Which cells take up glucose without needing insulin at all?

1. Insulin can only act where a cell carries insulin receptors on its membrane. 2. Red blood cells and the cells of brain, liver, kidneys and small intestinal lining carry none. 3. Those cells therefore take up glucose without insulin. 4. All other body cells do need insulin to pull glucose from blood. 5. Skeletal muscle cells and adipose cells are in fact the primary targets of insulin, so they are the opposite of the answer. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 17 "The Endocrine System", section 17.9 The Endocrine Pancreas_