Pathology

Question 1

what are aspects of disease

Answer 1

ETIOLOGY_ cause of disease.
PATHOGENESIS_ mechanism of development of disease.
MORPHOLOGY_ structural alterations induced in cell and tissues (Gross and microscopic findings)
CLINICAL MANIFESTATIONS_ Signs and symptoms
PROGNOSIS- Expected outcome of disease

Question 2

describe etiology types

Answer 2

There are two major classes of etiologic factors:
Genetic (e.g., Inherited mutations and disease-associated gene variants, or polymorphisms)
Acquired (e.G., Infectious, nutritional, chemical, physical).

Question 3

describe pathogenesis

Answer 3

Pathogenesis refers to the sequence of events in the response of cells or tissues to the etiologic agent, from the initial stimulus to the ultimate expression of the disease.

Even when the initial cause is known (e.g., infection or mutation), it is many steps removed from the expression of the disease.

Question 4

describe molecular and morphological changes

Answer 4

Morphologic changes refer to the structural alterations in cells or tissues that are either characteristic of a disease or diagnostic of an etiologic process.
More recently the limitations of morphology for diagnosing diseases have become increasingly evident, and the field of diagnostic pathology has expanded to encompass molecular, biologic and immunologic approaches for analyzing disease states.

Question 5

describe clinical manifestation

Answer 5

The end results of genetic, biochemical, and structural changes in cells and tissues are functional abnormalities, which lead to the clinical manifestations (symptoms and signs) of disease, as well as its progress (clinical prognosis)

all forms of disease start with molecular or structural alterations in cells course and outcome).

Question 6

define cell injury

Answer 6

sequence of events that occur if the limits of adaptive capability are exceeded or no adaptive response is possible

Question 7

describe irreversible injury

Answer 7

Cell injury is reversible up to a certain point, but if the stimulus persists or is severe enough from the beginning, the cell suffers irreversible injury and ultimately cell death

Question 8

describe cell death and its pathways

Answer 8

Cell death, the end result of progressive cell injury, is one of the most crucial events in the evolution of disease in any tissue or organ.
It results from diverse causes, including ischemia (reduced blood flow), infection, and toxins.
Cell death is also a normal and essential process in embryogenesis, the development of organs, and the maintenance of homeostasis.
There are two principal pathways of cell death, necrosis and apoptosis

Question 9

describe autophagy

Answer 9

Nutrient deprivation triggers an adaptive cellular response called autophagy that may also culminate in cell death.

Calcium is often deposited at sites of cell death, resulting in pathologic calcification.

Finally, the normal process of aging itself is accompanied by characteristic morphologic and functional changes in cells.

Question 10

what are the causes of cell injury

Answer 10

oxygen deprevation 
chemical and drugs
physical agents
infectious agents
immunological reactions 
genetic abnormalities 
nutrient imbalances

Question 11

define cellular adaptation

Answer 11

Adaptations are reversible changes in the
Size
Number
Phenotype
Metabolic activity
Functions of cells
in response to changes in their environment.

Question 12

what is hypoxia

Answer 12

decreased level of oxygen in blood

Question 13

causes of hypoxia

Answer 13

ischemia

hypoxemia due to lack of oxygen or lack of oxygen carrying capacity

Question 14

what is ischemia

Answer 14

reduced blood flow

Question 15

what is hypoxemia

Answer 15

hypoxia and ischemia

Question 16

what are intracellular adaptations

Answer 16

Cellular adaptation is a cellular response to severe physiological stress or an excessive pathological stimulus.

Question 17

what is atrophy

Answer 17

Reduced size of an organ or tissue resulting from a decrease in cell size and number.

Question 18

examples of physiological atrophy are

Answer 18

Notochord and thyroglossal duct, undergo atrophy during fetal development.
The uterus decreases in size shortly after parturition
Menopause - physiologic atrophy
Endometrium
Vaginal epithelium
Breast

Question 19

what are causes of pathological atrophy

Answer 19

starvation 
neuropathic atrophy (due to loss of innervation)
senile atrophy (in old age)

Question 20

what is the mechanism of atrophy

Answer 20

nutritional deficiency and disuse

activation of ubiquitin proteosomal pathway

autophagic vacuoles containing cell organelles formed, they fuse with lysosomes and organelles are digested

Question 21

define hypertrophy

Answer 21

Increase in the size of the cells, which results in enlargement of organ without any changes in the number of cells.

Question 22

physiological hypertrophy examples

Answer 22

kidney hypertrophy after one kidney removed

skeletal muscle hypertrophy in athletes

Question 23

examples of pathological hypertrophy are

Answer 23

hypertrophic heart in uncontrolled hypertension

Question 24

describe mechanism of cardiac hypertrophy

Answer 24

The mechanisms driving cardiac hypertrophy involve at least two types of signals:
mechanical triggers, such as stretch, and soluble mediators that stimulate cell growth, such as growth factors.
adrenergic hormones.
These stimuli turn on signal transduction pathways that lead to the induction of a number of genes
which in turn stimulate synthesis of many cellular proteins, including growth factors and structural proteins.
The result is the synthesis of more proteins and myofilaments per cell, which increases the force generated with each contraction, enabling the cell to meet increased work demands.

Question 25

degenerative changes in heart because of hypertrophy

Answer 25

When this happens in the heart, several degenerative changes occur in the myocardial fibers, of which the most important are :
Fragmentation
loss of myofibrillar contractile elements.
ventricular dilation and ultimately cardiac failure.

There may be finite limits on the abilities of the vasculature to adequately supply the enlarged fibers
the mitochondria to supply ATP
or the biosynthetic machinery to provide sufficient contractile proteins or other cytoskeletal elements.

Question 26

what are the degenerative changes because of hypertrophy

Answer 26

An adaptation to stress such as hypertrophy can progress to functionally significant cell injury if the stress is not relieved.

Whatever the cause of hypertrophy, a limit is reached beyond which the enlargement of muscle mass can no longer compensate for the increased burden.

Question 27

define hyperplasia

Answer 27

Increase in the number of cells in an organ or tissue, usually resulting in increased mass of the organ or tissue

Question 28

examples of physiological hyperplasia are

Answer 28

adult breast tissue during lactation

gravid uterus

regeneration of liver

Question 29

examples of pathological hyperplasia are

Answer 29

multinodular goiter
endometrial hyperplasia
benign prostatic hyperplasia

Question 30

what are the causes of pathological hyperplasia

Answer 30

Viral infections, papilloma viruses, cause skin warts and mucosal lesions composed of masses of hyperplastic epithelium

Growth factors produced by viral genes or by infected cells, stimulate cellular proliferation