Skeletal System & Bone Homeostasis Flashcards

Flashcards covering key vocabulary and concepts related to the skeletal system, calcium homeostasis, and bone maintenance.

Osteoblast

A type of cell important for bone maintenance, involved in bone formation which reduces blood calcium levels.

Chondrocyte

A type of cell important for cartilage maintenance

Osteoclast

A type of cell important for bone maintenance, involved in bone resorption which increases blood calcium levels.

Mesenchymal Stem Cells

A type of cell important for bone maintenance, stem cells that can differentiate into a variety of cell types including osteoblasts.

Hematopoietic Stem Cells

A type of cell important for bone maintenance, stem cells that give rise to blood cells,

Osteocyte

A type of cell important for bone maintenance, mature bone cells embedded in the bone matrix.

GH/IGF-1 Axis

pituitary gland releasing Growth Hormone (GH) stimulates the liver to produce Insulin-like Growth Factor 1 (IGF-1), ultimately increasing muscle mass and bone mineral density (BMD).

Thyroxine

A hormone produced by the thyroid gland that doesn't directly target bone tissue but has general metabolic effects on all tissues and promotes the release of growth hormone.

Estrogen on Bone Density

A sex hormone that maintains bone density in females. Reduction at menopause leads to bone density loss.

Vitamin D3 (Cholecalciferol)

A steroid hormone that facilitates intestinal absorption of calcium, phosphate, and magnesium by stimulating calcium transporters and bone matrix proteins as well as supressing synthesis of collagen

Calcitonin (CT)

A hormone produced by the thyroid gland that reduces calcium levels in the blood by promoting osteoblast activity and inhibiting osteoclast function.

Parathyroid Hormone (PTH)

A hormone secreted by the parathyroid gland in response to low blood calcium levels. It promotes osteoclast activity to increase blood calcium.

Wolff’s Law

The principle that bone remodels in response to the mechanical stresses it experiences, such that bone form follows function.

Osteoporosis

A bone-related disorder characterized by 'porous bones' due to increased osteoclast activity, often associated with aging.

Osteochondrosis

A bone-related disorder involving abnormal growth plate development, typically occurring in childhood and adolescence.

Effects of low blood ca+

bone weakness, osteoporosis, muscle twitches due to a higher action potential gradient ,

Effects of high blood ca+

can lead to calcification of tissues, kidney stones, and impaired muscle function due to reduced neuromuscular excitability.

Osteochondrosis

an abnormal growth plate leading to disruptions in normal bone development and potential joint issues.

Mechanotransduction in the bone: integrin

Integrin is a transmembrane protein which detects fluid movement in response to mechanical pressure and sends signals through the cytoskeleton to change cell behavior, influencing bone remodeling and adaptation.

Mechanotransduction: primary cilium

senses mechanical forces and fluid flow, playing a critical role in signaling pathways that regulate bone cell activities and homeostasis in response to mechanical loading.

Piezo1 Channel

a mechanosensitive ion channel that responds to mechanical stress bending the membrane by allowing ions to flow into bone cells, influencing bone formation and remodeling.