WK7- Acid Base Balance

Question 1

What are some conditions that promote metabolic acidosis or alkalosis ? Describe their physiology.

Answer 1

Metabolic Acidosis; is a result of increased free hydrogen ions in the blood, often from the metabolism of fat which releases acids. This is common in people who suffer from diabetes.

Metabolic Alkalosis: results from the loss of acids in the body, several kidney disorders, and vomiting, this results in the presence of too many bases in the body.

Question 2

Name the three different ways that hydrogen ions are produced in muscle during exercise.

Answer 2

1. Exercise induced production of carbon dioxide and carbonic acid in skeletal muscle ( during oxidative phosphorylation, CO2 as a product of cellular respiration )
2. Exercise induced production of lactic acid in the working muscle ( during anaerobic conditions)
3. Exercise induced ATP breakdown in the working muscle produces free hydrogen ions.

Question 3

Generally describe what kind of sports would lead to higher acid base imbalances in the human body.

Answer 3

Generally, any sport or exercise that last 45 seconds or longer and has sustained high intensity muscular contractions can produce enough hydrogen ions to disrupt body function.

Question 4

What is the importance of acid base regulation during exercise ?

Answer 4

Hydrogen ions can alter the shape and size of enzymes that are involved in the production of ATP, therefore disturbing a cell’s capacity to do work

Additionally, hydrogen ions can compete with Ca+2 for binding sites on troponin therefore inhibiting muscle contraction.

Question 5

Name the intracellular buffers.

Answer 5

1. Bicarbonate (20-30%) ( Acid Converters )
2. Phosphates ( 10-20%) ( Acid Converters )
3. Proteins + 4. Histidine-Dipeptides
   ( 60%) ( proton receptors )

Buffers typically are good proton receptors or can convert strong acids into weak acids

Question 6

Name the extracellular buffers.

Answer 6

1. Bicarbonate ( most important)
2. hemoglobin
3. blood proteins

Question 7

Discuss the benefits and contraindications of buffer consumption prior to sport competition.

Answer 7

Buffers can enhance performance since acid accumulation or drops in pH can be a limiting factor and a source of fatigue. However overconsumption can lead to severe metabolic alkalosis.

Question 8

Describe the role of the respiratory system in the regulation of acids and bases.

Answer 8

The respiratory system contributes to the expulsion of CO2 which in turn lowers the amount of carbonic acid that can be formed.

Question 9

Detail the process of acid regulation during exercise and the role that respiratory system takes in this process.

Answer 9

The first line of defense against acid accumulation are the buffer systems of the muscle cells which prevent severe declines in pH. The second line of defense against systemic acidosis is the blood buffer systems. Respiratory function becomes crucial when ‘blowing’ off CO2. This is called respiratory compensation for metabolic acidosis.