Hyperplasia (1)

Hyperplasia (1)

1. HYPERPLASIA Presented By Maryam Manzoor Lecturer Pharmacology Rashid Latif College of Pharmacy

2. DEFINITION “Hyperplasia is an increase in the number of cells in an organ that stems from increased cell proliferation”

3. Hyperplasia takes place if the tissue contains cell populations which is capable of replication. I t may occur concurrently with hypertrophy and often in response to the same stimuli.

4. TYPES

5. MECHANISM In both situations, cellular proliferation is stimulated by growth factors that are produced by a variety of cell types.

6. CAUSES Increased local production of hormones. Increased growth factor response on receptor cells. Activation of particular intracellular signaling pathway.

7. PHYSIOLOGICAL HYPERPLASIA The two types of physiologic hyperplasia are: H ormonal hyperplasia Proliferation of the glandular epithelium of the female breast at puberty and during pregnancy. C ompensatory hyperplasia In which residual tissue grows after removal or loss of part of an organ. For example, when part of a liver is resected , mitotic activity in the remaining cells begins as early as 12 hours later, eventually restoring the liver to its normal size.

8. The growth and multiplication of milk secreting glandular epithelial cells in response to pregnancy for future lactation

9. Compensatory Hyperplasia

10. PHYSIOLOGICAL HYPERPLASIA The stimuli for compensatory hyperplasia in case of liver resection is polypeptide growth factors produced by uninjured hepatocytes. After restoration of the liver mass, various growth inhibitors turn off cell proliferation

11. PATHOLOGICAL HYPERPLASIA Most forms of pathologic hyperplasia are caused by excessive hormonal or growth factor stimulation. 1- For example, after a normal menstrual period there is a burst of uterine epithelial proliferation. A disturbance in this process can lead to increased estrogenic stimulation causes endometrial hyperplasia, which is a common cause of abnormal menstrual bleeding --------------- endometrial hyperplasia

12. PATHOLOGICAL HYPERPLASIA 2- Benign prostatic hyperplasia -------------induced in responses to hormonal stimulation by androgens. 3- C ertain viral infections; for example , papillomaviruses cause skin warts and mucosal lesions that are composed of masses of hyperplastic epithelium . 4- wound healing . 5- Thyroid Hyperplasia

13. THYROID HYPERPLASIA

14. I n all of these situations, the hyperplastic process remains controlled; if the signals that initiate it abate, the hyperplasia disappears .