The Skeletal System Appendicular Skeleton • Includes the pectoral girdle, upper limbs, pelvic girdle and lower limbs What is the pectoral girdle? Pectoral girdle • These are the bones that attach the upper limbs to the axial skeleton. Clavicle • Aka collarbone • The most frequently broken bone. • It is an S- shaped bone that connects the upper arm to the trunk. • The medial end articulates with the sternum and the lateral end articulates with the scapula. Scapula • Aka shoulder blade. • This is a large flat, triangular shaped bone located on the posterior thoracic cage. Spine • a prominent ridge that runs diagonally across the scapula. Body • The main flat portion of the scapula. Acromion • The projection from the lateral end of the spine. Site of articulation with clavicle Glenoid Cavity/fossa • A depression inferior to the acromion where the head of the humerus fits into. Coracoid Process • An anterior projection that serves as a site of ligament and muscle attachment. Upper Limb / Extremity • Includes 30 bones in each limb. –Humerus (arm) –Ulna & radius (forearm) –8 carpals (wrist) –5 metacarpals (hand) –14 phalanges (fingers) Humerus • The longest and largest bone of the upper limb. • Articulates with the scapula proximally and radius and ulna distally. Anatomical Neck • Constricted region distal to the head. • Site of growth plate. Body • The main portion of the bone (diaphysis) Deltoid Tuberosity • Boney process on the lateral side of the humerus that serves as the site of attachment for the deltoid muscle. Capitulum • A small rounded eminence on the distal end of the humerus that articulates with the radius Trochlea • A spool-shaped surface that articulates with the ulna Olecranon Fossa • A depression in the back of the humerus that receives the ulna when the forearm is straight. Station Review • Number from 1- 10 on a scrap sheet of paper. The Forearm Ulna • The medial forearm bone. (Pinky side) • The longer of the 2 forearm bones. Olecranon • The bony process on the proximal end of the ulna. • The bony part of the elbow. Coronoid process • An anterior projecting process inferior to the olecranon. • Together they help hold the trochlea. Trochlear notch • A semicircular depression formed by the olecranon and coronoid process Radial Notch • A depression lateral to the trochlear notch that receives the head of the radius. Styloid process of the Ulna • A bony projection at the distal end of the ulna. Radius • The lateral forearm bone. (Thumb side) Radial tuberosity • A roughened bony region on the anterior proximal surface. • Site of biceps brachii attachment Styloid process of the Radius • Pointy projection at the distal end of the radius The wrist Carpals • 8 bones, 4 bones in 2 rows. • Short bones named for their shape. • Proximal row: scaphoid, lunate, triquetrum, and Pisiform • Distal row: Trapezium, Trapezoid, Capitate, and hamate Metacarpals • The 5 long bones that form the palm. • Numbered 1-5 starting at the thumb. Phalanges • 14 in each hand • 2 in the thumb (proximal and distal) • 3 in the remaining 4 digits (proximal, intermediate and distal) Review • Which bones make up a pectoral girdle? What is the function of the pectoral girdle? • With which part of the scapula does the humerus articulate? • What part of which bones make your “knuckles”? • What bones form the upper limb, from proximal to distal? Take out a ½ sheet of paper and number it 1-11 The Pelvic Girdle and Lower Limb Pelvic (hip) Girdle • The pelvis is made up of 2 bones called hip bones or Coxal bones • The pelvic bones attach to each other anteriorly by a fibrocartilage pad called the Pubic Symphasis. • The hipbones articulate with the sacrum in the posterior. Pelvis vs. pelvic girdle The pelvis is made up of: 1. The coxal bone 2. The sacrum 3. The coccyx What’s the difference between the pelvis and the pelvic girdle? Each hipbone is actually the fusion of 3 bones 1.Ilium - superior portion 2.Pubis - anterior portion – Site of pubic symphysis 3.Ischium – inferior and posterior portion Lower Limb • 30 bones in each – Femur (thigh) – Patella – Tibia & Fibula (leg) – Tarsals – Metatarsals – Phalanges Femur • Thigh bone • Longest, strongest and heaviest bone in the body • It articulates with the coxal bone proximally and the tibia distally. Lateral & Medial Condyles • Rounded projections that articulate with the tibia. Greater Trochanter • Large lateral boney projection that serves as a point of muscle attachment. Patella • Sesmoid bone • Found in the tendon of the quad muscle. Tibia • The shin bone • Larger of the 2 lower leg bones • medial Fibula • The smaller, lateral lower leg bone. • The tibia articulates with the femur and the Fibula at the proximal end and the talus at the distal end. • The patellar tendon attaches to the Tibial tuberosity on the tibia. Medial maleolus • The distal end of the tibia ends in the boney process that can be seen as a bump in the medial ankle. Fibula (– add this slide to notes) • Lateral lower leg bone. • Articulates with the tibia and the talus (tarsal bone) Lateral maleolus • Distal projection at the end of the fibula. The Foot Tarsals • 7 bones - 2 posterior: Talus and Calcaneus - 5 anterior: cuboid, navicular and 3 cuneiform Talus • This is the tarsal bone that articulates with the tibia. Calcaneus • Your heal bone. • The most posterior of the tarsal bones. Metatarsals • 5 bones that make up the pad of your foot. Phalanges • 14 in each foot • 2 in the Big Toe (Hallux) • 3 in the other toes. Warm Up • What are the 3 parts of the coxal bone? • What bone does the Achilles tendon attach to? (It is the most posterior of the tarsal bones) • What is the medial lower leg bone?.