Joints Articulation or Arthrosis

1
Joints- Articulation or Arthrosis

• Point of contact between
• Two bones
• Bone cartilage
• Bone teeth
• Arthrology- Study of joints
• Kinesiology- Study of motion of the human body

2
Classification of Joints

• Structural Classification based on the
  anatomical features (morphology)
• Functional Classification based on the type of
  movement they permit.

3
Structural Classification

• Based on
• Presence or absence of space between
• the articulating bones (synovial cavity)
• The type of connective tissue that binds
• the bone togather.

4
Type of Joints

• Fibrous joints The bones are held together by
  connective tissue that is rich in collagen fibers
  there is no synovial cavity.
• Cartilaginous Joints The bones are held together
  by cartilage there is no synovial cavity.
• Synovial Joints Have synovial cavity
  surrounded by connective tissue capsule.

5
Functional Classification

• Synarthrosis An immmovable joint
• Amphiarthrosis A slightly movable joint
• Diarthrosis A freely movable joint. All synovial
  joints. They have variety of shapes permit
  several different types of movements.

6
Fibrous Joints

• No cavity between Articulating Bones
• Articulating Bones are held together very closely
  by fibrous connective tissue (CT)
• 1- Sutures thin layer of dense CT between bones,
  e.g. skull bones
• 2- Syndesmoses The fibrous tissue is in the form
  of a sheet (interosseous membrane) or bundle
  (ligament).
• 3- Gomphoses Cone shaped peg fits into a
  socket, e.g. teeth their sockets

7
Fibrous Joints
(b) syndesmoses
(c) Gomphoses
8
Cartilaginous Joints

• No Cavity between Articulating Bones
• Articulating Bones are tightly connected by
  hyaline cartilage or fibrocartilage.
• 1- Synchondroses Epiphyseal plate of long bones-
  connect the diaphysis epiphysis of a growing
  bone
• 2- Symphysis Bones are connected by a broad flat
  disc of fibrocartilage. All symphysis occur in
  the midline of body.
• e.g., Manubriosternal joint, intervertebral joints

9
Cartilaginous Joints
10
Synovial Joint

• Synovial joint cavity space between articulating
  bones
• Articular cartilage covers the articular
  surfaces.
• Articular capsule surrounds the joint
• Synovial membrane inner lining of the capsule.
  It secretes syonovial fluid
• Synovial fluid lubricates the joint reduces
  friction, absorbs shocks supply nutrients.
• Accessory ligaments articular discs

11
Synovial Joint
12
Torn Cartilage

• The tearing of articular disc in the joint is
  called torn cartilage. (knee joint- menisci)
• Menisectomy surgical removal of the damaged
  meniscus.
• Arthroscopy (-scopy observation) This minimally
  invasive procedure uses a lighted pencil-thin
  instrument to examine the interior of the joint.
  It determines the nature extent of damage

13
Nerve Blood Supply

• Same nerves vessels supply the joint, those
  supply the surrounding skeletal muscles that move
  the joint.
• 2 type of nerves
• A) carry pain information from joints to CNS.
• B) nerve fibers which are concerned to the degree
  of movement stretch at a joint.

14
Sprain Strain

• A Sprain forcible twisting of a joint that
• stretches or tear the ligament,
• no dislocation of bones
• (damaged ligament)
• A Strain stretched or partially torn muscle
• (damaged muscle)

15
Bursae Tendon Sheaths

• Bursae
• Sac like structures
• Alleviate friction between skin bone, tendons
  bones, muscles bones, and ligaments bones.
• Tendon sheaths
• Tube like bursae that wrap around muscle tendons.
• Bursitis inflammation of bursa

16
6 Types of Synovial Joint

• Planar joints nonaxial
• Hinge joints uniaxial
• Pivot joints uniaxial
• Condyloid joints biaxial
• Saddle joints biaxial
• Ball Socket joints Multiaxial

17
Planar Joint

• Flat or slightly curved surfaces move against
  each other allowing sliding or gliding without
  any circular movement. This happens in the
  carpals in the wrist the tarsals in the ankle.

18
Hinge joint

• A convex surface of one bone fits into a
  concave depression in another permitting only
  flexion and extension as in the elbow and knee
  joints.

19
Planar Hinge Joints
20
Pivot joint

• Rounded or conical surface of one bone articulate
  with a ring formed partly by another bone
  partly by a ligament. An example is the joint
  between the axis and atlas in the neck the
  radioulnar joint.

21
Condyloid joint

• Also called an ellipsoidal joint. In this type an
  oval- shaped projection of one bone fits into the
  oval- shaped depression of another bone. This
  occurs between the metacarpals (bones in the palm
  of the hand) and phalanges (fingers) and between
  the metatarsals and phalanges (toes).

22
Pivot Condyloid Joints
23
Saddle joint

• This type of joint occurs when the touching
  surfaces of two bones have both concave and
  convex regions (like a saddle) with the shapes of
  the two bones complementing one other and
  allowing a wide range of movement. The only
  saddle joint in the body is in the
  (carpometacarpal joint) thumb.

24
Ball-and-Socket joint

• The ball-shaped end of one bone fits into a
  cup shaped socket on the other bone allowing the
  widest range of motion including rotation.
  Examples include the shoulder and hip joints.

25
Saddle joint Ball--Socket joint
26
Types of Movements

• Movements at Synovial Joints are grouped into 4
  main categories.
• 1- Gliding
• 2- Angular
• 3- Rotation
• 4- Special movements

27
Gliding

• Consist of two flat surfaces that slide past one
  another. Gliding movements are limited in range
  due to the articular capsule ligaments. Gliding
  occurs at planar joints

28
Angular movements

• In angular movements- decrease or increase in
  the angle between articulating bones.
• Flexion decrease in the angle
• Extension increase in the angle, sagital plane
• Lateral flexion lateral bending, frontal plane
• Hyperextension extension beyond the normal
  anatomical position.
• Abduction movement away from the midline
• Adduction movement towards the midline
• Circumduction combination of all movements,
  moving a body part in a circle for example,
  tracing a circle with your arm
• Rotation a bone resolves around its own axis

29
Special Movements

• Elevation- raising a part (shrugging the
  shoulders).
• Depression- lowering a part (drooping the
  shoulders).
• Protraction- moving a part forward (thrusting the
  chin forward).
• Retraction- moving a part backward (pulling the
  chin backward).

30
Special Movements

• Inversion- turning the sole of the foot medially
• Eversion- turning the sole of the foot laterally
• Dorsiflexion- flexing the foot at the ankle
  (bending the foot upward).
• Plantar flexion- extending the foot at the ankle
  (bending the foot downward).
• Supination- turning the hand so the palm faces
  upward
• pronation- turning the hand so the palm faces
  downward.
• Opposition- thumb tips of fingers