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Circulation & Respiration Chapter 42. Circulatory systems. Closed circulatory system Vertebrates Blood Enclosed in blood vessels & heart Lymph Lymph system Interstitial fluid. Functions. 1. Transportation Substances needed for cellular respiration A. Respiratory CO 2 and O 2 - PowerPoint PPT Presentation
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Circulatory systems
Closed circulatory system Vertebrates Blood Enclosed in blood vessels & heart Lymph Lymph system Interstitial fluid
Functions
1. Transportation Substances needed for cellular
respiration A. Respiratory
– CO2 and O2
B. Nutritive– glucose
C. Excretory– Metabolic wastes, ions, water
Functions
2. Regulation– Hormones– Temperature regulation (Endotherms)
3. Protection– Clotting
• Proteins, platelets
– Immune defense• WBC, AB
Heart
4 chambered Separates systemic & pulmonary
blood systems Systemic circulation: Blood flow in the body Pulmonary circulation: Blood flow between the heart &
lungs
Heart structure
Atrium Small chambers Receive blood Ventricles Larger chambers Pump blood from heart Septum Separates chambers
Heart structure
Valves Atrioventricular valves (AV) Between the atrium & ventricles Tricuspid---right Bicuspid or Mitral---left Semilumar valves Exits from the ventricles Aortic valve (L ventricle) Pulmonary valve (R ventricle)
Heart structure
Heart sounds “lub-dub” -valves closing “lub” closing of the AV valves “dub” closing of the semilunar valves Murmur: Abnormal heart sound
Heart structure
Superior & inferior vena cava Brings blood to heart from body Pulmonary arteries Blood from right side of heart to lungs Pulmonary veins Returns blood from lungs to heart Aorta Blood goes from the heart to body
Blood flow
Vena cava Right atrium Tricuspid valve (AV) Right ventricle Pulmonary valve (semilunar) Pulmonary artery Lungs
Blood flow
Pulmonary veins Left atrium Mitral valve (AV) Left ventricle Aortic valve (semilunar) Aorta
Blood flow
Cardiac cycle: One cycle of heart filling & emptying Diastole Heart resting Heart filling with blood AV valves open Semilunar valves closed
Blood flow
Systole Ventricles contracting Pumping blood out of the heart AV valves closed Semilunar valves open
Blood pressure
Measurement of pressure of blood in the arteries
Systolic measures ventricular contraction
Diastolic measures ventricular resting Sphygmomanometer or BP cuff Brachial artery 120/80 normal
Cardiac output
Volume of blood pumped by left ventricle to the body per minute
5 liters per minute Depends on heart rate Stroke volume Amount of pumped out per
contraction (70 ml)
Blood pressure
Cardiac output Flow resistance in the arteries Affect BP More constriction higher BP More dilation lower BP Baroreceptors Aorta & carotids Medulla oblongata
Conduction
Depolarization of heart muscle stimulates contraction
Heart contains autogenic cells Self stimulate SA node (sinoatrial) Pacemaker of the heart Located in R atrium wall Near the superior vena cava
Conduction
SA node Causes atrium to contract Sends signal to the AV node AV (atrioventricular) node Located in wall between R atrium
& ventricle Sends signal to the bundle of His
Contraction
Bundle of His Sends signal to the Purkinje fibers Ventricles contract
SA⇨AV⇨Bundle of His⇨Purkinje fibers
EKG
Electrocardiogram Records electrical impulses of the heart P-wave First wave-atrium contraction QRS-wave Ventricles contracting T-wave Heart re-polarization
Vessels
Arteries, arterioles Veins, venules Capillaries
arteries⇨arterioles⇨capillaries⇨venules⇨veins
Vessels
Structure (except capillaries) Inner layer is endothelium Next is a layer of elastic fibers Smooth muscle layer Connective tissue Capillaries Endothelium only
Arteries
Carry oxygen rich blood away from heart
Arterioles: Smaller arteries Larger the artery More elastic & recoil as blood is
pumped
Arteries
Vasoconstriction: Contraction of smooth muscle in
arterioles Decrease blood flow Vasodilation: Relaxation of smooth muscle Increase blood flow Precapillary sphincters: Regulate blood flow
Veins
Carry oxygen poor blood to heart Venules Smaller veins Less smooth muscle Skeletal muscles constrict Help flow of blood to heart Venous valves: Help blood flow to heart prevent backflow
Capillaries
Passage of oxygen & nutrients Into cells or extracellular fluids Passage of carbon dioxide &
wastes From cells to blood
Blood
Plasma (matrix) yellow Metabolites, wastes, hormones Ions Proteins Albumin (fluids), globulins (antibodies),
fibrinogen (clots) Cells RBC, WBC, platelets
RBC (erythrocyte)
O2 & CO2 transport Hemoglobin (protein) Erythropoietin Hormone (Kidney ) Stimulates RBC production Erythropoiesis RBC production from stem cells Spleen, bone marrow & liver remove
RBC
WBC (leukocyte)
Larger than RBC Contain a nucleus Fights against infection & FB Interstitial fluid as well as blood Granulocytes: neutrophils,
eosinophils, basophils Non-granulocytes: lymphocytes,
monocytes
Platelets
Megakaryocyte (bone marrow) Cell fragments Clotting First to site of injury Fibrin (protein that forms clot)
Clotting
Tissue damage Platelets arrive Cascade reactions start Prothrombin changes to Thrombin (enzyme) Changes fibrinogen to fibrin Forms clot
Lymph system
Interstitial fluid Fluid from blood plasma that leaves the
capillaries Surrounds the tissues Lymph: Returns to circulation via lymph system Lymph nodes, lymph vessels & organs
(spleen & thymus)
Edema
Swelling of tissues Usually ankles or feet Interstitial fluid cannot be returned Low protein (albumin) Liver disease Heart disease Pregnancy