Hyperplasia, Hypertrophy Flashcards
Hypertrophy
Increase in the size of a cell, or increase in the size of a tissue
Hyperplasia
Increase in the number of cells in a tissue
- often both hypertrophy and hyperplasia are present
What are the 3 causes for hypertrophy/hyperplasia?
- increased demand
- endocrine stimulation
- nutrition
Increased cell activity leads to _______
Proliferation of organelles and/or cell division until a new balance is reached
Hypertrophy and hyperplasia are _____ in many cases
Beneficial
- lymphoid hyperplasia
- persistent change in the environment leads to overcompensation = harmful effects
Physiologic
- hormonal: maturity/development
- compensatory: liver resection
Pathologic
- chronic irritation
- endocrine
- virus induced
- increased bloodflow
- nodular hyperplasia
Hypertrophy can occur in _____
Any tissue
- size/number of organelles increase
- physiologic or pathologic (cardiac hypertrophy)
5 causes/effects of hypertrophy
- increased workload
- endocrine stimulation
- thyroid (anabolic effect)
- adrenal (cortisol excess)
- estrogens - uterine/mammary development
Increased workload
Enlarged hearts and muscle mass in athletic animals
- myofilaments increase in length and number (resistance), mitochondria increase (endurance)
- kidney hypertrophy when the other is removed
What is an example of thyroid hypertrophy?
Hyperthyroidism in cats
- cardiac hypertrophy
What is an example of adrenal hypertrophy?
Hepatocyte hyperplasia = steroid hepatopathy
Nodular gingival hyperplasia
Reaction to chronic inflammation
- inherited in Boxers, Swedish silver foxes
Canine prostate can develop ______
Benign hyperplasia
- testosterone dependent
Cystic endometrial hyperplasia
Occurs in horse uterus
- hypertrophy of gland cells
Lmyphocystis disease is an example of _____
Hypertrophy
- iridovirus infection of dermal fibroblasts
Canine papillomavirus is an example of _____
Hyperplasia
- grows on any mucosal surface
Characteristics of hyperplasia
- definite structures
- increased cells
- well differentiated
Hyperplasia in the bone marrow
- enteritis, blood loss
- erythroid
- myeloid
Thyroid
- expansile nodules
- well differentiated cells
- colloid filled follicles
- hypertrophy and hyperplasia
Iodine deficiency
Occurs in goats, presented as large thyroids bilaterally
- goiter
- hypertrophy and hyperplasia
Hyperthyroidism in the cat
Chronic renal disease –> retained phosphorus –> increased FGF23 –> reduced calcitriol –> increase PTH synthesis –> parathyroid hypertrophy and hyperplasia
Fibrous osteodystrophy
- diet high in phosphorous (wheat bran)
- loss of maxillary/mandibular bone
- reactive fibroblast hyperplasia and connective tissue production
Hypertrophic osteopathy
Increased bloodflow due to hyperplasia
- will often see chronic process in the chest cavity
Nodular hyperplasia
Bulging pale tan/yellow nodules in the liver
- friable, glycogen and lipid
- not associated with hepatocellular dysfunction!
Also occurs in the pancreas
Nodules in the spleen
- hyperplastic white pulp and dilated red pulp sinuses
- can lead to hematomas
- marginal sidero-calcific plaques
Hyperplastic nodules in the spleen
- excessive white pulp
- expansile margin
- unencapsulated
Splenic hematomas
Bleeding from
- hyperplastic nodule
- hemangiosarcoma
Nodular cortical hyperplasia in the adrenal gland of horses is often _____
Incidental
Eimeria stiedae causes _____
Hyperplasia of biliary epithelium in the rabbit
- finger like projections of biliary epithelium
- many coccidian stages within epithelial cells
- cholestasis
- atrophy of surrounding tissues
Recurrent choke in horses due to ______
Muscular hypertrophy
- diverticula
Which condition in cats causes myofiber disarray?
Hypertrophic cardiomyopathy
- also causes fibrosis
Polyploidy is found in
Horse livers due to chronic toxicosis (pyrrolizidine alkaloids)
- hypertrophy
- megalocytes, necrosis, fibrosis (hepatic atrophy)
