1

Human Anatomy and

Physiology ILaboratory

Articulations and Body Movements

This lab involves study of the laboratory exercise “Articulations and Body Movements”, completing the Review Sheet for the exercise, and taking the relevant quiz. Click on the sound icon for the audio file (mp3 format) for each slide. There is also a link to a dowloadable mp4 video which can be played on an iPod.You will note that there are more bones and contours in the lab manual than are identified in this PDF. The PDF focuses on only the most important.

2

Classification of Joints by Movement• Synarthroses (synarthrotic joints) – non movable

most fibrous joints

e.g. sutures

• Amphiarthroses (amphiarthrotic joints) – semimovable

mostly cartilaginous

e.g. intervertebral disks

• Diarthroses (diarthrotic joints) – movable joints

synovial joints

Joints can be classified according to their degree of movement, and also their structure. Non-movable joints are fibrous, i.e. they have dense regular (fibrous) connective tissue holding the bones together. Semimovable joints are mostly cartilaginous, while movable joints have a joint capsule composed of synovial membrane.

3

Classification of Joints by Structure

Fibrous joints – composed of fibrous (inelastic) connective tissue.

sutures – between cranial bones

syndesmoses – e.g. tibia-fibular joint, sternum-clavicle and acromion-clavicle.

Most of the fibrous joints are non-movable, such as the sutures and the joints between the tibia and fibula. But certain fibrous joints can move slightly, for example the joints between the clavicle and the scapula and sternum.

4

Synovial Joints• movable joints

• contain a joint capsule of synovial membrane

Synovial joints are the movable joints, each utilizing a synovial sack as the lubrication for joint movement. The synovial sack secretes synovial fluid into the joint cavity which is surrounded by the joint capsule.

5

Structure of a SynovialJoint

periosteum

Extracapsular ligament

Fibrous capsule

Synovial membrane

Articular cartilage

Articularcapsule}

Joint cavity

The joint cavity inside the articular capsule is filled with synovial fluid which lubricates the movement of the joint. Extracapsular ligaments are found on virtually all synovial joints, as well as some other joints. They hold the bones in position. Certain synovial joints, for example the knee, also have intracapsular ligaments. These control degree and direction of movement.

6

Plane or Gliding Joint

Gliding or planar joints – bones slide against one another.

e.g. between carpals or tarsals

A Plane joint is a non-axial joint. Its sliding movement allows flexibility of the wrist and ankle.

7

Gliding Movement is Non-axial

When the bones of the wrist move against one another, the don’t move in a particular axis, they slide or glide. Therefore these joints are called non-axialjoints.

8

e.g. elbow, knee.

Hinge Joints

Hinge joints are uniaxial joints, they move in one plane or on one axis only. Flexion and extension are the reciprocal movements at these joints.

9

Movements at Uniaxial Joints:

Flexion – decreasing the angle between two bones or parts.

180o

•Begin at anatomical position

•Reduce angle from 180o

Consider each movement beginning with the body in anatomical position. A straight line drawn through the body indicates angles of 180 degrees at anatomical position. Reducing those angles ofr knee or brachium produces flexion.

10

Extension– increasing the angle between two bones or parts.

Increase angle back to anatomical position

Return to anatomical

position

Beyond anatomical position is hyperextension

Some of the terms for these movements are not intuitive. You need to remember that they are relative to normal anatomical position.

11

Flexion and Extension of

the VerterbralColumnFlexion

Extension

Hyperextension

When extension proceeds beyond anatomical position it is called hyperextension.

When extension proceeds beyond anatomical position it is called hyperextension.

The line of reference runs cephalo-caudally (direction from head to tail) through the body.

12

Flexion and Extension of the Head

FlexionExtension

HyperextensionFlexion

The line of reference runs cephalo-caudally through the body.

13

Pivot Joints

e.g. radius with ulna and humerus,

atlas-axis

Pivot joints are also uniaxial, the one axis being in the center of the movement.

14

Rotation of the Head and

Thigh

The brachium also rotates in the shoulder joint. To best demonstrate and distinguish between pronation and supination, first bend the elbow.

