Cartilage and Bone Flashcards
Where does connective tissue originate from?
The mesoderm. (paraxial)
Classification of connective tissues
Ordinary (proper) includes
- Loose/dense
- Regular/irregular
Special includes
- Cartilage
- Bone
- Blood
Most abundant protein in the human body
Collagen
Provides tensile strength
Secreted into the extracellular space
How many types of collagen
- Most common are 1, 2,3, 4, and 7
Tropocollagen
Amino acid monomer secreted by ___ and binds together to form a polymer, which is collagen.
Organization of collagen from collagen molecule to tendon unit
Collagen molecule- collagen fibril- collagen fiber- collagen fascicle- tendon unit
Fibrous collagen types
Type 1- most common. Dermis, ligaments, bone, and cornea.
Type 2- Think cartilage. Hyaline cartilage (which is articulating surfaces of bones, nose, and trachea)
Type 3- Reticular collagen. Meshwork in highly cellular organs (liver, spleen, kidney)
Collagen found in epithelial basement membranes
Type 4- 2D matrix that forms the basal lamina, mesh-like.
Type 7- Basement membrane anchoring fibrils
The 2 types of connective tissue fibers
Elastin (E) and microfibrils (M, ML)
Where do you find elastin?
Found where you want tissues to stretch, like your elbows and knees. Amorphous polymer of tropoelastin, which is similar to how collagen is produced.
Problem- Doesn’t lay down well in the extracellular matrix. Needs a scaffold for it to grow, which is composed of microfibrils.
Role of microfibrils
Structural scaffolding of elastin. Supports elastin deposition.
Fibril forming molecules
Fibrillin- scaffold for elastin deposition.
fibronectin- Helpful when closing gaping wounds.
Most common cartilage in human body
Hyaline Cartilage- can be found in the rib cage, trachea, bronchi, long bones, and joints
Costal cartilage
Hyaline cartilage of rib cage
Where is the only place that you can find hyaline cartilage without perichondrium
Joints
Where in the body can you find hyaline cartilage
Rib cage, trachea, bronchi, joints (without pericardium) and long bones
Elastic cartilage
Hyaline + elastic cartilage
Where can you find elastic cartilage
Outer ear and epiglottis
***Hyaline and elastic cartilage contain what type of collagen
2- where chrondroblasts and chondrocytes reside
Except the perichondrium has type 1 collagen (contains fibroblasts)
Fibrocartilage cartilage contains which type of collagen
Contains both fibroblasts and chondroblasts and chondrocytes together. Happy family. Therefore, there is not a perichondrium. As if the perichondrium is mixed in
Has properties of regular connective tissue and cartilage.
Allows flexibility and strength.
Hybrid between true cartilage and true connective tissue.
Contains type 1 and type 2 collagen
**The fibrous layer of the perichronidrum in hyaline and elastic cartilage specifically contains which type of collagen
Type 1
Where can you find fibrocartilage
Outer layer of intervertebral disc, called the annulus fibrosus
Ligaments
Lines inside/fills extra space of foramen lacerum, where sympathetic innervation enters. Sympathetic innervation hitches a ride with the internal common carotid that enters the carotid canal nearby.
Cell types in the bone
Osteoblasts- giveth
Osetocytes- maintenance
Osteroclasts- taketh away
Bone types
Compact (cortical)
Cancellous AKA trabecular/spongy
