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By the end of this section, you will be able to:
  • Identify the three blood variables considered when making a diagnosis of acidosis or alkalosis
  • Identify the source of compensation for blood pH problems of a respiratory origin
  • Identify the source of compensation for blood pH problems of a metabolic/renal origin

Normal arterial blood pH is restricted to a very narrow range of 7.35 to 7.45. A person who has a blood pH below 7.35 is considered to be in acidosis (actually, “physiological acidosis,” because blood is not truly acidic until its pH drops below 7), and a continuous blood pH below 7.0 can be fatal. Acidosis has several symptoms, including headache and confusion, and the individual can become lethargic and easily fatigued ( [link] ). A person who has a blood pH above 7.45 is considered to be in alkalosis, and a pH above 7.8 is fatal. Some symptoms of alkalosis include cognitive impairment (which can progress to unconsciousness), tingling or numbness in the extremities, muscle twitching and spasm, and nausea and vomiting. Both acidosis and alkalosis can be caused by either metabolic or respiratory disorders.

As discussed earlier in this chapter, the concentration of carbonic acid in the blood is dependent on the level of CO 2 in the body and the amount of CO 2 gas exhaled through the lungs. Thus, the respiratory contribution to acid-base balance is usually discussed in terms of CO 2 (rather than of carbonic acid). Remember that a molecule of carbonic acid is lost for every molecule of CO 2 exhaled, and a molecule of carbonic acid is formed for every molecule of CO 2 retained.

Symptoms of acidosis and alkalosis

This figure points out the symptoms of acidosis and alkalosis on a silhouette of a human torso. The effects of acidosis on the central nervous system include headache, sleepiness, confusion, loss of consciousness and coma. The effects of acidosis are given on the left side of the diagram. The effects of acidosis on the respiratory system include shortness of breath and coughing. The effects of acidosis on the heart include arrhythmia and increased heart rate. The effects of acidosis on the muscular system include seizures and weakness. The effects of acidosis on the digestive system include nausea, vomiting and diarrhea. The right side of the diagram describes the symptoms of alkalosis. The effects of alkalosis on the central nervous system include confusion, light-headedness, stupor, and coma. The effects of alkalosis on the peripheral nervous system include hand tremor and numbness or tingling in the face, hands, and feet. The effects of alkalosis on the muscular system include twitching and prolonged spasms.  The effects of alkalosis on the digestive system include nausea and vomiting.
Symptoms of acidosis affect several organ systems. Both acidosis and alkalosis can be diagnosed using a blood test.

Metabolic acidosis: primary bicarbonate deficiency

Metabolic acidosis occurs when the blood is too acidic (pH below 7.35) due to too little bicarbonate, a condition called primary bicarbonate deficiency. At the normal pH of 7.40, the ratio of bicarbonate to carbonic acid buffer is 20:1. If a person’s blood pH drops below 7.35, then he or she is in metabolic acidosis. The most common cause of metabolic acidosis is the presence of organic acids or excessive ketones in the blood. [link] lists some other causes of metabolic acidosis.

*Acid metabolites from ingested chemical.
Common Causes of Metabolic Acidosis and Blood Metabolites
Cause Metabolite
Diarrhea Bicarbonate
Uremia Phosphoric, sulfuric, and lactic acids
Diabetic ketoacidosis Increased ketones
Strenuous exercise Lactic acid
Methanol Formic acid*
Paraldehyde β-Hydroxybutyric acid*
Isopropanol Propionic acid*
Ethylene glycol Glycolic acid, and some oxalic and formic acids*
Salicylate/aspirin Sulfasalicylic acid (SSA)*

The first three of the eight causes of metabolic acidosis listed are medical (or unusual physiological) conditions. Strenuous exercise can cause temporary metabolic acidosis due to the production of lactic acid. The last five causes result from the ingestion of specific substances. The active form of aspirin is its metabolite, sulfasalicylic acid. An overdose of aspirin causes acidosis due to the acidity of this metabolite. Metabolic acidosis can also result from uremia, which is the retention of urea and uric acid. Metabolic acidosis can also arise from diabetic ketoacidosis, wherein an excess of ketones is present in the blood. Other causes of metabolic acidosis are a decrease in the excretion of hydrogen ions, which inhibits the conservation of bicarbonate ions, and excessive loss of bicarbonate ions through the gastrointestinal tract due to diarrhea.

Questions & Answers

what is oesophagus?
Bhavani Reply
oesophagus also known as food pip
ABDULLAH
What is the meaning of dissection
Beryl Reply
what's the meaning of polar?
Jackson Reply
Sign of anaemia or whitish color or Hgb luck
Kassahn
Are you talking of Polar anaemia or what, because the word polar doesnt have one meaning
Kingsley
what are the three types of adrenocorticoids hormones
Lubega Reply
glucocorticoids mineralocorticoid and catecholamines
Kartik
what is polar and non-polar
Jackson Reply
polar unequal share of electron while non polar is equal share
Quran
why are phosphate molecules negatively charged?
Jackson Reply
Bocz of unpaired elections
Javid
because of unpaired electrons
ABDULLAH
what are amphipathic molecules?
Jackson Reply
Amphipathic molecules are molecules with both polar and non polar regions
Mohammed
How does the male organ develop
MADUBULA Reply
Hw does the male organ develop
MADUBULA
Review your questions madam
Aliyu
what is anaphylaxis?
Rugut Reply
it is an imagency condition resulting from abnormal and immediate alagic response to a substance to which the body has become intensively sensitized
Lubega
different between drug and medicine
ado Reply
drugs have no medical application (cocaine, heroin, crystal meth). medicine have medical purpose (fentanyl, albuterol, aspirin, ect ect)
Jordan
medicine is a substance or preparation used in treating disease,drug is chemical compound medicine are drugs but all drugs are not medicines
Wafa
assalam o alaikum
Sidra
what happen to ECF and ICF regarding to OEDEMA
Zwanga Reply
what are the smooth muscles of the heart
Sintung Reply
stomach
Sidra
identify external features of kidney
saba Reply
kidney weight on males?
saba
and female ?
saba
Sle full name & treatment
Samim
Syplymic lupw erythematous
Samim
blood supply to spleen ?
saba
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saba
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saba
130 on male
saba
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saba
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saba
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saba
mbbs
saba
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Shahab
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saba
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saba
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saba
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Shahab
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saba
Define cranial nerves with oder
Javid
O-olfactory O-optic O-occumulator T-trochlear T-trigemenal A-abducent F-facial A-auditory G-glossopharyngeal V-vagus A-acessory
Aniee
opd mean?
Shahab
out patient department
mahesh
thnxx
Shahab
Ty Aniee singh
Javid
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Areeej
Read KD Tripathi book of Pharmacology.
mayank
Hello
mayank
CT Scan means
Sintung
what's health?
Sintung
hello
Philip
hi
Sintung
CT means - computerized tomography
Vivek
connective tissue
Dee
they link some body organs
Sintung
Difference between drug and medicine
Javid
hiii muskan
saba
what is tomography?
Gideon
tomography ☝
shahid
yes
Gideon
how hemolytic anemia cause due to gas gangrene?
Huma Reply
what's gangrene?
Sidra
why retro abdominal region called or named "flank "?
Huma Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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