121c chpt1 bones

Chapter 1

BONES & JOINTS

Arthrology – Joints (10-13)

Study of joints Classification

Function Structure Movement

ClassificationStructure Movement Types

Syn-arthrosis

Fibrous Immovable SyndesmosisSutureGomphosis

Ampi-arthrosis

Cartilaginous Slightly movable

SymphysisSynchondrosis

Di-arthrosis

Synovial Freely movable

Plane – glidingGinglymus – hingeTrochoid – pivotEllipsoid – condyloidSellar – saddleSpheroid – ball/socket

TYPES OF SYNOVIAL JOINTS

Preferred name

Old Name Direction of Movement Examples

Plane gliding slide over one another -carpals -tarsals

Ginglymus hinge movement in one direction – flex/ext

-elbow –knee

Trochoid pivot rotational movement -C1/C2 -radioulnar joints

Ellipsoid condyloid movement in 2 directions - 90° to each other- flexion/extension - abduction/adduction

-2nd through 5th MCP jts -MCT jts, - wrist

Sellar saddle opposing surfaces are concavoconvex

-1st CMP jt. -calcaneal-cuboid jt,-ankle

Spheroid ball &socket

movement in all directionscircumduction

-hip-shoulder

Parts of a Synovial Joint Fibrous capsule

Encircles the joint Joint cavity

Space within the capsule Synovial tissue

Lines the joint cavity Synovial fluid

Viscous lubricating fluid to reduce friction produced by tissue Hyaline articular cartilage

Protects the ends of the bone making up the joint Accessory ligament

Give the joint stability See page 219 - knee ACL, PCL, Medial, Lateral

Osteology – bones (6-9)

Study of bones 206 bones Born with 300+ Axial – 80 Appendicular – 126

Classification

Long - radius, ulna, phalanges Short – carpal and tarsal Flat – scapula, sternum Irregular - vertebrae Sesamoid - patella

Function

1. Protection2. Support3. Movement - work as levers4. Hemopoises5. Reservoir

Parts of a long bone Body 2 bone ends Spongy Cancellous Periosteum Medullary cavity Endosteum Bone marrow

Red bone marrow – cancellous bone – bone ends Yellow bone marrow – in medullary cavity

Hyaline cartilage Nutrient artery Nutrient foramen

Ossification

Bone formation Intramembaranous - starts as a membrane –

found in places that are needed for protection – forms rapidly

Endochondral – starts as cartilage – found in long bones – forms slowly

Ossification cont

Totally formed at age 25 – last bone to form is the clavicle

Primary ossification centers Diaphysis

Secondary ossification centers Epiphysis & metaphysis Epiphyseal plate – between epiphysis and

diaphysis/metaphysis

Bone Cells Osteoblasts

On surface of bone cells Have processes and organelles Very active Secrrete a substance to make osteoid tissue “bone forming cells”

Osteocytes Developed osetoblasts Found within matrix “bone cell”

Osteoclasts On surface of growing tissue giant cells with many

nuclei and organelles Secrete substance that breaks down mineral salts Bone destroying cells

COMPACT BONE Microscopic – dense and formed into a Haversian

system – surrounds all bone System – parts

Lamellae – concentric, cylinder shaped layers of calcified matrix

Lacunae – “little lakes”, small spaces containing tissue fluid where osteocytes are located between the layers of lamellae

Canaliculi – canals that connect the lamellae to each other and then to the Haversian canal

Haversian canal – extend lengthwise through the center of each system – contain a lymph and blood vessel

Volkmann’s canal small channels that connect the Haversian systems

CANCELLOUS BONE

Meshwork of bone tissue – spongy in appearance

Forms the ends of long bones and the middle of flat bones

No Haversian systems Web-like arrangement of marrow filled spaces

separated by thin processes of bone called trabeculae

Located along the lines of stress placed on the bone

Enhances bone’s strength

PARTS of a BONE Condyle – rounded process Coracoid/coronoid – beak-like process Cornu – horn-like process Crest – ridge-like process Epicondyle – process above a condyle Facet – smooth surface for articulation Hamulus – hook-like process Head – expanded end of the bone – prox or distal Line – ridge-like process – smaller than a crest Malleolus – mallet or hammer like process Protuberance – bony projection Spine – sharp process Styloid – long pointed process – 3 in body Trochanter – Tubercle - Tuberosity

BONE DEPRESSIONS Fissure – cleft or groove Foramen – hole in a bone Fossa – pit , fovea or hollow Groove – shallow linear depression Meatus – tubular boney passage in a bone Sinus

A channel for venous blood An air filled cavity – within bone Fistula or channel

Sulcus – trench or fissure-like depression

FRACTURES

Partial Complete Simple – closed Compound – open Non-displaced – anatomic apposition Displaced – lack of apposition

FXs cont Incomplete

Chip Avulsion Greenstick Torus - Buckle

Comminuted butterfly

Complete Transverse Oblique Spiral

Specifically named Salter – epipyseal fx Bimallar, Trimallar Colles’ –distal radius– posterior angulation Smith – distal radius – anterior angulation

HEALING of a FRACTURE

4 steps 1. Blood escapes from ruptured blood vessels

an d forms a hematoma 2. Spongy bone forms in regions close to

developing blood vessels and fibrocartilage (COLLAGEN) forms in more distant regions

3. Fibrocartilage is replaced by a BONY CALLUS

4. Osteoclasts remove excess bone tissue, making new bone structure much like the original

BONE DISORDERS

Osteoporosis – bones become less dense Osteopetrosis – bones become more dense Paget’s disease – irregular thickening and

softening of the bone Osteomyelitis – infectious diseases of the

bone Osteomalacia - (Demineralization) bones

loose their calcium content and become soft

POSITIONING ROUTINES pg 36 Long bone

2 images – AP/PA – shows if things are medial or lateral Lateral –shows if things are anterior or posterior

90 degrees from each other include both joints

Joints – min 3 images - AP/PA, Lateral and Oblique Do not remove splints, BBs If fractured – support proximal and distal to fx site Radiograph each side separately if ordered bilateral Radiograph each exam separately if multiple exams are

ordered

POSTIONING cont One exposure per cassette when using

CR/DR Place marker on lateral aspect for an AP/PA Place marker on the anterior aspect for a

lateral Name blocker

Patient name Date of exam Institution Patient/exam identification number