AnP Chapter 9 (LO7) Flashcards
JOINTS
Contains more than 300 joints
Articulations: joints; where bones meet
Some joints are immovable, others allow only limited movement
how are joints classified
According to how moveable they are
Fixed, semi-movable or freely movable
According to material that binds them together
Fibrous joints, cartilaginous joints and synovial joints
FIBROUS JOINT
aka synarthroses
result when collagen fibers form one bone penetrate the adjacent bone, anchoring the bones in place
Ex: adult skull
CARTILAGINLUS JOINTS
aka Amphiarthroses
2 bones are joined by cartilage
slightly movable
Symphysis
cartilage that joins the 2 pubic portions of the os coxae
Creates the joint symphysis pubis
SYNOVIAL JOINTS
aka diarthroses
freely movable
Most numerous and versatile of all body’s joints
Bursa
small sacs filled with synovial fluid
Every synovial joint contains the following:
- joint capsule
- synovial membrane
- joint cavity
- synovial fluid
- articular cartilage
- ligaments
Joint capsule
sheet of connective tissue that encloses the joint cavity
Synovial membrane
moist, slippery membrane secretes synovial fluid
Lines the inside of the joint
Joint cavity
small space between bones allows freedom of movement
Contains synovial fluid
Synovial fluid
slippery, viscous egg white fluid
Lubricates joint, nourishes cartilage, removes debris (phagocytes)
Articular cartilage
thin layer of hyaline cartilage covers bone surfaces
With synovial fluid, permits friction free movement
Ligaments
tough cords of connective tissue; help bind the bones more firmly
BALL AND SOCKET
- ball head fits into cup like socket
- offers widest range of motion
- ex: hip and shoulder joints
PIVOT JOINT
- projection from one bone articulates with a ring shaped socket allowing rotation
- ex) cervical vertebra and 1st vertebra ring
HINGE JOINT
- allow only back and fourth movement
- convex surface fits into a depression of bone
- ex: elbow, knee
SADDLE JOINT
- shaped like saddle-concave in one direction convex in the other
- allows movement front, back, side, side (limited)
- only in thumb
CONDYLOID JOINT
- oval convex surface fits into a similar depression
- ex) articulation of distal end of radius with the carpal bones of the wrist
- allows side to side movement
GLIDING JOINT
- 2 bone surfaces slide over each other
- least mobile because surrounding ligaments
- ex: tarsal bone of ankle, carpal bone of wrist
Flexion
Extension
Flexion: involves bending a joint so as to decrease the angle of the joint
Extension: involves straightening a joint, increasing the angle between the bones
Hyperextension
Dorsiflexion
Plantar flexion
Hyperextension: is the extreme extension of a joint beyond its normally straight position
Dorsiflexion: involves moving the toes or foot upward
Plantar flexion: involves moving the toes or foot downward (toward the plantar surface)
Abduction
Adduction
is the movement of a body part away from midline of the body
is the movement of a body part toward the midline of the body
Circumduction
distal end of appendage, such as the arm or leg, moves in a circle
Internal rotation
when a bone spins toward the body’s midline
External rotation
when a bone spins away from the body’s midline
Supination
is a movement that turns the palm upward
Inversion
a foot movement that turns the sol medially, toward the other foot
Eversion
a foot movement that turns the sole laterally, away from the other foot
Protraction
Moves a part forward
Retraction
moves a part backward
