subject : BMS ( basic medical science )
lecturer : miss shailaja
part c
CARDIOVASCULAR SYSTEM
wall of the heart .
1. epicardium
- outermost layer of the heart
- thin , transparent layer of serous tissue & mesothelium
- space bet. epicardium of the heart and the serous pericardium of the pericardium sac are called as pericardial cavity which contains pericardial fluid , to reduce friction and erosion of the tissue while the heart is contract or expand .
2. myocardium
- second layer of the heart . underneath the epicardium .
- cardiac muscle tissue , its tissue and fiber are involuntary , striated and branched .
- the tissue are arranged in interlacing and responsible for contraction of the heart .
3. endothelium
- innermost layer of the heart .
- the thin layer of endothelium of the heart are ovaries a thin layer of connective tissue that penetrated by tiny blood vessels and bundles of smooth muscle tissue .
- acts as lining of myocardium , and illness the chamber and valve of the heart .
pulmonary circulation
superior and interior vena cava -> right atrium -> right ventricle -> pulmonary artery -> lungs -> pulmonary veins -> left atrium -> left ventricles -> systemic circulation .
- the deoxygenated blood are returns back to right atrium via superior and interior vena cava .
- from the right atrium , the deoxygenated blood passes through the tricuspid valve to the right ventricle .
- deoxygenated blood went to pulmonary artery via pulmonary valve .
- then it went to the lungs for the exchange gases . carbon dioxide are diffuse out of the lungs via blood stream to the alveoli of the lungs while oxygen are diffuse in by the alveoli of the lungs to the blood in the capillaries .
- now , the oxygenated blood have been passes to the pulmonary veins .
- from pulmonary veins it passes through the left atrium then directly to the left ventricle via mitral valve .
systemic circulation
left ventricle -> aorta -> arterioles / arteries -> capillaries -> venules -> superior and interior vena cava -> right atrium -> right part of the heart .
- oxygenated blood went out to the all part of the body through aorta .
- it went through the arterioles and arteries then arrives at capillaries , where the exchanges of internal respiration between the blood in the capillary with the body cell happened . blood in capillary absorb the waste product from the body cell while the body cell absorb nutrients and oxygen from the blood in the capillary .
- after that , it went out to the venules before it goes back to the superior and interior vena cava as a deoxygenated blood.
- the systemic circulation complete when the deoxygenated blood passes to the right part of the heart .
RESPIRATORY SYSTEM
function of Respiratory system
1. ventilate the lungs
2. extract the oxygen from the air and transfer it to the blood stream.
3. excrete the carbon dioxide and water vapour
4. maintain the acid base of the heart .
pulmonary ventilation
consisting the inspiration and expiration is a mechanical process which depends on volumes changes in the thoracic cavity . a rules in the mined are following the discussion which is when the volume changes it leads to the changes of pressure . the other discussion is the volume changes will leads to flow of gases to equalizes the pressure .
external respiration
- the exchanges gases by diffusion between the blood in the capillary and the alveoli of the lung .
- the blood in the capillary carry the deoxygenated blood .
- carbon dioxide will diffuse out from the blood in capillary to the alveoli of the lung .
- oxygen will be diffuse in by alveoli of the lung to the blood in the capillary .
internal respiration
- the exchanges gases by diffusion between the body cell and the blood in the capillary .
- blood in the capillary carry the oxygenated blood with nutrients.
- the body cell will absorb all the nutrients and oxygen in the blood while the blood in the capillary will absorb all the waste product .
inspiration
- diaphragm and intercostal muscle contract
- diaphragm moves downward and increasing volume of the thoracic cavity.
- intercostal muscles pulls rib up and expanding the rib cage and further .
- increased the volume of thoracic cavity , leads to the lower pressure in the alveoli and below the atmospheric pressure .
- air always flow from the higher to the lower pressure . it rushes in through the respiratory tract and into alveoli.
expiration
- diaphragm and intercostal muscle relaxes
- diaphragm moves upwards and decreasing volume of the thoracic cavity.
- decreased volume in the thoracic cavity , leads to the increasing of air pressure in the lung and force out air from the lung .
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