Ch 5 Part 2 The Appendicular Skeleton Bones Song #1 The Appendicular Skeleton Composed of 126 bones, which attach the limbs to the axial skeleton Allows us to move and manipulate objects Limbs (appendages) Pectoral Girdle Pelvic Girdle The Pectoral Girdle Bones: Scapula Clavicle The Pectoral Girdle Consists of: Not in Notes page 2 clavicles 2 scapulae Connects with the axial skeleton only at the manubrium The Pectoral (Shoulder) Girdle Composed of two bones Clavicle – collarbone (Both start with C) It attaches to the arm away from the thorax and helps prevent shoulder dislocation Scapula – shoulder blade (Both start with S) Triangular and are commonly called wings These bones allow the upper limb to have exceptionally free movement Shoulder girdle is light and flexible, but very susceptible to dislocation The Clavicle The Clavicles (Not in Notes) Also called collarbones Long, S-shaped bones Originate at the manubrium (sternal end) Articulate with the scapulae (acromial end) Processes of the scapula Acromion Process – enlarged end of the spine and attaches to the clavicle Coracoid Process – points over the shoulder and anchors some muscles Borders of the Scapula Superior Inferior angle Vertebral (medial) Axillary (lateral) Glenoid cavity – a shallow socket that receives the head of the arm bone Bones of the Shoulder Girdle Figure 5.20a–b Bones of the Shoulder Girdle Figure 5.20c–d Scapula (shoulder blade) Video The Upper Limbs Arms, forearms, wrists, and hands Note: arm (brachium) = 1 bone, the humerus Bones of the Upper Limb The upper arm is formed by single bone Humerus (also called arm bone) Head of the humerus or proximal end fits into the glenoid cavity The distal end forms a joint with the ulna Figure 5.21a–b The Humerus The Lower Arm Bones (Forearm): Radius Ulna Bones of the Upper Limb The lower arm (forearm) is formed by 2 bones Radius – located on the lateral side or thumb side Ulna – located on the medial side or pinky side Figure 5.21c Bones of the Upper Limb The hand Carpals – eight bones arranged in two rows form the carpus, or the wrist Metacarpals – palm Phalanges – fingers Each hand consists of 14 phalanges – three in each finger Making proximal, middle, and distal The thumb is an exception, it has two, proximal and distal Bones of the Upper Limb Figure 5.22 Bones of the Upper Limb Done with the Upper Limbs Now…. WS Pg1-2 Due Tuesday January 21 Bones of the Pelvic Girdle Bones of the Pelvic Girdle Two Hip bones (Coxal Bones) Composed of three pair of fused bones Ilium Ischium Pubic bone Functions of Pelvic Girdle The total weight of the upper body rests on the pelvis Protects several organs Urinary bladder Reproductive organs Part of the large intestine 1. Ilium: The ilium connects posteriorly with the sacrum at the sacroiliac joint It is a large, flaring bone that forms most of the hip bone If you put your hands on your hips, they are resting on the ilium The upper edge of the ilium is the iliac crest 2. Ischium The ischium is the sitdown bone because it forms the inferior part of the coxal bone The ischial tuberosity is a roughened area that receives body weight when you are sitting 3. Pubis: The pubis is the most anterior part of a coxal bone The pubic bones of each hipbone fuse anteriorly to form a cartilaginous joint called the pubic symphysis Bones of the Pelvic Girdle The ilium, ishcium, and pubis fuse at a deep socket called the acetabulum (hip socket) The acetabulum receives the head of the thigh bone (femur) The male and female pelvis differs The Pelvis Figure 5.23a The Pelvis The Pelvis: Right Coxal Bone Figure 5.23b Gender Differences of the Pelvis Figure 5.23c Comparing the Male and Female Pelvis Female pelvis: smoother Lighter Wider Don’t write: less prominent muscle and ligament attachments Pelvis Modifications for Childbearing Enlarged pelvic outlet Broad pubic angle (> 100°) Less curvature of sacrum and coccyx Wide, circular pelvic inlet Broad, low pelvis Ilia project laterally, not upwards Bones of the Lower Limbs The thigh has one bone Femur – thigh bone Note: Leg = lower leg Thigh = upper leg Figure 5.24a–b Bones of the Lower Limbs Femur (thigh) Patella (kneecap) Tibia and fibula (leg) Tarsals (ankle) Metatarsals (foot) Phalanges (toes) Femur: Heaviest, strongest bone in the body The proximal end has a ball-like head, a neck, and greater and lesser trochanters It has many sites for muscle attachment such as the trochanters and gluteal tuberosity The head of the femur articulates or moves with the acetabulum of the hip bone in a deep, secure socket Distally, the femur has lateral and medial condyles that articulate or move with the tibia below The Patella Also called the kneecap Bones of the Lower Limbs The lower** leg has two bones Tibia Fibula Figure 5.24c Tibia: Larger and more medial (towards the middle of body), Supports body weight At the proximal end, the medial (inner) and lateral (outer) condyles articulate, or move, with the distal end of the femur forming the knee joint Patella is the kneecap The patellar tendon attaches to the tibial tuberosity, a roughened area on the anterior tibial surface Distally, the medial malleolus is the inner bulge of the ankle Fibula: Lies alongside the tibia is thin and sticklike The fibula has no part in forming the knee joint The distal end has the lateral malleolus, forming the outer part of the ankle Bones of the Lower Limbs The foot Calcaneus (Heel) Tarsus (ankle) Metatarsals (sole) Phalanges (toes) Figure 5.25 Foot Supports our body weight and serves as a lever that allows us to propel or move our bodies forward when we walk or run Tarsus makes up the ankle It is composed of seven tarsal bones Most weight is carried by two tarsal bones: Calcaneus or heel bone Talus (ankle bone) located between the tibia & the calcaneus Five metatarsals form the sole Phalanges make up the toes Each toe has three phalanges, except for the great toe which has two phalanges Arches of the Foot Bones of the foot are arranged to form three strong arches Medial longitudinal Lateral longitudinal One transverse Figure 5.26 Feet! Legitimate Bone Video 05 Human Body Skeletal System 7:40-10:10 Bones Song! Animated Bone Song! Best Video of Bones Ever.