Human Structure – Histology – Connective Tisue and Bone – Flashcards
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Unlock answersBasic Features of Cartilage |
Perichondrium – Surrounds all cartilage Matrix – Extracellular matrix Lacunae – Cavities within the matrix which correlate to where condrocytes are housed |
Basic, Specialized Functions of Cartilage |
1. Resistance to Compression 2. Smooth Areas for Reduced Friction with movement |
Typical form of Collage found in Cartilage |
Type II (Resists Compression) |
Differences between ECM of Cartilage and "Regular" CT |
1. Collogen Type (II vs. I) 2. Increased ratio of GAG's to Collogen |
The glycoproteins of ground substances serves what purpose? |
These are adhesion molecules which connect cells, ECM, and other materials together in Cartilage. |
Describe Hyaline Cartilage |
1. Found in fetus or growth plates of long bones 2. Resists compression (found in Trachea) 3. Reduces Friction (Cartilage found in Nose, Ribs |
Types of cells found in synovial fluid. |
1. Modified Fibroblasts 2. Macrophages |
Pathology behind Osteoarthritis |
Chondrocytes produced inflamatory cytokines, which recruit WBC's
This in turn causes: inhibition of collagen and proteoglycan synthesis and stimulates metalloproteases. |
Pathology behind Rheumatoid Arthritis |
Inflamation of the synovial membrane due to WBC and cytokine recruitment. Causes the thickening of the synovial membrane. This reduces the motion of the joint and recruits metalleoproteases which degrade bone and cartilage. |
Describe Elastic Cartilage |
Function: Flexible support
Structural Difference: Elastic fibers found in the matrix. |
Appositional Growth Entails:
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Litterally means "Growth Next To:"
In perichordium, the outer fibrous layer has Type I Collogen Fibroblasts, which differentiate into chondrogenic in the inner cellular layer. These become chondroblasts and then chondrocytes (once entrapped in a Lacunae) |
Interstitial Growth Entails: |
Occurs when chondrocytes in Lacunae undergo mitosis, which produce a new matrix. |
Differnces of Fibrocartilage to other cartilages: |
(1) No perichondrium (2) Relatively little matrix (3) Has Type I Collagen
Found in areas with lots of sheering / tensile stress |
Bone has two components, inorganic and organic, what is in each and what is the precentage of each? |
Inorganic - Calcium (supplies density to bone), composes 65% of bone (can vary from 40% to 90% depending on bone)
Organic - Collage (90-95% of organic part), Proteoglycans, Sialoproteins, Glycoproteins, composes ~35% of bone |
What role do Proteoglycans play in bone? |
Resist Compression Forces
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What role do Sailoproteins play in bone? |
Bind cells to the matrix |
What role do Osteonectin and Osteocalcin play in bone? |
These are glycoproteins which bind collagen to the matrix. |
Describe compact bone |
The enternal surface of a bone.
Used for support
Cortical, Dense, any spaces are occupied by blood vessels. |
Describe Spongy Bone |
Porous
Lighten's the bone ; Accomodates the marrow |
Describe the basics of the Periosteum |
Outer, fibrous layer ; similar to;dense regular;CT Inner cellular layer ; osteogenic cells (bone lineage committed cells) Endosteum ; single cell layer responsible for bone repair or growth |
What type of cell and what is the function of cells within the Periosteum /Endosteum (Bone-Lining Cells) |
Osteoblasts or Osteoprogenitory (Ambiguous) ; Provide nutrition to osteocytes and produce osteoid. |
What are Sharpey's Fibers? |
Bundles of Type I collagen that bind the periosteum to the bone. |
Identify the structures labeled below: [image] |
A - Haversion Canal B - Osteon |
What is contained within a Haversion Canal? |
A blood vessel |
What are concentric lamellae? |
Concentric layers of bone surrounding a Haversion Canal. |
What are Canaliculi? |
Little canals found in the concentric Lamellae, which have a source at the Haversion canal.
These allow for cell communication and nutrient supply. |
What is a Volksmann's Canal? |
A perpendicular canal (similar to a Haversion canal) which connects the blood supplies of the Haversion Canals. |
How;are nutrients and O2 supplied to Hyaline Cartillage. |
Diffusion thru the extensive ECM, large ratios of GAG's facillitate this movement. |
Locations of Hyaline Cartilage |
Trachea Rings Nasal Cavity Cartilages Costal Cartilages of Rib Cage |
Locations of Elastic Cartilage |
Pinna of External Ear Auditory Tube Cartilages of Larynx (Epiglottis, Corniculate and Cuneiform Cartilages)
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Locations of Fibrocartilage |
Intervertebral Discs Symphysis Pubis Menisci Insertions of Tendons |
Why is fibrocartilage used in the areas it is present instead of other cartillage and fibers? |
This is a combination of Dense Regular CT and Hyaline cartilage.
Contains Type I and II collagen fibrils, which is more resistant to compression, sheering, or tensile forces. |
What kind of living structures would you expect to find in a Haversion Canal? |
Blood Vessels |
What kind of structures would you expect to find in a Volkmann's Canal? |
Blood Vessels |
What kind of structures would you expect to find in Canaliculi? |
Cytoplasmic projections of an Osteocyte;for movement of waste, nutrients, and cell signalling. |
What is the functional role of an osteoclast ruffled border? |
Increases surface area, allows for increased exchange rates |
What are Interstitial Lamellae? |
Layers of bone that do not belong to a Osteon |
What is the Outer Circumflexial Lamellae? |
Layer of bone on the exterior surface, which forms a collar around the bone (plays a major role in development) |
What are Inner Circumflexial Lamellae? |
Differenly patterned lamellae which encircle the marrow cavity of bone. |
Osteoblast Functions: |
1. Secret Osteoid 2. Mineralized bone 3. Recruit and Formation of Osteoclasts 4. Binds Free Calcium |
Identify the tissue below and the structures labeled. [image] |
Hyaline Cartilage A - Chondrocyte B - Territorial Matrix C - Interterritorial Matrix D - Lacunae |
Identify the tissue in the upper left of the slide and the labeled items. ;[image] |
Perichondrium (CT) A - Chondroprogenitor Cell B - Chondroblast |
Identify the tissue below: [image] |
Elastic Cartilage |
Identify the major tissue in the slide below, and the tissue surrounding it. [image] |
Center - Elastic Cartilage Surrounding - Perichondrium |
Identify the tissues below: [image] |
A - Hyaline Cartilage B - Elastic Cartilage |
Please give a name to the slide below which describes both its preparation and tissue. ; Identify the labeled items. [image] |
Ground Bone A - Haversian Canal B - Lacunae C - Haversian Canal D;- Circumferential Lamellae E - Canaliculi F - Interstitial Lamellae |
Please give a name to the slide below which describes both its preparation and tissue. [image] |
Decalcified Compact Bone |
Why do canaliculi evident in decalcified bone? |
The decalcification process removes all soft tissues, because canaliculi are projections of a osteocyte's cytoplasm it is degraded. |