Skeletal Flashcards
What is the function of the skeletal system?
Support (Form internal framework that supports and anchors organs), Protection (protect soft body organs), Movement (powered by muscles which use bones as levers), Storage (fat is stored bones, minerals as well), Blood cell formation (haematopoesis within marrow filled bones)
What are the different shapes of bones?
Long (humerus), Short (carpals of wrist), Flat (parietal bone) and Irregular (vertebrae)
What are the 3 main structures of the bone and where do they sit?
Osteoblasts (build bone by clinging to each other and canaliculus) Osteocytes (build and reform bone and sense stressors and sit in lacuna). These both sit in lacunae. Osteoclasts (resorb and breakdown)
What differs osteoclasts and osteoblasts?
Osteogenic cells found in periosteum and endosteum.
What is the bone development prenatal?
Hyaline cartilage is broken down and built on by collar, the centre hypertrophies signals matrix to calcify collar , periosteal bud supplies nutrients and other cells (clasts erode cartilage matrix and blasts create spongy bone), bone lengthens creating centre, ends ossify and keeps budding until only hyaline left at ends
What is the bone development postnatal?
Is the growth in width, grows wide responding to load, becomes one of clast (cleaving) and blast (building) of bone and carries on under influence of hormones
What is the structure of a long bone?
Diaphysis(shaft), Epiphysis (ends), Epiphyseal plate (growth), Periosteum (outer layer linked in tendons), Endosteum (covers marrow), Articular cartilage (covers ends of bone -hyaline), Medullary cavity (in shaft contains yellow marrow-forms all types of blood-), Red marrow (in ends producing red blood cell), Spongy bone (open framework contained red marrow), Compact bone (hard structure), Sharpeys fibres (collagen fibre linked to periosteum)
What is the structure of a compact bone?
Osteons arranged in concentric ring like structure, contains holes for blood vessels and nerves, formed concentric lamellae, lacunae the spaces containing osteocytes, cannaliculi (channels with connect lacunae allow nutrient network), Central canal (run lengthways in osteon), perforating canals (pathway from o/s bone to haversian canal), Haversian system (towers with bone salts that align with collagen fibres)
What is the structure of spongy bones?
Compact looks more organised than spongy, trabeculae (struts that lay on lines of stress), no osteons, nutrition via diffusion through canaliculi from capillaries to endosteum
Why does remodelling occur?
In injury or change needed, if it remains too long bones become brittle
How does remodelling work?
Formation of Hematoma, Fibrocartilaginous callus forms, bony callus forms, bone remodels.
How does the homeostasis of Ca work?
Rising ca, thyroid gland releases calcitonin which stimulates calcium salt deposit in bones restoring to normal.
Low ca, parathyroid gland releases parathyroid hormone, where osteoclasts degrade bone matrix releasing ca into blood.
What are the characteristics of cartilage?
Mainly water, no nerves/blood vessels, surrounded by dense irregular CT , the higher the pressure the thicker the collagen
What are the 3 types of cartilage?
Articular (smooth joint- hyaline), Fibrocartilage (tough, mostly in invertebral discs) and Elastic (yellow, external ear, epiglottis)
What is the function of the Articulations (joints)?
To hold bones together allowing rigid skeleton to become somewhat flexible
What are the factors that influence joint stability?
Shape of surface (trochlear grooves), Tendons (provide stability and blend in periosteum), Synovial Tendon Sheaths (wrap around tendons to decrease wear and tear), Menisci (type of disc that divides joint in 2), Fat pods (fat cushioning in fibrous sack), Bursae (sack filled with synovial fluid), Ligaments (number location and direction), muscles (origin, insertion, location and tone)
What are the catagories of movement for joints?
Synarthroses (immobile), Amphiarthroses (Slightly mobile), Diathroses (freely mobile)
What are the catagories of structure for joints?
Fibrous (no joint cavity), Cartilaginous (united by cartilage), Synovial joint (fluid in capsule)
What are the types of fibrous joints?
Suture (short CT, ossifies as Synostosis immobile-skull sutures), Syndesmosis (connected by ligament, immobile-distal tibiofibular or slightly mobile- radio ulnar), Gornphosis (peg in socket, immobile-teeth)
What are the types of cartilaginous joints?
Synchondrosis (united by bar/plate/hyaline cartilage- first rib and manubrium), Symphysis (hyaline cartilage fused by pad/plate of fibrocartilage, shock absorbers - invertebral discs)
What are the characteristics of Synovial joints?
Articulating bones separated fluid filled cavity, freedom of movement, Diarthroses, provide locomotion and generalised movement
What are the features of the Synovial joints?
Hyaline cartilage to slide on opposing bones, articular capsule that folds over itself containing synovial membrane, synovial fluid with lots of phagocytes and slippery viscous fluid that decreases friction, when joint compressed fluid weeps and when resting reabsorbed, joint cavity and reinforcing ligaments
What are the catagories of synovial movement?
Nonaxial (gliding movements only), Uniaxial (Movement in 1 plane), Biaxial (movement in 2 planes) and Multiaxial (movement in 3 planes)
What are the types of movement?
Gliding (1 bone slips over another - intercarpal, intertarsal), Angular (increase angle between 2 bones - flexion and extension), Rotation (turning bone around long axis- hip/shoulder)
What are the 6 synovial joint catagories?
Plane, Hinge, Pivots, Condyloid, Saddle, Ball and Socket
What are the characteristics of plane joint?
articular surface glide over each other, nonaxial, side to side and back and forth- carpal/tarsal bones
What are the characteristics of Hinge joint?
1 bone fits into concave of another, unixial, flexion/extension-humerus with ulna
What are the characteristics of pivot joints?
Rounded, pointed or conical surface of 1 bone, Articulates in ring form partly by another bone and partly by ligament, monoaxial, provides rotation- ulna with radius
What are the characteristics of condyloid joints?
oval shaped condyle of 1 bone fits into elliptical cavity of another bone, biaxial, side to side and back and forth-Metacarpal and Phalanx or radius and carpals
What are the characteristics of saddle joint?
1 bone shaped like saddle and other shaped like riderm biaxial, side to side and back and forth- carpal and metacarpal #1
What are the characteristics of ball and socket joint?
ball like surface fits into cuplike depression of other, triaxial, flexion/extension-shoulders and hips
