1. Joints Lecture Outline
Chapter 9
Joints
Lecture Outline

2. Chapter 9 Joints Joints hold bones together but permit movement
Point of contact
between 2 bones
between cartilage and bone
between teeth and bones
Arthrology = study of joints
Kinesiology = study of motion
Principles of Human Anatomy and Physiology, 11e

3. Types of Joints Fibrous Joints Cartilaginous Joints Synovial Joints
Principles of Human Anatomy and Physiology, 11e

4. Fibrous Joints
Bones touch each other directly with no space between (called a synovial cavity)
They permit little or no movement and hold bones tightly together.
Examples: between skull bones, between tibia and fibula, holding the teeth in place
Principles of Human Anatomy and Physiology, 11e

5. Cartilaginous Joints
Also connect bones tightly (via cartilage) with no space between them
Allows little or no movement
Examples: joints between the ribs and sternum, or holding the vertebrae together
Principles of Human Anatomy and Physiology, 11e

6. Synovial Joints Allow movement Have space between the bones
Articular cartilage
reduces friction
absorbs shock
Articular capsule
surrounds joint
Synovial membrane
inner lining of capsule

7. Torn Cartilage Commonly occurs in athletes
Cartilage between joints is torn
Can be surgically repaired, often results in arthritis later in life
Arthroscopy is used to see the inside of a joint and repair it
Principles of Human Anatomy and Physiology, 11e

8. Sprain versus Strain Sprain Strain
twisting of joint that stretches or tears ligaments
no dislocation of the bones
may damage nearby blood vessels, muscles or tendons
swelling & hemorrhage from blood vessels
ankle is frequently sprained
Strain
generally less serious injury
overstretched or partially torn muscle
Principles of Human Anatomy and Physiology, 11e

9. TYPES OF MOVEMENT AT SYNOVIAL JOINTS
Gliding
Angular Movements
Rotation
Special Movements
Principles of Human Anatomy and Physiology, 11e

10. Gliding Movements
Gliding movements occur when relatively flat bone surfaces move back and forth and from side to side with respect to one another.
In gliding joints there is no significant alteration of the angle between the bones.
Gliding movements occur at plantar joints.
Example: waving your hand back and forth

11. Angular Movements
In angular movements there is an increase or a decrease in the angle between articulating bones.
Flexion results in a decrease in the angle between articulating bones
Extension results in an increase in the angle between articulating bones
Hyperextension is a continuation of extension beyond the anatomical position and is usually prevented by the arrangement of ligaments and the anatomical alignment of bones
Principles of Human Anatomy and Physiology, 11e

12. Flexion, Extension & Hyperextension
Principles of Human Anatomy and Physiology, 11e

13. Abduction, Adduction, and Circumduction
Abduction refers to the movement of a bone away from the midline
Adduction refers to the movement of a bone toward the midline
Circumduction refers to movement of the distal end of a part of the body in a circle
Principles of Human Anatomy and Physiology, 11e

14. Rotation Bone revolves around its own longitudinal axis
medial rotation is turning of anterior surface in towards the midline
lateral rotation is turning of anterior surface away from the midline
At ball & socket and pivot type joints
Principles of Human Anatomy and Physiology, 11e

15. Special Movements of Mandible
Elevation = upward
Depression = downward
Protraction = forward
Retraction = backward
Principles of Human Anatomy and Physiology, 11e

16. Special Movements
Inversion is movement of the soles medially at the intertarsal joints so that they face inward from each other
Eversion is a movement of the soles laterally at the intertarsal joints so that they face away from each other
Dorsiflexion refers to bending of the foot at the ankle in the direction of the superior surface
Plantar flexion involves bending of the foot at the ankle joint in the direction of the plantar surface
Principles of Human Anatomy and Physiology, 11e

