LAB - GENERAL PATHOLOGY

1. pathos – suffering,

2. logos – study

PATHOLOGY comes from the word

logos

________– study

pathos

suffering

PATHOLOGY

Study of suffering

PATHOLOGY

Study of the structural, biochemical, and functional changes in cells, tissues, and organs that underlie disease

RUDOLF VIRCHOW

Father of Modern Pathology

RUDOLF VIRCHOW

Proposed that injury to the smallest living unit of the body, the cell, is the basis of all disease.

GENERAL PATHOLOGY

SYSTEMIC (ORGAN AND ORGAN SYSTEM) PATHOLOGY

BRANCHES OF PATHOLOGY

GENERAL PATHOLOGY

Concern with the basic reaction of cells and tissues to abnormal stimuli that underlie the disease

GENERAL PATHOLOGY

Looks at all fundamental principles that are common to all diseases

SYSTEMIC (ORGAN AND ORGAN SYSTEM) PATHOLOGY

Examines the specific responses of specialized organs to defined stimuli

SYSTEMIC (ORGAN AND ORGAN SYSTEM) PATHOLOGY

Looks more closely at how a particular organ responds to a disease.

1. Etiology

2. Pathogenesis

3. Morphologic changes

4. Clinical manifestations

FOUR ASPECTS OF A DISEASE PROCESS THAT FORM THE CORE OF PATHOLOGY

Etiology

Cause (of the disease) e.g., Tuberculosis → Mycobacterium tuberculosis

Pathogenesis

Mechanism (by which the disease develops or how the cause leads to changes in the body)

Pathogenesis

e.g., The bacteria enter the lungs, triggering an immune response and leading to the formation of granulomas

Morphologic changes

Structural alterations (in cells or tissues)

e.g., Caseating granulomas that we see in the lung tissue under the microscope

Clinical manifestations

Functional consequences . How the structural changes result in the signs and symptoms that we observe in patients.

Clinical manifestations

e.g., Chronic cough, fever, night sweats, and weight loss.

ETIOLOGY

Can be genetic or acquired, but most commonly multifactorial

Multifactorial

_______, meaning a combination of both genetic and environmental factors.

PATHOGENESIS

Sequence of events that follow after injury

PATHOGENESIS

Explains how the initial cause leads to the development of disease.

MORPHOLOGIC CHANGES

Remains a diagnostic cornerstone

MORPHOLOGIC CHANGES

Because they provide visible evidence of the disease.

CLINICAL MANIFESTATION

The end result of the disease process

CLINICAL MANIFESTATION

Signs and symptoms that we observe in the patient

1. MANIFESTATION

2. SIGN

3. SYMPTOM

CLINICAL MANIFESTATIONS include

MANIFESTATION

Observable or measurable characteristics associated with a specific type of pathology

MANIFESTATION

Example: signs, symptoms, findings from laboratory or radiographic tests

SIGN

Objective observation that can be seen or measured

SIGN

Example: high blood pressure, fever

SYMPTOM

Subjective report that can be perceived only by the person affected

SYMPTOM

Example: headache, nausea

DISEASE

A specific set of signs and symptoms seen together frequently and become the basis for diagnosis

DISORDER

Disruption of the disease to the normal or regular functions in the body

SYNDROME

Disease or disorder that has more than one identifying feature or symptoms

Adaptation

If the stress is manageable, the cell undergoes __________. It adjusts to the stress without being damaged.

Cell Injury

If the cell is unable to adapt, or if the stimulus is more severe, it leads to ______

Reversible Injury

If the injury is mild and transient only, it results in a__________ – the cell can still recover and return to normal.

Irreversible Injury
Cell Death.

If the injury is already severe or progressive, it leads to _________ and, eventually, ________

Necrosis

Apoptosis

Two main outcomes of Irreversible Injury:

ADAPTATIONS

Reversible changes in the size, number, phenotype, metabolic activity, or functions of cells in response to changes in their development

ADAPTATIONS

Very important, because they allow cells and tissues to survive in different conditions and stresses.

1. Hypertrophy

2. Hyperplasia

3. Atrophy

4. Metaplasia

ADAPTATIONS FORMS:

TRUE

TF

ADAPTATIONS FORMS:

These forms of adaptations are very critical for maintaining homeostasis and allowing the body to respond to changes in its environment

However, if these adaptations go too far or happen inappropriately, they could lead to a disease.

