BMC L12 Flashcards
State the 3 types of adult human cartilage
- Elastic
- Hyaline
- Fibrocartilage
Describe the structure of hyaline cartilage
Amorphous matrix contains chondrin - gelatinous / rubbery substance
Chondrin contains condroitin sulphate
holds incompressible water -
negatively charged sulphates repel one=another to RESIST COMPRESSION, therefore, CUSHIONING
State where hyaline cartilage is found
Adults - Nose, respiratory tract, ribs, articular surface of bones
Fetus: in skeleton, before replaced by bone
Describe the structure of elastic cartilage
Amorphous matrix contains protein fibres
FIBRES: collagen, elastic fibre networks, therefore, this cartillage is more elastic than hyaline cartilahe
elastic fibres are ELASTIN
ELASTIN: elastic protein, provides flexibility + strength
FLEXIBLE BUT MAINTAINS SHAPE
YELLOW
Where is elastic cartilage found?
Externeal ear (pinna)
Walls of external auditory canal
Epiglottis
Larynx
Describe the structure of fibrocartilage
Amorphous matrix contains protein fibres
Fibres: collagen
COLLAGEN: resists tension / stretching
Why is fibrocartillage resistant to stretching?
Amorphous matrix conatins protein fibres
Protein fibres = collagen
Collagen arranged in bundles, all point in specific direction, therefore, resist stretching, compression, shearing (SLIDING / TEARING)
HIGH TENSILE STRENGTH
SHOCK ABSORBING
What is the most abundant type of cartillage?
Hyaline cartillage
State where fibrocartilage is found
Intervertebral disks
Menisci of knee
State the role of the perichondrium
Fibrous sheath surrounding cartilage except where cartilage merges
Contains blood vessels
BODY OF CARTILAGE IS AVASCULAR
Does fibrocartillage have a perichondrium layer? Explain your answer
No
Perichondrium is a sheath surrounding cartilage except from where it merges
Fibrocartilage merges into hyaline cartilage
What are the implications of cartilage being avascular?
Perichondrium contains blood vessels
Body of cartilage - avascular
NO BLOOD SUPPLY TO BODY OF CARTILAGE
AFFECTS FUNCTION, GROWTH, ABILITY TO HEAL
Limited ability to heal: NO DIRECT BLOOD SUPPLY, cells that repair cartilage, including chondrocytes, recieve nutrients and oxygen through diffusion from surrounding tissues rather than direct blood supply
Limited growth potential - lack of blood vessels = poor nutrient supply
Describe the blood supply of the cartilage
Supplied by blood vessels of:
- Perichondrium
- Synovial fluid
Describe the structure of fibrocartilage in the intervertabral disks
Annulus fibrosus - Layers of fibrocartilagein between the intervertebral disks in the spinal cord
Nuclues pulposus: Watery, (works like air in tire)
Intervertebral disks can resist lots of compression
Why can intervertebral disks resist a large amount of compression
-contain fibrocartilage
-in fibrocartilage, amorphous matrix conatins protein fibres
-fibres are collagen
-collagen provides tensile strength, resists tension / stretching - shock absorbing
-thereforee, resists compression
-the annulus fibrosus layer of fibrous cartilage in the intervertebrel disk
-nucleus pulposus - watery
State the 2 types of bones
- compact
-spongy
State the functions of bones
- Support
-Protection
-Leverage
-Storage of fats, minerals
-Synthesis of blood cells (RBC, WBC)
Bone anatomy
Diagram L12
Cartilage
Epiphyseal line
Spongy bone
Compact bone
Bone marrow
Nutrient foramen
Nutrient vessel
Endosteum
Periosteum
Medullary cavity
State the 5 divisions of bones
- Long bones - humerus, femur, radius
- Short bones - carpals, tarsals
- Flat bones - sternum, cranium, scapula
- Irregular bones - vertebra, facial
- Sesamoid bones
What is the difference between sesamoid bones and other divisions of bones
Sesamoid do not share joints with other bones - they “float”
Examples include:
patella
hyoid bone of larynx
Describe the structure of a bone
DIAGRAM L12
Epiphysis - END
-spongy bone, red marrow
-compact bone, articular cartilage
Diaphysis - Middle
compact bone
medullary cavity contains yellow marrow (fat)
lined with endosteum (squammus epithelium)
Periosteum
membrane of connective tissue - covers enter outer surface of bone except epiphysis
Endosteum
-COVERS INERNAL BONE SURFACE
-THIN LAYER OF CONNECTIVE TISSUE
-OSTEOGENIC: contains osteoprogenitor cells
How is the periosteum attached to the bone?
Periosteum is secured to the bone via Sharpey’s fibres