cardiovascular i. overview general introduction/function red blood cells hemoglobin hematopoiesis...
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Cardiovascular I
Overview• General Introduction/Function
• Red Blood Cells
• Hemoglobin
• Hematopoiesis
• Heart Anatomy
• Skeletal versus Cardiac Muscle
• Electrical conduction in the heart
Composition of Blood
• Blood is the body’s only fluid tissue
• Formed elements:
• Hematocrit
Composition of Blood
Figure 18.1
Protection
• Blood prevents blood loss by:– Activating plasma proteins and platelets – Initiating clot formation when a vessel is broken
• Blood prevents infection by: – Synthesizing and utilizing antibodies– Activating complement proteins– Activating WBCs to defend the body against foreign invaders
Formed Elements
• Erythrocytes, leukocytes, and platelets make up the formed elements
• Most formed elements survive in the bloodstream for only a few days
• Most blood cells do not divide
Erythrocytes (RBCs)
Figure 18.3
Erythrocyte Function
Figure 18.4a, b
Hematopoiesis
• Blood cell formation
• Hematopoiesis occurs in the red bone marrow
Production of Erythrocytes: Erythropoiesis
Figure 18.5
Hormonal Control of Erythropoiesis
Figure 18.6
Heart Anatomy
Figure 19.4e
Heart Covering & Heart Wall• Pericardium• Epicardium• Myocardium• Endocardium
Figure 19.2
Figure 19.4e
Figure 19.4e
Atria
Figure 19.4e
Ventricles
Figure 19.4e
Major Vessels
Pathway of Blood through the Heart and Lungs
• Right atrium tricuspid valve right ventricle pulmonary semilunar valve pulmonary arteries lungs pulmonary veins left atrium bicuspid valve left ventricle aortic semilunar valve aorta systemic circulation
Pathway of Blood through the Heart and Lungs
Figure 19.5
Coronary Circulation• Functional blood supply to the heart• Shortest circulation• Arterial supply arises from the base of the
aorta– Right coronary artery
– Left coronary artery
Homeostatic Imbalances
• Angina pectoris
• Myocardial infarction
Heart Valves• Heart valves insure unidirectional blood flow
through the heart
• Atrioventricular (AV) valves – Bicuspid
– Tricuspid
Heart Valves
Figure 19.9
Heart Valves
• Aortic semilunar valve
• Pulmonary semilunar valve
• Semilunar valves prevent backflow of blood into the ventricles
Heart Valves
Figure 19.10
Thought Question
Microscopic Heart Muscle Anatomy
Figure 19.11b
Skeletal vs. Cardiac Muscle
1) Means of Stimulation1) Cardiac muscle cells are self-excitable and can initiate
their own depolarization
Heart Physiology: Intrinsic Conduction System
Figure 12.10
Figure 12.22
Figure 12.23
Skeletal vs. Cardiac Muscle
1) Means of Stimulation1) Cardiac muscle cells are self-excitable and can initiate
their own depolarization
2) Organ versus Motor Unit Contraction1) Heart contracts as a unit or not at all
Skeletal vs. Cardiac Muscle
1) Means of Stimulation1) Cardiac muscle cells are self-excitable and can initiate
their own depolarization
2) Organ versus Motor Unit Contraction1) Heart contracts as a unit or not at all
3) Length of Absolute Refractory Period1) Long refractory period2) Sodium channels are inactivated for almost as long as
the contraction
Energy Requirements
• Needs oxygen to produce ATP
• Can use multiple fuel molecules including glucose and fatty acids
Homeostatic Imbalances
• If heart does not get enough oxygen production of lactic acid
• Gap junctions close and cells become electrically isolated
• If area is large, then pumping activity of the heart can be impaired
Heart Physiology: Sequence of Excitation
Figure 19.14a
Thought Questions
Homeostatic Imbalances
• Arhythmias
• Fibrillation
• Defective SA node
Electrocardiography
Figure 19.16
Figure 12.11
Thought Questions
Overview• General Introduction/Function
• Red Blood Cells
• Hemoglobin
• Hematopoiesis
• Heart Anatomy
• Skeletal versus Cardiac Muscle
• Electrical conduction in the heart
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