This document summarizes the body's responses to hypoxia, or low oxygen levels. It describes the immediate, urgent reactions of key systems to hypoxia, including increased heart rate and blood flow. It then outlines the long-term, permanent compensations the body makes, such as growing more mitochondria and capillaries to improve oxygen use and delivery. The body also makes metabolic and hormonal adaptations to optimize energy production and use oxygen more efficiently despite low oxygen levels.

1. Hypoxia
Compiled by Associate Professor of Pathophysiology Department
Arsenteva Ekaterina Vladimirovna
Ev.arsenteva@yandex.ru
Lecturer: Professor of Pathophysiology Department
Vlasova Tatyana Ivanovna
v.t.i@bk.ru

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3. Hipoxia
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Decreased brain activity in hypoxia
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4. 4

5. Hypoxia classification 5

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7. Due to cause factor
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8. 8

9. Due to cause factor
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11. Respiratory hypoxia
due to :
• alveolar hypoventilation ,
• impaired oxygen diffusion through the air-
blood barrier ,
• dissociation of the ventilation-perfusion ratio,
• reduced perfusion with blood of the lungs .
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12. Respiratory
hypoxia
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13. 13

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15. Haemic hypoxia
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24. Urgent reaction.
Cardiovascular system
Heart (by activation of sympathetic system):
• Tachycardia.
• Increased shock release of blood from the heart.
• Increase in the minute volume of blood circulation (cardiac blood
flow).
• Increased linear and volumetric blood flow velocity in the vessels.
Vascular system (by activation of sympathetic system and release of
catecholamines; by accumulation in the myocardium and brain tissue
of metabolites with a vasodilator effect):
• centralization of the blood flow (due to expansion of arterioles and
increased blood supply to the brain and heart, narrowing of the lumen
of arterioles and reduction of the blood supply in other organs and
tissues)
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25. Urgent reaction.
Blood system
• Activation of the release of red blood cells from the bone
marrow and blood depot;
• Increased degree of Hb02 dissociation in tissues;
• An increase in the affinity of Hb for oxygen in the
capillaries of the lungs.
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26. Urgent reaction.
Biological oxidation cell’s system
•Improving the efficiency of the processes of assimilation of oxygen and
oxidation substrates by the tissues of the body and their delivery to
mitochondria;
•Activation of oxidation and phosphorylation enzymes;
•Increasing the degree of conjugation of the oxidation and
phosphorylation of adenine nucleotides: ADP, AMP, and creatine;
• Activation of the glycolytic oxidation pathway.
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27. Permanent compensation.
Biological oxidation systems.
Providing optimal energy supply of functioning structures and the level
of plastic processes by:
- Increase in the number of mitochondria and the number of
mitochondrial cristae.
- An increase in the number of enzyme molecules of tissue respiration in
each mitochondria, as well as the activity of enzymes, especially
cytochrome oxidase.
- Improving the efficiency of biological oxidation and its conjugation
with phosphorylation.
- Improving the efficiency of the mechanisms of anaerobic resynthesis
of ATP in cells.
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28. Permanent compensation.
Biological oxidation systems.
Providing optimal energy supply of functioning structures and the level
of plastic processes by:
- Increase in the number of mitochondria and the number of
mitochondrial cristae.
- An increase in the number of enzyme molecules of tissue respiration in
each mitochondria, as well as the activity of enzymes, especially
cytochrome oxidase.
- Improving the efficiency of biological oxidation and its conjugation
with phosphorylation.
- Improving the efficiency of the mechanisms of anaerobic resynthesis
of ATP in cells.
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29. Permanent compensation.
Respiration systems.
The system regulates a level of gas exchange by:
- Hypertrophy of the lungs and an increase in the area of ​​the alveoli,
in the capillaries in the interalveolar septa, in the level of blood flow
in these capillaries.
- Increase the diffusion ability of the air-blood barrier of the lungs.
- Improving the efficiency of the ventilation-perfusion ratio.
-Hypertrophy and increase in the power of the respiratory muscles.
- Ascending the vital capacity of the lungs
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30. Permanent compensation.
Cardiovascular system.
Heart:
- Moderate balanced hypertrophy of all structural elements of the
heart: myocardium, vascular bed, nerve fibers.
- Increase in the number of functioning capillaries in the heart.
- Reducing the distance between the capillary wall and the sarcolemma
of the cardiomyocyte.
- Increasing the number of mitochondria in cardiomyocytes and the
effectiveness of biological oxidation reactions. In this regard, the heart
spends 30-35% less oxygen and metabolic substrates than in a state that
is not adapted to hypoxia.
- Improving the efficiency of transmembrane processes (ion transport,
substrates and metabolic products, oxygen, etc.).
- Increase in the power and speed of interaction of actin and myosin in
cardiomyocyte myofibrils.
- Improving the efficiency of adrenal and cholinergic systems of heart
regulation.
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31. Permanent compensation.
Cardiovascular system.
Vascular system:
Reduction of myogenic arteriole tone and
reduction of the reactive properties of the walls
of resistive vessels to vasoconstrictors/
-Increasing the number of functioning capillaries
in tissues and organs.
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32. Permanent compensation.
Cardiovascular system.
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33. Permanent compensation.
Blood system.
1. Increase in the affinity of deoxyhemoglobin for
oxygen in the capillaries of the lungs significantly.
2. Activation under the influence of ischemia and
hypoxia
education in the kidney erythropoietin
stimulating erythropoiesis
The increase in blood oxygen capacity
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34. Permanent compensation.
Metabolic processes
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35. Permanent compensation.
Metabolic processes
- High efficiency and lability of the reactions of anaerobic
resynthesis of ATP.
-The economical use of oxygen and metabolism substrates in
the reactions of biological oxidation and plastic processes.
-Reducing intensity of metabolic processes
-The dominance of anabolic processes in tissues compared with
catabolic.
-High power and mobility of transmembrane ion transfer
mechanisms.
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36. Permanent compensation.
Nervous and endocrine systems.
Nervous system:
- Increased resistance of neurons to hypoxia and ATP
deficiency, as well as to some other factors/
- Hypertrophy of neurons and an increase in the number
of nerve endings in tissues and organs.
- Increased sensitivity of receptor structures to
neurotransmitters.
Endocrine system :
- A lesser degree of stimulation of the adrenal medulla,
hypothalamic-pituitary-adrenal and other systems.
- Increased sensitivity of cell receptors to hormones.
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38. Thank you for your
attention!
To your success!
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