Chapter Six - Skeletal System Flashcards
Hyaline cartilage
Fibrocartilage
Elastic cartilage
Bone functions
-support and protection
-movement
-hematopoiesis
-storage of mineral and energy reserves
Hemopoiesis
Blood cell formation in red bone marrow
Bone types (four)
Long, short, flat, irregular
Long bone
Greater length than width
-most common
-varies in size
Example: fingers, thigh, toes
Short bone
Length nearly equal to their width
-external: compact
-internal: spongy
Example: wrist bone, kneecap
Flat bone
Flat, thin surfaces
-extensive surfaces for muscles attachment
-underlying soft tissue
Example: shoulder blade, breastbone
irregular bone
Complex shapes, that do not follow other categories
-compact bone covering the spongy bone
Example: hip bones
Compact bone
Osteocytes
Spongy bone
Bone marrow
Diaphysis
Elongated, rodlike part of a long bone
-the shaft of a long bone
Epiphysis
Expanded, knobby region at the end of a long bone
Osteon
Functional unit of a compact bone
Chondroblasts
Cells that produce the matrix of cartilage
Chondrocytes
Mature cartilage cell
-maintain matrix
-occupy small spaces named lacunae
-ensure matrix remains healthy
-avascular
Three types of cartilage
Hyaline
Elastic
Fibrocartilage
Two types of cartilage growth
-interstitial
-appositional growth
Appositional growth
Growth along the outside edge
-under perichondrium
Interstitial growth
Occurs within the internal regions of cartilage
Proximal epiphysis
End of the bone closest to the body trunk
Distal epiphysis
End farthest from the trunk
Metaphysis
Section of a long bone between epiphysis and diaphysis
Epiphyseal plate
Thin layers of hyaline cartilage that provides
Epiphyseal line
The remanent of the Epiphyseal plate
-thin layer of compact bone
Articulate cartilage
Thing layer of hyaline cartilage covering the epiphysis at a joint surface
-reduce friction
-absorb shock
Medullary cavity
Hollow, cylindrical space within diaphysis
-in adults contains yellow marrow
Endosteum
Incomplete layer of cells that covers all internal surfaces of the bone
Example: medullary cavity
Periosteum
Tough sheath, covers outer surface of the bone
-dense irregular connective tissue
-protects the bone
-anchors blood vessels
-provides stem cells
Perforating fibres
Anchors the periosteum to the bone
-strong collagen fibres
Osteoprogenitor
Stem cells derived from mesenchyme
-found in periosteum and endosteum
Osteoblast
-produces new bone and osteoid
-eventually differentiate into osteocytes
Osteoid
Organic form of bone matrix
-later calcifies and hardens due to calcium salt depositon
Osteocytes
Mature bone cells that are entrapped in the matrix
-maintain bone matrix
-detect stress
Lacunae
Small cavity or depresson
Osteoclasts
Derived from fused bone marrow cells
-phagocytic cells
-multinuclear
-important for bone resorption
Bone resorption
-osteoclasts secrete hydrochloride acid
-dissolves mineral parts of the bone matrix
-lysosomes within the osteoclasts secrete enzymes that dissolve organic part
-this dissolved part then enters the tissue fluid and then blood
Osteolysis
Softening, absorption and destruction of bone connective tissue
Osteoblasts ____ to bone matrix and osteoclasts ____ the matrix
-add
-remove
Osteoblast and osteoclast are affected by
Hormonal levels
Composition of the bone matrix
-calcium phosphate
-hydroxyapatite
Compact bone
Solid and relatively dense
Spongy bone
Appears more porous like a sponge
Trabeculae
Open lattice of narrow plates of bone
-found in spongy bone
Diploe
Flat bone of the skull, two layers of compact bone
-found in spongy bone
Central canal
Cylindrical channel that lies in the Center of the osteon
-blood vessels and nerves
-compact bone
Concentric lamellae
Rings of bone connective tissue surrounding the central canal, and form osteon
-alternating collagen fibre directions give bone strength and resiliance
Osteocytes are housed in
Lacunae
Canaliculi
Tiny channels through bone connective tissue
-nutrients, minder all etc can pass thru the these passageways
Example: dentist story
Circumferential lamellae
-rings of bone that run the entire circumference of the bone itself
Parallel lamellae
Make up spongy bone