15

Rotation of the Radius

Supination – to move palm up

Pronation – to move palm down

Despite popular usage, supination and pronation refer only to the hand.

16

Condyloid Joint

Phalange-metacarpal, Carpal-metacarpal,

occipito-atlas and tibia-talus joints.

Condyloid and saddle joints are very similar with slightly different shapes. Both are biaxial joints. The movements performed are flexion, extension, adduction, and abudction, along with circumduction, a combination of the other four.

17

Saddle Joint

The saddle joint is just a special version of a condyloid joint, found only at the carpo-metacarpal joint of the thumb.

18

Additional Movements at Biaxial

Joints

Abduction –to move away from the midline or apart.

Adduction –to move toward the midline or together.

Circumduction – a sequence of movements in which one end inscribes a circle.

Adduction and abduction are side-to-side movements: in adduction the parts move together or toward the midline, in abduction they move apart or away from the midline. All the biaxial as well as the multi-axial joints can perform these movements.

19

Ball-and-Socket JointsShoulder and hip joint

Ball-and-socket joints are multi-axial. They can perform all of the movements

20

Movements of the Foot

plantarflexion: point toes down

dorsiflexion: point toes up

Movements of the foot are given special names depending on whether they point the toes up (dorsiflexion) or down (plantar flexion).

21

Inversion and Eversion

Left foot

Inversion, incorrectly called

supination

Eversion, incorrectly called

pronation

Side to side movement is according to which way the sole of the foot points.

22

The Elbow Joint

trochlea

Trochlear notch

synovial cavity

Tendon of biceps b.

Tendon of triceps b.

Articularcartilage

The elbow is a hinge joint. Note the joint capsule which encloses the joint cavity, filled with synovial fluid; Also bursae which help lubricate the movement.

23

Annular ligament

Radial (lateral) collateral ligament

Articularcapsule

The radial head fits neatly in the collar produced by the annular ligamentand turns within this collar. Other primary ligaments are the radial (lateral) collateral ligament and the ulnar (medial) collateral ligament. These help to prevent lateral displacement of the bones at the joints.

24

Annular ligament

Ulnar (medial) collateral ligament

The annular ligament attaches to the lateral collateral ligament and to the ulna, so that the head of the radius is free to rotate.

25

Elbow radiograph, lateral view

Trochlear notch

Trochlea

Soft tissues such as the articular capsule and articular cartilage are not radio opaque, so they appear dark in the x-ray.

26

Elbow radiograph, dorsal view

Olecranon process

Head of the radius

The articular cartilage, not being radio-opaque, shows up clearly as a dark space between the bones.

27

Sagittal Section of The Right Knee

Articular capsule

Anterior cruciateligament

Posterior cruciateligament

Tibia

Femur Patella

Patellar ligament

Quadriceps tendon

The knee is the most complex of the joints, due to its menisci and intracapsular ligaments. It actually consists of three bones, the femur, tibia, and patella. The patella forms the fulcrum or pivot point for extension of the knee. And it translates the shortening action of the quadriceps muscle to its insertion on the tibial tuberosity.

28

Anterior View of the Right Knee

Tibia

Fibula

Patellar ligament

Patella

Quadriceps tendon

Medial condyleLateral condyle

Tibial (medial) collateral ligament

Fibular (lateral) collateral ligament

Posterior cruciateligament

Anterior cruciateligament

Lateral meniscus Medial meniscus

This view into the joint cavity of the knee (anterior aspect) shows the menisci, crescent bowl-shaped cartilages which cushion the knee and provide accommodation for the shapes of each bone’s condyles. The ligaments cross, hence the name cruciate ligaments. This restricts antero-posterior sliding of the tibia against the fibula, as well as twisting of the joint.

29

Patella Femur

Tibia Fibula

Condyles

Knee Radiograph

Radiograph shows the space where the soft tissues are located between the bones.

30

Lab Protocol

1. After studying the lab exercise and this PDF, complete the Review Sheet which accompanies the lab exercise.

2. Use ADAM to study the joints as per directions in the lab manual.

3. Take the quiz on the arthrology.