Human Anatomy and Physiology : Bone Marrow Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #1 : Bone Marrow Physiology

Erythropoiesis takes place in which section of long bones?

Possible Answers:

Diaphysis

Articular cartilage

Haversian canal

Epiphysis

Lacuna

Correct answer:

Epiphysis

Explanation:

The ends of long bones, called epiphyses, contain spongy bone. Spongy bone contains red bone marrow, which is the site of erythropoiesis.

The shaft of the long bone is the diaphysis and houses yellow bone marrow, which mainly functions for fat storage. Articular cartilage is found on the exterior of the bone and helps to lubricate and provide cushioning for joints. Lacunae are small gaps in the hydroxyapatite matrix that house osteocytes. The Haversian canal runs through the center of an osteon and serves to house the blood vessels and nerves associated with bone.

Example Question #2 : Bone Marrow Physiology

When there is decreased oxygen in circulation, an organ senses this and secretes a hormone. Which organ and what hormone are in play?

Possible Answers:

The kidneys and RBC factor 1

The kidneys and erythropoietin

The liver and RBC factor 2

The liver and RBC factor 1

The liver and erythropoietin

Correct answer:

The kidneys and erythropoietin

Explanation:

The bone marrow makes new red blood cells in a process called erythropoiesis. This is stimulated by the kidneys detecting decreased levels of oxygen in the blood stream. They then release a hormone called erythropoietin which stimulates the bone marrow to make more erythrocytes or red blood cells.

Example Question #2 : Bone Marrow Physiology

In which part of bones does hematopoiesis take place?

Possible Answers:

Red marrow

Spongy

Compact

Periosteum

Yellow marrow

Correct answer:

Red marrow

Explanation:

The correct answer is red marrow.

Hematopoiesis is the formation of blood cells, which is a function of red marrow. Red marrow forms red blood cells, white blood cells and blood platelets. The process beings with a stem cell that proliferates (reproduces rapidly), differentiates (becomes a specialized cell) and replicates (duplicates).

The other choices are all parts of bones, but have different functions/characteristics besides hematopoiesis. While red marrow contains the red and white blood cells and blood platelets, yellow marrow consists of mostly fat cells. Compact bones are hard and contain closely packed osteons that form a solid mass. The periosteum is the connective tissue covering the surface of a bone. Spongy bones are less dense than compact bone and are lighter than compact bones. It contains plates (trabeculae) of bone and cavities that contain the red marrow.

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