Calcium and Phosphate Metabolism Quiz

There is a significant difference in calcium concentration between the intracellular fluid (ICF) and extracellular fluid (ECF). ICF has a much lower calcium concentration (10^-7 M) compared to ECF (10^-3 M).

PTH is a hormone produced by the parathyroid glands, located near the thyroid. Its primary function is to regulate calcium levels in the extracellular fluid (ECF).

PTH secretion is regulated by calcium levels in the ECF. When calcium levels are low, PTH secretion increases, and when calcium levels are high, PTH secretion decreases.

PTH increases calcium levels in the ECF by acting on bone (releasing calcium), kidneys (increasing reabsorption of calcium), and intestines (enhancing absorption of calcium).

CaSR are located on chief cells, responsible for detecting changes in ECF calcium concentrations and regulating PTH secretion accordingly.

Bones provide a framework for the body, giving it shape and allowing for movement. This framework supports the weight of the body and helps maintain posture.

Bones protect vital organs and soft tissues from damage. For example, the skull protects the brain, the ribcage protects the heart and lungs.

Bones work with muscles and joints to allow movement. Bones act as levers, while muscles provide the force for movement.

These crystals are the main mineral component of bone, providing strength and hardness. They are composed of calcium and phosphate.

Besides calcium and phosphate, bone also contains other ions like sodium, potassium, and magnesium. These ions influence the flexibility and adaptation of bone.

Collagen is a protein that provides flexibility and resistance to pulling forces in bone. It's also a crucial component of ligaments and tendons.

These large molecules contribute to bone's structure and help regulate water content. They're found in various tissues, not just bone.

The process of bone growth in diameter, primarily controlled by forces like stress and gravity.

A principle stating that bone adapts to the mechanical stresses placed upon it, leading to increased density and strength in areas of high stress.

The ability of bone tissue to generate an electrical charge in response to mechanical stress, triggering bone remodeling processes.

The process by which bone-building cells (osteoblasts) create new bone tissue.

The process by which bone-breaking cells (osteoclasts) remove old or damaged bone tissue.

The phenomenon where an implant in bone carries some of the load, reducing the stress on the surrounding natural bone.

A decrease in the amount of bone mineral content, often caused by reduced stress or prolonged immobility.

The continuous process of bone breakdown and rebuilding, influenced by hormones like PTH and calcitonin.

Hormones like PTH and calcitonin regulate bone remodeling, determining when and where it occurs.

Mechanical stress dictates the location of bone remodeling, with high stress areas experiencing appositional growth.

Hyaluronic acid is a substance found in the extracellular matrix of bone. It helps to organize the matrix by attracting water and providing lubrication for the collagen fibrils, which are responsible for the strength and flexibility of bone.

Sialoproteins are important proteins in bone. They are highly glycosylated and sulphated, meaning they have a lot of sugar molecules attached to them. They are crucial for bone mineralization and formation.

Osteocalcin is a specific protein produced by osteoblasts. It plays a crucial role in bone formation and also influences the activity of osteoclasts, the cells responsible for breaking down bone.

Osteonectin is another protein produced by osteoblasts. It is involved in various processes in bone, including modulating the activity of growth factors, aiding in cell adhesion, and contributing to the mineralization of bone.

Osteopontin is a protein that plays a crucial role in regulating bone formation, cell migration, cell adhesion, and mineralization.

RANKL stands for Receptor Activator of Nuclear Factor κ-B Ligand. It is a key signaling molecule that controls the differentiation of osteoclasts, the cells responsible for bone resorption.

Osteoblasts are the bone-building cells. They produce the matrix of bone, which is primarily made up of collagen. They also have receptors for various hormones, such as PTH, CT, and Vitamin D, which influence their activity.

Osteoclasts are the bone-resorbing cells. They are large, multinucleated cells that dissolve bone by releasing enzymes and acids.

The total amount of calcium present in the blood. This includes calcium bound to proteins, calcium complexed with other molecules, and ionized calcium (free calcium ions).

A calculated value that estimates the true calcium level in the blood by adjusting for albumin levels. It helps to get a better picture of the body's calcium status, especially when albumin levels are abnormal.

The biologically active, free form of calcium in the blood, not bound to proteins. It plays the most important role in cellular functions like muscle contraction and nerve transmission.

The most abundant protein in blood serum. It is responsible for binding and transporting calcium, influencing the measurement of total calcium.

Different conditions can affect total calcium levels, not just ionized calcium. Low protein levels (e.g., malnutrition, liver disease) can falsely lower total calcium even if ionized calcium is normal.

Ionized calcium levels are affected by pH. Alkalosis reduces ionized calcium by increased calcium binding to protein, while acidosis increases ionized calcium by decreasing calcium binding to protein.

The body's regulation of calcium levels, maintained within a narrow range. This involves three main systems: bone, kidney, and intestine.

Three hormones regulate calcium: parathyroid hormone (PTH), calcitonin, and vitamin D. They work together, influencing calcium levels in bone, kidney, and intestine.

A hormone produced by the thyroid gland, lowering blood calcium levels by inhibiting bone breakdown and increasing calcium excretion in the kidney.