1. Introduction of MSK Flashcards
Examples of MSK DISORDERS
Osteoporosis (loss of bone usually age-related)
Osteomalacia (poor mineralisation, lack of vitamin D)
Bony metastases (esp. breast and prostate)
Rheumatoid arthritis
Osteoarthritis
3 FUNCTIONS of MSK system
- SUPPORT for other organs
- PROTECTION
- MOVEMENT
METABOLIC FUNCTIONS of BONE (3)
- a STORE for MINERALS especially CALCIUM
- HAEMOPOIESIS : production of BLOOD CELLS and PLATELETS from bone MARROW
- ENDOCRINE: OSTEOCALCIN hormone in bone, made by OSTEBLASTS
which HORMONE is found in BONE and what does it do
OSTEOCALCIN
improves body’s ability to handle sugar and keep fat mass low
approx TOTAL CALCIUM and IONISED CALCIUM in BONES
approx total: 2.4 mM
approx Ionised: 1.2 mM
MUSCLE ACTIVITY (EXERCISE) leads to: (4)
- INCREASED VENOUS RETURN (flow of blood back to heart)
- IMPROVED muscle INSULIN SENSITIVITY (more glucose uptake)
- RELEASE of MYOKINES (cytokines from myocytes)
- IMPROVED SERUM LIPID PROFILES (blood test that measures the amount of cholesterol and triglycerides in your blood)
MUSCOSKELETAL TISSUES (7)
- MUSCLE
- TENDON
- LIGAMENT
- HYALINE CARTILAGE
- FIBROCARTILAGE
- BONE
- SYNOVIUM
MUSCLE
Major mechanical function?
Composition?
- CONTRACTION
- HIGHLY CELLULAR
- very LITTLE ECM
TENDON
Major mechanical function?
Composition?
- RESIST UNIAXAL TENSION
- mainly COLLAGEN I
- SMALL amount of PROTEOGLYCAN
LIGAMENT
Major mechanical function?
Composition?
- RESIST TENSION
- mainly COLLAGEN I
- some PROTEOGLYCAN
TENDON BINDS..
MUSCLE to BONE
LIGAMENT BINDS…
BONE to BONE
HYALINE CARTILAGE
Major mechanical function?
Composition?
- RESIST COMPRESSION and TENSION
- COLLAGEN II
- PROTEOGLYCAN & WATER
FIBROCARTILAGE
Major mechanical function?
Composition?
- RESIST COMPRESSION and TENSTION
- COLLAGEN I & II
- PROTEOGLYCAN & WATER
BONE
Major mechanical function?
Composition?
- RESIST COMPRESSION & TENSION
- COLLAGEN I
- MINERAL - HYDROXYAPATITE (a naturally occurring mineral form of calcium apatite/calcium phosphate)
SYNOVIUM
Major mechanical function?
Composition?
- LUBRICATION
- mainly CELLULAR
which COLLAGEN is the MOST ABUNDANT collagen found in CONNECTIVE TISSUES including SKIN, TENDON, and BONE TISSUE
COLALGEN I
which COLLAGEN PRIMARILY makes up CARTILAGE
COLLGEN II
what make up ECM (extracellular matrix) of CONNECTIVE TISSUES (2)
GROUND SUSTANCE
glycosaminoglycans & proteoglycans
FIBROUS PROTEINS
- elastic fibre
- collagen fibre
- reticular fibre
RESIDENT CELLS in CONNECTIVE TISSUE
Mesenchymal cell
Macrophage
Adipocyte
Fibroblast
CONNECTIVE TISSUES (MESENCHYMAL TISSUES) provide…
STRUCTURAL & METABOLIC SUPPORT to OTHER TISSUES
CONNECTIVE TISSUES consist of
CONNECTIVE TISSUE CELLS EMBEDDED in a LARGE AMOUNT of EXTRACELLULAR MATRIX
what is SKELETAL/STRIATED MUSCLE
highly cellular, contractile tissue
3 TYPES of JOINTS
- FIBROUS JOINTS
- CARTILAGINOUR JOINTS
- SYNOVIAL JOINTS
FIBROUS JOINTS are
FIXED
CARTILAGINOUS JOINTS
LIMITED MOVEMENT
SYNOVIAL JOINT
FREELY MOVEABLE
SYNOVIAL JOINT
- joint capsule
- SYNOVIUM/SYNOVIAL MEMBRANE (lines inside of joint capsule)
- ARTICULAR CARTILAGE
- FIBROCARTILAGE
- synovial fluid
how does TENDON CONNECT to BONE
through SHARPEY’S FIBRES
TENDON
- HIGH TENSILE STRENGTH
- TRANSMITS MUSCULAR CONTRACTION to MOVEMENT OF BONE
- PARALLEL BUNDLES of DENSELY PACKED COLLAGEN FIBRES
- UNIAXAL force (single axis, 1 DIRECTION)
- connects to bone through Sharpey’s fibres
- some tendons have important ELASTIC properties
TENDONS are comprised of
PARALLEL bundles of DENSELY packed COLLAGEN fibres
FORCES in TENDONS (Axis)
UNIAXIAL
FORCES in LIGAMENTS (axis)
MULTIAXIAL
what do MULTIAXIAL FORCES of LIGAMENTS mean for the ligament
not so highly organised parallel bundles
ARTICULAR CARTILAGE is a…
HYALINE CARTILAGE
ARTICULAR CARTILAGE is..
