Question

Tell me differences between atrophy, hypertrophy, hyperplasia, and metaplasia. Also denote a condition where you find each of these cellular changes.

During a medical emergency of a heart attack and some other events, the patient is “cool down and warmed back up” by layman term. Why does the medical team perform this action in order to prevent hypoxic injury (why is hypoxic injury bad)?

Answer 1

ANSWER :

▪︎Difference between atrophy , hypertrophy , hyperplasia and metaplasia :

ATROPHY	HYPERTROPHY	HYPERPLASIA	METAPLASIA
Organ size decreases	Organ size increases	Organ size increases	No change in organ size
Decrease in number and size of the cells of an organ	Increase in the size of the cells of an organ	Increase in the number of cells of an organ	Reversible transformation of one mature cell type to another
Decrease in metabolic activity or nutrient defieciency	Increased functional demand	Capacity of cells to replicate	Differentiation of cells in different pathways due to cytokines, growth factors etc
Decrease in protein synthesis or increase protein degradation	Increase in protein synthesis	Stem cells and mature cells replicate.Can occur due to normal or abnormal stressors	Can be due to any abnormal stimulus from surrounding environmemt etc
Eg : Breast and ovaried atrophy in menopause , Chronic malnutrition etc	Eg : Hypertrophy of pregnant uterus	Eg: Endometrial hyperplasia	Eg : Squamous metaplasia in cervical intraepithelial neoplasia

▪︎'Cool down and warmed backup' is done after heart attack to prevent hypoxic injury because :

• Cool down for 24 hrs : Lowering brain temperature -----> decreases the need of energy by the brain cells------> decreases inflammation ------> decreases release of toxins -----> prevents brain cell death
• Again rewarming the patient after 24 hrs back to the normal temperature, brings the patient to the normal condition.
• When deprivation of oxygen supply to brain is continued -----> hypoxic injury ------> in few minutes death , coma or permanent damage to brain can occur
• Long term effects of hypoxic injury includes : Memory loss , amnesia , hallucinations , seizures , visual disturbances , ataxia etc