What are the three classifications of cells based on their regenerative capacity?

Cells are classified by their ability to regenerate into three groups: Labile cells – continuously dividing (e.g., skin epithelium, bone marrow). Stable cells – normally quiescent but can divide when needed (e.g., liver, kidney cells). Permanent cells – cannot regenerate after birth (e.g., neurons, cardiac muscle cells).

What is the difference between well-differentiated and poorly differentiated cells?

Well-differentiated cells closely resemble their parent cells in structure and function. Poorly differentiated cells lose these original features and are often linked to malignancy, making them hard to identify.

How do benign and malignant tumors differ?

Benign tumors are slow-growing, well-differentiated, usually encapsulated, and do not spread. Malignant tumors grow rapidly, are poorly differentiated, lack a capsule, and can spread through local infiltration, lymph, or blood, with a high recurrence rate.

What is apoptosis and why is it important?

Apoptosis is programmed cell death that removes defective or unnecessary cells without causing inflammation. It is crucial for development and homeostasis, such as in digit separation during embryogenesis and regulating neurons.

What are some examples of labile cells?

Labile cells include epithelial cells (like those in skin and mucous membranes), secretory glands and ducts, and cells in bone marrow, blood, spleen, and lymphoid tissue.

What role does the bcl-2 gene play in apoptosis?

The bcl-2 gene regulates apoptosis by inhibiting programmed cell death, helping control when cells survive or undergo this process.

Tissue Regeneration – Labile, Stable, Permanent Cells & Apoptosis