Exam 4: Hyperplasia, Hypertrophy

Question 1

What is hypertrophy?

Answer 1

An increase in the size of a cell, or increase in the size of a tissue

Question 2

What is hyperplasia?

Answer 2

An increase in the number of cells in a tissue

Question 3

What is the cause of hypertrophy and hyperplasia?

Answer 3

Increased demand, endocrine stimulation, or nutrition

Question 4

What does increased cell activity cause?

Answer 4

Proliferation of organelles and/or cell division until a new balance is reached

Question 5

Are hypertrophy and hyperplasia beneficial?

Answer 5

In many cases, yes

However, persistent change in the environment leads to overcompensation and harmful effects may occur

Question 6

What are causes of physiologic hyperplasia?

Answer 6

Hormonal: maturity/development
Compensatory: liver resection

Question 7

What are causes of pathologic hyperplasia?

Answer 7

Chronic irritation
Endocrine
Virus induced
Increased bloodflow
Nodular hyperplasia

Question 8

What are causes of hypertrophy?

Answer 8

Increased workload
Endocrine stimulation
Thyroid- anabolic effects
Adrenal- cortisol excess
Estroens- uterine and mammary development

Question 9

What are examples of hypertrophy from increased workload?

Answer 9

Enlarged hearts and muscle mass in athletic animals

Kidney hypertrophy when the other is removed

Question 10

What does hyperplasia look like histologically?

Answer 10

Definite structures
Increased cells
Well differentiated

Question 11

What is fibrous osteodystrophy?

Answer 11

Reactive fibroblast hyperplasia and connective tissue production

Question 12

What can a hematoma be caused by?

Answer 12

Hyperplastic nodule

Hemangiosarcoma

Question 13

What results due to hypertrophic cardiomyopathy?

Answer 13

Myofiber disarray

Fibrosis

Question 14

What is compensatory hypertrophy?

Answer 14

When much of the function of one organ (such as a kidney) is lost, hypertrophy occurs in the other

Question 15

How does a thrombus on the aortic valve cause hypertrophy?

Answer 15

Thrombus on aortic valve interferes with blood leaving left ventricle increases pressure in left ventricle –> increased workload –> myocardial fibers stretch and then increase in size –> hypertrophy of left ventricular myocardium

Question 16

How does an increase in muscular activity cause hypertrophy?

Answer 16

Increase in muscular activity increased blood and nutrient supply –> increase in muscle fiber size –> hypertrophy of muscle mass

Question 17

How do pyogenic organisms cause hyperplasia?

Answer 17

Neutrophil chemotaxis –> depletion of bone marrow reserves –> stimulaties granulopoiesis –> hyperplasia of myeloid cells of bone marrow

Question 18

How does persistent infection cause hypertrophy?

Answer 18

Antigenic stimulation of lymphoid organs –> stimulus for proliferation of lymphocytes –> increase in size of lymph nodes and spleen

Question 19

How does persistent chronic blood loss cause hyperplasia?

Answer 19

Depletion of erythrocyte reserves –> stimulation of erythroid stem cells in bone marrow –> erythroid hyperplasia

Question 20

Describe how iodine deficiency causes endocrine stimulation

Answer 20

Iodine deficiency –> overwork of thyroid gland to compensate –> enlargement –> goiter

Question 21

Describe how chronic renal disease causes endocrine stimulation

Answer 21

Chronic renal disease –> failure of phosphorus excretion and failure of conversion of vitamin D to active form –> failure to absorb calcium from gut and excretion of CaPO4 from gut as P is excreted in gut –> lowered blood calcium levers –> stimulate parathyroids –> parathyroid enlargement

Question 22

Describe how sexual maturity causes endocrine stimulation

Answer 22

Increased production of sex hormones –> development of secondary sex characteristics

Question 23

How does excess nutrition cause hyperplasia and hypertrophy?

Answer 23

It leads to an increase in fat tissue and increase of protein synthesis

Question 24

What is hyperplasia associated with?

Answer 24

Increased workload

Question 25

How can you differentiate neoplasia from hyperplasia?

Answer 25

Neoplasia will cause destruction, hyperplasia does not

Question 26

When are nodules of hyperplasia consequential?

Answer 26

When they form hematomas