Pathology Test 1

What are the 6 Key Steps of disease progression:

Etiology, pathogenesis, morphology, pathophysiology, clinical manifestations, prognosis.

What is Etiology? include etiologic agents and factors.

Etiology is the identification of factors provoking a particular disease.

-        Etiologic agents: specific agent which causes a disease, such as bacteria or viruses.

-        One etiologic agent can cause one disease.

-        Several etiologic agents can cause one disease.

-        One etiologic agent can cause multiple diseases.

-        Etiologic factors: contribute to the causing of disease, or influence the disease course, such as age or genetics. 

What is Pathogenesis? include an example of what this can look like

-        Pathogenesis is the development of the evolution of a disease, including the infection of and damage to the bodies cells which will lead to different symptoms.

-        For example, infection via a bacterium can include:

1. Invasion of the host body

2. Proliferation

3. Spreading

4. Infecting and damaging the body’s cells.

5. Triggering an immune response.

What is Morphology?

Morphology is the effect of the disease on the bodies cells and tissues. This could include cell death, inflammation, abnormal cell growth or necrosis.

What is Pathophysiology?

Pathophysiology is the effect of the disease on normal physiological functioning of the body, includes functional impairments of bodily systems resulting from structural damage.

This could include organ damage, biochemical imbalances, or bodily system malfunctioning.

What are clinical manifestations? also what is the difference between signs and symptoms, and what is required in a diagnosis.

-        The presentation of disease in a patient.

-        Symptoms: the patient’s perception of a change in bodily function. They are difficult to measure and require asking appropriate questions. May include headache, nausea, or fatigue.

-        Signs: physical manifestations of a disease which could be measured. This could include pulse rate, breathing rate or wheezing.

-        Diagnosis: requires a medical history, physical examination, and/or diagnostic procedures to identify a disease, disorder, or condition.

What is prognosis?

-        The likely course or outcome resulting from a disease.

-        This could include likelihood of recovery, likelihood of reoccurrence, treatment influence or mortality risks.

What is the difference between incidence and prevalence?

Incidence: The number of newly diagnosed cases of a disease.

Prevalence: the total number of cases of a disease existing in a population, both new and old, allowing determination of a person’s likelihood of having the disease.

What is the difference between morbidity and mortality?

Morbidity: refers to the condition of suffering from a disease or illness. Several co-morbidities can have had by a person.

Mortality: another term for death.

What is an idiopathic disease?

a disease of unknown origin

What is epidemiology?

the study of incidence, distribution, and control of disease in a population.

What is cellular stress, and what are some causes?

-        Defined as any change or stimulus which disrupts cellular homeostasis.

-        Causes of cellular stress can include:

-Physical agents like temperature

-Chemical agents like pH

-Microorganisms like bacteria

-Hypoxia - lack of oxygen to the tissues

-Free radicals – molecules with unpaired electrons in outer shell. Can enter key molecules in cell membranes or nucleic acids and cause damage.

What does the cell do in response to stress and why?

Make cellular adaptations in order to maintain homeostasis.

What are the 5 key types of adaptations made by the cell in response to stress?

 

Atrophy: Reductions in cell size undergone by cells if they are underused or undersupplied.

 

Hypertrophy: Increases in cell size undergone by cells if they are utilised more.

 

Hyperplasia: Increases in cell numbers, but only in cells which are able to multiply.

 

Metaplasia: Changes in cell type based on the demands placed upon a cell.

-        Transitional epithelium can become stratified squamous in bladder due to bladder stones.

 

Dysplasia: Changes in cells and cellular arrangements to become abnormal and irregular.

-        It is pre-cancerous or pre-neoplastic.

When do reversible cell injuries occur and the two key ones?

They occur when cells are placed under stress, and adaptations no longer allow the maintenance of homeostasis.

Cellular swelling: water accumulation in the cell due to inadequate ATP leading to malfunctioning of the sodium potassium pump, causing excess sodium into the cell, and attracting water by osmosis. This could occur due to blood blockages, preventing oxygen and nutrient access, is reversed by normal pump functioning.

Cellular accumulation: the accumulation of substances inside the cells (such as fat inside the liver) due to that substance being found in too high concentrations. This can be reversed often with lifestyle changes.

When do irreversible cell injuries occur and what are the three key types?

They occur when the stress placed on a cell causes an irreversible injury, which leads to cell death.

Necrosis: the death of a cell due to a pathological condition. Leads to cell enlargement and loss of membrane integrity, causing leaking of cell contents, triggering an inflammatory response.

