Anatomy and Physiology: The Skeletal System and Bone Tissue

Flashcards covering bone classification, anatomy, cellular structure, ossification processes, and the axial skeleton based on the lecture transcript.

Long bones

Bones such as the humerus, radius, ulna, femur, tibia, and fibula, excluding the patella, carpals, tarsals, phalanges, metacarpals, and metatarsals.

Patella

The kneecap, which is classified as a short bone or a sesamoid bone.

Tibia

The larger, more predominant bone of the lower leg.

Fibula

The thinner, longer bone located laterally in the lower leg.

Short bones

Bones that include the carpals, tarsals, metacarpals, metatarsals, phalanges, and the patella.

Flat bones

Bones where ossification happens in sheets, including the sternum, scapula, ribs, skull bones, and the mandible.

Irregular bones

Bones with non-uniform shapes and densities, such as the pelvis (ischium, ileum, and pubic bone) and the vertebrae.

Diaphysis

The shaft of the bone made of compact bone and surrounded by periosteum and endoastium.

Epiphysis

The ends of the bone which contain receptors for growth hormone and respond to puberty hormones like estrogens and testosterone.

Osteoblasts

Non-mitotic cells that build bone.

Osteoclasts

Cells derived from monocytes that break down bone by producing acid phosphatase enzyme to release calcium into the blood.

Yellow marrow

Bone marrow used to store fat as a secondary nutrient reserve.

Red bone marrow

Hematopoietic tissue in adults found in the spongy bone of the femur, humerus, sternum, and hip bone that originates all formed elements of the blood.

Articulation

A connection between bone to bone, muscle, or other tissues.

Periosteum

The membrane that lines the outer surface of the bone.

Endoastium

The membrane that lines the inner surface of all bones.

Diploe

The spongy bone located in the middle of flat bones.

Hydroxyapatite

An inorganic component representing approximately $65\%$ of bone that allows bone to withstand stress and provides tensile strength.

Osteoid

The organic matrix of bone comprised of collagen fibers and chondroitin that provides resistance to stretching and twisting.

Osteogenic cells

Differentiated cells found in the periosteum and endoceum that lay the framework for bone and become osteoblasts.

Osteocytes

Mature bone cells that cannot divide; they reside in concentric lamella to monitor and repair bone.

Osteon

The functional unit of bone organized as concentric rings of lamella looking like a bull's eye.

Central canal

Formerly known as the Haversian canal, it is the longitudinal blood vessel running through the center of the osteon.

Volkmann's canals

Canals that run perpendicular to the Haversian canals to supply them with blood.

Canaliculi

Small blood vessels that connect each of the osteocytes on the rings of the osteon.

Interstitial lamella

The extracellular matrix of bone that fills the spaces between osteons.

Ho Chipps Laguna

The specific location in bone where osteoclasts originate.

Intramembranous ossification

The process of bone formation from mesentine cells in flat bones, the mandible, skull, scapula, and ribs.

Endochondral ossification

The process where cartilage is replaced by bone, primarily in long bones like the femur and humerus.

Piezoelectric effect

The phenomenon where mechanical stress creates charges that pull minerals towards the bone to increase density.

Wolff's law

The principle stating that bones are remodeled to fit their mechanical functions and deposit where needed.

Vitamin A

A vitamin that stimulates chondroitin sulfate synthesis for healthy joints and resistance to stretch.

Vitamin C

A nutrient necessary for collagen synthesis, helping the skin and bone resist fracture.

Vitamin D3

A vitamin obtained from sunlight or fortified foods that forms calcitriol to increase absorption of calcium and phosphorus.

Calcitonin

A thyroid hormone that promotes osteoblast activity and bone growth.

Parathyroid hormone

A hormone that promotes osteoclast activity to breakdown bone and assists the kidney in absorbing calcium.

Scoliosis

An abnormal lateral curvature of the spine greater than $10^{\circ}$, often treated surgically if exceeding $30^{\circ}$.

Kyphosis

An excessive thoracic curvature of the spine, sometimes associated with aging or sitting in a hunched position.

Lordosis

An abnormal curvature of the lumbar spine that can develop from birth or due to failing knee and hip joints.

Nucleus pulposus

The gelatinous center of an intervertebral disc.

Annulus fibrosis

The exterior ligament and fibrocartilage surrounding the intervertebral disc.

Atlas

The C1 vertebra that lacks a body and has occipital condyles to allow the head to nod yes.

Axis

The C2 vertebra characterized by the dens structure which serves as a pivot point for turning the head.

Dens

A structure found only on the C2 vertebra that sits within the C1 space to allow lateral rotation.

Thoracic vertebrae

A group of 12 vertebrae with heart-shaped bodies and spinous processes angled downward that articulate with 12 pairs of ribs.

Lumbar vertebrae

The 5 largest vertebrae with square-shaped spinous processes that support the weight of the entire upper body.

Sacrum

A structure composed of 5 fused vertebrae without intervertebral discs.

Coxyl

A structure composed of 4 fused vertebrae at the terminal end of the spine.

Sternum

A flat bone about $15\,cm$ long consisting of the manubrium, body, and xiphoid process.