Chapter 14 Circulation and Blood Vessels 2009 Delmar

Objectives • Trace the path of cardiopulmonary circulation • Name and describe the specialized circulatory systems • Trace the blood in fetal circulation • List the types of blood vessels • Identify the principal arteries and veins of the body • Describe some disorders of the blood vessels • Define the key words that relate to this chapter © 2009 Delmar, Cengage Learning

Blood Circulation • Major circulatory systems – Cardiopulmonary circulation – Systemic circulation • Specialized circulatory systems – Coronary circulation – Portal circulation – Fetal circulation © 2009 Delmar, Cengage Learning

Cardiopulmonary Circulation • Deoxygenated blood from the heart to the lungs where carbon dioxide is exchanged for oxygen. The oxygenated blood then returns to the heart. • Review of blood flow through the heart and lungs © 2009 Delmar, Cengage Learning

Systemic Circulation • Circulates nutrients, oxygen, water, and secretions • Carries away waste products • Helps equalize body temperature • Aids in protecting the body from harmful bacteria • The aorta and its branches © 2009 Delmar, Cengage Learning

Coronary Circulation • Brings oxygenated blood to the heart muscle • Right and left branches of the coronary artery • Exchange of oxygen and waste occurs at capillary level • Deoxygenated blood returns through the coronary veins to the coronary sinus © 2009 Delmar, Cengage Learning

Portal Circulation • A branch of the general circulation • Veins from the pancreas, stomach, small intestine, colon and spleen empty their blood into the hepatic portal vein which goes to the liver • Liver ensures that the blood’s glucose concentration is kept within a relatively narrow range © 2009 Delmar, Cengage Learning

Fetal Circulation • Occurs in the unborn baby (fetus) • Fetus obtains oxygen and nutrients from the mother’s blood; not through their own lungs and digestive systems • The fetal blood does not mix with the mother’s blood; the exchange of gases, food and waste is passed through the placenta © 2009 Delmar, Cengage Learning

Blood Vessels • Arteries • Capillaries • Veins © 2009 Delmar, Cengage Learning

Arteries • Carry oxygenated blood away from the heart to capillaries (exception – pulmonary arteries) • Layers of the walls – Tunica adventitia or externa – Tunica media – Tunica intima • Aorta leads away from the heart and branches into smaller arteries • Smaller arteries branch into arterioles • Arterioles give rise to the capillaries © 2009 Delmar, Cengage Learning

Capillaries • • Smallest blood vessels Can only be seen through a microscope Connect the arterioles and venules Muscle and connective tissue disappear and they become a simple endothelial cell layer • Selective permeability • Control of blood flow by precapillary sphincters © 2009 Delmar, Cengage Learning

Veins • Carry deoxygenated blood away from the capillaries to the heart • Layers of the walls – Tunica externa, Tunica media, Tunica intima • Walls much thinner than arteries – Do not have to withstand as much pressure • Veins have valves so blood flows in one direction – Toward the heart • Largest vein is the vena cavae – Superior vena cava returns blood from upper part of body – Inferior vena cava returns blood from the lower part of the body © 2009 Delmar, Cengage Learning

Venous Return • Valves help keep venous blood moving • Skeletal muscles contract to push venous blood along its path • Pressure changes occur when we breath which helps bring venous blood back to the heart • Stationary positioning can decrease flow back to the heart for oxygenation © 2009 Delmar, Cengage Learning

Blood Pressure • • Systolic blood pressure Diastolic blood pressure Pulse pressure Normal values – Systolic pressure averages 120 mm/Hg – Diastolic pressure averages 80 mm/Hg – Normal range 95/60 to 120/80 © 2009 Delmar, Cengage Learning

Pulse • Can feel pulsating beat at certain points on the body • Should be same as heart rate • Can feel pulse on the body where the artery is near the surface of the skin and over a bone – These are called pulse points © 2009 Delmar, Cengage Learning

Pulse Points • 7 paired pulse points – – – – Brachial artery Common carotid artery Femoral artery Dorsalis pedis artery Popliteal artery Radial artery Temporal artery • Pressure points can be used to stop bleeding distal to the pulse point © 2009 Delmar, Cengage Learning

Congenital Heart Defects • Occur when there is a malformation of the heart during fetal development • Most common symptom – Cyanosis • Microscopic surgery – Can correct many congenital heart defects © 2009 Delmar, Cengage Learning

Disorders of the Blood Vessels • • • Aneurysm Arteriosclerosis Atherosclerosis Gangrene Phlebitis or thrombophlebitis © 2009 Delmar, Cengage Learning • • • Embolism Varicose veins Hemorrhoids Cerebral hemorrhage Peripheral vascular disease

Disorders of the Blood Vessels • Hypertension – Normal – Less than 120/80 – Pre-hypertension – 120 -130/80 -89 • Stage I hypertension – 140 -159/90 -99 • Stage II hypertension – 160 and above/100 and above © 2009 Delmar, Cengage Learning • White coat hypertension • Hypotension • Transient ischemic attacks (TIAs) • Cerebral vascular accident (CVA)

Hypoperfusion • Inadequate flow of blood carrying oxygen to the organs and body systems • Hypoperfused tissue will stop working properly • Hypoperfusion leads to shock – Body attempts to compensate for hypoperfusion by increasing respiratory rate, increasing the heart rate or sacrificing organs to protect blood flow to the brain © 2009 Delmar, Cengage Learning