17. Special Movements
Supination is a movement of the forearm at the proximal and distal radioulnar joints in which the palm is turned anteriorly or superiorly
Pronation is a movement of the forearm at the proximal and distal radioulnar joints in which the distal end of the radius crosses over the distal end of the ulna and the palm is turned posteriorly or inferiorly
Principles of Human Anatomy and Physiology, 11e

18. Special Movements
Opposition is the movement of the thumb at the carpometacarpal joint in which the thumb moves across the palm to touch the tips of the finger on the same hand.
Review
A summary of the movements that occur at synovial joints is presented in Table 9.1.
A dislocation or luxation is a displacement of a bone from a joint.
Principles of Human Anatomy and Physiology, 11e

19. TYPES OF SYNOVIAL JOINTS
Planar Joints: permit gliding at the wrists and ankles
Hinge Joints: open and closing motions; knee, elbow, fingers
Pivot Joints: Allows your head to turn from side to side

20. TYPES OF SYNOVIAL JOINTS
Condyloid Joints: knuckles
Saddle Joints: joints in the thumb
Ball and socket joints: shoulders and hips

21. Tempromandibular Joint (TMJ)
The TMJ is a combined hinge and planar joint formed by the condylar process of the mandible, the mandibular fossa, and the articular tubercle of the temporal bone.
Movements include opening and closing and protraction and retraction of the jaw.
When dislocation occurs, the mouth remains open.

22. FACTORS AFFECTING CONTACT AND RANGE OF MOTION AT SYNOVIAL JOINTS
Structure and shape of the articulating bone
Strength and tautness of the joint ligaments
Arrangement and tension of the muscles
Contact of soft parts
Hormones
Disuse
Principles of Human Anatomy and Physiology, 11e

23. Aging and Joints Decreased fluid and increased pain in joints
Cartilage becomes thinner
Joints become less flexible
You become more hunched over
Arthritis is common
Principles of Human Anatomy and Physiology, 11e

24. Arthroscopy & Arthroplasty
Arthroscopy = examination of joint
instrument size of pencil
remove torn knee cartilages & repair ligaments
small incision only
Principles of Human Anatomy and Physiology, 11e

25. Arthroscopy & Arthroplasty
Arthroplasty = replacement of joints
total hip replaces acetabulum & head of femur
plastic socket & metal head
knee replacement common

26. Techniques for Cartilage Replacement
In cartilage transplantation chondrocytes are removed from the patient, grown in culture, and then placed in the damaged joint.
Eroded cartilage may be replaced with synthetic materials
Researchers are also examining the use of stem cells to replace cartilage.

27. DISORDERS: HOMEOSTATIC IMBALANCES
Lyme disease is a bacterial disease which is transmitted by deer ticks. Symptoms include joint stiffness, fevers, chills, headache, and stiff neck.
Ankylosing spondylitis affects joints between the vertebrae and between the sacrum and hip bone. Its cause is unknown, and is common in males between 20 and 40 years old.
Ankle Sprains: ankles are the most commonly sprained bones in the bodies
Principles of Human Anatomy and Physiology, 11e

28. Rheumatoid Arthritis Autoimmune disorder Cartilage attacked
Inflammation, swelling & pain
Final step is fusion of joint
Principles of Human Anatomy and Physiology, 11e

29. Osteoarthritis Degenerative joint disease aging, wear & tear
Noninflammatory---no swelling
only cartilage is affected not synovial membrane
Deterioration of cartilage produces bone spurs
restrict movement
Pain upon awakening--disappears with movement
Principles of Human Anatomy and Physiology, 11e

30. Gouty Arthritis Urate crystals build up in joints---pain
waste product of DNA & RNA metabolism
builds up in blood
deposited in cartilage causing inflammation & swelling
Bones fuse
Middle-aged men with abnormal gene
Principles of Human Anatomy and Physiology, 11e

31. Hypermobility or Double Jointed
Describes joints that stretch farther than is normal
It can affect a single joint or multiple joints throughout the body.
Results from misaligned joints, abnormal bone shapes/joints, or a collagen/connective tissue defect where ligaments over stretch.