Skeleton and joints Flashcards
What cell constructs cartilage
Chondroblasts - secrete ground substance and collagen to form a rigid gel.
Why is cartilage generally thin?
Gets metabolites from diffusion as no neurovascular elements are present in cartilage
Wha are the functions of bone?
Movement
Protection
Haemopoesis - principle blood cells are formed in the bone marrow
Storage of calcium and phosphorus
What are the shapes of bones + examples
Long (femur) Flat (sternum) Short (trapezoid) Sesamoid (patella) Irregular
Periosteum
Connective tissue that envelopes bones except at joints.
How does trabecular bone tissue help bones deal with forces
Forces funnelled down towards the mature (hard, dense) bone, like a network of struts.
What are the origins of bone?
Endochondral ossification, intramembranous ossification
Head
Expanded end of the epiphysis, separated from shaft by narrow neck.
Neck
Narrow connection between epiphysis and diaphysis, also called diaphysis
Condyle
Smooth rounded articular process
Trochlea
Smooth grooved articular process, shaped like a pulley.
Facet
Small flat articular surface
Process
Bump
Ramus
Extension of the bone at an angle to the rest of the structure
Trochanter
Large projection
Tuberosity
Projection
Tubercule
Small projection
Process
Projection
Crest
A prominent ridge
Line
A low ridge
Fossa
Shallow depression
Sulcus
A narrow groove
Foramen
Hole
Fissure
Cleft
Meatus/canal
Passageway through the bone
Sinus/antrum
Chamber
What are the types of joints?
Fibrous = united by collagen (skull sutures) no movt
Cartilaginous (primary = first rib, secondary = between hips at pubic symphesis) little movt
Synovial = fluid filled cavity wide range of movt
Describe the formation of cartilage
Cartilage is formed by chondroblasts which secrete ground substance and collagen to form a rigid gel.
Once formed they remain in situ as condrocytes
What is the difference between chondrocytes and chondroblasts?
Chondroblasts secrete ground substance and collagen to form a rigid gel in the formation of cartilage, once formed they remain in situ as chondrocytes
How does the amount of cartilage change from foetus to adult
Much of foetal skeleton is preformed as hyaline cartilage; in adult cartilage remains in articular surfaces + in areas where rigidity and elasticity are required.
What types of joints are there?
Fibrous (united by collagen)
Cartilagenous (united by cartilage)
Synovial (fluid filled cavity)
What are the types of fibrous joints?
Sutures (no movt)
Symphoses (a little movt)
Gomphoses (a little movt, like a shock absorber)
What are the types of sutures?
Squamous (straight line)
Serrated (wavy)
Denticulate (waves in waves)
Give an example of a symphoses
Between ulna and radius, allows for a little movement in pronation/supination
Give an example of a gomphoses
Between jaw and tooth, acts as a shock absorber
What are the types of primary cartilagenous joints?
Synchondroses
Describe a synchondroses
Develops between bones of endochondral origin, solid plate of hyaline cartilage acting as an epiphyseal plate between primary and secondary ossification centres of long bones. Provide areas of growth
Describe a symphesis
Partially moveable joint - opposing surfaces covered in hyaline cartilage separated by fibrous tissue or fibrocartilage.
Found in midline of the body.
Describe the parts of a synovial joint
Hyaline cartilage covers the articular surface of each bone. A synovial membrane lines the interior of a joint capsule (which is continuous with the periosteum) it produces a small amount of synovial fluid.
Sometimes a disc may be present to act as a shock absorber.
Also there may be bursae, sacs of synovial fluid
What are bursae?
Sacs of synovial fluid
What are all the different shapes of joints?
Hinge Pivot Ball + socket Saddle shaped Ellipsoid Condyloid Plane
Uniaxial joint
Moves in one plane only
Biaxial joint
Moves in two planes
Nonaxial joint
Small bones that can just move in all directions
Why is the synovial joint so useful for movements
The shape of the articulations
The tension of joint capsule
Position of ligaments
Position of muscles surrounding joint