PECTORAL GIRDLE

Clavicle - the collar bone is the most frequently broken bone in the body.
Falling on an outstretched arm will do the trick.

Scapula - this ball and socket joint that is not nearly as tightly bound as the hip/femur joint.
Ligaments extend from the acromion and the coracoid processes which make a pocket
for the head of the humerus. Therefore "shoulder dislocations" are common. Impact fractures
of the humerus occur when it is driven against the glenoid process. Notice the prominent
posterior spine of the scapula. Above it lies the supraspinatus muscle, below it the
infraspinatus. Notice the relationship between bone naming and muscle naming?
ee pg. 226//230.
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Humerus - don't forget how to spell it! There is no 'o.' Just below the head is the
anatomical neck, just below that, at a 75 degree angle is the surgical neck, so called
because breaks occur there. At its distal/lateral end, the capitulum articulates with
the head of the radius. Medially the trochlea articulates with the ulna. See p. 231.
 
 
 

ELBOW - Also see p. 268.

Label: trochlea, radius, radial notch of the ulna, capitulum.

Label the radial notch and olecranon process.
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Radius - In lab notice how the head of the radius pivots in the radial notch of the ulna
- this is a pivot joint. The radius lines up with the thumb. Remember the Colles' fracture?
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Label the bones of the hand and wrist.
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Carpals - cuboid wrist bones. The joints between the radius/ulna and the carpals are called
ellipsoidal or condylar because their surfaces are rounded. The joint between the trapezium
carpal and the metacarpal of the thumb is called a saddle joint. 

Phalanges - if the tendon (joins muscle to bone) to the distal phalange is broken away
from the bone (distally) mallet finger results. The affected patient cannot straighten the distal phalange.

Label the phalanges.

See the e-handx rays, pictures, descriptions.

HIP OR PELVIC GIRDLE - Also see p. 270

Know the three bones of the os coxa or innominate bone. Label the acetabulum. See p. 237.
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:
Which is the female pelvis? Give two reasons for your choice.
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Sectional view: Why is the hip a tighter joint than the shoulder?-
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Identify the bones and ligaments of the hip joint. See pg. 270.
 
 

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Hip replacement, courtesy of a colleague who used it and had another implanted.
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LOWER EXTREMITY - Also see p. 266..

Femur - the thighbone is bound to the hip by ligaments. The trochanters are points
of attachment for hip and buttocks muscles.

Patella- the patella is a sesamoid bone imbedded in tendons. If it does not track
properly in the center of the patellar groove of the femur, a condition called "runner's
knee" results.

Fibula - is a very thin bone which may be fractured by a lateral impact. See Pott's
fracture in previous study guide.

Tibia - is medial to the fibula. Its the leg bone.
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Ankle - the ankle is formed by the lateral maleolus (condyle) of the fibula and the
medial maleolus of the tibia.
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Label the bones of the foot.
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Tarsals - the calcaneus forms the heel bone and the talus supports the ankle and leg. Many of the
articulations between the tarsals, e.g., the navicular and cuneiforms, are elipsoid and gliding
or plane joints. See pg. 241//245.

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Lable as above. Review the "Pott's fracture." Which is the right ankle?
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ARTICULATIONS (joints), Chapter 8 - See pg. 253.

TYPES

Structural

1. Fibrous - sheet like, no joint cavity seen.
2. Cartilagenous - no joint cavity here.
3. Synovial - they have a joint cavity, surrounded by a ligaments and lined by a synovial membrane.
 

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Dorsal phalange #2-5 typical.


Which structure is the tendon? The ligaments?
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Synarthrosis/Immovable joints

1. Suture - found between the flat bones of the skull.
2. Gomphosis - aided by collagen, holds a tooth in its socket.
3. Synchondrosis - the epiphyseal plate is an example.
4. Synostosis- e.g., a bony connection between the frontal bones.

1. Syndesmosis - a ligamentous, sheet-like fibrous joint. An example is found
between the tibia and the fibula.
2. Symphysis - see pubic symphysis, above.

The synovial membrane secretes synovial fluid into the synovial cavity. This phrase
is not redundant! A fibrous capsule of ligaments (join bone to bone) surrounds the
joint.

Movements - see p. 260-263.

