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Hypoxia is a pathological condition in which the body as a whole (generalized hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. Hypoxia in which there is complete deprivation of oxygen supply is referred to as anoxia. General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...
Hypoxia is often associated with high altitudes, where it is called altitude sickness. Hypoxia can also occur while diving underwater, especially with closed-circuit rebreather systems that control the amount of oxygen in the air breathed in. Altitude sickness, also known as acute mountain sickness (AMS) or altitude illness is a pathological condition that is caused by lack of adaptation to high altitudes. ...
Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ...
Symptoms
Symptoms of generalized hypoxia depend on its severity and speed of onset. They include headaches, fatigue, shortness of breath, nausea, unsteadiness, and sometimes even seizures and coma. Severe hypoxia induces a blue discoloration of the skin (deoxygenated blood cells lose their bright red color in favor of a dark blue/red color). A headache (medically known as cephalgia) is a condition of mild to severe pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ...
For other uses, see Nausea (disambiguation). ...
This article is about the medical term, epileptic seizure, as distinct from psychogenic non-epileptic seizure. ...
In medicine, a coma (from the Greek koma, meaning deep sleep) is a profound state of unconsciousness. ...
Categories and causes of hypoxia
Generalised hypoxia This may be due to low levels of oxygen in the blood (Hypoxemia) or where tissues throughout the body are unable to utilise the oxygen supplied. - Hypoxic hypoxia when there's an inadequate supply of oxygen. this may be due to:
- Low partial pressure of atmospheric oxygen (e.g. at high altitudes or as may be caused on scuba diving).
- Inadequate pulmonary ventilation (e.g. in chronic obstructive pulmonary disease or respiratory arrest).
- Shunts in the pulmonary circulation or a right-to-left shunt in the heart. Shunts can be caused by collapsed alveoli that are still perfused or a block in ventilation to an area of the lung. Whatever the mechanism, blood meant for the pulmonary system is not ventilated and so no gas exchange occurs (the ventilation/perfusion ratio is zero). Standard existing shunts include the thebesian vessels which empty into the left ventricle and the bronchial circulation which supply the bronchi with oxygen.
- Carbon monoxide poisoning which inhibits hemoglobin's ability to bind oxygen.
- Anemic hypoxia in which arterial oxygen pressure is normal, but total oxygen content of the blood is reduced. This may be due to:
- Reduced hemoglobin content in erythrocytes. Since hemoglobin carries oxygen and carbon dioxide (and/or carbon monoxide), the quantity (volume) of oxygen carried is affected by how much hemoglobin is present in the red blood cells. For example iron deficiency anemia lowers hemoglobin levels in red blood cells and therefore hinders there carrying capacity.
- Decreased hematocrit e.g. from blood loss (blood loss anemia).
- Hypemic Hypoxia when there's an inability of the blood to carry oxygen.
- Histotoxic hypoxia in which quantity of oxygen reaching the cells is normal, but the cells are unable to effectively use the oxygen.
Hypoxic hypoxia is hypoxia resulting from a defective mechanism of oxygenation in the lungs; may be caused by a low tension of oxygen, abnormal pulmonary function or respiratory obstruction, or a right-to-left shunt in the heart. ...
In Chemistry, the partial pressure of a gas in a mixture or solution is what the pressure of that gas would be if all other components of the mixture or solution suddenly vanished without its temperature changing. ...
Saturns atmosphere is made up of hydorgen, helium and methane ...
SCUBA is an acronym for Self-Contained Underwater Breathing Apparatus. ...
Chronic obstructive pulmonary disease (COPD) is an umbrella term for a group of respiratory tract diseases that are characterised by airflow obstruction or limitation. ...
Respiratory failure is a medical term for inadequate gas exchange by the respiratory system. ...
In medicine, a shunt is a device designed to drain excess cerebrospinal fluid from the brain and carry it to other parts of the body. ...
The alveoli (singular:alveolus), tiny hollow sacs which are continuous with the airways, are the sites of gas exchange with the blood. ...
In the heart, a ventricle is a chamber which collects blood from an atrium (another heart chamber) and pumps it out of the heart. ...
A bronchus (plural bronchi, adjective bronchial) is a caliber of airways in the the respiratory tract that conducts air into the lungs. ...
Carbon monoxide, chemical formula CO, is a colorless, odorless, tasteless, flammable and highly toxic gas. ...
