NR283 Exam Pathophysiology Study Guide 2024/2025 with Complete Solutions.
NR283 Pathophysiology Study Guide
Chapter 1: Intro to Pathology
1 & 2. Descr... [Show More] ibe the cellular adaptations made in each of the following processes and their causative
factors: atrophy, hypertrophy, hyperplasia, dysplasia, and metaplasia
Atrophy- a decrease in the size of cells, resulting in a reduced tissue mass. Common causes
include reduced use of the tissue, insufficient nutrition, decreased neurologic or hormonal
stimulation, and aging
Hypertrophy- an increase in the size of individual cells, resulting in an enlarged tissue mass. This
increase may be caused by additional work by the tissue, as demonstrated by an enlarged heart
muscle resulting from increased demands
Hyperplasia- an increased number of cells resulting in an enlarged tissue mass. Hyperplasia may
be a compensatory mechanism to meet increased demands, or pathologic when there is a hormonal
imbalance, or it may mean there is an increased risk of cancer
Dysplasia- tissue in which the cells vary in size and shape, large nuclei are frequently present, and
the rate of mitosis is increased. May result from chronic irritation infection, or may be a
precancerous change. Detection of dysplasia is the basis of routine screening tests for atypical
cells such as the Pap smear
Metaplasia- when one mature cell type is replaced by a different mature cell type. May result
from a deficit of vitamin A. Metaplasia is sometimes an adaptive mechanism that provides a more
resistant tissue (i.e. when stratified squamous epithelium replaces ciliated columnar epithelium in
the respiratory tracts of cigarette smokers. The new cells make a stronger barrier but they decrease
defenses for the lungs because they lack cilia)
3. Identify the most common cause of cellular injury.
The most common cause of cellular injury is ischemia (decreased supply of oxygenated blood to a
tissue or organ, due to circulatory obstruction), which results in hypoxia (reduced oxygen in
tissue) and reduced cellular metabolism
Other causes of cell injury:
● Physical agents - excessive health or cold or radiation exposure
● Mechanical damage such as pressure or tearing of tissue
● Chemical toxins
● Microorganisms such as bacteria, viruses, and parasites
● Abnormal metabolites accumulation in cells
● Nutritional deficits
● Imbalance of fluids or electrolytes
4. Describe cellular injury caused by infection and inflammation.
Infectious diseases cause cell injury through microorganisms (i.e. bacteria & viruses). Some
microorganisms induce pyroptosis (a type of cell death by lysis/dissolution of the cell), resulting
in the rupture of the plasma membrane and release of destructive lysosomal enzymes into the
tissue, which causes inflammation (swelling, redness, and pain) as well as damage to nearby cells
and reduced function
5. Describe the major mechanism of tissue damage caused by chemical injury.
Chemicals from both the environment (exogenous) and inside the body (endogenous) may
damage cells, either by altering cell membrane permeability or producing free radicals, which
continue to damage cell components
6. Discuss the manifestations of the four major types of necrosis, and give examples of the tissue types
affected by each type of necrosis.
Liquefaction necrosis- the process by which dead cells liquefy under the influence of certain cell
enzymes. Occurs when brain tissue dies, or in some bacterial infections in which a cavity or ulcer
develops in the infected area
Coagulative necrosis- when the cell proteins are altered or denatured and the cells retain some
form for a time after death. Occurs in a myocardial infarction when a lack of oxygen causes cell
death
Fat necrosis- when fatty tissue is broken down into fatty acids in the presence of infection or
certain enzymes. These compounds may increase inflammation.
Caseous necrosis- a form of coagulation necrosis in which a thick, yellowish, “cheesy” substance
forms. When TB develops, the first stage is characterized by development of a Ghon complex
a.k.a. granuloma (small solid mass of macrophages & lymphocytes covered by connective tissue).
Caseous necrosis can be seen inside this mass. The Ghon complex heals like a scar, containing the
infection. If the infection continues to develop, the area may undergo liquefaction necrosis,
forming a cavity. [Show Less]
