1 Basic Concepts Flashcards
What are the 3 major components with a similar developmental origin?
Bone
Skeletal muscle
Connective tissues
What are the functions of bone?
Support Protection Metabolic (Ca, P) Storage (fat) Movement Haematoopoeisis
What are the functions of skeletal muscle?
Locomotion Posture Metabolic (store glycogen) Venous return Heat production Continence
What are tendons?
Contain lots of collagen, little elastin
Don’t stretch much
Connect muscle to bone
What are ligaments?
Support bone to bone
What are fascia?
Sheets of connective tissue
Used for compartmentalisation of muscle
Protection
Superficial fascia fatty
What is the role of articular cartilage in bone?
Hyaline cartilage
Slippery to decrease friction
Blue/grey
What is the role of fibrocartilage in bone?
Shock absorption
Increase bone congruity
Stronger than articular
Found in knee
What is the role of the synovial membrane?
Secretes synovial fluid for joint and tendon lubrication
What is the bursa?
Synovial fluid-filled sacs to protect tendons, ligaments etc from friction
Why is CaPO4 present in ECM of bone/connective tissue?
Calcified
Gives bone strength
Contributing to compressive strength
What is the role of collagen in ECM of bone?
Gives high tensile strength
What are the roles of osteoblasts?
Build bone
Lay down osteoid
What are the roles of osteoclasts?
‘Macrophage’ of bone
Dissolve away bone to liberate Ca2+
Multinucleated
What are osteocytes?
Trapped osteoblast in bone
Detect force owing through bone
What are the 5 types of bone?
Long bone Short bone Flat bone Irregular bone Sesamoid bone
What are long bones for?
Good lever
What are flat bones for?
Protection
What are short bones for?
Work together to perform task
With many together, gives points of attachment for ligaments and tendons
What are sesamoid bones for?
Form within tendons to protect tendons
What are bony prominences for?
Muscle attachments
Size indicates what kind of muscle attaches, whether it’s powerful or not
What are the 5 surface features of bones?
Bony prominence
Grooves - related to nerves
Fossa - depressions for bone prominence to sit
Notch - for nerves
Foramen - holes for nerves and blood vessels
What is avascular necrosis?
Bone dies due to deprivation of blood supply, particularly important in fractures of the scaphoid and neck of femur
What are the 2 important things to consider with joints?
Range of movement
Stability
What are the 3 classes of joints?
Fibrous - move least
Cartilaginous
Synovial - move most
What are fibrous joints?
Collagen fibres joining bones
Very limited mobility
Found where great strength/stability are required
What are cartilaginous joints?
Cartilage acts as glue holding bones together
Limited mobility
Found at ends of growing bones or along midline of adult body (intervertebral discs)
What are synovial joints?
Separate bones are capped by smooth articular cartilage with a thin film of synovial fluid separating them
Frequently highly mobile
Found all over skeleton
What are the types of synovial joint?
Plane Hinge Pivot Saddle Condyloid Ball and socket
How do synovial joints develop?
Bone is made from a cartilage template, surrounded by perichondrium
Some cartilage cells die off and create a space between 2 bones
Incomplete apoptosis occurs so ligaments are formed across the gap
Perichondrium is a continuation of the periosteum which goes around the joint
What are the 3 classes of levers?
First-class lever - lifting chin up, scissor motion Second-class lever - standing on tip toes, wheelbarrow motion Third-class lever - holding object in hand and bringing towards body, tweezer motion
What is the origin?
Usually the stationary proximal anchor point
What is the insertion?
Usually the mobile distal attachment point
What happens if the insertion point is fixed?
Origin and insertion are inverted
Can muscles pull or push?
PULL ONLY
But don’t always shorten
What is concentric contraction?
Muscle pulls while shortening
E.g. biceps curl
What is eccentric contraction?
Muscle pulls while lengthening
E.g. knee extensors walking downhill
What is isometric contraction?
Muscle pulls while staying same length
Where are muscles found?
Within fascial compartments
Compartments have one nerve and blood vessel suppling the whole muscle
What are the 5 types of muscles?
Parallel - lengthen lots, not powerful Fusiform - more muscle fibres Circular (sphincter) Triangular - diversity in action Pennate (feather shaped) - don’t shorten much, very powerful
What causes skin creases?
Adhesion of skin to underlying fascia
What is the aponeurosis?
Tissue that slides over underlying tissues
Rich in collagen
E.g. on scalp
