Cell Injury and Biomarkers

Question 1

hypertrophy

Answer 1

cells get larger but there are not more cells

Question 2

atrophy

Answer 2

reversible decrease in muscle mass

can be reversed through use and exercise

Question 3

can hyperplasia be reversible?

Answer 3

yes

Question 4

hyperplasia

Answer 4

increase in the number of cells

proliferation

Question 5

cytoplasmic eosinophilic

Answer 5

early cell injury due to RNA spilling into cytoplasm

Question 6

necrosis

Answer 6

cell membrane is not intact

loss of nuclei

loss of distinguishing cell features (ex: microvilli)

Question 7

blebs

Answer 7

irregular bulge in the plasma membrane due to membrane breaking down

Question 8

can membrane blebbing be reversed?

Answer 8

yes

Question 9

myelin figures

Answer 9

whirls and clumps of membrane

phospholipid dense

seen in stressed / dying cells

Question 10

metaplasia

Answer 10

normal epithelium being replaced by different cells

Question 11

example of metaplasia

Answer 11

Barret’s esophagous

Question 12

troponin I

Answer 12

specific for cardiac muscle

peak 1 day after MI

Question 13

lactate dehydrogenase

Answer 13

converts lactate to pyruvate in anaerobic glycolysis

cytoplasmic enzyme

Question 14

does an increase in troponin I always indicate an MI?

Answer 14

no

can indicate any pathology that causes cardiac cell death

Question 15

What does lactate dehydrogenase indicate?

Answer 15

broad cell death, found in many tissues

Question 16

When does LD peak following an MI?

Answer 16

~3 days

Question 17

AST function

Answer 17

convert aspartate to oxaloactate and glutamate

Question 18

Where is AST found?

Answer 18

in many tissues including heart and liver

Question 19

AST and alcohol abuse

Answer 19

liver makes more AST when metabolizing alcohol

leads to increased ratio of AST : ALT

Question 20

When does AST peak after MI?

Answer 20

~ 2 days

Question 21

Rank when the biomarkers for MI peak

Answer 21

1) CKMB
2) Troponin I and troponin T (1 day)
3) AST (2 days)
4) LDH (3 days)

Question 22

troponin T

Answer 22

more general troponin than troponin I (specific for cardiac)

Question 23

ALT

Answer 23

found in the liver

converts alanine to pyruvate

shows hepatocyte damage

Question 24

where is ALT expressed besides the liver? when can ALT be increased in this tissue?

Answer 24

skeletal muscle and can be increased in response to vigorous exercise

Question 25

Where is amylase found?

Answer 25

pancrease and salivary gland

Question 26

amylase function

Answer 26

hydrolyze a-1,4 linkages in starch

*breaks down complex carbs

Question 27

What does amylase indicate?

Answer 27

pancreatitis

Question 28

Lipase function

Answer 28

hydrolyze fat (triacylglycerol)

Question 29

What does lipase indicate?

Answer 29

presence in blood indicates pancreatitis

Question 30

what does an increase in unconjugated bilirubin indicate?

Answer 30

pre-liver damage

Question 31

what does an increase in total bilirubin indicate?

Answer 31

post-liver or biliary tree damage

Question 32

bilirubin general pathway

Answer 32

produced in the tissues and conjugated in the liver

Question 33

where is unconjugated bilirubin found?

Answer 33

the blood

Question 34

AlkPhos function

Answer 34

breaks down pyrophosphate to 2-phosphates

Question 35

What does increased AlkPhos indicate?

Answer 35

bile duct or bone disorders

Question 36

If AlkPhos is elevated, what can we check to determine between bile duct and bone disorder?

Answer 36

GGT

Question 37

GGT function (general)

Answer 37

important in biliary excretion of substances such as drugs

uses glutathione to break down drugs

Question 38

What does elevated INR indicate?

Answer 38

increased bleeding time and lack of clotting factors

Question 39

increased AST and ALT indicates

Answer 39

destruction of hepatocytes

parenchymal liver disease

Question 40

increased conjugated bilirubin w/ alkphos and ggt increase indicates …

Answer 40

obstructive bile duct disease

Question 41

examples of obstructive bile duct disease

Answer 41

gallstone, pancreatic head tumor

Question 42

how can gallstones elevate liver and pancreas enzymes?

Answer 42

gallstones can block the ampulla of VAter

leads to backup of bile into the common hepatic duct (liver) and pancreatic duct (pancreas)

Question 43

ampulla of Vater

Answer 43

where the common bile duct meets the duodenum

Question 44

selective vulnerability of liver to acetamenophin

Answer 44

metabolism of drug by cytochrome P450 makes drug present in the liver to become toxic??

Question 45

how is most acetaminophen eliminated?

Answer 45

renally

Question 46

P450 oxidation of acetaminophen

Answer 46

oxidizes the remaining acetaminophen which creates reactive metabolite NAPQI

too much NAPQI can be toxic