish, Amphibian, & Mammal Electrocardiogram (ECG) • • • P = atrial depolarization ~ 0.1 sec atria contracts QRS = ventricular depolarization ventricles contract (lub), contraction stimulated by Ca++ uptake T = ventricular repolarization ventricles relax (dub) Vein Artery Tunica intima Valve Tunica media Tunica externa Artery vein Arteries • Carry blood away from the heart. • Thick-walled to withstand hydrostatic pressure of the blood during ventricular systole. • Blood pressure pushes blood through arteries. Veins • Carry blood to the heart. • Thinner-walled than arteries. • Possess one-way valves that prevent backwards flow of blood. • Blood flow due to body movements, not from blood pressure. One-Way Valves in Veins Capillaries capillary vessel arteriole venule capillaries arteriole blood capillaries lymphatic capillaries venule lymphatic vessel Lymph Transport • lacks pump for circulation • relies on activity of skeletal muscles and pulsation of nearby arteries for movement of fluid • 3L of lymph enters blood stream every 24 hrs • proteins easily enter lymphatic system • uptake of large particles such as cell debris, pathogens, and cancer cells • lymph nodes where it is cleansed of debris and examined by cells of the immune system (WBC) Formation of Lymph interstitial fluid blood capillary lymphatic capillary tissue cell Sphygnomamometer Measuring Blood Pressure Superficial Pulse Points- arteries, not veins temporal 60 beats/minute – avg. facial carotid brachial radial popliteal Posterior tibial femoral • • • • • • • • • Dorsal pedis Temporal artery Facial artery Common carotid artery Brachial artery Radial artery Femoral artery Popliteal artery Posterior tibial artery Dorsal pedis artery Artery White blood cells Platelets Red blood cells • Deliver O2 • Remove metabolic wastes • Maintain temperature, pH, and fluid volume • Protection from blood loss- platelets • Prevent infection- antibodies and WBC • Transport hormones Plasma-55% Buffy coat-<1% Formed elements-45% 90% Water 8% Solutes: • Proteins Albumin (60 %) Alpha and Beta Globulins Gamma Globulins fibrinogens • Gas • Electrolytes • Organic Nutrients Carbohydrates Amino Acids Lipids Vitamins • Hormones • Metabolic waste CO2 Urea • Leukocytes • Platelets • Erythrocytes (red blood cells) • Leukocytes (white blood cells) • Platelets Erythrocytes Erythrocyte 7.5m in dia - (lacks a nucleus)so can't reproduce from themselves, reproduced in red bone marrow Hematopoiesis- production of RBC Function- transport respiratory gases Hemoglobin- quaternary structure, 2 chains and 2 chains Lack mitochondria. Why? 1 RBC contains 250 million hemoglobin molecules Men- 5 million cells/mm3 Women- 4.5 million cells/mm3 Life span 100-120 days and then destroyed in spleen (RBC graveyard) Types of Leukocytes 4,000-11,000 cells/mm 3 Granulocytes Neutrophils- 40-70% Eosinophils- 1-4% Basophils- <1% Agranulocytes (lacks ganulocytes) Monocytes- 4-8% Lymphocytes- 20-45% Diapodisis Leukocyte Squeezing Through Capillary Wall Parapodium (functions as gill) (a) Marine worm Gills (b) Crayfish Coelom Gills Tube foot (c) Sea star Fluid flow through gill filament Oxygen-poor blood Anatomy of gills Oxygen-rich blood Gill arch Lamella Gill arch Gill filament organization Blood vessels Water flow Operculum Water flow between lamellae Blood flow through capillaries in lamella Countercurrent exchange PO2 (mm Hg) in water 150 120 90 60 30 Gill filaments Net diffusion of O2 from water to blood 140 110 80 50 20 PO2 (mm Hg) in blood Countercurrent exchange system Tracheal Systems Air sacs Tracheae External opening Tracheoles Mitochondria Muscle fiber Body cell Air sac Tracheole Trachea Air Body wall 2.5 µm Branch of pulmonary vein (oxygen-rich blood) Branch of pulmonary artery (oxygen-poor blood) Terminal bronchiole Nasal cavity Pharynx Larynx Alveoli (Esophagus) Left lung Trachea Right lung Bronchus Bronchiole Diaphragm Heart SEM 50 µm Colorized SEM 50 µm Rib cage expands as rib muscles contract Air inhaled Rib cage gets smaller as rib muscles relax Air exhaled Lung Diaphragm INHALATION Diaphragm contracts (moves down) EXHALATION Diaphragm relaxes (moves up) Air Anterior air sacs Posterior air sacs Air Trachea Lungs Lungs Air tubes (parabronchi) in lung INHALATION Air sacs fill EXHALATION Air sacs empty; lungs fill 1 mm Cerebrospinal fluid Pons Breathing control centers Medulla oblongata Carotid arteries Aorta Diaphragm Rib muscles Uptake of Oxygen by Hemoglobin in the Lungs O2 binds to hemoglobin to form oxyhemoglobin High Concentration of O2 in Blood Plasma High pH of the Blood Plasma Unloading of Oxygen from Hemoglobin in the Tissues When O2 is releaseddeoxyhemoglobin Low Concentration of O2 in Blood Plasma Lower pH of the Blood Plasma Carbon Dioxide Chemistry in the Blood CO2 + H2O H2CO3 HCO3- + H+ carbonic acid bicarbonate ion enzyme = carbonic anhydrase Transport of Carbon Dioxide from the Tissues to the Lungs • 60-70% as bicarbonate dissolved in the plasma (slow reaction) • 7-10% dissolved in the plasma as CO2 • 20-30% bound to hemoglobin as HbCO2 CO2 + hemoglobin HbCO2 Haldane Effect- the amount of CO2 transported in the blood is markedly affected by the degree of oxygenation of the blood The lower the P02 and hemoglobin saturation with O2, the more CO2 that can be carried by the blood 7. Deep-diving air-breathers stockpile oxygen and deplete it slowly Deep Diving Breath-holding • Adaptations to pressure - Collapse of lung cavity (ribs) - Collapse of lungs 7. Deep-diving air-breathers stockpile oxygen and deplete it slowly Adaptations to oxygen conservation • Oxygen stores 2-3 x more than humans – Humans: 36% of our total O2 in lungs and 51% in our blood. – Weddell seal holds 5% of its O2 in its small lungs and stockpiles 70% in the blood. • Skeletal muscles and blood as primary storage site (myoglobin) • Weddell seal to store about 25% of its O2 in muscle, 13% in humans Deep-diving air-breathers stockpile oxygen and deplete it slowly Adaptations to oxygen conservation • Reduce heart rate when diving (120 beats/min to 6 b/min) • Seals and sea lions store oxygenated blood in their extra-large spleen (which can be 45% of their body weight) • Maintain blood flow to brain, heart Average Dive Times • • • • • • • • Sperm whale: 90 minutes to 2 hrs Northern elephant seal: 20 to 35 minutes Harbor seal: 3 to 7 minutes Walrus: 10 minutes Bottlenose dolphin: 8 minutes Killer whale: 10 minutes Amazon river dolphin: 2 minutes Loggerhead turtle: 20 minutes
