Is it Okay to Crack Your Knuckles?https://www.youtube.com/watch?v=TIBydD49-xM

Joint Facts

Joints - are places where two bones meet

There are 400 + jointsApproximately 230 movable and semi-

movable jointsMuscles span joints, crossing from 1

bone to anotherWhen muscles contract, they tug on

the bones, producing movement at the joint

CartilageThere are three types: 1.Hyaline2.Fibrous and 3.Elastic

Hyaline cartilage: Covers the ends of bonesCushions and reduces friction during

movementKey to preventing wear and tear on joints

Knee Joint

Ligaments

Ligaments - Connects bone to bone

Bands of tough, fibrous collagen and stretchy elastin

Bind joints to help strengthen and stabilizePermit movement in certain directionsAlso support organs, such as the liver and

bladder

Knee Joint

TendonsTendons – Connect muscle to bone.

When a muscle contracts, it pulls on a tendon, which then tugs on the attached bone

Also help stabilize joints

Achillies Tendon

Types of JointsImmovable - craniumHinge – elbow, knee, jawPivot – head/neck, elbowEllipsoidal - hand/wrist, foot/ankleBall and socket – shoulder, hipSaddle – knuckles, thumb, wristGliding – hand, foot

Joints continued……

Ligaments join with other connective tissue to form a joint capsule, enclosing the moveable joint

The joint capsule is lined with a membrane that secretes synovial fluid, which acts as a lubricating substance

Clinical Conditions

GigantismChildhood hyper secretion of growth

hormone by the pituitary gland causes excessive growth.

Tallest Man Ever: Robert Wadlow – 8 ft 11 inch

Pituitary dwarfismGrowth hormone deficiency in

children resulting in extremely short long bones and maximum stature of 4 feet.

Shortest man: http://www.usatoday.com/story/news/nation-now/2015/09/04/shortest-man-world-has-died/71743044/