Define granuloma with example.

Granulomatous inflammation is a form of chronic inflammation characterized by collections of activated macrophages, often with T lymphocytes, and sometimes associated with central necrosis. The activated macrophages may develop abundant cytoplasm and begin to resemble epithelial cells, and are called epithelioid cells. Some activated macrophages may fuse, forming multinucleate giant cells. Granuloma formation is a cellular attempt to contain an offending agent that is difficult to eradicate. In this attempt there is often strong activation of T lymphocytes leading to macrophage activation, which can cause injury to normal tissues. 

There are two types of granulomas.

• Immune Granulomas
• Foreign body Granulomas
  

What are the types of cellular adaptation?

Adaptations are reversible changes in the size, number, phenotype, metabolic activity, or functions of cells in response to changes in their environment.
Cellular adaptation is mainly of four types:

1. Hypertrophy: Hypertrophy refers to an increase in the size of cells, that results in an increase in the size of the affected organ.
2. Hyperplasia: Hyperplasia is defined as an increase in the number of cells in an organ or tissue in response to a stimulus.
3. Atrophy: Atrophy is defined as a reduction in the size of an organ or tissue due to a decrease in cell size and number.
4. Metaplasia: Metaplasia is a reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type.

What are the morhological types of irreversible cell injury?

Morphological pattern of irreversible cell injury are as follows: 

A. Necrosis

• Coagulative necrosis
• Liquefactive necrosis
• Gangrenous necrosis
• Caseous necrosis
• Fat necrosis
• Fibrinoid necrosis

B. Apoptosis.

What is cell injury? What are the types of cell injury?

Cell injury:

When cells are stressed so severely that they are no longer able to adapt or when cells are exposed to inherently damaging agents or suffer from intrinsic abnormalities. Injury may progress through a reversible stage and culminate in cell death.

Types of cell injury:

1. Reversible cell injury.

2. Irreversible cell injury or cell death.

Isotope: Definition, Types.

Definition:

• Atoms with same atomic number (number of proton), but different atomic weight (number of protons and neutrons).
• Atoms of same element with different atomic weight.

Types of isotope:

1. Stable isotope
• Stability of an isotope depends on the definite neutron to ration which is specific for a specific atom.
• In atoms of low atomic weight stability is usually achieved with neutron to proton ration around one.
• In atoms of high atomic stability is usually achieved with more neutron than proton
• Neutrally occurring isotopes of most of the predominant elements are stable isotopes.
2. Unstable isotope
• These are the isotopes having neutron to proton ration far away from its stability ratio.
• Neutrally occurring isotopes of heavy elements are usually unstable
• Rarely some naturally occurring isotopes of lighter elements can also be unstable
• Unstable isotopes tend to become stable by radio active decay

What are the types of colloid?

1. Hydrophilic or lyophilic colloid

• These are solvent loving and having affinity to water.
• They exist as emulsoid
• Practically all colloid of living body are emulsoid
• They are easily solvated or hydrated where a shell of water molecule is formed around them. This provides stability to colloid solution by preventing aggregation of colloid
  particles since the solvated particles repel Each other.
• They can be adsorbed on hydrophobic colloid followed by solvation (hydration) around it and
  thereby can stabilize the solution of hydrophobic colloid by preventing their precipitation that
  would otherwise occur. Therefore, hydrophilic colloids are also called protective colloid.
• Common hydrophilic colloids are: protein, polysaccharide and gelatin.

2. Hydrophobic or lyophobic colloid

• These are solvent hating and have no affinity to water.
• They exist as suspenoid
• They are kept in solution by hydrophilic colloid absorbed around them. 

eg. Colloid Gold.