Skin

Question 1

Under what circumstance should you not administer ear drops?

Answer 1

If the tympanic membrane is ruptured

Question 2

Name the 3 main systemic treatments used to treat skin disease

Answer 2

Antibiotics/antifungals
Anti-parasitics
Anti-inflammatories

Question 3

Sulphur is often combined with what when used as an anti-seborrheic agent?

Answer 3

Salicylic acid

Question 4

Why should tar not be used on cats?

Answer 4

Toxic to cats!!!

Question 5

Benzoyl peroxide is metabolised to what?

Where does this take place?

Answer 5

Benzoic acid and oxygen free radicals

Metabolised in epidermis

Question 6

What are the active ingredients in Hibiscrub and Malaseb shampoo?

Answer 6

Hibiscrub: Chlorhexidine
Malaseb: Chlorhexidine and Miconazole

Question 7

What is ethyl lactate metabolised to?

Where does this happen?

Answer 7

Ethanol and lactic acid by bacterial lipases

In hair follicles and sebaceous glands

Question 8

What is the function of emolients?

Answer 8

Act as a vehicle for other agents
Softens/protects the skin
Forms a thin film of oil on stratum corneum
Decreases water loss

Question 9

Give some examples of moisturisers

Answer 9

Urea, essential fatty acids, propylene glycol, glycerin, colloidal oatmeal

Question 10

Give 3 examples of anti-pruritic agents

Answer 10

Hydrocortisone, anti-histamines, aloe vera

Question 11

Give some causes of Otitis externa

Answer 11

Malassezia pachyderma
Dermatophytes
Candida
Mites eg otodectes cynotis

Question 12

What are autocoids?

Answer 12

Chemicals that act like local hormones. They are short-lived and rapidly degraded.

Question 13

What are the 3 classes of autocoids?

Answer 13

Biogenic amines
Lipid-derived
Polypeptides

Question 14

Where is histamine stored?

Answer 14

Mast cells and basophil granules in lungs, skin and mucosal layer of stomach

Question 15

What effect does histamine have on the cardiovascular system?

Answer 15

Dilates arterioles, increases heart contractility and heart rate

Question 16

What is the difference between a 1st and 2nd generation H1 antihistamine antagonist?

Answer 16

1st generation is not ionised at physiological pH and thus can cross the blood brain barrier
2nd generation is ionised at physiological pH so can’t cross the blood brain barrier

Question 17

Give some effects of histamine

Answer 17

Vasodilation (H1)
Increased vascular permeability (H1)
Increased gastric secretion (H2)
Contraction of most smooth muscle except blood vessels (H1)
Cardiac stimulation (H2)

Question 18

What are H2 antihistamines used in the treatment of?

Answer 18

Gastritis, reflux, gastric abomasal ulcers

Question 19

Give an example of an inhibitor of histamine release

How does it work?

Answer 19

Sodium chromoglycate

Inhibits the release of histamine from mast cells by opening up chloride channels and hyper-polarising them

Question 20

How many types of serotonin receptor are there?

Answer 20

14

Question 21

Where is serotonin found?

Answer 21

Platelets, enterochromaffin cells, CNS, and myenteric plexus (provide motor innervation to both layers of the muscular layer)

Question 22

What are the functions of serotonin?

Answer 22

Regulate gut motility
Regulate body temperature 
Regulate sleep
Enhance mood 
Contraction of smooth muscle (GI, uterus, bronchi)

Question 23

What is cisapride used for?

Answer 23

Is a GI prokinetic agent

To treat feline idiopathic megacolon and GI stasis in rabbits and herbivorous rodents

Question 24

In which animals in ketanserin (serotonin agonist) used?

Answer 24

Horses

Question 25

Which 2 hormones cause pyrexia?

Answer 25

IL-1, PGE2

Question 26

Which 3 hormones cause chemotaxis?

Answer 26

PAF(platelet-activating factor), LTB4, (involved in inflammation), 12-HETE (regulates cell behaviour)

Question 27

Prostanoids is a general term for what?

Answer 27

Prostaglandins and thromboxanes

Question 28

What is the function of PGF2a?

Answer 28

Acts on FP receptors in uterine and other smooth muscles, and corpus luteum, producing contraction of uterus and luteolysis

Question 29

What is the function of PGE2?

Answer 29

Acts on EP receptors. | Inflammatory response, fever, pain

Question 30

What is the function of TXA?

Answer 30

Acts on TP to cause vasoconstriction and encourages platelet aggregation to prevent blood loss

Question 31

What is the function of PGI2?

Answer 31

Acts on IP to cause vasodilation and inhibition of platelet aggregation

Question 32

Circulating prostaglandins are rapidly catabolised by enzymes in which organs?

Answer 32

Lung, kidney, spleen, adipose tissue, and intestine

Question 33

Why should care be taken when administering PGF2-alpha?

Answer 33

Readily absorbed through skin so wear gloves | Risk to asthmatics (causes bronchoconstriction) and pregnant women

Question 34

What are 2 adverse effects of PGF2-alpha?

Answer 34

Bronchoconstriction and increased GI motility

Question 35

How do PGE analogues help protect against gastric ulceration?

Answer 35

Directly inhibit gastric acid secretion | Facilitate PGE-mediated mucosal defence

Question 36

What is the difference between constitutive and regulated secretion?

Answer 36

``` Constitutive= continuous, regardless of environmental factors Regulated= only secreted in response to a specific signal ```

Question 37

What is the difference between B1 and B2 bradykinin receptors?

Answer 37

B1=induced in inflammation | B2=constitutive

Question 38

What are the functions of bradykinin?

Answer 38

``` Increase vascular permeability Vasodilation Stimulation of pain nerve endings Fluid secretion in GI tract and airways Contraction of intestinal and uterine smooth muscle ```

Question 39

What are the 4 main classes of cytokines?

Answer 39

Chemokines Interferons Interleukins Colony stimulating factors

Question 40

What is a cytokine?

Answer 40

Soluble protein or polypeptide released from a cell

Question 41

Give and explain some clinical signs associated with a disturbance of skin homeostasis

Answer 41

Pruritis Scaling due to epidermal hyperplasia (increased keratinocytes) Greasiness due to increased sebum secretion Odour due to microbial proliferation (decreased resistance to microbes)