HB4- MetHb

Hb

100

What is Hb short for?

Hemoglobin

200

Which metal is Hb rich in?

Iron (Fe)

300

How does a right shift of the Hb-O2 dissociation curve affect O2 delivery to the tissues?

Reduced O2 affinity and increased O2 delivery

400

What is carboxyhemoglobin?

Carbon monoxide (CO) and hemoglobin complex.

500

Hematocrit measures the percentage of total blood volume that is made up of red blood cells, and can be used as a measure of hemoglobin levels. How would you expect extreme dehydration to affect hematocrit levels?

Extreme dehydration would reduce blood plasma volume, therefore increasing hematocrit levels.

MetHb

100

What does MetHb stand for?

Methemoglobin

200

What percentage of an average person's hemoglobin is MetHb?

1%-2%

300

In Hb, iron is in the ferrous state (2+). In MetHb, the iron is in the ferric state (3+). Has the iron in MetHb been oxidized or reduced?

Oxidized. (OIL RIG)

400

MetHb increases O2 affinity at neighbouring Hb in the same RBC. Would this shift the Hb-O2 dissociation curve to the left or right?

Left shift.

500

What colour does blood with a high MetHb level appear as?

Dark red/blue/brown

Let's get Clinical

100

Excess MetHb levels can be diagnosed via blood gas tests. This test measures blood gas levels and can be performed on arterial or venous blood. Which type of blood would you expect to have higher PO2 levels?

Arterial blood

200

Excess MetHb can cause the skin to appear blue in affected individuals. What is this symptom called?

Cyanosis

300

Name a symptom someone might experience if their MetHb levels were between 30-50%.

Fatigue, confusion, dizziness, palpitations, tachypnea.

400

Excess MetHb ultimately leads to reduced production of health red blood cells. What condition does this describe?

Anemia

500

What is a potential treatment for excess MetHb?

Supplemental O2. Methylene blue, vitamin C (both promote reduction of MetHb, returning 3+ Fe to 2+ Fe state.