Human Anatomy, First Edition McKinley & O'Loughlin Chapter 8 : Appendicular Skeleton 8-1
Appendicular Skeleton Includes the bones of the upper and lower limbs. The girdles of bones that attach the upper and lower limbs to the axial skeleton. pectoral girdle consists of bones that hold the upper limbs in place pelvic girdle consists of bones that hold the lower limbs in place 8-2
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APPENDICULAR SKELETON Upper limb bones (upper extremity bones) pectoral girdle Bones of the arm: Bones of the forearm Bones of the hand Scapula Humerus Radius Carpal Clavicle Ulna Metacarpal Phalanges 4
Bones of the two pectoral girdle:- Scapula + Clavicle 5
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a) Supraspinous fossa (origin for the supraspinous muscle). b) Infraspinous fossa (origin for the infraspinous muscle). c) Scapular spine with its superior and inferior lip (insertion for mm trapezius and deltoideus). d) Acromion (insertion for mm trapezius and deltoideus). e) Glenoid surface (acromial clavicular extremity). f) Coracoid process (insertion for ligaments trapezoideum, conoidium, and coraco-acromial; mm pectoralis minor, coracobrachialis, and short head of biceps brachii). B A
Posterior Shoulder Anatomy Showing Major Muscle (Supra & 10 Inferspinatus Muscle)
Bone Prominences Condyle Rounded process where bones articulate.
A condyle : is the round prominence at the end of a bone, most often part of a joint - an articulation with another bone. On the femur, in the knee joint: Medial condyle Lateral condyle On the tibia, in the knee joint: Medial condyle Lateral condyle On the mandible, in the temporomandibular joint: Mandibular condyle On the occipital bone, in the atlanto-occipital joint: Occipital condyles
Bones of the arm: Humerus is the largest longest bone of the upper limb located between shoulder and elbow 13
Glenohumeral joint Possible exam question: Which bones of Pectoral Girdle form the Glenohumeral joint? 14
Shoulder joint (Glenohumeral joint) Shoulder joint is a the ball and socket articulation The articulation is between the head of humerus and glenoid fossa of Scapula. 15
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Radius Radius which has rounded head (disk shape head) Proximally articulates with humerus radius is located laterally on the thumb side 19
Ulna Ulna is the longer of the two bones extends between elbows and wrists. Ulna has large depression, serving for articulation with the humerus. 20
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Bones of the hand Carpal Metacarpal Phalanges 23
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Joints of the upper limb:- Shoulder joint, between the head of humerus and glenoid fossa of Scapula. Elbow joint, between humerus and Radius and Ulna. Wrist joint, between Radius and Carpal bones. 27
Possible questions Name the Joints of the upper limb and list the bones that constitute them. Name the bones that form the upper limb from proximal to distal. Name the bones of the hand 28
APPENDICULAR SKELETON Bones of Lower limb (lower extremity) pelvic girdle (2 hips ) Thigh bones Leg bones Foot bones ilium Ischium Pubis Femur Patella Tibia Fibula Tarsal metarsal Phalanges 29
Pelvis The adult pelvis is composed of four bones: the sacrum, the coccyx, and the right and left ossa coxae. The 2 hip bones each consists of 3 large fused bones:1- ilium 2- Ischium 3- pubis Protects and supports the viscera in the inferior part of the ventral body cavity. Pelvic girdle refers to the left and right ossa coxae only. 8-30
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Os Coxae Commonly referred to as the hip bone or innominate bone. Each is formed from three separate bones: the ilium, the ischium, and the pubis Each articulates posteriorly with the sacrum at the sacroiliac joint. 8-33
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Femur bone which is the largest, heaviest, and the strongest. Located in the body between hip bone and knee joint. 39
The head of the femur articulates with the acetabulum. The femur is the strongest bone in the body, about as strong as steel. It has the ability to support up to 30 times the weight of an adult 40
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Left knee-joint from behind, showing interior ligaments 42
Right knee-joint, from the front, showing interior ligaments. 43
Femur A. Origins: Gastrocnemius, Vastus lateralis, Vastus medialis, Vastus intermedius. B. Insertions: tensor fasciae latae, gluteus medius, gluteus minimus, Gluteus maximus. C. Articulations: 1. Hip: acetabulum of pelvis superiorly 2. knee: with the tibia and patella inferiorly. 44
Bones of the thigh: Patella Patella bone is a small bone at the anterior side, it protects the knee. It is formed within the tendon of the quadriceps femoris muscle. Note: a bone formed within a tendon of a muscle is called sesamoid bone Patella. A. Anterior view. B. Posterior view. C. Superior view. Patella is the largest sesamoid bone in the body 45
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Tibia located at the anterior and medial part of leg between the Knee joint and ankle joint. Tibia is the only bone that articulates with the femur at the knee joint 47
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Bones of the leg: Tibia The distal end of the tibia articulates with the tarsal bone (talus) to form the larger part of the ankle joint. A. Anterior view. B. Posterior view. C. Cross-section through shafts. D. Posteromedial view of distal ends 49
Bones of the leg: Fibula Fibula is a long slender bone parallel and lateral to tibia Its proximal end articulates with tibia and its distal end articulates with talus. 50
Bones of the foot:- Consist of three groups of bones: Tarsal bones (7 short bones) Metarsal bones (5 bones) Phalanges 14 in number 3 phalanges in each digit except the big toe which has 2 phalanges 51
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Arches of the Foot The sole of the foot does not rest flat on the ground. Helps it support the weight of the body. Ensures that the blood vessels and nerves on the sole of the foot are not pinched (squeezed) when standing. 8-54
Aging of the Appendicular Skeleton Skeletal mass and density decline. Erosion and porosity increase. Bones become more brittle and susceptible to fracture. Articulating surfaces deteriorate, contributing to osteoarthritis. Osteoarthritis (OA) is the most common joint disorder, which is due to aging and wear and tear on a joint. Changes begin in childhood and continue throughout life. 8-55
High heels have also been linked to overworked or injured leg muscles, osteoarthritis of the knee, plantar fasciitis and low back pain. The increased weight on your toes causes your body to tilt forward, and to compensate, you lean backwards and overarch your back, creating a posture that can strain your knees, hips, and lower back. "The change to the position of your spine puts pressure on nerves in the back and can cause sciatica, a condition where nerves become trapped, triggering pain and numbness as far down as the feet, women who wear high heels often suffer a shortening of the Achilles tendon because once the heel is pointed upwards, it tightens up. 8-56