Download Appendicular skeleton

Anatomy and Physiology
Appendicular Skeleton
Appendicular Skeleton
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126 bones
Pectoral girdle
Pelvic girdle
Arm and leg bones
Hands and feet
Shoulder Girdle
• Two Bones
– Clavicle or Collar
Bone
– Double Curve
– Attaches to
Manubrium of
sternum and
scapula
– Braces the
shoulder joint
Shoulder Girdle cont
• Scapula or Shoulder Blade
• Triangular “wings”
• Two important processes
– Acromion connects to clavicle to form
acomioclavicular joint (AC joint)
– Coracoid points over the top of the shoulder for
muscle attachment
• Suprascapular Notch for nerve passage “stinger”
• Glenoid cavity receives the head of the
humerous
• Not directly attached to the axial skeleton
Shoulder Joint
• Attached only at the sternoclavicular joint
• Allows for much flexability
• Glenoid cavity is shallow and poorly
reinforced by ligaments
• All the above lead to easy dislocation!!!!
Upper Arm Bone
• Humerus
– Long bone
– Proximal end= head- fits into glenoid cavity
– Anitomical neck vs surgical neck
– Trochlea and Capitulum Articulate with forearm
Lower Arm
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Two bones the Radius and Ulna
Radius associated with the thumb (1st phal)
Ulna with the pinky (5th phalange)
Radius rotates over the ulna
Radius articulates with the capitulum
Ulna grabs the Trochlea with processes
The Hand
Sad
Scaphoid
&
Lonely
Lunate
Travis
Triquetrum
Pushes
Pisiform
His
Hamate
Cart
Capitate
Through
Trapezoid
Texas
Trapezium
Pelvic Girdle
• Two Coxal Bones
• With the sacrun and
coccyx = bony pelvis
• Bears the weight of a
standing person
– Must be strong and
stable
– Better than the
shoulder joint!!!
Hip Bones
• Fusion of three bones
– Ilium
– Ischium
– Pubis
• Ilium
– Connects to sacrum (sacroiliac joint)
– Big flaring alae (iliac crest)
Hip Bone
• Ischium
– Inferior “Sit-down” bone
– Ischial spine narrows the outlet of the pelvis
– Sciatic Notch for nerves and blood vessels
• Pubis
– Anterior bone
– Forms obturator Formen with ischium
– Two fuse at the symphysis pubis
Pelvis
• All three bones form
acetabulum for thigh
bone
Male Versus Female
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Female inlet and outlet (ischial spines) larger
Female shallower and lighter
Females alae flare more
Female has smaller sacrum
Smaller Pubic arc in females
Lower Limb Bones
• Thigh bone = Femur
• Heaviest and strongest bone in the body
• Slants medially
– Seen more in females due to wider pelvis
• Lower leg = Tibia and Fibula
• Tibia is the shin bone
• Fibula smaller and lateral
– only involved in ankle not knee
Femur
•Proximal end is the
head (acetabulum)
•Greater and lesser
trochanter & gluteal
tuberosity for muscle
attachment
•Largest and strongest
bone in the body
Tibia/Fibula
• Joined proximally and
distally at tibiofibular
joint
• Connected by
interosseous membrane
• Both have a malleolus
• Tibial tuberosity for
patellar tendon
Foot
• Similar to hand
• Supports and moves
• 7 tarsal bones
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Talus
Calcaneus
Navicular
Cuboid
3 Cuneiforms
• Metatarsals
• Phalanges
Foot
• Form 3 arches
– Medial
– Lateral
– Transverse
• Flat feet caused by
“fallen arches
• Plantar fasciitis
Joints
• Called articulations
• All bones but the hyoid join at least one
other bone
• Allow for flexibility
• Classified by structure and function
Functional classification
• Synarthroses
– Immoveable joints
– Axial skeleton
• Amphiarthroses
– Semi-moveable joints
– Axial skeleton
• Diarthroses
– Freely moveable
– limbs
Structural Classification
• Fibrous
– Usually immoveable
• Cartilagenous
– Semi-moveable usually
• Synovial
– Freely moveable
• Based on the tissue separating the bones
Fibrous Joints
• Skull sutures
• Also the distal ends of
the tib/fib
Cartilaginous Joints
• One ends are joined by cartilage
– Causes them to be amphiarthrotic
• Symphysis pubis
• Intervertebral Joints
– Fibrous cartilage
• Rib and sternum joints are synarthrotic
Cartilaginous joints
Synovial Joints
• Articulating bones separated by a joint
cavity
• Cavity filled with synovial fluid
• All of the limb joints
• 4 distinguishing features
Synovial joints
1. Articular cartilage
2. Fibrous capsule lined with synovial
membrane
3. Joint cavity filled with fluid
4. Ligaments to stabilize the joint
• The often have bursae and tendon
sheaths associated
– May become inflammed causing
pain/swelling
Types of Synovial Joints
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Based on shape of
bones articulating
1. Plane joint
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Flat short bones
No rotation ex:
intercarpal joints
Hinge Joint
2. Hinge joint
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Uniaxial or
movement in one
plane only
Ulna of the elbow
grabs the humerus
Pivot Joint
3. Pivot Joint
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Round end of one
into a ring on
another
Also uniaxial
(rotation around long
axis)
Proximal radioulnar
joint
Condyloid Joint
4. Condyloid Joint
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Round end fits into
concave structure
Biaxial (no rotation)
Between the
proximal phalange
and metacarpal
Saddle Joint
5. Saddle joint
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Much like the
condyloid just slight
shape difference
Biaxial
Ball and Socket Joint
6. Ball and socket joint
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Round end (head) of
one bone fits into
round socket
Multiaxial including
rotation
Hip and shoulder