BIO 1130: Chapter 6

Yellow marrow

Soft, fatty material found in the medullary cavity of long bones.

Red marrow

Produces red blood cells.

Flat bone

Features: Thin and curved

Functions: Points of attachment for muscles; protectors of internal organs

Examples: Sternum, ribs, scapulae, cranial bones

Long bone

Features: Cylinder-like shape, longer than it is wide

Functions: Leverage

Examples: Femur, tibia, fibula, metatarsals, humerus, ulna, radius, metacarpals, phalanges

Sesamoid bone

Features: Small and round; embedded in tendons

Functions: Protect tendons from compressive forces

Examples: Patellae

Irregular bone

Features: Complex shape

Functions: Protect internal organs

Examples: Vertebrae, facial bones

Short bone

Features: Cube-like shape, approximately equal in length, width, and thickness

Functions: Provide stability, support, while allowing for some motion

Examples: Carpals, tarsals

Proximal epiphysis

End of the bone closest to the body trunk

Metaphysis

Where diaphysis and epiphysis meet

Diaphysis

Shaft of a long bone

Distal epiphysis

End of the bone farthest from the body trunk

Articular cartilage

Covers the surfaces of bones where they come together to form joints

Spongy bone

Composed of small needle-like pieces of bone and lots of open space

Epiphyseal line

Remnant of the epiphyseal plate, seen in adult bones

Red bone marrow

Found in cancellous bone; site of hematopoiesis

Endosteum

Membranous lining of the hollow cavity of the bone

Compact bone

Hard, dense bone tissue that is beneath the outer membrane of a bone

Medullary cavity

Cavity within the shaft of the long bones filled with bone marrow

Yellow bone marrow

Gradually replaces red bone marrow in adult bones; functions as storage for fat tissue and is inactive in the formation of blood cells

Periosteum

A dense fibrous membrane covering the surface of bones and serving as an attachment for tendons and muscles

Nutrient artery

Large artery that enters compact bone near the middle of the diaphysis

Periosteum (fibrous layer)

Outer layer consisting of dense irregular connective tissue consisting of Sharpey's fibers that secure to bone matrix

Periosteum (cellular layer)

Includes osteoprogenitor cells, osteoblasts, and osteoclasts

Osteocytes in lacuna

Bone cells in cavities between lamella rings

Endosteum

Membranous lining of the hollow cavity of the bone

Osteoclast

Bone-destroying (cleaning) cells

Bone matrix

Nonliving, structural part of bone

Osteocyte

A mature bone cell, formed when an osteoblast becomes embedded in the matrix it has secreted

Osteogenic cell

Undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts

Osteoblast

Developing (baby) bone cell

Fovea capitis

Pit in the head of a femur

Head

Prominent, rounded, articulating end of a bone

Tubercle

Small rounded projection or process

Sulcus

Narrow groove

Tuberosity

Large rounded projection; may be roughened

Fossa

Shallow depression

Facet

Smooth, nearly flat articular surface

Condyle

A smooth, rounded articular process

Crest

Narrow ridge of bone; usually prominent

Sinus

Cavity within a bone

Foramen

Round or oval opening through a bone

Canal

Tubular Passage/Tunnel (Optic Canal)

Fissure

Narrow, slit-like opening

Protuberance

A bony outgrowth or protruding part

Osteocyte

A mature bone cell, formed when an osteoblast becomes embedded in the matrix it has secreted

Osteoblast

Developing (baby) bone cell

Osteogenic cell

Undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts

Osteoclast

Bone-destroying (cleaning) cells

Compact bone

Hard, dense bone tissue that is beneath the outer membrane of a bone

Medullary cavity

Cavity within the shaft of the long bones filled with bone marrow

Spongy bone

Layer of bone tissue having many small spaces and found just inside the layer of compact bone

Periosteum

A dense fibrous membrane covering the surface of bones and serving as an attachment for tendons and muscles

Circumferential lamellae

Located deep to periosteum and superficial to endosteum and extend around entire circumference of the diaphysis and resist twisting of long bone

Periosteal artery

Enters the diaphysis of a bone through a perforating (Volkmann's) canal and delivers blood to the periosteum and outer part of compact bone tissue

Periosteal vein

Found in the periosteum; carries blood away from periosteum and outer layers of the bone

Outer fibrous layer of periosteum

Dense irregular connective tissue

Inner osteogenic layer of periosteum

Composed of osteoblasts and osteoclasts

Interstitial lamellae

Fill in the spaces between osteons in compact bone, remnants of osteons whose matrix components have been almost completely recycled by osteoclasts

Perforating canal

Canal perpendicular to the central canal, carries blood vessels and nerves

Central canal

Contains blood vessels and nerves (haversian canal)

Blood vessels

Tubelike structures that carry blood to and from the bone

Lymphatic vessel

A vascular duct that carries lymph which is eventually added to the venous blood circulation

Nerve

A bundle of nerve fibers that runs through the bone

Trabeculae

Supporting bundles of bony fibers in cancellous (spongy) bone

Osteon

Structural unit of compact bone

Concentric lamellae

Layers of bony matrix around a central canal

Spongy bone

Layer of bone tissue having many small spaces and found just inside the layer of compact bone

Compact bone

Hard, dense bone tissue that is beneath the outer membrane of a bone

Trabeculae

Supporting bundles of bony fibers in cancellous (spongy) bone

Lamellae

Concentric rings made up of groups of hollow tubes of bone matrix

Endosteum

Membranous lining of the hollow cavity of the bone

Canaliculi openings on surface

Openings to canaliculi

Lacunae

Small cavities in bone that contain osteocytes

Osteocyte

Mature bone cell

Osteoclast

Bone-destroying (cleaning) cells

Canaliculi

Hairlike canals that connect lacunae to each other and the central canal

Paget's disease

A disease of unknown origin that is characterized by extensive breakdown of bone tissue followed by abnormal bone formation

Intramembranous ossification

Process by which bone forms directly from mesenchymal tissue

Endochondral ossification

Process in which bone forms by replacing hyaline cartilage

Longitudinal bone growth

Cartilage cells on the epiphysis side of the epiphyseal plate undergoes mitosis while the diaphysis side calcifies

Open fracture

Compound fracture; broken bone with an open wound

Closed fracture

One in which the bone is broken, but there is no open wound in the skin

Spiral fracture

A fracture in which the bone has been twisted apart

Transverse fracture

Complete fracture that is straight across the bone at right angles to the long axis of the bone

Comminuted fracture

Fracture in which the bone is splintered or crushed

Impacted fracture

Broken bone ends are forced into each other

Greenstick fracture

Bending and incomplete break of a bone; most often seen in children

Oblique fracture

Occurs at an angle across the bone

Step 1 bone repair (a)

Hematoma formation

Step 2 bone repair (b)

Callus formation

Step 3 bone repair (c)

Bony callus formation

Step 4 bone repair (d)

Healed fracture