Introduction To Pathology & Pharma.

Question 1

Define Pathology.

Answer 1

The structural and functional canine in cells, tissue and organs that underlie disease.

Question 2

What is Hypertophy? Examples?

Answer 2

Increase in cell size (e.g. exercise, hypertrophied L.V)

Question 3

What is Hyperplasia? Examples?

Answer 3

Increase cell number (e.g. breast growth in pregnancy)

Question 4

What is Atrophy? Examples?

Answer 4

Decrease in cell size (e.g. decrease in uterus size after birth)

Question 5

What is Hypoplasia? Examples?

Answer 5

Incomplete development of tissue/organ.

Question 6

What is Dysplasia? Examples?

Answer 6

Abnormality in the maturation of cells within a tissue(e.g. epithelial dysplasia of the cervix)

Question 7

What is Metaplasia? Examples?

Answer 7

Normal epithelium in abnormal location(e.g. cigarettes destroy the collimated columnar epithelium which is replaced with squamous epithelium).

Question 8

Explain the basis of Disease Classification.

Answer 8

• Bodily region or system involved [topography]; (e.g. cardiovascular disease)
• The organ or tissue involved [anatomic]; (e.g. heart disease, etc..)
• Underlying pathophysiological derangement; (e.g. metabolic disease, diabetes, etc…)

Question 9

What are the causes of cellular injury?

Answer 9

Physical (e.g. metaplasia)
Chemical (e.g. alcohol)
Biological (e.g. bacteria, viruses, etc…)

Question 10

How does homeostasis play into pathology?

Answer 10

Disordered homeostasis can have a significant effect on health (significance dependent on which body I’ll parameter is affected).

Question 11

What are the two routes of progression do tissue cells take in response to injury?

Answer 11

Injury to cells or tissue results in either death or adaptation. Death may not be preceded by an attempted adaption. Both death and adaption occur via a number of mechanisms.

Question 12

Cell death can be defined as…?

Answer 12

Necrosis; uncontrolled cell death

Apoptosis; programmed cell death

Question 13

Descibre Necrosis.

Answer 13

Necrosis coves various types of uncontrolled cell death;
Coagulative necrosis; protein desaturation more than enzymatic breakdown (e.g. MI)
Liquefactive(organ liquifies) necrosis; enzymatic breakdown more than protein denaturation (e.g. brain infarcts)
Caseous necrosis; occurs in TB

Question 14

Descibre Apoptosis and the phases it occurs in.

Answer 14

Controlled cell death due to damaged DNA with no inflammation since its a normal function. Apoptosis takes place in 2 phase: initiation (caspases become active) & execution caspases cleave DNA causing cell death

Question 15

What is the most common form of an adaptive response?

Answer 15

Inflammation. A normal adaptive response is a set of interactions that an arise in tissue in response to traumatic, infectious, etc.. injury.

Question 16

List the components of the Inflammatory Response.

Answer 16

1. Initiation
2. Vascular changes
3. Cell recruitment and instruction
4. Microbial killing
5. Tissue degradation
6. Initiation of tissue healing process
   * process is tightly controlled to ensure the response is relative to the initial stimulus.

Question 17

Define Pharmacology.

Answer 17

Study of medicine and drugs, including action, their use, and effects on the body.

Question 18

What does the formulation of a drug depend on?

Answer 18

The formulation of a drug depends on the following factors:

• The barriers that the drug is capable of passing(e.g. drugs used in Parkinsons’ treatment need to cross the blood-brain barrier)
• The setting in which the drug will be used(e.g. an oral pill is more appropriate for a drug to be taken outside of a medical facility compared to an IV drip)
• The urgency of the medical situation

Question 19

What are the three names given to drugs?

Answer 19

Chemical; represents the molecular structure of the drug
Non-propriety; simplified name based on chemical name
Propriety; given to the drug by the manufacturer (e.g. aspirin)

Question 20

What are the three primary routes of drug administartion via injection?

Answer 20

Intravenous; drug has direct access to the bloodstream via needle in vein.
Intramuscular; drug delivered into the muscles.
Subcutaneous; drug injected into the tissue layer between the skin and muscle.

