Joint (Articulations) Flashcards
Musculoskeletal System (50 cards)
What is a fibrous joint?
When no movement occurs when between the bones concerned
Describe the structure of a fibrous joint
The bones are held in in place by fibrous connective tissue.
It is very difficult to damage this type of joint, as it is so strong that the bone is usually broken, resulting in a fractured skull, before the joint gives way.
Where is fibrous joint located?
- Joints of the skull
- Between the teeth and jaw
What is a cartilaginous joint?
Cartilaginous joints are held in place by cartilage, which allows slight movement to occur.
Where is a cartilaginous joint located?
The junction of the two pelvic bone (the pubic symphysis)
Joints between adjacent vertebrae
Joints between the ribs and the sternum
What are synovial joints?
Most joints of the body are freely movable, with the amount of movement limited by ligaments, muscles, tendons and adjoining bones
Categorised by type of movement that occurs between articulating surfaces of bones.
Where are synovial joints located?
These joints occur at the shoulder, elbow, wrist, fingers, hip, knee, ankle, and toes.
Describe a ball & socket joint
Form when the spherical head of one bone fits into a cup-like cavity of another.
Where are ball and socket joints located?
The head of the humerus fits into the depression of the scapula.
Describe a hinge joint
Allow movement in only one plane. They form when the convex surface of one bone fits into the concave surface of another.
Where are hinge joints located?
The elbow and the knee. Also occurs at the ankle & between the bones of fingers and toes.
Describe a pivot joint
Formed when the rounded, pointed, or conical end of one bone articulates with a ring, formed partly by bone and partly by ligament.
Where are pivot joints located?
The joint between the first vertebra, on which the head is balanced (atlas) and the second vertebra (axis).
Describe a gliding joint
Allow movement in any direction in a side- to-side or back-and-forth motion, restricted only by the ligaments or bony processes surrounding the joint.
Where are gliding joints located?
Between carpal bones, tarsal bones, the sternum and clavicle and the scapula and clavicle.
Describe a condyloid joint
Have one surface of bone slightly convex that fits into a slightly concave depression in another bone.
Where are condyloid joints located?
Between the radius and carpal bones. The metacarpal bones and phalanges of the fingers.
Why are freely movable joints also called synovial joints?
Because there is a space, or synovial cavity, between the articulating surfaces of the bones.
Describe the structure and function of the articular capsule
- Comprises two layers
- Surrounds and encloses joint
Describe the structure of the fibrous capsule
The outer layer, consisting of dense, fibrous connective tissue attached to the periosteum of the articulating bones
Describe the function of the fibrous capsule
Its flexibility permits movement at the joints, whereas its strength resists dislocation.
It is one of the main structures that hold the bones together.
Describe the structure of the synovial membrane
The inner layer of the capsule.
It consists of loose connective tissue, the inner surface of which is well supplied with blood capillaries.
Describe the function of the synovial membrane
Lines the entire joint cavity, except the articular cartilage and articular disc if present.
Describe the structure of the synovial fluid
Fills the synovial cavity and forms a thin film over surfaces within the capsule.
Only a small amount of fluid is normally present (0.5mL in knee joint.
