A&P Chapter 9

fibrous structure

bones are joined by connective tissue

cartilaginous structure

bones united by cartilage

synovial structure

bones are separated by a fluid cavity

sutures

seams formed between the skull

synostosis

two bones fuse and joint line disappears

syndesmosis

two bones are joined tightly together by a ligament

gomphosis

bond between the periodontal ligament and teeth to hold them in their sockets

what are the two types of cartilaginous joints

1.synchondrosis- connecting material is hyaline cartilage

2. symphysis- bones are separated by a pad of cartilage

synovial joints (diarthroses) allow what

most movement and are the most common type of joint

articular cartilage

Smooth surface at the two ends of bones, made up of cartilage abdominal reduces friction and acts as a shock absorber

joint (synovial) cavity

space between the bones that contain fluid

articular capsule

double layer membrane, provides the border of the joint cavity

fibrous capsule- continuous with the periosteum of the bones

synovial membrane- lines the inside of the fibrous capsule

synovial fluid

egg white consistency, found within the joint cavity

lubrication- reduces friction between bones

nutrient distribution- circulates within a joint to provide nutrients and waste disposal for chondrocytes

shock absorption- helps to distribute pressure evenly across the joint

ligaments

connect bone to bone and provide strength and reinforcement for the joint

cartilage pads

called menisci and found in the femur and tibia

fat pads

small mass of adipose provide some extra cushioning and fill in empty spaces created when the joint moves

tendons

cross over joints and limit movement and provide support

bursae

fluid filled pockets that contain synovial fluid

reduce friction and acts as a shock absorber

relationships between mobility and stability in a joint

lot of mobility = less stable

less mobility = more stable

three factors that affect stability in a joint

shapes of articular surfaces and menisci

ligaments- provide stability but not very effective if they are the only source of support

muscle tone- tendons stabilize the joint

define luxation

dislocation

define reduction

putting a joint back in a position

define subluxation

partial dislocation

planar joints and example

two flat surfaces slide along each other but very little movement occurs

ex. intercarpal joints

hinge joints and example

permit movement in one plane

ex. humorous and ulna

pivot and example

permit rotation only

ex. atlas and axis

ellipsoidal or condyloid joints and example

oval articular face sits in a depression on the opposite bone

ex. metacarpals and phalanges

saddle joints and example

two bones fit together like a rider in a saddle

ex. trapezium and first metacarpal

ball and socket joints and example

round head of one bone sits in a depression in the other bone

ex. shoulder and hip

most mobile joints

flexion and extension and example

the angle between two bones

ex. bending at the waist, leaning your head forward, bending your arm

extension and example

increases the angle between two bones

ex. standing upright, bringing head up, straightening arm

hyperextension and example

going beyond anatomical position

ex. looking at ceiling, bending wrist back

abduction and example

movement away from the midline of the body

ex. moving arm side toward the midline

adduction and example

movement toward the midline

ex. bringing arm back to body

circumduction and ex

rotation of limb in a circle

ex. turning head left or right

pronation

turing palm over

supination

palms facing forward; anatomical position

dorsiflexion

toes move up toward leg; dig in your heels

plantar flexion

point toes; stepping on gas

inversion

turning sole of the foot inward

eversion

turing sole of the foot out

protraction

movement anteriorly; sticking jaw out

retraction

movement superiorly; pulling jaw in

elevation

superior movement; shrugging shoulders

depression

inferior movement; open mouth

opposition

touching thumb to other fingers

lateral flexion

bending to the side

what are the three articulations that make up the knee

medial condyles and lateral condyles and one between the patella and patellar surface of the femur

three functions of the menisci

acts as cushion

change shape to conform to the shape of the articular surfaces as the femur moves

provide lateral stability

patellar ligament

continuation of the tendon of the quadriceps femoris

attaches to the tibial tuberosity

popliteal ligaments

extend from the femur to the heads of the tibia and fibula posteriorly

anterior and posterior cruciate ligaments

attach the intercondylar area of the tibia to the condyles of the femur

run at angles to each other to form a cross

limit anterior and posterior movement of the femur

tibial (medial) and fibular (lateral) collateral ligaments

stabilize the medial and lateral surfaces of the knee when the leg is extended

what part of the body is most mobile and most frequently dislocated joint in the body

the shoulder

what is the difference between a shoulder separation and a shoulder dislocation

separation- dislocation of the acromiclavicular joint

dislocation- head of the humorous slips out of the glenoid cavity

what is the elbow joint made up of

humerous, radius, and ulna

what is the strongest part in the elbow joint

the trochlea of the humerous articulates with the trochlear notch of the ulna

what is the hip made up of

head of the femur and the acetabulum of the coral bone

arthritis

group of diseases that affect synovial joints

osteoarthritis

results from wear and tear on the joint surfaces

rheumatoid arthritis

inflammation of the joints

gouty arthritis

crystals of uric acid from within the synovial fluid