Question 21

What is the difference between topical formulation and transdermal patches(e.g. nicotine patches)?

Answer 21

Topical(e.g. reaches dermis) and transdermal(e.g. reaches bloodstream) routes of delivery is disguised via the depth of penetration.

Question 22

List/Describe membrane transport mechanisms used in drug absorption.

Answer 22

• Passive Diffusion; rapid for lipophilic and non-ionic
• Facilitated Diffusion; with carrier, doesn’t need energy
• Aqueous Channels; through a pore, doesn’t need energy
• Active Transport; with carrier, needs energy

Question 23

What factors dictate the distribution of a drug?

Answer 23

1. Membrane Permeability; (If a substance can is membrane permeable it will be quicker than using a facilitated transporter)
2. Plasma Protein Binding: Free VS. Bound (Whether plasma protein is bound or free depends on whether it’s lipophilic or lipophobic; because plasma is a very aqueous environment, therefore if [hydrophobic = carrier needed\ hydrophilic = dissolvable]).
3. Depot Storage: lipophilic drugs - accumulate in fat stores, calcium-binding drugs accumulate in bone and teeth.

Question 24

What is the unit of measure used to indicate the distribution of a drug?

Answer 24

Volume of Distribution (Vd).

Question 25

Define the Volume of Distribution (Vd).

Answer 25

The Volume of Distribution(Vd): is the volume of plasma that would contain the total body content of the drug at a content equal to that in plasma.

Question 26

What are the three factors that affect drug excretion?

Answer 26

• Glomerular Filtration; the process by which the kidneys filter the blood, removing excess wastes and fluids.
• Tubular Secretion; the transfer of materials from peri-tubular capillaries to the renal tubular lumen(Urinate Drug).
• Tubular Reabsorption; the process that moves solutes and water out of the filtrate and back into your bloodstream(Drug Reabsorbed).

Question 27

Define pharmacokinetics

Answer 27

The absorption and distribution of drugs in the body.

Question 28

Explain drug clearance

Answer 28

Pharmacokinetic variable of elimination (Clp) is a constant for substances eliminated by first order kinetics of elimination.

Question 29

What happens following drug binding?

Answer 29

1. Ion channel is opened.
2. Messengers activated which initiates a series of reaction in a cell which transducer the signal stimulated by the drug.
3. Normal cellular function is inhibited.

Question 30

Define all aspects of antagonism.

Answer 30

• Antagonist; inhibitor (Drugs that are unable to activate receptors to which they bind i.e. efficacy of 0)
• Competitive antagonists; bind reversibly to the same site as the substrate, without activating the receptor. The molecules competes with the agonists for receptor-binding sites.
• Non-competitive antagonists; act at a different site on the target molecule to that of the agonist, and prevent the action of the agonist, triggering a conformational change to the active site.
• Irreversible antagonists; bind covalently to their target, effectively removing the molecule permanently as a target.

Question 31

Describe pharmacology at the organism level.

Answer 31

• Efficacy; the ability of a drug to activate its receptor and the degree to which a it’s able to induce maximal effects.
• Potency; the amount of drug required to produce 50% of the maximal response that the drug is capable of inducing. This is determined by the number of receptors present on the tissue and the of the drug to its target.
• Graded dose-response curves; graphs the magnitude of drug actions against the concentration/dose of drug required to induce these actions.

Question 32

Describe pharmacology at the population level.

Answer 32

• EC50; the concentration of drug which induces a specified clinical effect in 50% of the subjects to which the drug is administered.
• LD50; the concentration of drug which induces death in 50% of the subjects to which the drug is administered.
  
  • Therapeutic Index; a measure of the safety of a drug. Calculated by: LD50/EC50
• Margin of Safety; the margin between the therapeutic and lethal dose of a drug.

Question 33

List drug interactions.

Answer 33

Altered absorption, metabolism, and excretion, as well as, plasma protein competition.

Question 34

Define tolerance, dependence, and withdrawal.

Answer 34

• Tolerance; a decreased response to a drug. More is required to produce the same effect.
• Dependence; when a patient needs a drug to “function normally”.
• Withdrawal; occurs when a drug is no longer given to a dependent patient.