Joints
JOINT- A place where two or more bones meet.
1. Fixed or Immoveable JointsThe bones at an immoveable joint cannot move - they overlap or interlock, and are held together by a tough fibre, e.g. the skull.
2. Slightly Moveable JointsThe bones at a slightly moveable joint can only
move a little - they are held together by strong straps called ligaments and are joined by protective
pads known as cartilage, e.g. the ribs.3. Freely Moveable JointsAt a freely moveable joint the bones move
freely.They are also known as synovial joints, andare the largest group of joints found in the
body, e.g. the hips, shoulders and knees.
Types of Joints
There are 3 main types of joint found in the body.
CLASSIFICATION OF JOINT BY STRUCTURE
Fibrous: Have no cavity and are held together by fibrous connective tissue – e.g. the sutures of the skull bones
Cartilaginous: Also have no cavity. There is cartilage between the bones of the joint. May be found between the vertebrae of the spine
Synovial: Has a fluid filled cavity surrounded by an articular capsule. The articulating surfaces are covered in hyaline cartilage – e.g. the hinge joint of the knee
CLASSIFICATION OF JOINT BY MOVEMENT
Fibrous or synarthrosis: Does not allow any movement, which makes more sense when you know where in the body they occur, as they supply protection – e.g. for the brain
Cartilaginous or amphiarthrosis: Allows only limited movement
Synovial or diarthrosis: Is freely moving, as much as the shape of the articulating surface will allow.
JOINT / MOVEMENT TYPES
Joint type Shape of joint Movement range Body place : articulating bones
Ball + socket ball shaped bone fits 3 axes F/E AB/AD R C hip : femur, acetabulum of pelvis into cup shaped socket shoulder : scapula, humerus
Hinge convex and concave 1 axis F/E knee : femur, patella, tibia surfaces fitting together elbow : humerus, radius, ulna
Pivot ring shaped surrounding 1 axis R spine / atlas : odontoid process of axis a cone (turns head from side to side) elbow : proximal ends of radius and ulna
Condyloid modified ball and socket 2 axes F/E AB/AD C knuckle joints of fingers : metacarpals, giving circumduction phalanges
wrist : radius, carpals
Saddle shaped like a saddle 2 axes F/E AB/AD C joint at base of thumb : carpal, giving circumduction metacarpal
Gliding two flat gliding surfaces a little in all directions centre of chest : clavicle, sternum wrist : carpals
ankle : tarsals spine : articulating surfaces of vertebrae
In the picture below the ball and socket joint at the hip allows the player to get height and then the ball and socket joint at the shoulder allows him to SLAM DUNK!!
Hinge joint (the elbow) in use taking a set shot
The knee (HINGE JOINT) is used when flexing (bending) and extending (straightening) the
leg to kick a football
Spin bowling requires a complex movement of the wrist joint – what type of joint?
Bowling underarm involves extension and flexion of the shoulder – what type of joint?
RELATIONSHIP of MUSCULAR SYSTEM to SKELETAL SYSTEM
NAMES OF MAJOR MUSCLE GROUPS
Example : biceps
ORIGIN (static end) : coracoid process / glenoid fossa tubercle of humerus
INSERTION (moving end) : tuberosity of radius
FASCI Aconnective tissue
exam ple : epim ysium
LI GAMEN TSattach bone to boneexam ple : knee jo int
cruciate ligam ents
TEN DON Sattach m uscle to bone
via PER I O ST EUMexam ple : ach illes tendon
PER I OSTEALLAYER S
attach tendons to bone
M USCULARATTACHM ENTS
APON EUR OSI Sa flattened ribbon
shaped tendon
Cartilage, Tendons, Ligaments: What’s the difference?
Cartilage Tendons Ligaments
ToughAttaches bone to muscle
Attaches bone to bone
Flexible Sturdy Elastic
At end of bone Non elastic Stabilise
CushionsSize changes depending on muscle
Made of many fibres
Anchor Strong
Types of Synovial Joints
KEY
Ball & Socket JointHinge Joint
Pivot Joint
Gliding Joint
Saddle Joint
Condyloid Joint
Freely moveable (synovial) joints can be divided into six groups depending upon how they move.
Joints
Synovial Joints
• The articular capsule is a fibrous tissue encasing the joint, forming a capsule
• The synovial membrane acts as a lining to the joint capsule and secretes synovial fluid
• The articular/hyaline cartilage covers the ends of the articulating bones
• Synovial fluid fills the joint capsule nourishes and lubricates the articular cartilage
Joints
Synovial Joints• Ligaments are white fibrous connective
tissues joining bone to bone, making the joint more stable
• Bursa is found where tendons are in contact with bone. It forms a fluid filed sac between the tendon and bone and helps reduce friction
• Articular discs of cartilage act as shock absorbers
• Pads of fat act as buffers to protect the bones form wear and tear
Synovial Joints
Ligament
Cartilage
Ligament
SynovialFluid
Pelvis
SynovialMembrane
Capsule
Femur
Hip Joint
Ball-and-Socket Joint• hip• shoulder
Condyloid Joint• between
metacarpals and phalanges
8-9
Gliding Joint• between carpals• between tarsals
Hinge Joint• elbow• between phalanges
8-10
Pivot Joint• between
proximal ends of radius and ulna
Saddle Joint• between carpal
and metacarpal of thumb
8-11
• ball-and-socket• head of humerus• glenoid cavity of scapula• loose joint capsule• bursae• ligaments prevent displacement• very wide range of movement
8-15
Shoulder Joint
• hinge joint• trochlea of humerus• trochlear notch of ulna• gliding joint
• capitulum of humerus
• head of radius• flexion and extension• many reinforcing ligaments• stable joint
8-17
Elbow Joint
• ball-and-socket joint• head of femur• acetabulum• heavy joint capsule• many reinforcing ligaments• less freedom of movement than shoulder joint
8-19
Hip Joint
• largest joint• most complex• medial and lateral condyles of distal end of femur
• medial and lateral condyles of proximal end of tibia
• femur articulates anteriorly with patella
• modified hinge joint• flexion/extension/little rotation 8-21
Knee Joint
• strengthened by many ligaments and tendons
• menisci separate femur and tibia
• bursae
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