Lab 6: General Skeletal System Flashcards
Number of bones
206
Main divisions of the bones of the skeleton
Axial Skeleton (80 bones)
Appendicular Skeleton (126 bones)
Axial Skeleton
skull, vertebral column, sternum, ribs
Appendicular Skeleton
bones of the appendages (arms and legs), and the girdles that connect the appendages to the axial skeleton
Various Connective Tissue Types
-
Connective Tissue Proper
- Adipose
- Dense Regular
- Cartilage
-
Osseous
- Spongy
- Compact
-
Blood
- Red Bone Marrow
Shapes of Bones
- Long
- Short
- Flat
- Sesamoid
- Sutural (Wormian)
- Irregular
Examples of long bones
- humerus
- radius
- ulna
- metacarpals/ metatarsals
- tibia
- fibula
- femur
Examples of short bones
- carpals
- tarsals
Examples of flat bones
- cranium
- ilium
- sternum
Examples of pneumatized bones
“air pockets”
- maxilla
Examples of sesamoid bones
- patella
Examples of sutural (wormian) bones
“fused”
-skull
Examples of irregular bones
- vertebrae
- mandible
- coxal bones
- most abundant
- collagen fibers too thin to see
- resists stretching
- Found at: Articular end of bones
Hyaline Cartilage
- matrix has elastic fibers
- tolerates repeated bending
- Found in: epiglottis and ears
Elastic Cartilage
- Resists twisting and compression
- hylaine + dense CT
- alternating rows of collagen and chondrocytes
- Found in: intervertebral discs, meniscs, pubis symphysis
Fibrocartilage
Types of osseous tissue
Compact & Spongy bone
- Concentric Lamellae
- Spongy Bone
- Canaliculi
- Lacuna
- Osteocyte within lacunae
- Periosteum
- Haversion (central) Canal
- Osteon
- Volkmann’s Canal
- Proximal Epiphysis
- Diaphysis
- Distal Epiphysis
- Epiphyseal line
- Spongy bone
- Medulary Cavity
- Endosteum
- Periosteum
- Articular Cartilage
Growth of bone or cartialge due to the addition of bony matrix or cartilage to the outer surface (deep to the periostuem)
Inceases the bone organ in width
Appositional Growth
“little canals” that connect lacunae and osteocytes to each other
Canaliculi
Immature cartilage cell (responsible for matrix production)
Chondroblast
Mature cartilage cell (usually trapped in lacunae)
Chondrocyte
Canal lined with endosteum to supply blood vessels, lymphatics, and nerve to bone
Haversian (central) Canal
Enlargement of cells
Hypertrophy
Cartilage growth due to mitosis of chondrocytes (may occur along epiphyseal plate of long bone to increase bone length)
Interstitial Growth
A small cavity (often houses cartilage or bone cells)
Lacunae
Concentric rings or tubes of bone matrix
lamellae
Embryonic connective tissue cell (gives rise to all other CT)
mesenchymal cells
process of bone formation
Ossification
immature, matrix producing bone cell
Osteoblast
Cells that act to reabsorb or breakdown bone tissue
osteoclasts
mature bone cell (usually trapped in lacunae)
Osteocyte
(Haversian System) The functional and structural unit of compact bone. They consist of tiny structural “pillars” made of concentric rings or tubes of bone
Osteon
Tiny, needle-like bits of bone (connect to form trabeculae)
Spicules of bone
A thick, fibrous connective tissue layer surrounding the entire external surface of bone, with the exception of the articular surface
Periosteum
A cellular membrane lining the spicules, trabeculae, canals, and medullary cavity of bone
Endosteum
Microscope components of Dense Regular CT
- fibroblasts
- collagen fibers
Microscope components of Fibrocartilage
- collagen fibers
- chondrocytes within lacunae
- matrix
Microscope components of Compact Bone
- osteons
- osteocytes within lacunae
- Haversian (central) canals
- Lamellae
- Canaliculi
Microscope components of Spongy Bone
- osteoblasts
- osteocytes within lacunae
- red bone marrow
- trabeculae
- endosteum
Microscope components of Intramembranous Ossification
- osteoblasts
- osteocytes
- mesenchymal tissue
- developing bone spicules/trabeculae
- endosteum
Microscope components of Endochondral Ossification
- Hyaline catilage model
- Hypertrophied chondrocytes
- Developing bone spicules/trabeculae
- Endosteum
- Periosteum
- Osteoblasts
- Osteocytes
STEP 1 Intramembranous bone development
mesenchyme → mesenchymal cells differentiate into osteoblasts → osteoblasts secrete matrix → osteoblasts surrounded by matrix become osteocytes trapped in lacunae → spicules formed → spicules unite to form spongy bone (endosteum forms around spongy bone) → remodeling of spongy bone forms compact bone (periosteum forms around bone)
STEP 1 Hyaline Cartilage Model Development
mesenchyme → mesenchymal cells differentiate into chondroblasts → chondroblasts secrete matrix → chondroblasts surrounded by matrix become chondrocytes trapped in lacunae → cartilage model formed, surrounded by perichondrium
STEP 2 Endochondral bone development
Hyaline cartilage model (STEP 1) → blood vessels of perichondrium bring in osteoblasts to form perosteum collar → hypertrophy and death of cartilage cells at primary ossification center → invasion of blood vessels and osteoblasts at primary ossification center → bone begins to replace cartilage (osteoblasts form spicules) → formation of secondary ossification center in epiphysis → bone replaces cartilage at 2° ossification center → hyaline cartilage remains in the epiphyseal plate (until growth completed) and on the articular surfaces (for life)
Dense Regular CT
Fibrocartilage
Compact Bone
Spongy Bone
Intramembranous Ossification
Endochondral Ossification
