week 1-6 theory

Question 1

Identify the Causes of Disease

Answer 1

Genetic: Diseases that are caused entirely by inherited or prenatally acquired genetic defects.
Multifactorial: Diseases that result from the interaction of both genetic and environmental factors.
Environmental: Diseases caused entirely by environmental factors, such as infections, toxins, and physical injury

Question 2

Describe the Various Forms of Cellular Injury

Answer 2

1. Chemical Injury:
   Direct injury: Toxins directly interact with cellular components (e.g., mercuric chloride).
   Indirect injury: Chemicals are converted to toxic metabolites that damage the cell (e.g., free radicals causing membrane damage).
2. Physical Injury:
   Kinetic force: Trauma or injury caused by mechanical forces.
   Thermal injury: Damage due to extreme heat (burns) or cold (frostbite).
3. Infective Injury: Caused by microorganisms such as bacteria, viruses, fungi, and parasites​

Question 3

Describe the Physiological and Pathological Role of Apoptosis

Answer 3

Physiological Role: Apoptosis is a form of programmed cell death that helps regulate tissue homeostasis. It eliminates damaged or unwanted cells without triggering an inflammatory response.
Pathological Role: When apoptosis is deregulated, it can contribute to various diseases, including cancer (failure to undergo apoptosis) or neurodegenerative diseases (excessive apoptosis). Apoptosis can be triggered by external factors such as radiation, toxins, and free radicals

Question 4

Identify and Describe the Types of Necrosis

Answer 4

1. Coagulative Necrosis:
   Preserves the underlying tissue architecture. Common in hypoxic injuries to solid organs (e.g., heart, kidneys).
2. Liquefactive Necrosis:
   Characterized by enzymatic digestion of dead cells, often seen in bacterial infections or ischemic infarcts in the brain.
3. Caseous Necrosis:
   Creates a “cheesy” appearance and is most characteristic of tuberculosis.
   Fat Necrosis:
   Seen in acute pancreatitis, where pancreatic lipases digest fat, leading to the release of fatty acids and chalky white areas of fat saponification.
4. Gangrenous Necrosis:
   A form of tissue death due to ischemia, often affecting soft tissues. It can be classified as dry or wet depending on the presence of infection

Question 5

Define Ischemia and Infarction

Answer 5

Ischemia: A condition where there is impaired vascular perfusion, leading to a lack of oxygen and nutrients in tissues. This can result from conditions like thrombosis, embolism, or atherosclerosis​
Infarction: Refers to tissue death (necrosis) caused by ischemia. This results when the blood supply to a part of the body is completely cut off, leading to irreversible cell death​

Question 6

Causes of Ischemia

Answer 6

Thrombosis: The formation of a solid mass of blood constituents in vessels, which can obstruct blood flow.
Embolism: A mass traveling in the bloodstream that can lodge in vessels and block blood flow.
Atheroma: Plaque formation in arteries, commonly due to atherosclerosis.
Vasculitis: Inflammation of blood vessels.
Vascular Spasm: Sudden contraction of blood vessel muscles.
Compression: External pressure on blood vessels (commonly in veins).
Hyperviscosity: Thickened blood impairing its flow, commonly due to blood disorders

Question 7

Thrombosis occurs when…

Answer 7

Thrombosis occurs when blood clots form abnormally within a blood vessel. It can lead to infarction, embolism, or edema.

Question 8

what is
Virchow’s Triad

Answer 8

Virchow’s Triad: Three factors that contribute to thrombus formation:
Endothelial injury.
Abnormal blood flow (stasis or turbulence).
Hypercoagulability

Question 9

Signs of inflammation

Answer 9

Redness (rubor), heat (calor), swelling (tumor), pain (dolor), and loss of function (functio laesa).

Question 10

Process of Inflammation

Answer 10

Vascular Phase: Increased blood flow and permeability of blood vessels.
Cellular Phase: Movement of immune cells, like neutrophils, from the blood to the tissue​(

Question 11

Vascular Mediators of Inflammation

Answer 11

Vascular mediators: Histamine, prostaglandins, and nitric oxide cause vasodilation and increased vascular permeability.

Question 12

cellular Mediators of Inflammation

Answer 12

Cellular mediators: Neutrophils, macrophages, and lymphocytes respond to injury by migrating to the site of damage.

Question 13

chemical Mediators of Inflammation

Answer 13

Chemical mediators: Cytokines, bradykinin, and complement proteins act to stimulate the inflammatory response​

Question 14

Acute inflammation

Answer 14

A short-term, immediate response to injury with the main goal of removing the causative agent and repairing tissue. Characterized by fluid accumulation, immune cell infiltration, and swelling.

Question 15

Chronic inflammation

Answer 15

Prolonged inflammation resulting from persistent stimuli. It involves ongoing tissue destruction and repair processes, often leading to scarring or fibrosis. Chronic inflammation can be associated with diseases like rheumatoid arthritis or tuberculosis

Question 16

Describe Oedema

Answer 16

Oedema is the abnormal accumulation of fluid in the interstitial spaces of tissues.

