Skeletal System
Parallel Lamellae
Bone Matrix. Osteocytes between lamellae. Canailculi radiate from lacunae
Perichondrium
Dense, irregular CT. Covers cartilage and helps it maintain its shape.
Medullary Cavity
Hollow, usually cylindrical space within the diaphysis. Contains red and yellow bone marrow.
Axial Skeleton
Skull bones, ossicles of middle ear hyboid, ribs, sternum vertebral column.
Ligaments
Anchor bone to bone.
Tendons
Anchor muscle to bone.
Vascularized
Apart of blood supply and innervation of bone. Vessels that enter the periosteum
Peroforating Canals
Blood vessels and nerves travel through. (Volkmann's canal)
Storage of the Skeletal System
Bone stores the body's reserve of calcium and phosphate. (calcium is essential for muscle contraction, blood clotting and nerve impulse transmission) and (phosphate is ATP utilization). Lipid is stored in yellow bone marrow of adult bones.
Movement of the Skeletal System
Bones serve as attachment sites for skeletal muscles, tissues, some organs. Also acts as a system of levers by altering directions and magnitude of forces.
Interstitual Lamellae
Compact bone between Osteons, Resorbed osteons, no central canal.
Endosteum
Covers all internal surfaces of bone within medullary cavity. Contains osteoprogenitor cells, osteoblasts, and osteoclasts.
Central Canal of an Osteon
Cylindrical channel at center of osteon and parallel to it.
Zone of Disposition
Demonstrates the area where the chondrocytes die and are replaced by blood vessels and osteoblasts, which then form the final trabeculae and osteoclasts that refine the distal contours of the medullary chamber.
Calcification
Deposition of the hydroxyapatite crystals.
Parts of the Long Bone
Diaphysis, epiphysis, epiphyseal plate, metaphysis, medullary cavity, peritoneum and endosteum
Irregular Bones
Elaborate, sometimes complex shapes.
Diaphysis
Elongated, usually cylindrical shaft located within compact bone with thin spicules of spongy bone extending inward.
Flat Bones
Flat, thin surfaces, may be slightly curved. (Top of skull, scapulae, sternum, ribs)
Osteoblasts
Form from Osteoprogenitor cells. Synthesize and secrete osteoid. Turns into osteocytes.
Chondrocytes
Have lacunae, maintain the matrix and chondroblasts are encasted within the matrix.
Red Bone Marrow
Hemopoietic, Reticular CT, and fat. IN CHILDREN- located in Spongy Bone. IN ADULTS: located ONLY in areas of the axial skeleton.
Osteoid
Initial semisolid organic form of bone matrix.
Epiphyseal Plate
It is a hyaline cartilage located in the metaphysis. It is the part of the long bone where new bone growth takes place.
Periosteum
It is a tough sheath around the outer surface of the bone. It serves as protection as well as a channel for the blood supply and nutrients for bone tissue. It is attached to the bone by numerous collagen fibers.
Epiphysis
Knobby region at each end of the bone. (Proximal and Distal). Contains Articular cartilage (Covers joint surface).
Osteoclasts
Large, multinuclear, phagocyte cells. Involved in bone resorption.
Short Bones
Length nearly equal to width. ( carpal bones, tarsals, sesamoid bones)
Spongy Bone
Located internal to compact bone, porous. 20% of bone mass.
Osteocytes
Mature bone cells from derived from Osteoblasts. Detect mechanical stress on bone.
Zone of Calcification
Mineralization of the cartilaginous walls between lacunae provides a temporary framework in the______ by which the final stages of ossification will take place.
Long Bone
Most common bone shape and greater in length than width
Hyaline Cartilage
Most common in the body and grows within growth plates. Connects ribs to sternum and covers end of some bones.
Trabeculae
Narrow rods and plates of bones. Resistance to stress.
Zone of Cell Proliferation
Nearer to the medullary cavity, the ______ is marked by an expansive production of chondrocytes that align in rows in order to replenish those undergoing calcification.
Appositional Growth of Cartilage
Occurs on cartilage's outside edge.
Intersitutial Growth of Cartilage
Occurs within internal regions of cartilage.
Decreases Blood Calcium
Osteoblastic activity, increased use of sunblock, calitonin
Increases Blood Calcium
Osteoclasic activity, caltricol, parathyroid hormone, increased bone resorption
Organic
Osteoid produced by osteoblasts contains collagen protein and semisolid ground substance of proteoglycans and glycoproteins. (Flexible)
Chondroblasts
Produce cartilage matrix
Yellow Bone Marrow
Product of red bone marrow degeneration as children mature. Fatty Substance
Hemopoiesis
Production of blood cells. Occurs in red bone marrow Connective tissue. Stems cells form blood cells and platelets.
Support and Protection of the Skeletal System
Provides structural support and framework for the body. Protects the heart and lungs (rib cage), the brain (cranial bones), the spinal cord (vertebrae) and the urinary and reproductive organs along with terminal end of GI tract (pelvis).
Metaphysis
Region of mature bone between the diaphysis and epiphysis. Ossifies during childhood.
Circumferential Lamellae
Rings of Bone
Concentric Lamellae
Rings of bone CT, surrounding the central canal.
Inorganic
Salt, Crystals and Calcium Phosphate. Forms crystals (hydroxyapatite). (Strong)
Appendicular Skeleton
Shoulder, upper limbs, pelvic girdle, and lower limbs.
Nutrient Foramen
Small opening or hole in bone.
Osteoprogenitor Cells
Stem Cells derived from mesenchyme. Matures to become an Osteoblast. (Located in periosteum and endosteum)
Zone of Hypertrophy
The next layer is the______ where the existing, columnar chondrocytes enlarge and thus force the separations between lacunae to become very thin
Canailculi
Tiny, interconnecting channels within bone CT. Allow exchange of nutrients,minerals, gases, and wastes between blood vessels and osteocytes.
Ossification
To turn into bone or bony tissue.
Compact Bone
White, smooth solid dense connective tissue. 80% of bone mass.
Resorption Lacuna
a groove or cavity usually containing osteoclasts that occurs in bone which is undergoing reabsorption.
Fibrocartilage
weight-bearing cartilage that withstands compression. Located in the invertebral discs, pubic symphasis, pads in knees.