On Flow Cytometric Analysis of a Sample of Fetal Thymus

question 91

Multiple Choice

On flow cytometric analysis of a sample of fetal thymus, a certain population of cells is identified that is positive for both CD4 and CD8 cell surface antigens.  These cells are best characterized as which of the following cells?

• A)Immature cortical T lymphocytes
• B)Mature cytotoxic T lymphocytes
• C)Mature helper T lymphocytes
• D)Antigen presenting cells
• E)Natural killer (NK) cells
• F)Thymic epithelial cells

---

Definitions:

Enzymatically

Pertaining to the process or action facilitated by enzymes, which are proteins that catalyze biochemical reactions.

Jejunum

The middle section of the small intestine in most higher vertebrates, including humans, where the absorption of nutrients and minerals from digested food occurs.

Chyme

The semi-fluid mass of partly digested food that moves from the stomach to the small intestine.

Ileum

The final and longest segment of the small intestine, where most of the absorption of nutrients and minerals from food takes place.