Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Physiology 33 Cardiovascular System PPT-Powerpoint Presentations and lecture notes
Cardiovascular system
Introduction
? Need of circulatory system
? Components of circulatory system
? Type of pump
? Primary & secondary roles
Cardiovascular system of mammals
Systemic circulation
General Plan
Pulmonary circulation
RV RA
LV LA
System of vessels that carry blood
The force for movement of blood is provided by heart
Two major loops of flow : systemic circulation and pulmonary circulation
Components
? 4 chambered heart
? Arteries
? Capillaries
? Veins
Morphology of heart
? The average adult human heart is about 12 cm from base to
apex, 8 ? 9 cm wide at its broadest transverse diameter and
6 cm anterioposteriorly.
? The weight of the heart is about 300 g in males and 250 g in
females
? Double layered pericardial layer containing fluid allow
contractile motion of the heart without friction
? The atrium myocardium is electrically separate from the
ventricular myocardium by fibrous tissue
Functional features of the heart
1. Pump the blood
2. Maintain unidirectional flow
3. Generate high pressure
4. Separation of pulmonary circulation
5. Modify the function as per specific requirements of circulation
Functional Organization of the heart
Heart as a set of two functional pumps
Right pump
Components
Right atrium and Right ventricle
Input :
vena cava
Output :
pulmonary artery
Valves : Vena cava and Right atrium
Right atrium and Right ventricle
Right ventricle and pulmonary artery
Thickness of right ventricle wall : 3 -5 mm
Pressure generated : 25 mmHg during systole
Left pump
Components
left atrium and left ventricle
Input : Pulmonary vein
Output :
Aorta
Valves : Pulmonary vein and Left atrium
Left atrium and Left ventricle
Left ventricle and Aorta
Thickness of ventricle wall : 9 mm
Pressure generated : 120 mmHg during systole
Relative position of different chambers and valves
Distribution of blood in circulation
Functional aspects of cardiovascular
system
? Changing metabolic needs
? Integration with other systems
? Safety margin or physiologic reserve
? Pathology resulting in diseases
Functional aspects of cardiovascular
system
? Intermittent cardiac output but continuous
flow to tissues
? Dampening of pulsatile arterial flow at
capillary level
? Inverse Relation of cross-sectional area with
velocity of blood flow
Pressures in circulatory system
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This post was last modified on 08 April 2022