Cell Injury Adaptation and Death

Question 1

Incidence - define and how to calculate

Answer 1

number of new cases occurring in a given population within a given time period- usually 1 year.

calculate- incidence of down syndrome in the US is 1 in 690 births (1/690 x 100 = 0.14%)

Question 2

Prevalence- define and calculate

Answer 2

number of old and new cases in a given time period.

prevalence of down syndrome in the US is 400,000 for a population of 314 million.
ex. 400,000/314,000,000 x 100 = 0.13%

Question 3

define pathogenesis-

Answer 3

involves the sequence of events that occurs between the stimulus event/s and the manifestations of the disease

Question 4

clinical manifestations-

Answer 4

includes symptoms, results of physical and mental assessment, and results of diagnostic studies in general.

Question 5

primary prevention vs. secondary and tertiary prevention-

Answer 5

primary prevention- is to prevent the initial occurrence of a disorder.
secondary- is to reduce the impact of a disease that has already occurred.
tertiary- is to slow down the progression of a disease.

Question 6

ATP depletion-

Answer 6

causes 1. Na/K+ ATPase pump fails. Sodium and calcium flow inward. Potassium flows out freely. Water follows sodium and cell swells.
2. anaerobic respiration occurs-> increase in prod of lactic acid-> lower pH-> pyknosis, karyorrhexis, and karyolysis. along with rupture of lysosomes and disruption of cell membrane-> increased calcium influx and activation of proteases, endonucleases, and phospholipase that proceed to destroy the cell and contents

Question 7

oxygen and oxygen derived free radicals-

Answer 7

lipid peroxidation- free radicals are unstable and avidly combine with phospholipid bilayer. which leads to dissolution of the membrane.

Question 8

intracellular calcium and loss of ca steady state

Answer 8

causes 1. increased mitochondrial permeability 2. activation of multiple cellular enzymes

Question 9

defects in membrane permeability-

Answer 9

caused by 1. free radicals and 2. lysis by enzymes or lysis by viruses.

Question 10

how does the body handle free radicals and ROS?

Answer 10

Antioxidants such as vitamin e, C, cysteine, glutathione, albumin, ceruloplasmin, and transferrin.

Enzymes- like catalase, glutathione peroxidase, can modulate the cellular destructive effects of free radicals which are also released in inflammation.

Question 11

describe the pathophysiological basis of repercussion injury-

Answer 11

increased amounts of ROS, Superoxide, and hydrogen peroxide-> membrane damage and mitochondrial calcium overload.

rapid restoration of intracellular pH-> opening of pore in mitochondrial membrane called the mitochondrial permeability transition pore (MPTP) with massive escape of ATP and solutes-> apoptosis.

tx- use of antioxidants, blockage of inflammatory mediators, and inhibition of apoptotic pathways