BIOS 256 Week 5 Case Study
Student Name
Chamberlain University
BIOS-256: Anatomy & Physiology IV with Lab
Prof. Name
Date
Week 5: Case Study 2
1. What physiological imbalances are expected from vomiting stomach contents containing hydrochloric acid (HCl)?
When hydrochloric acid (HCl) is expelled from the stomach through persistent vomiting, several physiological disturbances are likely to occur. These include dehydration, metabolic alkalosis, hypochloremia, and hypokalemia. The loss of gastric fluids results in significant depletion of body volume and vital electrolytes such as sodium (Na⁺), chloride (Cl⁻), hydrogen ions (H⁺), and potassium (K⁺). In response, the kidneys work to restore equilibrium by retaining sodium and excreting excess bicarbonate (HCO₃⁻). This compensatory mechanism may result in further hydrogen ion loss, thereby worsening alkalosis. The body prioritizes sodium conservation, often at the expense of hydrogen and potassium ions. Therefore, the continued loss of fluids inevitably causes ionic imbalance, pushing the body to adapt by sacrificing less critical ions to preserve homeostasis.
2. How does repeated vomiting affect chloride levels and acid-base balance?
Repeated vomiting leads to a pronounced decline in chloride levels, contributing to a condition known as hypochloremic metabolic alkalosis. This occurs because the body loses essential electrolytes—including sodium, potassium, calcium, magnesium, bicarbonate, and chloride—each time gastric contents are expelled. The frequent loss of hydrochloric acid significantly reduces both hydrogen and chloride ions in the body. As bicarbonate builds up in the bloodstream without sufficient counterbalancing hydrogen ions, the blood’s pH rises, making it more alkaline. This shift can disturb multiple physiological functions and, if left untreated, may lead to serious complications (Saladin, 2020).
3. What is the physiological effect of administering normal saline intravenously?
Normal saline is an isotonic solution, meaning it has the same salt concentration as cells and blood plasma. When administered via intravenous (IV) infusion, there is no net movement of water into or out of the body’s cells. This helps maintain cellular stability without causing cells to swell (as in hypotonic solutions) or shrink (as in hypertonic solutions). Normal saline is especially effective in restoring fluid volume and electrolyte balance during episodes of dehydration caused by fluid loss, such as vomiting (Tonog & Lakhkar, 2022).
4. What are the most common clinical signs of dehydration?
The primary indicators of dehydration include:
- Dry mouth or mucous membranes
- Absence of tears
- Constipation
- Dark-colored, concentrated urine
- Decreased frequency of urination
These signs suggest that the body is experiencing a fluid deficit, potentially affecting organ function and systemic circulation if not corrected promptly.
| Clinical Sign | Implication |
|---|---|
| Dry mouth | Inadequate hydration of mucous membranes |
| No tears | Reduced fluid volume affecting tear glands |
| Constipation | Water reabsorption from the colon |
| Concentrated urine | Kidneys conserving water |
| Low urine output | Decreased kidney perfusion |
5. How does the respiratory system contribute to maintaining acid-base balance?
The respiratory system plays a key role in regulating acid-base balance by eliminating carbon dioxide (CO₂), a byproduct of cellular metabolism. Under normal conditions, the rate of CO₂ exhalation matches its production by body cells. The partial pressure of carbon dioxide (PCO₂) in the blood is typically maintained between 35-45 mm Hg. However, if respiratory function becomes impaired, CO₂ is retained, leading to the formation of more carbonic acid (H₂CO₃), which can lower blood pH.
The carbonic anhydrase reaction, which converts carbonic acid to CO₂ and water, shifts to the left when PCO₂ decreases. This shift also leads to a decrease in hydrogen ion concentration, thereby raising the blood pH. Conversely, impaired CO₂ removal can push the reaction to the right, increasing hydrogen ions and lowering pH (Chamberlain University eDapt, 2021).
References
Saladin, K. S. (2020). Anatomy & Physiology: The Unity of Form and Function (9th ed.). McGraw-Hill Higher Education (US).
Tonog, P., & Lakhkar, A. D. (2022). Normal Saline. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK545210/
BIOS 256 Week 5 Case Study
Chamberlain University eDapt. (2021). Physiology and Homeostasis Learning Module.