Healing and Repair 2. Flashcards
When does primary healing occur?
When the edges of the wound lie quite close to each other.
When does secondary healing occur?
When there is a very large gap between the wound edges.
The intervening tissue must be filled in before the skin can join back together.
What are the 6 steps in primary healing?
Clot formation.
Inflammatory response.
Fibroblast and endothelial cell proliferation.
Continuity of blood flow.
Epithelial regeneration.
Collagen formation.
What occurs during clot formation?
The gap between the opposed tissues becomes sealed with coagulated blood.
What occurs during the inflammatory response of healing?
There will be inflammation around the wound.
This means we will see immune cells such as neutrophils and macrophages.
When do macrophages appear at a site of inflammation?
When it becomes chronic.
What happens during the fibroblast and endothelial cell proliferation of healing?
These 2 cell types form a lattice like formation to help stabilise the injured tissue.
What happens in healing once the granulation tissue has been formed?
We get blood vessels from one side of the wound joining up with blood vessels on the other side of the wound.
What is neo-vascularisation?
The process by which blood vessels on one side of a wound join up with blood vessels on the other side of a wound.
What happens in the epithelial regeneration stage of healing?
Epithelial cells grow on top of the granulation tissue.
What is collagen formation also known as?
Scarring
What is the point of collagen formation during wound healing?
It strengthens the injury site.
What are the 7 steps of secondary healing?
Fibrosis.
Blood coagulation.
Inflammatory response.
Fibrin deposition in the wound.
Granulation tissue proceeds from the edges to completely fill the wound.
Fibrous connective tissue forms.
Collagen contraction.
What 2 things are lost in injury sites that have undergone secondary healing?
The adnexa.
Some vascular components.
What are 5 things that affect healing?
The strength of the stimuli for cell proliferation.
Physiologic conditions.
The mobility of the tissue.
The tissue type.
Immunodeficiencies.
What is important about the stimulus for healing?
The amount of stimulus, as too much healing leads too proud flesh and too little does not solve the problem.
What is essential for healing stimuli to function correctly?
Good perfusion to the area.
This is why we don’t make bandages too tight.
Getting rid of what from a wound will help lead to an appropriate healing stimuli?
Dead tissue.
What can we use to increase healing stimuli?
Drugs.
What vitamin affects protein and collagen synthesis?
Vitamin C.
What are 4 factors that affect healing speed?
Nutrition.
Stress.
Blood supply.
Temperature.
How do steroids affect healing time?
They slow it down.
Is it best for animals to rest areas of the body if there is an injury to a mobile area?
Yes.
Where do primary immunodeficiencies arise from?
They are inherited.
Where do acquired immunodeficiencies arise from?
The environment.
What are 4 examples of primary immunodeficiencies?
Bovine leukocyte adhesion deficiency.
Canine cyclical neutropenia.
Severe combined immunodeficiency.
Hypotrichosis with thymic aplasia.
What are 4 examples of acquired immunodeficiencies?
Viral infections.
Toxins.
Age.
Failure of passive transfer.
Bovine leukocyte adhesion deficiency occurs in what types of cattle?
Holstein calves.
What causes bovine leukocyte adhesion deficiency?
A mutation in the gene that codes for integrin.
Intergrin helps with leukocyte rolling and adhesion.
How does bovine leukocyte adhesion deficiency affect the cows healing process?
There is reduced inflammatory cell response and granule production during inflammation.
What are the clinical signs of bovine leukocyte adhesion deficiency?
Severe ulcers on the oral mucosa.
Loss of teeth.
Chronic pneumonia.
Recurrent or chronic diarrhea.
Canine cyclical neutropenia is most likely to occur in what animals?
Rough and smooth coated collies.
What causes canine cyclical neutropenia?
An autosomal recessive mutation.
What are visible signs seen in collies with canine cyclical neutropenia?
They have a diluted coat colour.
How does canine cyclical neutropenia affect collies?
Every 2 weeks bone marrow stops producing white blood cells for a short period and then it starts again.
This causes white blood cell numbers to rise and fall periodically.
What white blood cell is particularly affected by canine cyclical neutropenia?
Neutrophils as they are very short lived and constantly need to be replaced.
What are the clinical signs of canine cyclical neutropenia?
Recurrent bacterial septicemia.
Pneumonia.
Gastroenteritis.
How can we treat dogs with canine cyclical neutropenia?
Bone marrow transfusion.
What 5 animals are affected by the 2 forms of severe combined immunodefficiency syndrome?
Form 1.
Arabian horses.
Jack Russells.
Mice.
Form 2.
Basset Hounds.
Welsh Corgis.
How does SCID affect Jack Russells, Arabians and mice?
It affects DNA kinase which helps lymphocytes detect antigens.
Without DNA kinase lymphocyte receptors don’t work and there is no immune response.
In what 3 ways does SCID affect corgis and bassets?
The IL-2 receptor is affected and this means there cannot be T cell proliferation.
B cells produce low amounts of IGG, no IGA and normal amounts of IGM.
Class switching cannot occur.
How does hypotrichosis with thymic aplasia occur mice and cats?
There is a mutation in the FOXN1 gene which codes for hair and thymus development.
How does hypotrichosis with thymic aplasia affect mice and cats?
No T -lymphocytes are produced.
Failure of pssive transfer is most likely to occur in what animal?
Foals.
