Unit 4 - Skeletal System Histology and Physiology

Interstitial Lamellae

layers between osteons

Circumferential Lamellae

outer surface of compact bone; thin plates that extend around the bone

Concentric Lamellae

circular layers of bone matrix that surrounds central canal

Central Canal

The hollow center of an osteon, also known as a Haversian canal. Contains blood vessels, lymphatic vessels, lymphatic vessels, and nerves.

Haversian Canal

a network of tubes running through compact bone that contains blood vessels and nerves

Volkmann's Canal

connects haversian canals (central canal), running perpendicular to them.

Perforating Canal

run perpendicular to central canal (Haversian Canal) and connects them

Osteon

basic functional unit of compact bone; a repeating structural unit of bone consisting of a central canal, concentric lamellae, lacunae, osteocytes, and canaliculi; also called a haversian system

Haversian System

basic functional unit of compact bone; a repeating structural unit of bone consisting of a central canal, concentric lamellae, lacunae, osteocytes, and canaliculi; also called an osteon

Osteocyte

Mature bone cell

Osteoblast

Bone forming cells

Osteoclast

multinucleated cells that destroy and reabsorb bone

Lacuna

small cavities in bone that contain osteocytes

Canaliculi

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

Trabeculae

The interconnecting tiny arches of bone tissue found in spongy bone

Woven Bone

Bone where the collagen fibers are randomly oriented in many directions

Lamellar Bone

Mature bone that is organized into thin sheets or layers

Collagen

the part of the bone matrix that gives it flexibility

Minerals

the part of the bone matrix that gives it strength

Short

cube-shaped bones; as broad as they are long

Short

carpal bones of the wrist and tarsal bones of the ankle are examples of ______ bones.

Flat

thin, flat, and curved bones

Flat

skull bones, ribs, sternum, and scapulae are examples of ______ bones.

Irregular

bones that don't fit into other groups

Irregular

vertebrae and facial bones are examples of _____ bones.

Long

bones that are longer than they are wide

Long

most bones of the upper and lower limbs are examples of _____ bones.

long bone

short bone

flat bone

irregular bone

diaphysis

shaft of a long bone

articular cartilage

type of hyaline cartilage that covers end of bones to prevent friction

epiphysis

End of a long bone

epiphyseal plate

cartilaginous area at the ends of long bones where lengthwise growth takes place in the immature skeleton

epiphyseal line

the bony structure that results when the cartilage in the epiphyseal (growth) plate is replaced by bone at about ages 18-21, and bone has stopped growing in length

medullary cavity

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

red marrow

type of bone marrow that makes blood cells

hematopoiesis

scientific term for blood cell formation

yellow marrow

type of bone marrow that stores fat

periosteum

A dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles.

sharpey's fibers

bundles of collagen fibers that penetrate the periosteum and some bone itself to help strengthen the attachment of the tendons or ligaments to the bone. also known as perforating fibers.