Lecture 6: Cell Adaptation Flashcards
What is the definition of hyperplasia?
Hyperplasia is the increase in number of cells
What are the two types of Hyperplasia?
What are the two causes of hyperplasia?
Two types of hyperplasia: Nodular or cystic
Two causes of hyperplasia: Physiologic and pathologic
What are some characteristics of physiologic hyperplasia?
Physiologic hyperplasia
- Often a response to hormones
- Often compensatory
- May be regenerative, acting to repair a site
What are some characteristics of pathologic hyperplasia?
Pathologic hyperplasia:
- Due to Inappropriate or excessive hormones (ACTH -> Adrenal cortex)
- Due to Irritation
- Unknown/idiopathic cause
What organs are commonly affected by hyperplasia?
Common examples:
- Liver
- Spleen
- Pancreas
- Lymph node/spleen
Very common example: Cystic endometrial hyperplasia
Why do we care about hyperplasia?
Why do we care?
We need to know what the cause is. What is this in response to?
Also, possibly preneoplastic.
Hyperplasia vs neoplasia?
Hyperplasia:
- Controlled growth, normal process
- Reversible, if the inciting cause is determined and removed
- The cause is known.
Neoplasia:
- May be harder to recognized the cause, may not see a justification for an increase in cell number.
- Unregulated, unorganized.
- May not be reversible, if it’s a genetic change
Is hypertrophy cell swelling?
No, hypertrophy is an increase in the size of cells or organ.
This is not cell swelling.
Cells swell because they are taking on water, or lipids. The cells got very big, but it’s not because they were able to do more a job. They were very fragile.
Why does hypertrophy happen?
Hypertrophy is an increase in the size of cells or organ, due to the increase in volume of organelles. The increase in organelles leads to an overall increase in cell size.
What are the two types of hypertrophy?
Two types of hypertropy are physiologic or compensatory.
In response to work/increased demand
What types of cells can’t undergo hyperplasia?
“Permanent” cells, like neurons or myocardiocytes. These cells don’t regenerate, so they can’t become hyperplastic.
They could potentially become hypertrophic.
When labile cells (skin, GI, respiratory, or hematopoietic) become hyperplastic, what are they typically working to do?
When labile cells become hyperplastic, they are typically working to repair something.
(From review session, not from lecture)
When a stable cell type (glandular, liver, kidney, or endocrine) undergoes hyperplasia, what type of hyperplasia will that typically be?
The hyperplasia of stable cell types typically results in nodular hyperplasia.
(from review session, not lecture)
How would you describe the circled kidney?
The circled kidney is a hypoplastic kidney.
The contralateral kidney had more work to do, so it increased in size as an organ to handle the increased workload
Sometimes we see this change in a cat/animal that has no renal abnormalities in the bloodwork at all
Can be an incidental finding
What’s happening in this image?
This is hypertrophic cardiomyopathy.
For reasons we don’t always understand, the myocardium of the left ventricle becomes very large, due to the increased size of the myofibers. The cats can be asymptomatic until you go to do a dental, or spay.
We don’t have a good antemortem test at this time.