Download Chapter 4 Cardiovascular

Chapter 4
Circulatory System
List Blood Components and Explain the Functions of Blood
Plasma = fluid portion of blood; 91-94% water & 5-8% protein (3 types)
1.
Albumin - major protein in blood; maintains water in the blood stream
2.
Globulins - antibodies produced to fight disease
3.
Fibrinogen - aids in clotting blood; serum - plasma minus clotting proteins
Formed elements of blood = 3 types of cells; 30-45% of total blood sample
1. Erythrocytes - red blood cells; carry oxygen
• biconcave disc with no nucleus
• produced in bone marrow (erythropoiesis)
• limited life span and are constantly replaced
• contain the protein hemoglobin (iron containing molecule; makes blood red)
2. Leukocytes - white blood cells; help fight infection
• produced in bone marrow
• spend short time in bloodstream; moved to tissues to fight infection
• five major types are divided into 2 classes based on the appearance of cytoplasm
GRANULOCYTES - have granules within cytoplasm
Neutrophils- predominant WBC in dogs, cats, horses
main function to destroy microorganisms and cellular debris
Eosinophils- fight parasites and allergic reactions
Basophils- fight allergic reactions with histamines
AGRANULOCYTES - smooth cytoplasm
Lymphocytes- produce antibodies
Monocytes- destroy microbes; mature into macrophages (remove foreign
particles)
3. Platelets - aid in normal clotting of blood
• produced in bone marrow
• attach to edges of damaged blood vessel and plug hole
Identify the Basic Structures of the Mammalian Heart
• 4 chambered heart; 2 separate circulatory paths
• pulmonary - blood pumps to the lungs to exchange O2 and CO2
• systemic - oxygenated blood moves into the body
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pericardium - membrane that protects the heart
myocardium - cardiac muscle making up heart wall
endocardium - innermost layer of heart; lines chambers
valves - structures that separate chambers and keep blood flowing in one direction
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artery - blood vessel that carries blood away from heart
vein - blood vessel that carries blood towards the heart
capillary - smallest blood vessels that exchange O2 and CO2
vena cava - largest vein in body
aorta - largest artery in body
• ventricle - caudal chambers of heart
• atrium - cranial chambers of heart
Trace the Flow of Blood through the Heart and Body
Figure 4-7
1. Right Ventricle
2. Pulmonary Semilunar Valve
3. Pulmonary Arteries
4. Lungs
5. Pulmonary Veins
6. Left Atrium
7. Left Atrioventricular Valve (Bicuspid)
8. Left Ventricle
9. Aortic Semilunar Valve
10.
Aorta
11.
Systemic Circulation
12.
Cranial & Caudal Vena Cava
13.
Right Atrium
14.
Right Atrioventricular Valve (Tricuspid)
Explain Clinical Significance of EKG, Heart Sounds and Blood Pressure
Pacemaker System - system of cells, nodes, and fibers that maintain the heart’s regular
rhythm
• Sinoatrial Node - specialized group of pacemaker cells in the right atrium that send out
electrical signals to surrounding cells; forces atrial contraction and pumps blood to
ventricles
• Atrioventricular Node - picks up signal from SA node, sends through to ventricles;
blood is pumped out through arteries
• Cardiac cycle - one complete contraction and relaxation
• systole - contraction phase
• diastole - relaxation phase
• blood pressure = systole/diastole millimeters/mercury (120/80mmHg)
Electrocardiogram (ECG/EKG) - tracing made by the instrument (electrocardiograph)
that measures the small electrical current made by heart muscle contractions
• PQRST WAVE (Figure 4-13)
• P = SA node fires and atria contract
• QRS = ventricles contract
• T = ventricles prepare for next contraction
Arrhythmia - any change in rate, rhythm, or conduction within the heart
• Sinus tachycardia - HR faster than normal with normal rhythm
• Sinus bradycardia - HR slower than normal with normal rhythm
• Sinus arrhythmia - HR increases with inspiration, decreases with expiration
• Atrial fibrillation = rapid and irregular; quivering of atria
• Ventricular fibrillation = very serious; rapid firing of ventricles, required defibrillator
• Asystole = flatline; cardiac arrest; CPR may be used to stimulate the heart to deliver
O2 to the lungs (Cardiopulmonary resuscitation)