Question

1. A 30-year old woman with a 2-day history of diarrhea is admitted to the hospital after fainting. Her blood pH is lower than normal and her respiratory rate is dangerously high. Identify the patient's primary acid-base disorder, and identify the response of the patient's body. Briefly explain your reasoning.

2. Explain the concept of antagonistic pairs. Describe the functions of one antagonistic hormone pair. Be sure to include where each hormone is secreted and how each hormone acts upon its target organ.

Answer 1

Answer 1

Identify the patient's primary acid-base disorder

Patient is suffering from Metabolic Acidosis.

The patient with two day history of diarrhea will have decreased HCO₃^- . It is due to increased acid or loss bicarbonate.

serum anion gap = [Na⁺] - ([Cl^-] + [HCO₃⁻]

There are unmeasured anions which help to measure the positive charge of Na. They cause the gap between Na⁺ and Cl^- and HCO₃⁻. So there is a higher anion gap. This higher anion gap causes Metabolic acidosis.

The acid added to the bloodstream has a negative charge which balances the positive charge of sodium and replaces the lower bicarbonates. Thus blood pH is low.  

In metabolic acidosis, there is an increased H⁺ in ECF (extra cellular fluid) because of reduced filtration of HCO₃⁻. Thus there is reduced pCO₂. This increased the respiraory rate in patient.

Identify the response of the patient's body

Patient with acute metabolic acidosis may exhibit deep, rapid breathing called Kussmaul respirations. Rapid deep breaths increase the amount of carbon dioxide exhaled, thus lowering the serum carbon dioxide levels, resulting in some degree of compensation.

In metabolic acidosis, the physiological response is an increase in alveolar ventilation. The stimulation of chemoreceptors in metabolic acidosis is responsible for an increase in tidal volume.

Bicarbonate therapy is generally safe and appropriate.

There is need for Arterial blood gas (ABG) and serum electrolyte measurement and patient can be treated accordingly.

Answer 2

Antagonistic pair

When one drug decreases or inhibits the action of another, they are said to be antagonistic.

Effect of drugs A+B < Effect of drug A + effect of drug B.

In antagonistic pair one drug is inactive as such but decreases the effect of the other.

Antagonist prevents the action of an agonist on a receptor or the subsequent response but does not have any effect of its own.

Agonist activates a receptor to produce an effect.

Functions of one antagonistic hormone pair

Glucagon is a hormone secreted by alpha cells of pancreas. It is secreted when blood glucose levels are low. It performs several functions which are exactly opposite to insulin. It is called as antagonist of insulin.

Insulin is secreted by beta cells of pancreas. Immediately, after high carbohydrate meal the glucose which is absorbed in blood causes rapid secretion of Insulin.

Glucagon is responsible for release of insulin. Insulin inhibits glucagon secretion.

BSL in the diagram is Blood Sugar Level