Flashcards
Th3L08 Cartilage and bone
Cards in this deck (58)
- 1Describe the main characteristics of the cartilage matrix: (4)* Electro-osmotic
* Deformable (semi-rigid)
* Permeable (to water and small molecules)
* Generally lacks blood vessels - 2How does cartilage enlarge?Via interstitial growth
- 3What is the main collagen found in cartilage?Type II
- 4What is type II collagen like? (2)* Very thin fibrils dispersed between proteoglycan molecules so that they do not clump together
* Characteristic cross-banding
- 5What is the composition of cartilage (%)?75% water, 25% organic
- 6What are the major organic components of collagen II (60%)?GAGs (40%) coupled to proteins to form proteoglycans (negatively charged) which attracts sodium ions (osmotic, suck water in with them)
- 7Describe the main characteristics of the bone matrix: (3)* Rigid
* Impermeable (need a blood supply)
* Bones enlarge via appositional growth
- 8What is the main collagen found in bone?Type I
- 9What are the main functions of the bone? (5)* Support
* Protection
* e.g. cranium, thoracic cage
* Systems of levers
* Contains bone marrow
* Reservoir of calcium, phosphate and ions - 10What are the two main characteristics of cartilage?Pliant and load-bearing
- 11What is cartilage covered in?Perichondrium
- 12What are exceptions to cartilage always being covered in perichondrium?Junctions with bones and other articular surfaces of synovial joints
- 13How does cartilage grow?interstitial and appositional growth
- 14How does cartilage grow via appositional growth?Fibroblasts in perichondrium give rise to chondrocytes capable of it
- 15How does cartilage grow via interstitial growth?Fibroblasts in matrix give rise to chondrocytes capable of it
- 16What are the three types of cartilage?Hyaline, white fibrous, yellow elastic
- 17What is the most common cartilage?Hyaline
- 18What is hyaline cartilage composed of?Abundant collagen fibres, rubbery matrix
- 19What is foetal skeleton composed of?Entire hyaline cartilage
- 20Where is hyaline cartilage found?Between tips of ribs and bones of sternum, covering bone surfaces at synovial joints, supporting the larynx, trachea and bronchi, part of the nasal septum
- 21Where is elastic cartilage found?Auricle of the ear, epiglottis, auditing tube cuneiform cartilage of larynx
- 22Where is fibrous cartilage found?Pads within knee joint, between pubic bones of the pelvis, IV discs
- 23What is fibrous cartilage resistant to?compression
- 24What are chondrocytes?Bone cells that synthesise and secrete all the major components of the cartilage matrix
- 25What are chondrocytes filled with?rough ER, transport vesicles, Golgi, mitochondria and lysosomes
- 26What are inactive chondrocytes?Mature cells where the nucleus becomes heterochromatic, nucleolus smaller and protein synthetic material becomes reduces
- 27Where may inactive chondrocytes accumulate?In large lipid droplets
- 28What is hyaluronon?A GAG that lacks a protein core and is synthesised by enzymes on the surface of chondrocytes
- 29Why does hyaluranan lack a protein core?It is not modified post-synthetically
- 30What is the rate (generally speaking) of collagen turnover?Slow
- 31What is collagen vulnerable to?Non-enzymatic glycation
- 32What is non-enzymatic glycation?Makes collagen yellow, stiff and vulnerable to injury
- 33What are the mesenchymal bone cells? (4)Osteoprogenitor cells, osteoblasts, osteocytes, bone-lining cells
- 34What are osteoproginetor cells?Mesenchymal, fibroblast-like bone cells that serve as the stem cell for next generation of osteoblasts
- 35Where are osteoproginetor cells found? (2)* Found in spongy bone near blood vessels
* Found in compact bone at periosteum and endosteum
- 36What are osteoblasts?Mesenchymal bone cells responsible for deposition of osteoid (organic components of bone matrix)
- 37Where are osteoblasts found?On the surface of bone
- 38What kind of cell do osteoblasts resemble?secretory cells
- 39How do osteoblasts deposit osteoid?Induce mineralisations through the secretion of matrix vesicles that contain alkaline phosphates
- 40What is the role of alkaline phosphate?Neutralise the inhibitory effects of pyrophosphate on calcium deposition
- 41What are osteoblasts in contact with?Desmosomes and gap junctions
- 42What are osteocytes?Bone cells with numerous canals (canaliculi) that radiate outwards and contain the cells processes to permit diffusion of substances through the bone
- 43Where are osteocytes found?In lacunae as a result of mineralisation in them
- 44What do osteocytes contain?Contain a nucleus and thin ring of cytoplasm but very few other organelles
- 45How do osteocytes cooperate within one another?Coordinate and communicate via gap junctions
- 46What are the main roles of osteocytes? (3)* Calcium homeostasis
* Responsive to mechanical forces
* May mediate mechanically adaptive bone remodelling by acting as strain receptors - 47What are bone lining cells?Undifferentiated, flattened cells that may be inactive osteocytes or may function in ion exchange
- 48Where are bone lining cells found?Located on surface of bone where they are not being remodelled
- 49What are the haemopoeitic bone cells?Osteoclasts
- 50What are osteoclasts?Highly motive, haemopoeitic bone cells involved in resorption (dissolving bone and returning its minerals to the blood stream) of bone
- 51Where are osteoclasts found AND what does it help them do?In resorption cavities (Howship's lacunae) what allows them to contribute to bone remodelling and calcium homeostasis
- 52What is the lineage of osteoclasts?Monocyte/ macrophage
- 53Describe how osteoclasts look: (5)* Variable size/shape from small mononuclear cells to multinucleated
* Foamy, striated appearance known as a ruffled border
* Ruffled boarder of osteocytes
* Tightly packed with microvilli
* Clear zone around them forms a tight seal with the bone surface
- 54Describe the organelles found in osteoclasts?* Mainly contain mitochondria throughout the cytoplasm
* ER less prominent than in osteoblast
* Prrominent Golgi, esp. perinuclear
* Many vesicles, some with acid phosphatase
- 55What is the functionality of the osteoclast ruffle border?* Protons are secreted from ruffled border of osteoclasts
* Acidify the sub-osteoclastic space and demineralise the matrix
* Organic components of the matrix are then degraded by lysosomal enzymes - 56What are osteoclasts inhibited by?Calcitonin
- 57How are osteoclasts influenced by the parathyroid hormone?Stimulates osteoblasts to release inducts of osteoclast differentiation
- 58How are Haversian systems formed? (3 steps)* Osteoclast tunnel through pre-existing bone (old osteons)
* Tunnel is invaded by blood vessels and osteoprogenitor cells
* Osteoblasts lay down successive bone lamellae on walls of tunnel
Information
- Description
- Medicine Y1 (Theme 3 | Tissues and systems) Flashcards on Th3L08 Cartilage and bone , created by Emma Allde on 09/09/2016.
- Created by
- Emma Allde
- Views
- 0
- Rating