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Comparative anatomy( Chordates)
Cardiovascular System Cardiovascular System 1-Human 2-Ruminant 3-Avian 4-Fish
Dr.Omer
The Human Cardiovascular System The Human Cardiovascular System
Circulatory or Cardiovascular SystemCirculatory or Cardiovascular System
• Circulatory System – Keeps the body working by delivering oxygen to body cells and removing waste (Co2) from the cells.
RemovingDelivering
Functions of the circulatory systemFunctions of the circulatory system
Transport nutrients, hormonesRemove waste productsGaseous exchange Immunity Blood vessels transport blood◦Carries oxygen and carbon dioxide◦Also carries nutrients and wastes
Heart pumps blood through blood vessels
COMPONENTS OF CARDIOVASCULAR SYSTEM
•HEART
•BLOOD VESSELS
•BLOOD
HEART The heart is a hollow, muscular organ that is enclosed in the mediastinumand rests on the top surface of the diaphragm, flanked by the lungs.
Its four chambers include two atria (the upper right and upper left portions of the heart) and two ventricles (the lower right and lower left portions).
Muscular walls called septa (singular: septum) separate the two atria and the two ventricles.
6
How Blood Moves Through the Heart
Layers of the Heart WallLayers of the Heart Wall
The heart wall is made of three layers.1-Outermost = Pericardium & Epicardium (external layer) :
Pericardium secretes lubricant (serous fluid) Epicardium is outermost muscle tissue
2-Myocardium : 95% of heart is cardiac muscle3-Endocardium (inner layer) Smooth lining for chambers of heart, valves and continuous with lining of large blood vessels
Serous membrane
Continuous withblood vessels
FUNCTIONS OF THE HEART• Generating blood pressure• Routing blood : Heart separates pulmonary and systemic circulations• Ensuring one-way blood flow Heart valves ensure one-way flow• Regulating blood supply Changes in contraction rate and force match blood delivery to changing metabolic needs
Blood VesselsBlood Vessels
Five types of blood vessels exist within the body: •Arteries •Arterioles •Veins •Venules •Capillaries Blood vessels gradually become smaller as they migrate away from the heart. Arteries divide into arterioles and veins divide into venules.
Blood VesselsBlood Vessels
• ArteriesArteries : Strong, elastic vessels that carry blood away from the heart.• they carry blood high in oxygen known as oxygenated blood (oxygen rich blood)• No valves
ArteriolesArterioles : are small arterial branches that deliver blood to capillaries,
called resistance vessels because their size and pressure change with changes in blood flow and they play a major role in the distribution and
regulation of blood pressure.
Blood VesselsBlood Vessels• VeinsVeins :
Carry blood back to the heart called capacitance vessels because they can hold a large amount of blood with very little pressure change
• They have one-way valves which prevent blood from flowing backwards. • They carry blood that is high in carbon dioxide known as deoxygenated blood. • VenulesVenules : are small veins that collect blood from capillaries and delivers it to a
vein.
CapillariesCapillaries • CapillariesCapillaries are the smallest blood vessels that are involved in the transfer
of oxygen, nutrients and gases to the cells of the body and the removal of carbon dioxide and metabolic waste.
• Sites of gas exchange External respiration: External respiration: Gas exchange between the alveoli and pulmonary capillaries Internal respiration Internal respiration : Gas exchange between the systemic capillaries andthe tissues.
BLOOD VESSELS
• General structure General structure 1.Tunica intima (1.Tunica intima (Tunica interna )Tunica interna )
2.Tunica media2.Tunica media
3.Tunica adventitia3.Tunica adventitia (Tunica externa ) (Tunica externa )
Circulation Systems Circulation Systems
Coronary circulation Coronary circulation – the circulation of blood within the heart.
Pulmonary circulation Pulmonary circulation – the flow of blood between the heart and lungs.
Systemic circulation Systemic circulation – the flow of blood between the heart and the cells of the body.
Chapter 18, Cardiovascular System 24
CORONARY CIRCULATION
Figure 18.7a
BLOOD
•Blood : is made of specialized cells suspended in a liquid substance called plasma•Blood provides organs, tissues and cells with oxygen, nutrients, gasses, hormones, and antibodies, and removes carbon dioxide and metabolic wastes.
•These specialized cells include: 1- Erythrocytes - Red Blood Cells 2- Leucocytes (white blood) 3- platelets or cell fragments (thrombocytes)
Parts of the Blood• Red Blood Cells – Made in bone
marrow; carries oxygen, food, and rids body of CO2 and Waste
• White Blood Cells – Help fight disease and infection by destroying bacteria and germs that enter the body. Made in the lymph nodes
Parts of the Blood
• Platelets – Help blood to clot, to prevent excess bleeding.
• Plasma – Water portion of the blood; 55% of blood is plasma
Four Filters of the Blood1. Liver
2. Kidneys
3. Lymph Nodes – located in the neck
4. Spleen – Cemetery for the red blood cells
Lymphatic System
They lymphatic system is comprised ofThey lymphatic system is comprised of lymph vesselslymph nodeslymph organs The lymphatic system maintains internal fluid balance and is an important component of the body’s immune system.
Lymphatic System • Lymph vessels are thin-walled and blind-ended,they originate
in the body tissue and take lymph towards the heart. • Lymphatic organs include bone marrow, tonsils, thymus, and
the spleen.
• Lymph nodes are located throughout the body along the lymph vessels.
• Lymph nodes filter lymph and act as a barrier against infection by harboring lymphocytes, monocytes and plasma cells.
Ruminant Circulatory System Ruminant Circulatory System
Ruminant Circulatory System Ruminant Circulatory System
• A cow's heart is a bit bigger than a human's heart, due to it's massive body size. Thus, more power is needed so that blood could be pump to each and every part of the cow's body. But other than that, the heart of the cow is really the same as a human's
Fish Circulatory SystemFish Circulatory System
Fish Circulatory SystemFish Circulatory System• The simplest of the vertebrate hearts• Single circuit• Two chambers• Thin walled atrium• Muscular ventricle• Bulbus arteriolus, also ”conus”, does not pump but is elastic and
can stretch and squeeze.
• Blood is pumped from the heart to the gills• From the gills it is directly transported through the body• Oxygen poor blood from the body returns to the heart
Circulatory Systems in Fish,& Mammal
Avian circulatory systemAvian circulatory system
Avian circulatory systemAvian circulatory systemBirds have very efficient cardiovascular systems that permit them to meet the metabolic demands of flight , running, swimming and diving). Birds like mammals, have a 4-chambered heart (2 atria & 2 ventricles) and have larger hearts than mammals (relative to body size and mass). Avian heart also tends to pump more blood per unit time than mammalian hearts.
Bird red blood cells unlike those of mammals, are elliptical in shape and nucleated. Avian thrombocytes are larger than mammalian platelets, have a nucleus unlike mammalian platelets.
Typical Heart Beats Per Typical Heart Beats Per MinuteMinuteSpecies Typical RangeHuman 60-100
Horse 28-40
Cow 48-84
Chicken 250–300
Fish 60-240