Jointsrev2

Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn

Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.

Joints = Articulations

Joints = Articulations• A joint is a site where two or more bones meet

• Classified based on (a) Function (b) Structure

• Functional Classification of Joints based on the amount of movement allowed at the joint:

3 Functional Classes:

(i) Synarthroses – immovable joints

(ii) Amphiarthroses- slightly movable joints

(iii) Diarthroses – freely movable joints

3 Structural classes of Joints• Based on the material uniting the bones and the presence or absence of a joint

cavity: (1) Fibrous joints – Joint cavity absent. Bones united by fibrous CT. 3 types of fibrous joints: Sutures – only in the bones in the skull Syndesmoses – ligaments, cords or bands unite the bones Gomphoses- “peg-in-a-socket” joints- located only between teeth and the bony sockets in the mandible and maxillae(2) Cartilaginous Joints – Joint cavity is absent. Bones are united by

cartilage 2 types: Synchondroses – Hyaline cartilage unites the bones Symphyses - Fibrocatrtilage unites the bones

– Synovial Joints – Joint cavity present. Bones united by ligaments 6 types:



Figure 8.1: Fibrous joints, p. 253.

(a) (b)

Densefibrousconnectivetissue

Suture line

FibulaTibia

Suture Syndesmosis

Ligament



Figure 8.2: Cartilaginous joints, p. 254.

(a)

(c)

(b)

Epiphysealplate(hyalinecartilage)

Synchondroses

Sternum (manubrium)

Joint between first riband sternum (immovable)

Symphyses

FibrocartilaginousintervertebraldiscBody of vertebra

General characteristics of Synovial Joints

• Articular cartilage – caps the ends of the bones• Joint Cavity – space that contains synovial fluid which acts like a

lubricant to reduce friction• Articular Capsule – double-layered consists of an outer fibrous capsule and an inner synovial membrane• Ligaments – 3 types of ligaments in relation to the articular capsule:

Capsular or intrinsic ligaments – part of the fibrous capsule Extracapsular ligaments – located outside of the articular capsule Intracapsular ligaments – located deep to the articular capsule

MENISCI – discs of fibrocartilage that improve the fit at a synovial joint to

minimize wear and tear

BURSAE – flattened fibrous bags of synovial fluid associated with synovial joint; they reduce friction as the joint moves

TENDON SHEATHS – elongated bursae that wrap around tendons to reduce friction



Figure 8.8b: Knee joint, p. 266.

(b)

Fibularcollateralligament

Posteriorcruciateligament

Medialcondyle

Tibialcollateralligament

Anteriorcruciateligament

Medialmeniscus

Patellarligament

Patella

Quadricepstendon

Lateralcondyleof femur

Lateralmeniscus

Fibula

Tibia



Figure 8.8d: Knee joint, p. 266.

(d)

Medialfemoralcondyle


Medialmeniscuson medialtibialcondyle



Figure 8.3: General structure of a synovial joint, p. 255.

(a)

(b)

Periosteum

Ligament

Joint cavity(containssynovial fluid)

Fibrouscapsule

Synovialmembrane

Articular (hyaline)cartilage

Articularcapsule



Figure 8.4: Friction-reducing structures: Bursae and tendon sheaths, p. 257.

(a)

(b)

Acromionof scapula

Glenoid cavitycontainingsynovial fluid

CoracoacromialligamentSubacromialbursa

Cavity inbursa containingsynovial fluid

Synovial membraneFibrous capsule

Humerus

Hyalinecartilage

CoracoacromialligamentSubacromialbursaFibrousarticular capsule

Tendonsheath

Tendon oflong headof bicepsbrachii muscle



Figure 8.8a: Knee joint, p. 266.

(a)

Femur

Tendon ofquadricepsfemoris

Suprapatellarbursa

Patella

Subcutaneousprepatellar bursa

Synovial cavity

Lateral meniscus

Posteriorcruciateligament

Infrapatellarfat pad

Deep infrapatellarbursa

Patellar ligament

Articularcapsule

Lateralmeniscus


Tibia



Figure 8.9: A common knee injury, p. 267.

Lateral

Medial

Patella(outline)

Tibialcollateralligament(torn)

Medialmeniscus(torn)

Anteriorcruciateligament(torn)

Hockey puck

6 Types of Synovial Joints

6 types of synovial joints• 1. Plane joint : articulating surfaces are flat intercarpals/intertarsals 2. Hinge joint: one articular surface is cylindrical and the other a

trough; Elbow joint 3. Pivot joint: one articular surface is round and the other a sleeve

or ring atlantoaxial joint = motion “NO” 4. Condyloid (Ellipsoidal) joint: one articular surface is oval

protrusion and the othe an oval depression atlanto-occipital joint = motion “YES” 5. Saddle joint: one articular bone has convex and concave surfaces

and the other articular bone has a concave and convex surfaces carpometacarpal joint of the thumb

6. Ball-and-socket joint: one articular surface is spherical and the other is a cuplike socket.

hip joint, shoulder joint

ATLANTAXIAL JOINT allows one to motion “NO”

Pivot joint

ATLANTO-OCCIPITAL JOINT allows one to motion “YES”

Condyloid joint



Figure 8.10a: The elbow joint, p. 268.

(a)

Articularcapsule

Synovialmembrane

Synovial cavity

Articular cartilage

Coronoid process

Tendon ofbiceps muscle

Ulna

Humerus

Fat pad

Tendon oftricepsmuscleBursa

Trochlea

Articular cartilageof the trochlearnotch



Figure 8.10c: The elbow joint, p. 268.

(c)

Anularligament

Humerus

Medialepicondyle

Ulnar(medial)collateralligament

Ulna

Articularcapsule

Radius

Coronoidprocess



Figure 8.11a: The shoulder joint, p. 269.

(a)

Acromion

CoracoacromialligamentSubacromialbursa

Coracohumeralligament

Greatertubercleof humerusTransversehumeralligamentTendon sheath

Tendon oflong headof bicepsbrachiimuscle

Articularcapsulereinforced byglenohumeralligaments

Subscapularbursa

Tendon of thesubscapularismuscleScapula

Coracoidprocess



Figure 8.11b: The shoulder joint, p. 269.

(b)

Acromion

Coracoidprocess

Articularcapsule

Glenoid cavity

Glenoid labrum

Tendon of longhead of bicepsbrachii muscleGlenohumeralligamentsTendon of thesubscapularismuscleScapula

Posterior Anterior



Figure 8.11c: The shoulder joint, p. 269.

(c)

Head ofhumerus

Muscle ofrotatorcuff (cut)

Acromion(cut)

Glenoidcavity ofscapula

Capsule ofshoulderjoint(opened)



Figure 8.12a-b: The hip joint, p. 270.

(a)(b)

Articular cartilageCoxal (hip) bone

Ligament of thehead of the femur(ligamentum teres)

Synovial cavity

Articular capsule

Acetabular labrum

Femur

Acetabularlabrum

Synovialmembrane

Ligamentof the headof the femur(ligamentumteres)Headof femur

Articularcapsule (cut)



Figure 8.12c-d: The hip joint, p. 270.

(c) (d)

Anterior inferioriliac spine

IliofemoralligamentPubofemoralligament

Greatertrochanter

Ischium

IliofemoralligamentIschiofemoralligament

Greatertrochanterof femur

Jointsrev2

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