1. Joints of the human body

2. Joints Of The human body
Joint Classification
Synovial Joints
Characteristics of synovial joint
Types of synovial joints
Naming joints:
Pectoral Girdle
Upper Limb
Pelvic Girdle
Lower Limb

3. Joint is a point of connection between two bones
Strands of connective tissue, ligaments, hold the bones together and ensure the stability of joints

4. JOINT CLASSIFICATION Synarthroses - Immovable
Joints are classified according to their motion capabilities:
Three terms
Synarthroses - Immovable
Amphiarthroses - Slightly movable
Diarthroses - Allow the greatest amount of motion

5. Joint Classification
Joints are further classified by the material that joints them:
Fibrous joint
-allow no movement
-E.g. sutures of the skull
Cartilaginous joints
-allow limited movement
-E.g. inverterbral discs
Synovial joints
-allow large range or movements
-E.g. hip joint

6. Characteristics of synovial joints
Hyaline cartilage
A protective layer of dense white connective tissue that covers the ends of the articulating bones
Joint Cavity
Synovial Membrane
Covers joint cavity, except over the surfaces of the articular cartilages
Secretes the lubrication fluid
Synovial Fluid
Lubricates the joint
Capsule
May or may not have the thickenings called intrinsic ligaments
Extrinsic ligaments
Support the joint and connect the articulating bones of the joint

7. Types of sYNovial Joints
There are thee basic types of synovial joints:
Unilateral (rotation only about one axis)
Biaxial joints (movement about two perpendicular axes)
Multiaxial Joints (movement about all three perpendicular axes

8. Types of Synovial joints cont’d
Synovial Joints are further classified into:
1) Hinge joint
2) Pivot joint
3) Condyloid
4) Saddle shaped joint
5) Ball and socket joint
6) Plane joint

9. Hinge (ginglymus) Joint
Uniaxial
Has one articulating surface that is convex, and another that is concave
E.g. Humero-ulnar elbow joint, interphalangeal joint

10. Pivot Joint
Uniaxial
E.g. head of radius rotating against ulna

11. Condyloid (knuckle) joint
Biaxial (flexion-extension, abduction-adduction)
The joint surfaces are usually oval
One joint surface is an ovular convex shape, and the other is a reciprocally shaped concave shape surface
E.g. Metacarpophalangeal Joint

12. Saddle Joint Biaxial (flexion-extension, abduction- adduction)
The bones set together as in sitting on a horse
E.g. carpometacarpal joint of the thumb

13. Ball and socket joint Multiaxial ( rotation in all planes )
A rounded bone is fitted into a cup = like receptacle
E.g. shoulder and hip joints

14. Plane (gliding) Joint Uniaxial (permits gliding movements)
The bone surfaces involved are nearly flat
E.g. intercarpal joints and acromioclavicular joint of the vertebrae

15. Joints of the pectoral girdle

16. Sternoclavicular joint
Connects sternum to the clavicle
The only joint connecting the pectoral girdle to the axial skeleton
True Synovial joint strengthened by an intracapsular disc and extrinsic ligaments

17. Acromioclavicular joint
Unites the lateral end of the clavicle with the acromion process of the scapula
Where shoulder separations often occur in sports such as hockey, baseball and football

18. Glenohumeral joint Connects the upper limb and the scapula
A Typical multiaxial joint
Has a wide range of movement at this joint
Compromise = relative lack of stability

19. Upper Limb Joints

20. Elbow Joint There are three joints at the elbow humero-ulnar joint
Medial (with respect to anatomical position)
Between the trochlea of the jumerus and the olecranon process on the ulna
Humero-radial joint
lateral
between the capitulm of the humerus and the head of the radius
Radio-ulnar joint
between the radius and the ulna

21. Elbow joint con’t

22. Joints of the wrist
Radio-carpal joint -between distal end of the radius and the carpals -movements : Flexion – extension and abduction – adduction

