Articulations

Question 1

Articulations

Answer 1

occur where bones meet each other

used interchangeably with “Joints”

Question 2

How are articulations classified?

Answer 2

1. Functional - amount of movement allowed
2. structural - what is found between the bones

Question 3

types of functional classification articulations

Answer 3

synarthroses - no movement
amphiarthroses - slight
Diarthroses - freely moveable

Question 4

Types of structural classifications of articulation

Answer 4

fibrous
cartilaginous
synovial

Question 5

Synarthroses joint (functional classification)

Answer 5

essentially immovable

slight expansion and contraction may occur

example: sutures of the skull

Question 6

amphiathroses joint (functional classification)

Answer 6

slight movement

example: cartilaginous discs between vertebral bodies

Question 7

Diarthroses joints (functional classification)

Answer 7

freely moveable

shoulder, wrist, hip, knee, ankle, most joints where there is noticeable amount of movement

Question 8

Fibrous joints (Structural classification)

Answer 8

united by fibrous connective tissue;

little if any movements (synarthrotic or amphiarthrotic)

SUBTYPES
1. Sutures

P. 20 in coloring book

Question 9

Cartilaginous joints (Structural classification)

Answer 9

connected by a disc or plate of either HYALINE OR FIBROCARTILAGE (not articular cartilage)

little if any movement (synarthrotic or amphiarthrotic)

Question 10

Synovial joints

Answer 10

have a SPACE FILLED WITH FLUID between articulating bones and tend to ALLOW FREE MOVEMENT (diarthrotic)

Question 11

Components of a synovial joint

Answer 11

Articular (joint) capsule

synovial membrane

synovial fluid

articular cartilage

ligaments

tendons

bursae

discs/menisci

Question 12

Articular (joint) capsule - component of a synovial joint

Answer 12

a “sleeve” that surrounds the joint and encloses the synovial cavity

an outer fibrous layer is a thickening and continuation of the periosteum of the articulating bones

an inner fibrous layer is made up of a synovial membrane

some use “joint capsule” to only refer to the outer fibrous layer

Question 13

Synovial membrane -component of a synovial joint

Answer 13

inner layer of the joint capsule - secretes synovial fluid

Question 14

synovial fluid - component of a synovial joint

Answer 14

secreted by the synovial membrane

slippery clear/pale yellow fluid is similar in consistency with raw egg whites

reduces friction between articulating bones, absorbs shock and provides nutrients and removes waste from cells in the articular cartilage

Question 15

Articular cartilage - component of a synovial joint

Answer 15

a smooth layer of hyaline cartilage seen on the articulating surfaces of joints that reduces friction and absorbs shock

synovial fluid in turn reduces friction between articular cartilage

Question 16

ligaments

Answer 16

many synovial joints have a band like ligament that add stability to the joint capsule

these ligaments are most often outside of the joint space (collateral ligaments of the knee) or rarely inside the joint space (cruciate ligament of the knee)

ALWAYS CONNECT BONE TO BONE

Question 17

tendons

Answer 17

ALWAYS CONNECT MUSCLE TO SOMETHING ELSE

often to bone, but occasionally to other structures

tendons help add stability to some synovial joints

Question 18

Bursae

Answer 18

fluid-filled acs that REDUCE FRICTION between joint structures, such as between tendons and bones that they cross

filled with fluid similar to synovial fluid

some ar found at synovial joints such as the subacromial bursa of the shoulder, some form spontaneously

Question 19

Disc/menisci

Answer 19

a few joints such as the knee and TMJ have pads of fibrocartilage between the articular cartilage of the bones

these pads are attached to the joint capsule and provide CUSHIONING and allow bones of different shapes to fit together

menisci direct synovial fluid to areas of the most friction in the joint

Question 20

Subtypes of synovial joints

Answer 20

ball and socket
hinge
pivot
ellipsoid (condyloid)
saddle
planar (gliding)

Question 21

Ball and Socket Synovial joint

Answer 21

have a ball shaped surface that fits into a round socket

freely moveable in any direction (triaxial or three planes)

the most diarthrotic of the synovial joints

hip and shoulder joints

BONE MARKING
the head of the humorous in the glenoid fossa

the head of the femur and the acetabulum of the coral bone at the hip

Question 22

Hinge synovial joint

Answer 22

have a convex surface of one bone fitting into a concave surface of another

monoaxial (uniaxial) in that they allow free movement (diarthrotic) but only in one place, like a door hinge

examples:
- the trochlea of the humerus and the trochlear notch of the ulna at the elbow

