ANAPHY Lab ( 2nd reviewer mas mahaba and detailed)

Skeletal System Components

Includes bones, cartilages, tendons, and ligaments.

Functions of the Skeletal System

Provides body support, organ protection, facilitates body movement, stores minerals, and produces blood cells.

Bone Histology

Characteristics determined by extracellular matrix composition, which includes collagen, ground substance, organic molecules, water, and minerals.

Collagen

A fibrous protein that provides flexibility and resists pulling or compression.

Proteoglycans

Water-tapping proteins that help cartilage remain smooth and resilient.

Bone Matrix Composition

35% organic (primarily collagen and proteoglycans) and 65% inorganic (primarily hydroxyapatite).

Osteoblasts

Cells responsible for bone formation, repair, and remodeling; produce collagen and proteoglycans.

Ossification

The process of new bone formation by osteoblasts.

Osteocytes

Mature bone cells that maintain bone matrix, formed from osteoblasts; account for 90-95% of bone cells.

Lacunae

Spaces in the bone matrix where osteocytes are located.

Canaliculi

Narrow spaces housing the extensions of osteocytes.

Osteoclasts

Bone-destroying cells that contribute to bone repair and remodeling through bone reabsorption.

Lamellar Bone

Mature bone organized into thin, concentric sheets or layers called lamellae.

Spongy Bone

Bone with less matrix and more space, consisting of trabeculae.

Compact Bone

Solid outer layer surrounding each bone, with more matrix and less space.

Osteon

The functional unit of compact bone, composed of concentric rings of matrix surrounding a central canal.

Diaphysis

The center portion of a long bone, composed of compact bone surrounding the medullary cavity.

Epiphyses

The ends of a long bone.

Articular Cartilage

Hyaline cartilage covering the ends of long bones.

Epiphyseal Plate

Located between the epiphysis and diaphysis, involved in bone growth.

Epiphyseal Line

The ossified epiphyseal plate indicating the end of bone growth in length.

Axial Skeleton

Comprises the skull, auditory ossicles, hyoid bone, vertebral column, and thoracic cage.

Appendicular Skeleton

Consists of upper limbs, lower limbs, and the two girdles.

Girdle

Zones where limbs attach to the body (pectoral and pelvic girdles).

Long Bones

Bones longer than they are wide, such as upper and lower limb bones.

Short Bones

Bones approximately as wide as they are long, like wrist and ankle bones.

Flat Bones

Bones with a thin, flattened shape, such as the skull and sternum.

Irregular Bones

Bones with shapes that do not fit into other categories, like vertebrae and facial bones.

Foramen

A hole in a bone.

Fossa

A depression in a bone.

Process

A projection from a bone.

Condyle

A smooth, rounded end of a bone.

Meatus/Canal

A canal-like passageway in a bone.

Tubercle/Tuberosity

A lump of bone.

Tuberosity

A large rounded projection that may be roughened.

Crest

A narrow ridge of bone, usually prominent.

Trochanter

A very large, blunt, irregularly shaped process on the femur.

Epicondyle

A raised area on or above a condyle.

Spine

A sharp, slender, often pointed projection from a bone.

Head

A bony expansion carried on a narrow neck.

Facet

A smooth, nearly flat articular surface.

Ramus

An armlike bar of bone.

Groove

A furrow in a bone.

Fissure

A round or oval opening through a bone.

Notch

An indentation at the edge of a structure.

Sinus

A bone cavity filled with air and lined with mucous membrane.

Sutures

Immovable joints connecting cranial bones.

Cranial Bones

Include frontal, parietal, occipital, temporal, sphenoid, and ethmoid bones.

Maxillae

Forms the upper jaw and part of the hard palate.

Mandible

The lower jawbone, the only movable skull bone.

Paranasal Sinuses

Cavities within certain bones associated with the nasal cavity.

Vertebral Column

Central axis of the skeleton, consisting of 26 individual bones grouped into 5 regions.

Thoracic