Term
| What are the major functions of connective tissue? |
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Definition
Exists as
- Ground substance - water + GAGs
- Fibers - collagen
- Cells |
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Term
| What are some different types of connective tissue? |
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Definition
- Loose - acts as a filler
- Dense - gives tensile strength. Both come from fibroblasts
- Cartilage - from chondrocytes, cushions and supports
- bone and blood |
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Term
| What are componeHnts of ground substance? |
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Definition
water (mostly) + proteoglycans: Protein core + glucosamine/chondroitin/hyaluronic acid (GAGs). PGs form aggregates attached to a hyaluronic core
- Adhesion molecules - fibronectin, laminin |
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Term
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Definition
| A type of ground substance in cartilage with a high concentration of chondroitin bound to hyaluronic acid |
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Term
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Definition
Able to withstand trauma, primarily collagen and elastin
Type 1 collagen in bone, Type 2 in joints |
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Term
| What type of cells are in connective tissue? |
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Definition
- Loose and dense CT - fibroblasts (immature) and fibrocyte (mature)
- Cartilage - chondroblasts and chondrocytes
- Bone - Osteoblasts and osteocytes |
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Term
What are the kinds of cartilage?
What are characteristics of cartilage? |
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Definition
- Hyaline - covers ends of bones, allows free movement
- Elastic - many elastic fibers - ear, trachea
- Fibrocartilage - in between discs in vertebrae
- all cartilage is avascular, without nerves and lymphatic drainage. |
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Term
| How does synthesis of cartilage occur? |
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Definition
| - MMP inhibitor and PAI are actively produced, inhibiting metalloproteanases and plasmin. Collagen, PGs, and adhesion molecules can grow cartilage. |
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Term
| How does degredation of cartilage occur? |
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Definition
| MMP inhibitor and PAI are NOT produced, so proteases are produced instead. Plasmin is produced, which then activates MMPs. Plasmin, MMPs, and Aggrecanases break down PGs. |
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Term
| What are the functions of bones? |
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Definition
- Support - anchor for tendons
- Protect organs
- Movement
- Store Calcium and Phos
- form blood cells. |
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Term
| What are the axial and appendicular skeleton? |
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Definition
Axial - Skull, ribs, vertebrae
Appendicular - everything else |
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Term
| What is the structure of a long bone? |
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Definition
80% compact bone - type 1 collagen
20% trabecular bone - bone marrow |
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Term
| Where is red marrow found? |
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Definition
In flat bones - sternum, hips
In the epiphysis of long bones |
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Term
| What is the structure of compact bone? |
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Definition
Organic - osteoblast/clasts/cytes. Type 1 collagen
Inorganic - mineral salts made from calcium
Lamellae - contain mature osteocytes
Haversian/central canals - arteries/veins/nerves |
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Term
| What are the functions of cells within the bone? |
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Definition
- Osteoblasts - bone deposition, combine Ca2+ and Phos to form hydroxyapatite crystals within collagen
- Osteoclasts - bone resorption usually due to D3 and PTH signalling
- Osteocytes - most abundant, trappen within lacunae |
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Term
| What 3 molecules promote/are involved in bone resorption? |
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Definition
- RANK - receptor activator for NFkB (inflammatory)
- RANKL - ligand for RANK
- OPG - binds to and inactivates RANKL - stops bone resorption
RANK + RANKL = osteoclasts. RANKL upregulated by TNF and IL-1 |
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Term
| What effects do PTH and D3 have on bones? |
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Definition
- PTH - turns osteoblasts into osteoclasts, increased expression of RANKL, decreased OPG --> increased bone resorption
- D3 - Active D3 increases circulating calcium, absorption of calcium, and reabsorption of calcium. Bone reabsorption. No active D3 --> extra PTH |
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Term
| What is necessary for osteoclast action on bone? |
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Definition
Integrins act as adhesion molecules, are necessary and can be interfered with.
RANKL/RANK lead to activation. |
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Term
| On the anterior view of the skull, what are the major bones? |
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Definition
Biggest - Frontal
To the left - Parietal. Beneath the parietal is the temporal. Nasal on top of the nose. Jaw = mandible. Zygomatic in between frontal and temporal bones. |
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Term
| On the posterior view of the skull, what are the major bones? |
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Definition
Top - parietal bones
Bottom -occipital bone |
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Term
| What does a herniated disk look like? |
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Definition
| In a herniated disc, the annulus (outside) of the cartilage has broken or worn away, and the nucleus is now compressing the nerve. |
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Term
| what sign in the arm is seen in arthritis? |
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Definition
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Term
| What is the meniscus of the knee made of? |
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Definition
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Term
| Where is the calcaneus and what does it do? |
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Definition
| On the heel, connects the achilles tendon |
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Term
| What are the different kinds of joints? |
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Definition
- Fibrous - synarthrosis, no cartilage and lacks mobility. Skull
- Cartilagenous joints - amphiarthrosis - joined by cartilage, lack cavity and mobility. Vertebrae
- Synovial - diarthrosis - cartilage, separate space containing fluid, freely movable. |
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Term
| What cells make up the synovium? |
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Definition
Type A macrophage-like cell (1/3) engulfs material. Produces prostaglandins, cytokines, and growth factors.
Type B cells - fibroblast-like (2/3)
Fluid in the synovium nourishes cartilage, contains hyaluronic acid |
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Term
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Definition
| A sack of fluid found between the bone and the tendon, lubricates the area. |
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Term
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Definition
| Nerves ennervate all parts of the joint except cartilage. Pain is associated w/ inflammation - release of mediators makes nerves more sensitive to painful stimuli |
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