Musculoskeletal Flashcards
Give an example of a long bone.
Radius.
Also femur, tibia, fibula, humerus, ulna, metatarsals, metacarpals, phalanges.
Give an example of a short bone.
Tarsals (in the ankle).
Also carpals.
Give an example of a flat bone.
Scapula.
Also sternum, ribs, cranial bones.
Give an example of a sesamoid bone.
Patella.
Give an example of an irregular bone.
Vertebrae.
Also facial bones.
Give an example of a pneumatic bone (irregular and contains air filled spaces).
Maxilla.
Name the three regions of a long bone.
Epiphysis, (physis), metaphysis, diaphysis.
What is the other name for the primary cartilaginous joints and secondary cartilaginous joints?
Primary = synchrondroses. Secondary = symphyses.
What’s the difference between bipennate and unipennate muscles?
Unipennate muscles have fibres arranged obliquely and inserting on only one side of a tendon. Bipennate muscles have a central tendon with fibres converging on both sides like a feather.
What are the canals at the centre of osteons called? What are the transverse canals called?
Longitudinal = Haversian Transverse = Volkmann's
List the layers of connective tissue surrounding muscle.
Epimysium - dense connective tissue surrounding entire muscle belly
Perimysium - surrounds fascicles (groups of 10-100 muscle fibres)
Endomysium - surrounds sarcolemma of a muscle fibre
Sarcolemma - muscle cell membrane
What are T tubules?
Invagination a of the sarcolemma which carry the membrane depolarisation signal into the muscle cell for the excitation-contraction coupling.
What are three effects of hypercalcaemia?
Stones - renal stones causing colicky pain
Bones - bone pain from calcium resorption
Abdominal groans - abdominal pain from stones, pancreatitis and peptic ulcers
What are the five parts of a long bone?
Proximal epiphysis, physis, metaphysis, diaphysis [the shaft], (then distal metaphysis, distal physis, distal epiphysis).
There is also articular cartilage on the epiphysis, which reduces friction and absorbs shock.
What is the connective tissue called that surrounds the bone where it’s not covered by articular cartilage?
Periosteum.
What are the two layers of the periosteum?
Outer fibrous layer of dense irregular connective tissue.
Inner osteogenic layer of cells which allows bone to increase in width.
What are the thick bundles of collagen extending from the periosteum into the bone matrix called?
Sharpey’s fibres.
What is the advantage of the medullary cavity in the diaphysis which contains yellow bone marrow?
It minimises bone weight, but the tubular structure maximises bone strength.
What lines the medullary cavity?
Endosteum
Bone is comprised of cells in an extracelluar matrix, what are the two parts of the extracellular matrix?
Fibres and ground substance.
What proportion of the bone extracellular matrix is organic and what is it comprised of?
40% - Type 1 collagen fibres and other non-collagenous proteins
What proportion of the bone extracellular matrix is non-organic and what is it comprised of?
60% - hydroxyapatite (calcium, phosphate, other minerals)
What makes bone hard?
The crystallised organic mineral salts.
What makes bone flexible?
Type 1 collagen fibres provide tensile strength.
What are the four types of cells present in bone?
Osteogenic cells - bone stem cells derived from mesoderm, found in endosteum and inner periosteum
Osteoblasts - build bone, synthesise and secrete calcium and initiate calcification, form osteocytes when trapped in ECM
Osteocytes - mature bone cells in lacunae of osteons, maintain bone metabolism, projections extend to surface osteoblasts through cannaliculi.
Osteoclasts - derived from fused monocytes, large and multinucleate with ruffled border.
What are the two types of bone?
Spongy/trabecular/cancellous bone.
Compact bone.
What are osteons?
Rings of concentric lamellae surrounding a central Haversian canal (containing blood vessels, lymphatics, nerves). There are lacunae between the lamellae which contain osteocytes, and cannaliculi allowing lacunae to communicate with neighbouring osteoclasts and osteoblasts.
What are the transverse canals across the compact bone called?
Volkmann’s canals.
What are the remains of osteons that have been partially destroyed by bone remodelling called?
Interstitial lamellae.
Why are trabecular aligned along lines of stress?
They are organised for maximum resistance to compression.
What are the characteristics of spongy bone?
It doesn’t contain osteons.
It is always inside bones, protected by compact bone.
It contains lamellae irregularly arraigned as trabeculae.
Each trabeculae is concentric lamellae, with cannaliculi radiating from each lacunae.
What fills the spaces between trabeculae in cancellous bone?
Red/yellow bone marrow.
What are the 6 types of synovial joint?
1) Ball and socket - triaxial e.g shoulder and hip joint
2) Plane - biaxial/triaxial e.g intercarpal joints in wrist
3) Saddle - biaxial e.g carpometacarpal joint in thumb
4) Pivot - uniaxial (rotation around longitudinal axis) e.g between Atlas and Dens
5) Hinge - uniaxial (only flexion and extension) e.g knee
6) Condyloid - biaxial e.g radiocarpal joint in wrist
What type of muscle is orbicularis oculis?
Circular
What type of muscle has an origin wider than the point of insertion (e.g pectoralis major)?
Convergent
What are the two types of parallel muscle?
Fusiform - muscle belly wider than its origin or insertion e.g biceps brachii
Non-fusiform - muscle belly not wider so not spindle shaped e.g rectus abdominis
What are the three types of pennate muscles?
Unipennate - fibres insert in a diagonal direction onto only one side of the tendon e.g extensor digitorum
Bipennate - a row of muscle fibres insert diagonally onto each side of the central tendon like a feather e.g rectus femoris
Multipennate - central tendon branches into two or more tendons so there are multiple rows of diagonal fibres
