Bone Anatomy, Bone Cells, & Hormonal Regulation of Bone Calcium [Bone Histology Part 1 of 3]

Epiphyses

The dilated, bulbous ends of a long bone.

Diaphysis

The shaft or midsection of a long bone.

Compact Bone

Also known as cortical bone, it is the solid outer layer of bone.

Trabeculae

Branches of bone tissue that form networks within spongy bone.

Spongy Bone

Bone tissue that resembles a sponge, consisting of trabeculae and spicules.

Red Marrow

Hematopoietic tissue that generates red and white blood cells, appearing red.

Yellow Marrow

Unilocular adipose connective tissue found in the marrow space, appearing yellow.

Wolff's Law

Principle stating that bones change in response to mechanical load.

Osteoblasts

Bone cells that produce the bone matrix.

Osteocytes

Bone cells that maintain the bone tissue and reside in lacunae.

Osteoclasts

Large cells that break down bone matrix and release calcium into the blood.

Canaliculi

Tiny tunnels within the bone matrix that connect lacunae and allow for communication between osteocytes.

Howship's Lacunae

Irregularly shaped depressions in bone tissue occupied by osteoclasts.

Parathyroid Hormone (PTH)

Hormone produced by the parathyroid glands that increases blood calcium levels.

Calcitonin

Hormone produced by the thyroid gland that inhibits osteoclast activity, decreasing blood calcium levels.

Hematopoietic Tissue

Tissue that generates blood cells, found in red marrow.

Periosteum

Dense connective tissue covering the exterior of the bone.

Endosteum

A thin layer of cells lining the inner surface of the bone.

Mineral Storage

The bone's main function in storing minerals, especially calcium.

Cortical Bone

Another term for compact bone, referring to its dense outer layer.