HYPERTROPHY

Increase in cell size, leading to overall organ enlargement

This enlargement happens because individual cells grow larger.

HYPERTROPHY

No new cells are formed; cells grow larger by synthesizing more structural components.

Existing cells synthesize more structural components to accommodate increased demand

1. Cells capable of division

2. Cells incapable of division

Depending on whether the cells can divide or not, hypertrophy may present in different ways:

Cells capable of division

• may show hypertrophy (increase in size) with hyperplasia (increase in number).

• Giving it a larger capacity for function

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Cells incapable of division:

11

Key example is myocardial fibers (heart muscle cells)

Cells incapable of division:

These cells are post-mitotic

Cells incapable of division

Tissue mass increases only by hypertrophy.

hypertrophy

Cells incapable of division

Tissue mass increases only by ______

3

Cells incapable of division

3

Individual myocardial fibers grow larger in size to meet functional demands, such as in the case of heart muscle working harder during chronic hypertension

1. PHYSIOLOGIC HYPERTROPHY

2. PATHOLOGIC HYPERTROPHY

TYPES OF HYPERTROPHY

PHYSIOLOGIC HYPERTROPHY

Caused by increased functional demand or stimulation by hormones or growth factors.

A body’s way of adapting to a change in its environment to maintain or enhance function.

PHYSIOLOGIC HYPERTROPHY

EX:

Increased workload – hypertrophy in bodybuilders’ muscles.

When muscles are subjected to regular intense exercise, the fibers experience increased workload. As a result, the muscle cells grow larger in size, increasing muscle mass. This is a positive form of hypertrophy as it enhances muscle function and performance.

1

PHYSIOLOGIC HYPERTROPHY

1

EX:

Estrogen-induced - uterine enlargement during pregnancy.

Stimulated by estrogen, a hormone that causes the smooth muscle cells of the uterus to enlarge in response to the growing fetus.

This allows the uterus to accommodate the increasing size of the pregnancy and prepare for labor

9

PATHOLOGIC HYPERTROPHY

9

Caused by chronic hemodynamic overload (hypertension, faulty valves)

2

PATHOLOGIC HYPERTROPHY

2

Results from chronic, unhealthy conditions

Most common example is the heart, where it is under constant stress due to factors like hypertension or faulty valves.

When the heart has to work harder over time to pump blood due to high blood pressure or issues with bowel function, the myocardial fibers or heart muscle cells become hypertrophic.

PATHOLOGIC HYPERTROPHY

This type of hypertrophy is maladaptive, meaning it doesn’t benefit the heart in the long run.

PATHOLOGIC HYPERTROPHY

Leads to hypertrophy of myocardial fibers

1. Heart failure

2. Arrhythmias

3. Sudden death

PATHOLOGIC HYPERTROPHY

Maladaptive effects when excessive:

Myocardial cells can no longer cope – regressive changes

Lysis and loss of contractile elements – cardiac failure

PATHOLOGIC HYPERTROPHY

Progression:

cardiac failure

PATHOLOGIC HYPERTROPHY

Progression:

Lysis and loss of contractile elements

regressive changes

PATHOLOGIC HYPERTROPHY

Progression:

Myocardial cells can no longer cope

HYPERPLASIA

An increase in the size of an organ or tissue caused by an increase in a number of cells in response to a stimulus, such as hormonal changes or injury.

HYPERPLASIA

Frequently occur together with hypertrophy

As a complementary response to a stimulus

For example, in the case of muscle growth due to exercise. Both hypertrophy and hyperplasia are a combined effec

HYPERPLASIA

Occurs only in cells that are capable of division.

Examples: typical cells in tissues like the skin, liver, and glandular tissues where cell turnover is high and division is possible

1. PHYSIOLOGIC HYPERPLASIA

2. PATHOLOGIC HYPERPLASIA

TYPES OF HYPERPLASIA

PHYSIOLOGIC HYPERPLASIA

Due to hormonal or growth factor stimulation

A normal and adaptive response to stimuli.

Here, the body needs to increase the number of cells in a tissue to meet functional demands or repair damage.

1. Increase in functional capacity of hormone-sensitive organs

2. Compensatory increase after damage or resection

PHYSIOLOGIC HYPERPLASIA

Occurs in several situations:

Compensatory increase after damage or resection

Happens when the body compensates for damage or the removal of part of an organ.