function…
smooth, white tissue that covers the ENDS of BONES where they come together to form joints
provide a SMOOTH, LUBRICATED SURFACE
what do we have at ARTICULAR SURFACE
FLATTENED CHONDROCYTES
CONSEQUENCE of LOSS of ARTICULAR CARTILAGE
NO PROTECTION from wear & tear
BONE BREAKS DOWN / RUB TOGETHER
leads to OSTEOARTHIRITIS
what is SYNOVIUM / SYNOVIAL MEMBRANE
- Specialised connective tissue
- lines inside of joint CAPSULE
- DELICATE tissue which is hard to identify but can become THICKENED in DISEASES such as rheumatoid arthritis
SYNOVIUM / SYNOVIAL MEMBRANE produces…
COMPONENTS of SYNOVIAL FLUID
including HYLURONIC ACID
SYNOIVUM/ SYNOVIAL MEMBRANE consists of 2 CELL TYPES:
- FIBROBLASTS
- MACROPHAGE-LIKE cells
what is BONE
SPECIALISED form of CONNECTIVE TISSUE designed to withstand HIGH COMPRESSIVE LOADS
by the inclusion of mineral in the fibrous matrix
- STORE for MINERAL IONS particularly CALCIUM
LONG BONES ARE COMPOSED OF
Cylindrical Shaft: DIAPHYSIS
connected to Expanded Ends via EPIPHYSES
joined by METAPYSES
SHELL of COMPACT BONE surrounds the…
MEDULLARY / MARROW CAVITY
what happens in the MEDULLARY / MARROW CAVITY
SITE of PRODUCTION of BLOOD CELLS in immature animals - RED MARROW
becomes progressively REPLACED by ADIPOSE TISSUE -YELLOW MARROW
the OUTER SURFACE of bone is COVERED BY…
(except at articular surfaces)
which is composed of…
PERIOSTEUM (periosteal surface)
- This tissue is composed of an
INNER LAYER of OSTEOGENIC CELLS
and an OUTER FIBROUS LAYER
INNER LAYER of PERIOSTEUM
OSTEOGENIC CELLS
OUTER LAYER of PERIOSTEUM
FIBROUS LAYER
the INNER SURFACE of BONE (including all trabecular surfaces) are covered by ..
the ENDOSTEUM
(endosteal surface)
- a CELLULAR LAYER
what OCCUPIES the MEDULLARY CAVITY at the METAPHYSIS
SPONGY BONE
2 FORMS of BONE
- COMPACT BONE
high proportion of bone with few spaces - SPONGY/CANCELLOUS/TRABECULAR BONE
n which there is a low proportion of bone and a lot of space
SPONGY/CANCELLOUS/TRABECULAR BONE is composed of…
a network of rods and plates called TRABECULAE
BONE MATRIX
- Type I collagen, bone proteoglycan and some non-collagenous proteins osteocalcin, osteonectin
- Mineral, hydroxyapaptite, a complex calcium phosphate salt
in BONE MATRIX, COLLAGEN can be laid down into distinct patterns: (2)
- WOVEN BONE
- LAMELLAR BONE
what is WOVEN BONE
an IMMATURE form with RANDOM fibre orientation,
laid down during RAPID GROWTH and FRACTURE REPAIR (callus)
what is LAMELLAR BONE composed of
SUCCESSIVE LAYERS of COLALGEN FIBRES
with DISTINCT orientation.
what is the main form of BONE FORMATION and GROWTH
ENDOCHONDRAL OSSIFICATION
- BONE REPLACES existing CARTILAGE model
what does BONE ADAPT TO
LOADING
- WOLFF’S LAW
what are OSTEOBLASTS
cells that PRODUCE NEW BONE
what is an OSTEOID
NEW BONE MATRIX
- NOT YET MINERALISED
what are OSTEOCLASTS
DEGRADE/RESORB BONE
- to initiate normal bone remodelling
how does BONE MASS CHANGE with AGE
DECREASES
(peak around 30 years old)
(women- bone loss due to menopause)
