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Chapter 42. Circulation & Gas Exchange. 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.
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Chapter 42 Circulation & Gas Exchange
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
Ventricle Atrium
Circulatory Systems in Fish, Amphibian, & Mammal Endotherm Ectotherms
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.
Capillaries capillary vessel
arteriole capillaries venule
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)
interstitial fluid blood capillary lymphatic capillary tissue cell Formation of Lymph
Superficial Pulse Points- arteries, not veins temporal 60 beats/minute facial carotid • Temporal artery • Facial artery • Common carotid artery • Brachial artery • Radial artery • Femoral artery • Popliteal artery • Posterior tibial artery • Dorsal pedis artery brachial radial femoral popliteal Posterior tibial Dorsal pedis
Blood Artery White blood cells Platelets Red blood cells
Function Blood • Deliver O2 • Remove metabolic wastes • Maintain temperature, pH, and fluid volume • Protection from blood loss- platelets • Prevent infection- antibodies and WBC • Transport hormones
Blood Plasma-55% Buffy coat-<1% Formed elements-45%
Blood Plasma Components-55% 90% Water 8% Solutes: • Proteins Albumin (60 %) Alpha and Beta Globulins Gamma Globulins fibrinogens • Gas • Electrolytes
Blood Plasma Components • Organic Nutrients Carbohydrates Amino Acids Lipids Vitamins • Hormones • Metabolic waste CO2 Urea
Buffy Coat- <1% • Leukocytes • Platelets
Formed Elements of the Blood-45% • Erythrocytes (red blood cells) • Leukocytes (white blood cells) • Platelets
Erythrocyte7.5m in dia ·Anucleate- so can't reproduce; however, repro 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 Never let monkeys eat bananas Granulocytes Neutrophils- 40-70% Eosinophils- 1-4% Basophils- <1% Agranulocytes Monocytes- 4-8% Lymphocytes- 20-45%
Diapodisis Leukocyte Squeezing Through Capillary Wall
Fig. 42-21a Parapodium (functions as gill) (a) Marine worm
Fig. 42-21b Gills (b) Crayfish
Fig. 42-21c Coelom Gills Tube foot (c) Sea star
Fluid flow through gill filament Fig. 42-22 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 diffu- sion of O2 from water to blood 110 80 50 20 140 PO2 (mm Hg) in blood
Tracheal Systems Air sacs Fig. 42-23 Tracheae External opening Tracheoles Mitochondria Muscle fiber Body cell Air sac Tracheole Trachea Body wall Air 2.5 µm
Branch of pulmonary vein (oxygen-rich blood) Branch of pulmonary artery (oxygen-poor blood) Fig. 42-24 Terminal bronchiole Nasal cavity Pharynx Larynx Alveoli (Esophagus) Left lung Trachea Right lung Bronchus Bronchiole Diaphragm Heart SEM Colorized SEM 50 µm 50 µm
Rib cage expands as rib muscles contract Fig. 42-25 Rib cage gets smaller as rib muscles relax Air inhaled Air exhaled Lung Diaphragm INHALATION Diaphragm contracts (moves down) EXHALATION Diaphragm relaxes (moves up)
Fig. 42-26 Air Air Anterior air sacs Trachea Posterior air sacs Lungs Lungs Air tubes (parabronchi) in lung 1 mm EXHALATION Air sacs empty; lungs fill INHALATION Air sacs fill
Cerebrospinal fluid Fig. 42-27 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