Question 17

oedema cause

Answer 17

It is caused by:
Increased vascular permeability (e.g., inflammation).
Increased hydrostatic pressure (e.g., heart failure).
Reduced oncotic pressure (e.g., hypoalbuminemia).
Lymphatic obstruction (e.g., lymphatic damage)​

Question 18

what are types of Systemic Oedema

Answer 18

Cardiac Oedema: Caused by heart failure, leading to increased venous pressure and fluid retention, often presenting as peripheral oedema or pulmonary oedema.
Renal Oedema: Results from nephrotic syndrome, causing protein loss in the urine and hypoalbuminemia, leading to fluid accumulation.
Nutritional Oedema: Seen in malnutrition (e.g., kwashiorkor) due to low protein levels leading to decreased oncotic pressure.
Liver Failure Oedema: Due to impaired synthesis of albumin, leading to hypoalbuminemia and ascites (fluid in the abdomen)​

Question 19

Define different types of cell and tissue growth

Answer 19

Multiplicative: Increase in the number of cells.
Auxetic: Growth by an increase in cell size.
Accretionary: Growth by the accumulation of extracellular substances.
Combined: A combination of these processes occurs in various tissues.

Question 20

Endocrine factors in growth disorders

Answer 20

Growth hormone (GH) plays a key role, released from the anterior pituitary and stimulates Insulin-like Growth Factors (IGFs). Conditions like dwarfism (due to GH deficiency) and gigantism (due to excess GH before puberty) highlight the importance of GH regulation.

Question 21

Genetic factors in growth disorders

Answer 21

Genetic factors: Parental characteristics like height are often inherited. Conditions like achondroplasia are due to a lack of fibroblast growth factor receptors, while Down syndrome (trisomy 21) affects growth.

Question 22

nutritional factors in growth disorders

Answer 22

Nutritional factors: Nutritional deficiencies, like those seen in kwashiorkor (protein deficiency) and marasmus (caloric deficiency), greatly impact growth.

Question 23

Environmental factors in growth disorders

Answer 23

Environmental factors: Maternal substance abuse, birth weight, and illnesses can interfere with normal growth.

Question 24

Describe normal and abnormal tissue growth:

Answer 24

Atrophy: A reduction in cell size or organ size due to decreased workload, aging, or poor nutrition.
Hypertrophy: Increase in cell size, usually in response to increased workload (e.g., muscle hypertrophy due to exercise).
Hyperplasia: Increase in the number of cells, often seen with hypertrophy (e.g., epithelial hyperplasia in response to hormonal stimulation).
Hypoplasia: Failure to reach normal size during development.
Metaplasia: Replacement of one differentiated cell type with another, often as a response to stress (e.g., squamous metaplasia in the lungs of smokers).
Dysplasia: Disordered growth, often precancerous, involving abnormal cell shapes and increased growth rates (e.g., in epithelial tissues).

Question 25

Neoplasia Terminology

Answer 25

Neoplasm: An abnormal growth of tissue (tumor).
Metastasise: Spread of cancer cells to distant sites in the body.
Cancer: Uncontrolled growth and division of abnormal cells.
Oncology: The medical field focused on the study and treatment of tumors.

Question 26

General Features of Neoplastic Cells

Answer 26

Neoplastic cells are less dependent on oxygen and better adapted to anaerobic conditions.
They experience autonomous growth, meaning they grow independently of normal cellular controls.
Loss of specialized function and contact inhibition are common features, resulting in unregulated growth.
Neoplastic cells may undergo anaplasia, showing a loss of cellular differentiation.

Question 27

Benign Tumors

Answer 27

Do not metastasize.
Often encapsulated.
Slow-growing and well-differentiated.

Question 28

Malignant Tumors

Answer 28

Can invade surrounding tissues and metastasize.
Poor differentiation, less uniform, and often more vascularized.
Rapidly spreading.

Question 29

Tumor Classification by Tissue of Origin

Answer 29

Sarcoma: Arises in bone, cartilage, fat, muscle, or blood vessels.
Carcinoma: Originates from epithelial cells lining the skin or internal organs, representing the majority of cancers.

Question 30

Carcinogenesis

Answer 30

Initiation: Mutation or genetic alteration of a cell.
Promotion: Proliferation of mutated cells.
Progression: Aggressive growth and spread of cancer.
Carcinogens: Factors causing cancer, including chemicals (e.g., tobacco), radiation, viruses (e.g., HPV), hormones, and some microbial agents.

Question 31

Metastasis

Answer 31

Lymphatic Spread: Common in carcinomas.
Hematogenous Spread: More typical in sarcomas.
Transcoelomic Seeding: Spread within body cavities.
Metastasis requires enhanced cell mobility, enzyme release for tissue invasion, and loss of cellular cohesion.

Question 32

Grading and Staging of Tumors

Answer 32

Grading: Measures how differentiated the tumor cells are. Grade I is the most differentiated.
Staging: Describes the size, spread, and lymph node involvement:
T: Size and extent of the primary tumor.
N: Spread to nearby lymph nodes.
M: Presence of distant metastasis.