Anatomy and Physiology II Practice Test 2025 - Free Anatomy Practice Questions and Study Guide

The type of anemia characterized by a deficiency of intrinsic factor, which leads to vitamin B12 deficiency, is pernicious anemia. Intrinsic factor is a protein produced by the stomach that is essential for the absorption of vitamin B12 in the intestine. Vitamin B12 is crucial for the production of red blood cells, and a lack of it can lead to the production of large, abnormal red blood cells, resulting in symptoms of anemia.

Pernicious anemia typically occurs due to an autoimmune condition where the immune system attacks the cells in the stomach that produce intrinsic factor. Without sufficient intrinsic factor, the body cannot absorb vitamin B12 effectively from dietary sources, leading to the deficiency.

The other types of anemia differ in their causes. Hemorrhagic anemia is primarily due to blood loss, either from trauma or conditions causing chronic bleeding. Aplastic anemia results from a failure of the bone marrow to produce enough red blood cells due to factors such as radiation, chemicals, or autoimmune diseases. Iron deficiency anemia occurs from a lack of iron, which is essential for hemoglobin production. Each of these anemias has distinct underlying mechanisms that do not involve the intrinsic factor or vitamin B12 absorption.