Cell Adaptation and Death: Study Notes

• Study notes on Cell Adaptation & Death

Cell Types

• Epithelial cells include squamous, cuboidal, and columnar types, found in skin and intestines
• Connective tissues include fibroblasts, adipocytes, and chondrocytes, found in bone, cartilage, and fat
• Other cell types include muscle cells (skeletal, cardiac, and smooth) and neurons

Cell Division

• Labile cells constantly divide, exemplified by skin and gut epithelium
• Stable cells divide when needed, such as in the liver and kidneys
• Permanent cells cannot divide, like neurons and cardiac muscle

Apoptosis vs Necrosis

• Apoptosis is programmed cell death that occurs without inflammation
• Necrosis is uncontrolled cell death which causes inflammation

Infarct

• Infarct is tissue death that occurs due to lack of blood supply, for example, myocardial infarction

Factors for Atrophy

• Factors that determine atrophy or infarction: blood supply, oxygen availability, workload, and hormonal signals

Effects of Ageing

• Ageing effects on cells and organs: reduced cell division, DNA damage, accumulation of waste products, and organ shrinkage

Adaptation & Reversibility

• Cellular adaptation includes: Hypertrophy (increase in size), Hyperplasia (increase in number), Atrophy (decrease in size), and Metaplasia (change in cell type)
• Cellular adaptation notes: Most adaptations are reversible except metaplasia if it progresses to dysplasia

Metaplasia

• Metaplasia is a change from one cell type to another, for example, smoking causes columnar cells in the bronchi to become squamous

Type of Cell Death

• Cell death occurs in normal embryogenesis and inflammatory response

• Apoptosis occurs without inflammation

Increase in Size

• Cellular processes leading to tissue or organ size increase: Hypertrophy (cell enlargement) & Hyperplasia (cell multiplication)

Decrease in Size

• Cellular processes leading to tissue or organ size decrease: Atrophy (cell shrinkage) & Apoptosis (programmed cell death)

Cell types

• Neurons and cardiac muscle cells are examples of permanent cell types

• Stratified squamous epithelium, such as in skin and the esophagus, is best for withstanding physical stress

Study notes on cell adaptation and death, covering various cell types such as epithelial, connective, muscle, and neurons. Explains cell division in labile, stable, and permanent cells. Discusses apoptosis, necrosis, infarct, and factors determining atrophy or infarction.