Example: Liver regeneration after transplantation

After part of the liver is removed or damaged, the remaining liver cells increase in number to restore the liver’s mass and function

22

Compensatory increase after damage or resection

22

Bone marrow hematopoiesis increases up to 8-fold with erythropoietin stimulation.

• Increases the production of blood cells in response to signals like erythropoietin.

• In situations like anemia or blood loss, the bone marrow may increase hematopoiesis by up to 8-fold to produce more RBCs and restore normal function.

PHYSIOLOGIC HYPERPLASIA

Often occurs together with hypertrophy.

This combined response helps the organ or tissue meet increasing functional demands.

Example: Uterine enlargement during pregnancy

smooth muscle hypertrophy

hyperplasia.

PHYSIOLOGIC HYPERPLASIA

Uterus undergoes both ______ + ___

Hypertrophy occurs as the smooth muscle cells of the uterus enlarge to handle the increasing physical stretch and mechanical workload as the fetus grows.

Hyperplasia happens because the number of smooth muscle cells increases to accommodate the growing size of the uterus.

66

PATHOLOGIC HYPERPLASIA

66

Caused by excessive or inappropriate hormonal or growth factor stimulation.

PATHOLOGIC HYPERPLASIA

Examples:

Endometrial hyperplasia from excess estrogen

Endometrial hyperplasia

PATHOLOGIC HYPERPLASIA

____ is where the endometrial lining of the uterus becomes excessively thick due to prolonged or unopposed estrogen stimulation.

This can occur when the estrogen is very high without the balancing effect of the progesterone, as seen in some hormonal imbalances. Although now cancerous, endometrial hyperplasia increases the risk of developing endometrial cancer if left untreated.

22

PATHOLOGIC HYPERPLASIA

22

EXAMPLE:

Benign prostatic hyperplasia from excess androgens

Non-cancerous enlargement of prostate

Driven by an excess of androgens like testosterone causing an increased in prostate cell numbers

epidermal hyperplasia

PATHOLOGIC HYPERPLASIA

Papillomavirus infection (Human Papillomavirus or HPV) – _______

5

PATHOLOGIC HYPERPLASIA

5

Distinct from cancer but can create a fertile ground for malignancy

When cells proliferate uncontrollably, it increases the chance or risk of genetic mutations that could lead to cancer.

Example: Endometrial hyperplasia – risk for endometrial cancer

ATROPHY

Defined as a reduction in the size of an organ or tissue due to a decrease in cell size and number

1. Disuse (immobilization)

2. Nutritional or oxygen deprivation

3. Diminished endocrine stimulation

4. Aging, Denervation (loss of nerve supply)

ATROPHY Causes:

Presence of autophagic granules

ATROPHY Characteristic feature:

ATROPHY

Presence of autophagic granules

Intracellular vacuoles containing degraded organelle debris

Essentially, the cells start breaking down their own components in an effort to survive under reduced conditions. A process known as autophagy, where damaged organelles and proteins are recycled.

PHYSIOLOGIC ATROPHY

TYPE OF ATROPHY

Common during normal development

Common example: The decrease in the uterus shortly after pregnancy

TRUE

Physiologic Atrophy is a normal and reversible process.

PATHOLOGIC ATROPHY

Abnormal atrophy due to disease or dysfunctional process

1. Decreased workload / Atrophy of disuse

2. Loss of innervation

3. Diminished blood supply

4. Inadequate nutrition

5. Loss of endocrine stimulation

6. Pressure

PATHOLOGIC ATROPHY Causes:

Decreased workload / Atrophy of disuse

Occurs when an organ or tissue is no longer used or is immobilized.

Atrophy of disuse

Decreased workload / _________

22

Decreased workload / Atrophy of disuse

22

Example: Skeletal muscle atrophy after fracture immobilization or bed rest

When muscles aren’t regularly reused such as during healing from a fracture, they begin to shrink in size and loss strength.

11

Decreased workload / Atrophy of disuse

11

May be accompanied by osteoporosis

As lack of physical activity can decrease bone density.

Loss of innervation

When nerve supply to a tissue or organ is lost, it leads to atrophy.

Denervation

loss of skeletal muscle metabolism and function

Denervation

Classic example is patients with polio.

Other conditions are peripheral neuropathy and spinal cord injury.

Diminished blood supply

A reduction in the blood flow can lead to Ischemia which results in the lack of oxygen and nutrient needed for tissue maintenance.

Diminished blood supply

Example:

ischemia from atherosclerosis;

Senile atrophy in brain (Alzheimer’s disease)