Anatomy Flashcards
(43 cards)
What are the types of collagen?
- Type I: Bone, tendon, skin (OI, Ehlers-Danlos)
- Type II: Hyaline cartilage (chondrodysplasia)
- Type IV: Basement membrane (Alport syndrome)
OI: Osteogenesis imperfecta; GAG: Glycosaminoglycan.
What is the structure of collagen?
Triple helix (Gly-X-Y repeats), crosslinked by lysyl oxidase.
The structure is critical for its tensile strength.
What vitamin is required for collagen synthesis?
Vitamin C.
Hydroxylation defects can lead to scurvy.
What role do elastin and fibrillin play in the body?
Stretch/recoil in ligaments, aorta, skin.
Diseases related to these proteins include Marfan’s syndrome and cutis laxa.
What is aggrecan?
Major proteoglycan in cartilage with a ‘bottle brush’ structure.
It plays a key role in cartilage hydration and resilience.
What is the function of hyaluronic acid?
Non-sulfated GAG; contributes to synovial fluid viscosity.
It helps in lubrication and shock absorption in joints.
What are the two main types of joints?
- Synarthroses: Immovable (skull sutures)
- Diarthroses: Synovial joints (knee, hip)
Each joint type serves different functions in mobility.
What is the composition of articular cartilage?
- Type II collagen (60% dry weight)
- Aggrecan
- Water (80%)
This composition is vital for the cartilage’s mechanical properties.
What are the zones of articular cartilage?
- Superficial: Lubricin (boundary lubrication)
- Middle: High PG/water content (shock absorption)
- Deep: Radial collagen fibers (anchors to bone)
Each zone has distinct functions and structural characteristics.
What is the role of the synovium?
- Type A cells: Phagocytic
- Type B cells: Hyaluronic acid production
The synovium is crucial for joint health and function.
How is normal synovial fluid characterized?
WBC <200/mm³, glucose ≈ serum, viscosity (string sign).
These parameters help assess joint health.
What are the two main types of bone?
- Cortical: 80% skeleton (long bone shafts)
- Cancellous: Vertebrae/pelvis (osteoporosis-prone)
The distribution of these types affects bone strength and health.
What is the Wnt/β-catenin pathway’s role in bone biology?
Osteoblast activation (↑ bone mass).
Inhibitors like sclerostin and Dkk-1 are targets for osteoporosis treatment.
What does the RANK/RANKL/OPG pathway regulate?
Osteoclast differentiation.
RANKL from osteoblasts/T cells activates osteoclasts; OPG blocks RANKL.
What distinguishes Type 1 muscle fibers?
Slow-twitch, oxidative (endurance).
These fibers are more fatigue-resistant and are utilized in prolonged activities.
What distinguishes Type 2b muscle fibers?
Fast-twitch, glycolytic (sprinters).
These fibers are designed for short bursts of power and speed.
What triggers muscle contraction?
Ca²⁺ release → actin-myosin crosslinking → sarcomere shortening.
This process is essential for muscle function.
What are common collagen disorders?
- Osteogenesis imperfecta (Type I)
- Ehlers-Danlos syndrome (Types I/III)
- Alport syndrome (Type IV)
These disorders affect connective tissue integrity and function.
What enzymes are involved in cartilage degradation?
- MMPs (collagenases)
- Aggrecanases (ADAMTS-4/5)
These enzymes are often elevated in osteoarthritis.
What is osteoporosis associated with?
Wnt/RANKL dysregulation.
This condition leads to increased fracture risk due to decreased bone density.
What is Paget’s disease characterized by?
↑ osteoclast activity.
Bisphosphonates are often used to target RANKL in treatment.
Nennen Sie die 5 Hauptkomponenten des Bewegungsapparates.
Muskeln, Sehnen, Bänder, Knorpel, Knochen.
Welche zwei Hauptfunktionen hat das muskuloskelettale System?
Strukturelle Unterstützung und gezielte Bewegung.
Welches ist das häufigste Protein im Körper?
Kollagen (20-30% der Körpermasse).
