The term “formed elements” used in relation to the blood include which of the following?
A. fibrinogen.
B. white blood cells.
C. electrolytes.
D. plasma proteins.
The correct answer and explanation is :
The correct answer is B. white blood cells.
Explanation:
In the context of blood, the term “formed elements” refers to the cellular components of the blood, which are suspended in the liquid portion known as plasma. These formed elements include:
- Red Blood Cells (Erythrocytes): These are the most abundant cells in the blood and are responsible for transporting oxygen from the lungs to the tissues and carbon dioxide from the tissues back to the lungs.
- White Blood Cells (Leukocytes): These cells are part of the immune system and play a critical role in defending the body against infections and foreign invaders. There are several types of white blood cells, such as neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with specific roles in immune responses.
- Platelets (Thrombocytes): These are small cell fragments involved in blood clotting. They help in the formation of blood clots to prevent excessive bleeding when blood vessels are injured.
Now, let’s review why the other options are incorrect:
- A. Fibrinogen: Fibrinogen is a plasma protein, not a formed element. It plays a vital role in blood clotting but is not a cellular component. In the presence of clotting factors, fibrinogen is converted into fibrin, which helps in the formation of a clot.
- C. Electrolytes: Electrolytes, such as sodium, potassium, calcium, and chloride, are essential ions found in the blood but are not considered formed elements. They are part of the plasma, which is the liquid portion of the blood, and help regulate fluid balance, nerve function, and muscle contractions.
- D. Plasma Proteins: Plasma proteins, such as albumin, globulins, and fibrinogen, are important for maintaining osmotic pressure, immune responses, and blood clotting. However, they are not classified as formed elements because they are non-cellular components found in the plasma.
Thus, white blood cells are the correct formed elements in the blood, playing a crucial role in immune defense.