• the ankle joint, composed of the talus and the medial malleolus of the tibia and the lateral malleolus of the fibula
• interphalangeal joints of the fingers and toes

Question 23

Pivot types of synovial joints

Answer 23

occur when the rounded or pointed surface of one bone articulates with a ring-like or curved surface of another bone

allow rotational movement in one plane (monoaxial)

Example:

• the atlantoaxial joint between C1 and C2
• the proximal radioulnar joint between the radius and the ulna (between the head of the radius and the radial notch of the ulna)
• the radial head also articulates with the capitulum of the humerus

Question 24

Ellipsoid (condyloid) types of synovial joints

Answer 24

like call and socket types but they have an elliptical or oval ball that fits into an elliptical or oval socket as opposed to round

allow biaxial movement in two planes

examples:

• the wrist joint (radoiocarpal joint) between the distal radius and the proximal carpal bones as a group
• the metacarpophalangeal joints between the distal end of the metacarpal and the proximal end of a proximal phalanx
• some prefer to classify the knee as a double or bicondylar type of ellipsoid joint as opposed to a hinge joint

Question 25

Saddle type of synovial joint

Answer 25

have saddle-shaped surfaces of bones articulating with other saddle-shaped surfaces limited triaxial movement examples - carpometacarpal joints of the thumb, between the proximal end of metacarpal 1 and the trapezium (of the carpal bones) provides with an "opposable" thumb

Question 26

Planar or gliding types of synovial joints

Answer 26

allow gliding movements between flat or slightly curved articulating surfaces most often biaxial movements are allowed, in a back and forth, side-to-side manner examples: - inter carpal joints in the wrist or inter tarsal joints of the ankle. sternoclavicular (SC) and acromioclavicular (AC) joints at either end of the clavicle interfacet joints of the adjacent vertebrae

Question 27

Movements

Answer 27

many different movements are allowed at different joints of the body

Question 28

Types of movements

Answer 28

flexion extension hyperextension lateral flexion elevation depression retraction protraction

Question 29

Flexion

Answer 29

occurs when the angle between the (typically anterior) articulating surfaces of the bone is decreasede

Question 30

extension

Answer 30

return from flexion, which tends to involve increasing the angle between the articulating bones

Question 31

hyperextension

Answer 31

a continuation of extension beyond anatomical position can occur at some joints, but not others does not necessarily refer to an injury

Question 32

lateral flexion

Answer 32

only produced between vertebra, where the spine bends laterally to either side

Question 33

Rotational movements

Answer 33

when one bone rotates around another generally involves movement around a long axis at joints such as the shoulder and hip, rotation is broken down into INTERNAL OR MEDIAL ROTATION AND EXTERNAL OR LATERAL ROTATION, based on the direction that the anterior surface of the limb moves PRONATION (internal) AND SUPINATION (external) of the ulna

Question 34

elevation and depression

Answer 34

elevation is upward movement and depression would be movement in a downward direction - mandible and scapula

Question 35

retraction and protraction

Answer 35

retraction- movement in a posterior direction protraction - a horizontal movement in an anterior direction -mandible, scapula

Question 36

abduction and adduction

Answer 36

abduction - body part is taken away in a frontal plane from midline adduction - movement in frontal plane where something is added towards the midline

Question 37

plantarflexion

Answer 37

a movement at the ankle where you move towards the plantar or bottom surface of the foot

Question 38

dorsiflexion

Answer 38

movement at the ankle that brings the top of the foot up towards the shin

Question 39

inversion and eversion

Answer 39

inversion - movement between tarsal bones that bring the sole of the food up towards the medial arch eversion- turns the sole of the food outward and up, laterally

Question 40

circumduction

Answer 40

unique type of movement at triaxial joints such as the shoulder or hip, where the proximal end of the limb stays relatively stable while the distal end moves in a circle

Question 41

opposition

Answer 41

movement of the thumb towards the little finger