23. Joints of the HAND
Intercarpal joints -between the bones of the carpus -gliding joints Carpometacarpal joint -between carpals and metacarpals -the characteristics of the carpometacarpal joint of the thumb allows the range of movement necessary for opposition

24. Joints of the hand cont’d
Metacarpophalangeal joints -joint between metacarpals and carpals -the knuckles -movements : flexion-extension, and adduction-abduction Interphalangeal joints -joints between the phalanges -permit flexion-extension

25. Joints of the pelvic girdle

26. Hip joint
Between the head of the femur and the cup (acetabulum ) of the hip bone (os coxae) -Like shoulder joint, hip joint is: -ball and socket joint -multiaxial joint that allows : flexion- extension, adduction-abduction and circumduction

27. Hip joint con’t
-unlike shoulder joint, hip joint is very stable
-in fact it is the body’s most stable synovial joint due to
-deepened socket (via lip or fibrocartilaginous labrum)
-an intrinsic and very strong extrinsic ligaments
Dislocations in sports is not common, but can occur in car collisions
Dislocate the head posteriorly or drive it through the posterior lip of the acetabulum

28. Lower limb joints

29. Knee joint Tibiofemoral or knee joint Incredible range of movement
(flexion-extension)

30. Knee joint cont’d
However, the knee joint is relatively stable due to additional supports from:
Menisci
Shock absorbing fibrocartilaginous discs
Anterior and posterior cruciate ligaments
In the center of the joint
Lateral and medial collateral ligaments
Extending from the sides of the femur to the tibia and fibula
The musculature that surrounds it

31. Knee joint cont’d Movements:
Primary action is flexion – extension (e.g. squat or jump)
When flexed, medial and lateral rotation can also occur

32. Ankle Joint Talocrural or ankle joint Involves several bones:
Medial and lateral malleoli of the tibia and fibula
Head of the talus
calcaneus ( heel bone )

33. Foot and toe joints Intertarsal joints Between tarsals
Transverse tarsal joint
Between the proximal and distal row of tarsal bones
Movement – inversion- eversion of the sole of the foot
This action enables you to adjust to uneven ground when walking or running

34. Foot and toe joints cont’d
As in the hand, there are joints between the tarsal bones, metatarsals and phalanges.
Tarsometatarsal
Metatarsophalangeal
Interphalangeal
They are strengthened by planter ligaments which aid in maintaining the arch of the foot

35. Muscles of the human body

36. Over 600 in the human body
Allow the skeleton to move
To cause movement, both ends of each muscle must be attached to bone
Origin or proximal attachment – the attachment closer to the center of the body
Insertion or distal attachment – the attachment away from the center of the body

37. Facial muscles

38. Various functions of the facial muscles
Enable you to change expression and display your emotions outwardly
Allow you to close your eyes and blink
Essential for opening and closing the mouth for:
Keeping food in the mouth
Allowing you to chew
Allowing you to form words
Tongue
Function:
Allows you to move food around in your mouth and get it to a position to be swallowed
Allows you to pronounce words and speak intelligently

39. Neck muscles

40. Neck muscles
There are muscles posterior, lateral and anterior tot eh neck or cervical region
These muscles
Maintain the position in which the sits on the 1st cervical vertebra (atlas) i.e. they hold up our head
Also permit a wide range of movement

41. Sternocleidomastoids
The most important anterior pair of muscles
Movements:
Acting together, they flex the head toward the chest
Individually, each muscle tilts the face up and toward the opposite sid

42. Erector spinae muscles
Important posterior neck muscles
Attach to sacrum inferiorly and to the skull superiorly
Maintain your erect position
Therefore they are also called anti-gravity muscles
When someone faints, these muscles no longer function and the body falls face forward to the ground

43. Trapezius, upper fibres
Important lateral neck muscles
Movements:
Acting alone tilt the head to the same side
Acting together, they assist in neck extension