Joints (Articulations) Definition: Site at which two or more bones come together Some joints have no movement some only slight movement some are freely moveable

Fibrous (Fixed) Joints In these joints, the bones are in very close contact and are separated only by a thin layer of fibrous connective tissue An example of this type of joint is the sutures in the skull between skull bones

Cartilaginous (slightly moveable) joints These joints are characterized by bones that are connected by hyaline cartilage (fibro cartilage) Example: The joints between the vertebral bodies

Synovial (freely moveable) joints (Diarthrosis joint) Most joints are freely movable Considerable movement is permitted at all synovial joints

Types of movement Movements which can occur are: Flexion - Extension Abduction - Adduction Rotation - Circumduction Pronation - Supination Inversion - Eversion

Flexion and Extension Extension at the elbow joint Flexion at the elbow joint

Abduction and Adduction Abduction at the hip joint Adduction at the hip joint

Rotation and Cicumduction Rotation at the atlas – axis joint Circumduction at the shoulder joint

Types of Synovial joint Synovial joints are subdivided according to the movements possible They are subdivided into: Ball and Socket Condyloid Saddle Pivot Hinge Gliding

Ball and Socket joints 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

Condyloid joints Oval shaped condyle fits into elliptical cavity of another allowing angular motion but not rotation. This occurs between the metacarpals (bones in the palm of the hand) and phalanges (fingers) and between the metatarsals (foot bones excluding heel) and phalanges (toes).

Saddle joints This type of joint occurs when the touching surfaces of two bones have both concave and convex regions, the shapes of the two bones complement one another and allow a wide range of movement The only saddle joint in the body is in the thumb

Pivot joints Rounded or conical surfaces of bone fit into a ring of bone or tendon allowing rotation An example is the joint between the axis and atlas in the neck

Hinge joints A convex projection on one bone fits into a concave depression in another permitting only flexion and extension Examples of hinge joints = elbow and knee joints

Gliding joints Flat or slightly flat surfaces move against each other allowing sliding or twisting without any circular movement This happens in the carpals in the wrist and the tarsals in the ankle.

Characteristics of a synovial joint Articular or Hyaline Cartilage Strong enough to support the weight of the body Provides smooth surface for articulation Capsular Ligament Sleeve of fibrous tissue which joins the bones together, therefore provides joint stability Sufficiently loose to allow movement

Synovial membrane This is composed of secretory epithelial cells that secrete a thick, sticky fluid which: a) acts as a lubricant b) provides nutrients c) helps maintain joint stability (prevents the ends of bone separating) (Little sacs of synovial fluid – bursae - are found in some joints, act as cushions)

Extra capsular structures Ligaments help stabilise the joint Muscles enable movement Nerves

Case Study 1 Callum is four years old. He has just fallen from the slide in the park and has banged his head. He is developing a bit of a lump on his forehead (there is no skin injury) and he has started crying. His mother is also really upset and wants to take him to A & E. What advice would you give his mother? What sort of bone is the skull? What is the function of the skull bone?

Case Study 2 Stephen is 21 years old and has been trying to get fit and improve his health. He has started playing rugby and has injured his ankle in a match. He finished the game but now is limping and his ankle is looking very bruised and swollen. What advice would you give Stephen? What is the collective name for the bones in the ankle? What sort of bones are these? What injuries are common in the ankle?

Case Study 3 Melanie has been diagnosed with schizophrenia and has been taking antipsychotic medication for a few years. Unfortunately, she has put on five stone in weight during this time. The CPN calculates her BMI as 31.6 (5ft 6ins and 14stone). How might this excess weight affect Melanie’s joints? Which joints are more likely to be affected? What advice would you give her?

Case Study 5 Mrs Evans (who is 65 years of age) has Non Insulin Dependent Diabetes Mellitus (NIDDM). She is quite concerned about her risk of osteoporosis (her mother had the condition and fractured her hip, twice). Is she at risk? What nutrients and hormones are required for bone health? What advice would you give to Mrs Evans?