3-dimensional structure of hemoglobin. ...
Anemic hypoxia occurs when there is sufficient oxygen in the lungs, but the blood has lost some of its capacity to carry it. ...
3-dimensional structure of hemoglobin. ...
Human red blood cells Red blood cells are the most common type of blood cell and are the vertebrate bodys principal means of delivering oxygen to body tissues via the blood. ...
The hematocrit (Ht or HCT) and packed cell volume (PCV) are measures of the proportion of blood volume that is occupied by red blood cells. ...
results from tissue poisoning such as from Alcohol, Narcotics and certain poisons ...
Localised tissue hypoxia In medicine, ischemia (Greek ισχαιμία, isch- is restriction, hema or haema is blood) is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. ...
Cerebral ischemia is an ischemic condition where the brain or parts of the brain do not receive enough blood flow to maintain normal neurological function. ...
Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ...
Ischaemic heart disease is a disease characterized by reduced blood supply to the heart. ...
Cerebral hypoxia (the pathological condition is called hypoxic encephalopathy) is to a hypoxic condition in which there is a decrease of oxygen supply to the brain or parts of the brain despite adequate blood flow (compare with cerebral ischemia). ...
Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ...
General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...
Pathophysiology The measurement of oxygen supply involves calculating its Partial pressure by multiplying atmospheric pressure (e.g. 760 mmHg minus the 47mmHg of water vapor) by the gas's fraction in air (e.g., 713mmHg x 21% = 150mmHg). After mixing with expired CO2 in the lungs, oxygen diffuses down a pressure gradient to enter arterial blood around where its partial pressure is 100mmHg. Arterial blood flow delivers oxygen to the peripheral tissues, where it again diffuses down a pressure gradient into the cells and into their mitochondria. These bacterial like cytoplasmic structures strip hydrogen from fuels (glucose, fats and some amino acids) to burn with oxygen to form water. Released energy (originally from the sun and photosynthesis) is stored as ATP, to be later used for energy requiring metabolism. The fuel's carbon is oxidized to CO2, which diffuses down its partial pressure gradient out of the cells into venous blood to finally be exhaled by the lungs. Experimentally, oxygen diffusion becomes rate limiting (and lethal) when arterial oxygen partial pressure falls to 40mmHg or below. The torr (symbol: Torr) or millimetre of mercury (mmHg) is a non-SI unit of pressure. ...
Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ...
Section of an artery An arterial road is a class of highway. ...
In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ...
Cytoplasm is a homogeneous, generally clear jelly-like material that fills cells. ...
General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...
Glucose (Glc), a monosaccharide (or simple sugar), is one of the most important carbohydrates. ...
This article or section is in need of attention from an expert on the subject. ...
An amino acid residue is what is left of an amino acid once a molecule of water has been lost (an H+ from the nitrogenous side and an OH- from the carboxylic side) in the formation of a peptide bond. ...
Water (from the Old English waeter; c. ...
The Sun is the star at the center of Earths solar system. ...
Leaf. ...
Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide primarily known in biochemistry as the molecular currency of intracellular energy transfer. ...
If oxygen delivery to cells is insufficient for the demand (hyoxia), hydrogen will be shifted to pyruvic acid converting it to lactic acid. This temporary measure (anaerobic metabolism) allows small amounts of energy to be produced. Lactic acid build up in tissues and blood is a sign of inadequate mitochondrial oxygenation, which may be due to hypoxemia, poor blood flow (e.g. shock) or a combination of both. If severe or prolonged it could lead to cell death. Pyruvic acid (CH3COCO2H) is an alpha-keto acid, of the keto acid group. ...
Lactic acid, also known as milk acid or 2-hydroxypropanoic acid, is a chemical compound that plays a role in several biochemical processes. ...
See also Suffocation redirects here, for the band, see Suffocation (band). ...
A hypoxic tumor is a tumor whose cells have been deprived of oxygen. ...
Wikipedia does not have an article with this exact name. ...
Time of useful consciousness (TUC) is defined as the amount of time an individual is able to perform flying duties efficiently in an environment of inadequate oxygen supply. ...
References Hobler KE, Carey LC (1973). "Effect of acute progressive hypoxemia on cardiac output and plasma excess lactate". Ann Surg 177 (2): 199-202. PMID 4572785. |
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