Intro To Pathology

Question 1

What is pathology?

Answer 1

The study of diseases: causes, diagnosis, effects on the body

Question 2

What is “disease?”

Answer 2

Any harmful deviation from the normal structural or functional state of an organism, generally associated with certain signs and symptoms and differing in nature from physical injury
Simple definition: occurs when there is a disruption of loss of “normal”

Question 3

Types of pathology

Answer 3

Anatomical: study disease by looking at tissues and organs (think necropsies, biopsies)
Clinical: assess disease by study body fluids (blood, urine, joint fluids)

Question 4

Microbiologist

Answer 4

Study infectious organisms( bacteria, virus, fungus)

Question 5

Parasitologist

Answer 5

Study parasites

Question 6

Immunologist

Answer 6

Study antibodies and antigens (proteins on the surface of organisms)

Question 7

Toxicologist

Answer 7

Study toxins/poisons

Question 8

Hematologist

Answer 8

Study blood

Question 9

Veterinary nurse responsibilities

Answer 9

Must be familiar with:
-Types of analytic instruments available
-Testing procedures used (in house vs send out testing)
-Proper sample collection, handling, and sometimes interpretation of
-The need for and the knowledge of “normal”

Question 10

Etiology

Answer 10

The study of the cause of disease

Question 11

Pathogenesis

Answer 11

Formation of beginning of a disease

Question 12

Pathogen

Answer 12

An infectious agent capable of causing a disease

Question 13

Knowledge of etiology remains the basis of:

Answer 13

-Diagnosis of disease
-understanding the nature of disease
- treatment of the disease

Question 14

Etiology agents

Answer 14

Factors capable of causing disease or tissue damage

Question 15

Internal etiologic factors

Answer 15

Genetic: defects, mutations
Immune response: abnormal response
Aging: natural or premature

Question 16

External etiologic factors

Answer 16

Physical: trauma
Chemical: toxins
Infectious: bacteria, parasites
Environment: nutrition, temperature, husbandry, radiation

Question 17

Cause of disease; Pathogens VS Nonpathogens

Answer 17

Pathogens: infectious organisms that have the potential to cause a disease (bacteria, viruses, fungi, parasites)
Non-pathogens: Disease caused by trauma (mechanical, sonic, thermal, electrical, temperature radiation, would or injury.)

Question 18

Classifications of diseases

Answer 18

-Acquired
-Congenital
-Idiopathic

Question 19

Classifications of disease: Acquired

Answer 19

Develop as a result of the effects of one or more etiologic agents.
(pneumonia, dermatitis)

Question 20

Classifications of disease: congenital

Answer 20

The animal is born with-
•Etiological agent acts on the developing embryo or fetus, on the uterus or placenta, or on the mother (before or during pregnancy)
•Clinical signs may not be seen at birth
•Developmental abnormalities – heart defects, orthopedic defects

Question 21

Classifications of disease: Idiopathic

Answer 21

Diseases of which we do not (yet) know the cause

Question 22

Factors that influence the course of the disease

Answer 22

Age
Immune system
Drugs
Genetics
Environment
Secondary diseases

Question 23

Cellular injury: response to harmful stimuli

Answer 23

Degeneration
Necrosis
Changes

Question 24

Degeneration

Answer 24

Pathological condition that causes cells to change in structure and function. Injury is mainly the cytoplasm of the cell, these lesions of reversible when the pathological stimuli are reduced or eliminated

Question 25

Necrosis

Answer 25

Cellular death irreversible

Question 26

Changes

Answer 26

Cell growth, size +/- numbers Reversible Irreversible

Question 27

Types of cellular degeneration

Answer 27

-Accumulation of cellular component; As cells age, old and non-functional organelles may shrivel up or be broken down Their constituents remain in the cytoplasm -Hydropic change; Damage to cell membranes  cells swell with fluid -Fatty change; Lipids accumulate in cells because of increased or long-term fat breakdown in the body Or because the ability of cells to metabolize normal amounts of fat is decreased by cell damage

Question 28

Cellular death: necrosis

Answer 28

Death of cels or tissues in a living animals Common causes: decreased blood supply, Pressure, burns, trauma, poisons and toxins, infectious agents

Question 29

Types of necrosis

Answer 29

Coagulative Liquefactive Caseation Fat Gangrene

Question 30

Types of necrosis: coagulative

Answer 30

MOST COMMON ●Occurs due to loss of blood supply to an area ●Occurs in “solid” organs (e.g. kidney, heart) ●Dead cells retain their outline but are pale and ghost-like (look cooked) ●After a period of time, inflammatory cells move in to remove the dead cells

Question 31

Types of necrosis: Liquefactive

Answer 31

Areas of necrosis become liquified by powerful enzymes which degrade dead cells and surrounding tissues ●Characteristic to the brain Interruption of the blood supply or bacterial infection (meningitis)

Question 32

Types of necrosis: Caseation

Answer 32

●Dead tissue is converted to a cheesy texture ●Usually associated with chronic bacterial infections (tuberculosis)

Question 33

Types of necrosis: Fat

Answer 33

Occurs after inflammation in/around fatty tissue, due to enzymes which degrade fat cells ●The fat becomes hard and nodular ●Seen after pancreatitis, when pancreatic enzymes leak into the abdomen

Question 34

Types of necrosis: Gangrene

Answer 34

Bacteria usually involved, affected part is cold to the touch 4 Types 1. Dry- No bacteria (cold, shriveled, discolored) 2. Gas- gas producing bacteria (crepitus) 3. Moist- pus producing bacteria (rotten, foul smelling) 4. Wet- bacteria w/inflammation of surrounding tissue (cellulitis

Question 35

Body’s response to infection or injury

Answer 35

Fever Inflammation

Question 36

Fever

Answer 36

Pyrexia- the bodies response to pyrogens; activates phagocytes and causes iron to be removed from the blood

Question 37

Inflammation

Answer 37

5 signs- Heat Swelling Pain Redness Loss of function

Question 38

Tissue repair: regeneration

Answer 38

replacement of cells by the same type of

Question 39

Tissue repair: organization

Answer 39

Replacement by fibrovascular connective tissue (scar tissue)

Question 40

Tissue healing: first intention

Answer 40

Edges of wounds close together No scaring Bandages, Sutures, skin tape

Question 41

Tissue healing: second intention

Answer 41

Greater tissue damage Granulation tissues (connective tissues) Fibrosis/scar tissue- contracts long process