Infarction: cell death caused by a lack of oxygen, either anoxia (complete lack), or hypoxia (reduced). This is caused by thrombosis (blood clot), embolism (foreign object) or atherosclerosis (plaque), all of which block the bloodstream.

Apoptosis: programmed cell death when a cell reaches the end of its lifecycle. The cell shrinks and nuclear fragmentation occurs. Apoptopic bodies bud off and phagocytosis occurs, meaning the cell is engulfed.

What are the 6 types of necrosis?

Coagulative: occurs due to reduced blood supply, such as an embolism, where cell and organ shape are preserved, but internal contents are damaged.

Liquefactive: digestion of dead cells by neutrophils releasing lysosomal enzymes to form a viscous mass containing dead cells, debris and water. A cavity remains once fluid is drained, meaning tissue shape is not preserved.

Caseous: caused by fungal infections, where the infected area is surrounded by WBCs, causing dead tissue to become soft, white and crumbly. Tuberculosis.

Fat: the death of fat cells due to enzymes or trauma. death of fat cells can release lipase, causing further death, where free fat then binds to calcium (saponification).

Fibroid: blood vessel walls become damaged, causing fibrin and proteins to deposit on the wall, causing vessel to lose elasticity and become thicker.

Gangrenous: organ or tissue death. it occurs due to ischema (lack of blood supply) and commonly occurs in peripheral regions.

What are neoplasms and how are they formed?

An abnormal growth unresponsive to normal control mechanisms.

Proto-oncogenes (normal genes) become mutated to form oncogenes, which are cancer-causing.

Name 3 factors which can cause cancer

UV radiation, carcinogens, cigarette smoke,

What are the two types of tumours

Benign: non-cancerous masses which do not spread to other parts of the body.

Malignant: cancerous masses characterised by uncontrolled growth and the ability to spread.

How are benign and malignant neoplasms named?

Benign: Suffix ‘-oma’. Some exceptions include lymphoma and melanoma which are malignant.

Malignant: Suffix ‘-carcinoma’ (epithelium) or ‘-sarcoma’ (connective tissue)

What are the anatomical differences between benign and malignant tumours?

Benign:

• Smooth and round with a symmetrical shape and a uniform cut surface.

• Encompassed in a capsule.

• Slow growing with no metastases.

• No necrosis or haemorrhage.

• Closely resemble normal cells.

Malignant:

• Stellate, irregular shape with a non-uniform cut surface.

• No defined capsule.

• Rapid growth with lymphatic or vascular invasion.

• Necrosis or haemorrhage can occur.

• Dont resemble normal cells.

Describe the rapid growth of cancer cells

Tumour cells divide more rapidly than other cells. Tumor cells secrete their own growth factor, meaning that the more cells there are the more rapidly they divide. The continual division of tumour cells increases growth rate.

Describe the process of epithelial malignancy

1. The nucleus darkens (dysplasia)

2. Fully malignant cells develop, but the basement membrane remains in tact (carcinoma in situ)

3. Malignant cells invade the basement membrane, but no lymphatic or vascular invasion occurs (early invasive carcinoma)

4. The invasion of blood vessels or lymphatics with metastasis can then occur.

Describe what well vs poorly differentiated cancer cells indicate.

Well Differentiated: generally resemble normal cells with slight abnormalities, and generally grow and spread slower.

Poorly Differentiated: show little structural resemblance to normal cells, and generally grow and spread more aggressively

Describe 4 key abnormalities of cancer cells

• Proliferate even when space is not available.

• Make and respond to own growth factors (removed from feedback control).

• Lose normal adhesion for easy metastasis

• Can closely resemble normal cells to avoid immune system

Describe 4 structural characteristics of cancer cells

• Large, variably shaped nuclei

• many cells in disorganised arrangements

• Vary in shape and size

• Loss normal cellular features

What is metastasis? what stage is metastatic cancer?

The invasion of cancer cells at different locations, occurring when cancer cells spread to a different part of the body from where they started via clumps of malignant cells which have broken off into the interstitial fluid.

-        Metastatic cancer is considered stage 4.

Describe the process of metastasis

1. tumour cells invade capillaries.

2. They are carried by platelets in the bloodstream.

3. They invade a new tissue.

4. Divide and replicate in the new tissue.

5. Capillaries supply the new tissue via release of tumor-angio-genesis factors.

What are common sites of metastasis

Brain, liver, lung, adrenals, bone.

What are the key symptoms of cancer?