1. flexion - reduces the angle between bones in a joint. A dorsiflexion is toes pointing
superiorly. Toes pointing inferiorly is called a plantar flexion. Plantar means sole. Is this
really an extension of the foot?
2. extension - increases angle between bones in a joint. A hyperextension is an extreme
extension, like making a hitchiker's thumb or bending your head backwards as far as it will go.
3. adduction - bone is moved towards the mid-line.
4. abduction - bone is moved away from mid-line.
5. circumduction - means moving the limb in a circle.
6. rotation - pivoting in a circle.
7. protraction - sticking your chin out.
8. retraction - pulling your chin in.
9. supination -palms face anteriorly.
10. pronation - backs of the hand face forward.

Types of Diarthroses/Synovial Joints

Types of Diarthroses  (See page 263-264.)

1. Gliding - articulation between bones makes a straight line (see above, tarsals and cuneiforms).

2. Hinge - the articulation of the ulna and trochlea of the humerus.

3. Pivot - radius rotates or pivots in the radial notch of ulna.

How is the atlantoaxial joint like a pivot joint and the atlanto-occipital joint like a hinge joint?
Nod your head “no” and “yes.”

4. Ellipsoidal or condyloid - articulations have rounded or cupped surfaces; e.g., radius and carpals and the atlanto-occipital joint.

5. Saddle - literally a saddle is made by the trapezium as it articulates with the first metacarpal of the thumb.

6. Ball and Socket - can do three movements - flexion-extension, adduction-abduction, and rotation.
 

1. Meniscal Cartilages broken - the wedge-like cartilages that cushion the impact between the femur and tibia break. They can be removed by fiber optic arthroscopic surgery. Which meniscus is more likely to be broken if the impact is medial?
2. Cruciate ligaments -the anterior cruciate ligament is more likely to break or detach than the posterior cruciate.
3. Collateral ligaments -are ruptured. Which collateral ligament, the medial or lateral, is more likely to rupture if the impact is lateral?

 Label the structures of the "unhappy triad."
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See x-rays, drawings and descriptions from the Univ. of Newcastle, U.K.,
http://numedsun.ncl.ac.uk/sg/tutorials/knee/

Sprains- stretching and rupture (partial) of ligaments.

Pulls - tears and stretching in the series elastic elements.

Arthritis-Types (See p. 273)

1. Osteoarthritis- wear and tear to the articular cartilages causes the edges to be
rough with increased friction, then inflammation and fusion of the articulating bones results.
2. Rheumatoid - an auto immune disease in which white blood cells attack joint tissues.
See http://www-medlib.med.utah.edu/WebPath/BONEHTML/BONE044.html
3. Gouty - crystals of sodium urate (from uric acid waste) form in joints, usually the
big toe-metatarsal joint. The problem is a formation of too much uric acid by the liver
(from protein and nucleic acid metabolism) or inability of the kidney to excrete normal
amounts. See http://www-medlib.med.utah.edu/WebPath/BONEHTML/BONE062.html
4. Lyme - bacterial infection acquired from deer tick bites. Treatment of acute Lyme disease
(bull's eye rash of the skin) is easy with antibiotics, but hard to get rid of if the infection is
chronic because the bacteria are in deep tissues.

Classes of Levers - See Chapter p. 328-329.

First Class Lever - resembles a see-saw with a fulcrum in the middle of the force and
effort. It is diagrammed as E-F-R. An example is the splenius capitis which inserts on the
occipital bone of the skull, extending it (the force) and pulling the chin (the resistance).
Examine the illustration, which joint is the fulcrum?

Second Class Lever - resembles a wheel barrow - the gastrocnemius muscle pulls the heel
(calcaneus) upward [like you are lifting the handles of the wheel barrow], this causes the
metatarsal/phalange [the wheel] joint to press against the floor. When you stand up on your
toes, the resistance is the weight of the body pressing down on the ankles. The second class lever
is diagrammed F-R-E.

Third Class Lever - the fulcrum and resistance are at opposite ends, the effort in between.
The historical Jesus picked up and shouldered his cross this way. Examples are the adductors of
the thigh, tweezers, and lifting a shovel of dirt. The fulcrum is the hip joint, the effort is the
adductors' contractions and the resistance is the weight of the leg. The third class lever is
diagrammed F-E-R.
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Study Question
1. Describe the articulating bones and lever relationships in a forearm flexion, standing on your toes,
and a hyperextension of the head.
2. Describe the cause and effects of the typical athletic knee injury.

Bone Review and Study Site

http://www.fleshandbones.com/
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Email:jaliff @ gpc.edu