Download Periodic Breathing

Hypoxia
Oxygen Supply to tissues is not
sufficient
1. Hypoxic Hypoxia
Oxygenation in the lungs is not proper e.g. High altitude,
obstructive and restrictive lung diseases or Pulmonary ventilation
is not proper as in depression of respiratory centers
2. Anemic Hypoxia
O2 carriage is improper e.g. Decreased Hb, impure Hb etc.
3. Stagnant Hypoxia
Poor blood flow e.g. Heart failure, circulatory shock
4. Histotoxic Hypoxia
Tissues are unable to utilize o2 e.g. cyanide poisoning which
inhibits cytochrome oxidase
Asphyxia
 Gaseous exchange is badly affected. There is both
hypoxemia and Hypercapnia i.e. O2 level is decreased
and CO2 level is increased.
 Hanging, drowning, strangulation etc.
 Unconsciousness, heart dilates, Ventricular fibrillation
etc.
 Death occurs within 2 – 3 minutes
Non respiratory functions of the lungs
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Act as reservoirs of blood
Helps in return of blood to heart
Secrete surfactant
Synthesizes prostaglandins, histamine, heparin
Partially inactivates serotonin, bradykinin, noradrenalin
Angiotensin converting enzyme is present on surface of
pulmonary capillary endothelial cells
Lymphocytes, plasma cells and macrophages
Pulmonary venules can trap particles so prevent entry
into systemic vessels
Mucous secretion contains IgA, lysozymes
Secretes ADH and ACTH in tuberculosis, lung abcess
Caisson’s Disease or Dysbarism or Decompression Sickness or Bends
 2.5 – 3 ml of N2 is dissolved in 100 ml of blood
In deep sea divers, more nitrogen is dissolved in
 lipids of body e.g. Brain, subcutaneous tissue,
adrenal cortex etc.
 When come out at land, nitrogen bubbles in
blood, lungs, coronary arteries, bones etc.
 Severe pain i.e. Bends
 Treatment is gradual decompression or in special
chambers