Podcast
Questions and Answers
What was the significant discovery made by Ringer in 1883?
What was the significant discovery made by Ringer in 1883?
- Protein-bound Ca2+ affects heart contraction.
- Ca2+ is not necessary for heart function.
- Ca2+ is essential for myocardial contraction. (correct)
- Citrate-bound Ca2+ enhances heart contraction.
Which forms of calcium did McLean and Hastings find to have no effect on frog heart contraction?
Which forms of calcium did McLean and Hastings find to have no effect on frog heart contraction?
- Protein-bound Ca2+
- Both B and C (correct)
- Citrate-bound Ca2+
- Ionized/free Ca2+
What is the mean concentration of blood-ionized Ca2+ in humans?
What is the mean concentration of blood-ionized Ca2+ in humans?
- 1.18 mmol/L (correct)
- 1.00 mmol/L
- 0.5 mmol/L
- 2.5 mmol/L
Why is it crucial to maintain ionized Ca2+ levels during surgery?
Why is it crucial to maintain ionized Ca2+ levels during surgery?
What condition may arise from decreased ionized Ca2+ concentrations in the blood?
What condition may arise from decreased ionized Ca2+ concentrations in the blood?
Which of the following was a limitation of the first assay developed for ionized/free Ca2+?
Which of the following was a limitation of the first assay developed for ionized/free Ca2+?
Flashcards
Calcium (Ca2+)
Calcium (Ca2+)
A mineral that is essential for muscle contraction and function.
Calcium Physiology
Calcium Physiology
The study of how calcium functions in the body.
Calcium's Role in Myocardial Contraction
Calcium's Role in Myocardial Contraction
The ability of calcium to cause muscles to contract.
Ionized Calcium (Free Ca2+)
Ionized Calcium (Free Ca2+)
Signup and view all the flashcards
Tetany
Tetany
Signup and view all the flashcards
Calcium Ionized Concentration Regulation
Calcium Ionized Concentration Regulation
Signup and view all the flashcards
Study Notes
Calcium's Role in Myocardial Contraction
- Ringer demonstrated in 1883 that calcium ions (Ca2+) are crucial for heart muscle contraction.
- McLean and Hastings' research showed a direct relationship between free calcium concentration and the strength of frog heart contractions.
- Bound calcium (protein-bound and citrate-bound) did not affect contraction strength.
- This led to the development of the first assay for measuring free calcium using isolated frog hearts.
- While the initial method lacked modern precision, it proved blood calcium concentrations are tightly regulated.
- The average free calcium concentration in human blood is approximately 1.18 mmol/L.
Importance of Calcium Regulation
- Maintaining normal free calcium levels is critical, especially during surgery and in critically ill patients, as low levels impair heart function.
- Low free calcium levels in the blood can cause neuromuscular irritability, leading to muscle spasms (tetany).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz explores the critical role of calcium ions in heart muscle contraction, highlighting key research findings. It reviews the historical context of calcium's impact on myocardiac function and the importance of maintaining normal calcium levels for heart health, particularly in surgical settings.
