Hypertrophy and Hyperplasia.pdf

Hypertrophy and Hyperplasia CELL ADAPTATION 00:20 Reversible change in size number Phenotype Metabolic activity HYPERTROPHY AND HYPERPLASIA 01:10 HYPERTROPHY HYPERPLASIA Def : Cell size Cell number Stimulus : Stress Stress work load) work bad) Mechanism : synthesis of Controlled cell division structural protein (mitosis) Tissue : Can't divide can divide Physiological: Skeleton muscle in athlets. Uterus in pregnancy Example Uterus in pregnancy Breast in puberty Breast in puberty, pregnancy Pregnancy lactation

BIOCHEMICAL MECHANISMS OF MYOCARDIAL HYPERTROPHY 16:40 mechanical stretch & adregenic action Growth Factor (Due to work load) Hormones Angiotensin IGF-1 Repeated stimulation of cardiac muscle Transcription Factor (GATA-4,NFAT,MEF-2) fetal gene expression Syn of contractile protein G Growth Factor in cardiac muscle Effective contraction x (Adult isoform of myosin Myocardial Enhancing Factor 2 Heavy chain) (MEF-2) More effective contraction Nuclear Factor activated T-Cells (NFAT) Transcription Factor (GATA-4)