The Structure and Function of the Skeletal System 1

Objectives: Describe the structure and function of the skeletal system Describe the different classifications of joints Identify the location of the major muscles of the human body 2

Structure of the Skeletal System The skeletal system is made up of bones, cartilage and joints. Its important you know how the structure and function of the skeletal system contribute to the vast range of motion required to participate within Sport. 3

Task Labelling a skeleton 4

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The Skeleton It provides a framework that supports your muscles and skin and protects your internal organs. It is made up of 206 bones, which are divided into two groups: 80 form your axial skeleton – the long axis of your body 126 form your appendicular skeleton – the bones that are attached to the axis. 6

Axial Skeleton This forms the main axis or core of your skeletal system and consists of the: A: skull (cranium and facial bones) 7

Axial Skeleton Continued B: thorax (sternum and ribs) 8

Axial Skeleton Continued C: vertebral column 9

Appendicular Skeleton This consists of the following parts: A: 60 bones from the upper limbs. Each upper limb is made up of 1 humerus, 1 radius, 1 ulna, 8 carpals, 5 metacarpals and 14 phalanges 10

Appendicular Skeleton Continued B: 60 bones from the lower limbs. Each lower limb is made up of 1 femur (thigh bone), 1 tibia (shin bone), 1 fibula, 1 patella (kneecap), 7 tarsals, 5 metatarsals and 14 phalanges. These bones are designed for weight-bearing, locomotion and maintaining an upright posture. They need to have a higher degree of strength and stability than the bones of the upper limbs. 11

Appendicular Skeleton continued C: The shoulder girdle consists of 4 bones – 2 clavicles and 2 scapulae – which connect the limbs of the upper body to the thorax 12

Appendicular Skeleton Continued D: The pelvic girdle is made up of 3 bones: the ilium, pubis and ischium. These bones fuse together with age. The principal function of the pelvic girdle is to provide a solid base through which to transmit the weight of the upper body. It also provides attachment for the powerful muscles of the lower back and legs, and protects the digestive and reproductive organs. 13

Types of Major Bone Long Bones – found in limbs. They have a shaft known as the diaphysis and two expanded ends known as the epiphysis. 14

Types of Major Bone Short Bones – small, light, strong, cube-shaped bones consisting of cancellous bone surrounded by a thin layer of compact bone. The carpals and tarsals of the wrist and ankles are examples of short bones. 15

Types of Major Bone Flat Bones – are thin, flattened and slightly curved. They have a large surface area. Examples include the scapulae, sternum and cranium. 16

Types of Major Bone Sesamoid Bones – have a specialised function. They are usually found within a tendon such as the patella in the knee. Irregular Bones – have complex shapes that fit none of the above categories. i.e. The bones of the spine. 17

Activity 1 A fitness instructor regularly draws on anatomical knowledge to design and develop fitness programmes for clients. Draw two large tables to describe the structure and function of the axial and appendicular skeletons. Your descriptions should Include the location of all the major bones of the skeleton and their different types. P1: Describe the axial and appendicular skeletons and locate and name all the following major bones: Cranium, clavicle, ribs, sternum, humerus, radius, ulna, scapula, ilium, pubis, ischium, carpals, metacarpals, phalanges, femur, patella, tibia, fibula, tarsals, metatarsals, vertebral column, vertebrae – cervical, thoracic, lumbar, sacrum and coccyx. 18

ANSWER: Axial Appendicular Cranium (Flat) Ribs (Flat) Sternun (Flat) Vertebral Column: Cervical, Thoracic, Lumbar, Sacrum and Coccyx (Irregular) Clavicle (Long) Humerus (Long) Radius (Long) Ulna (Long) Scapula (Flat) Ilium (Irregular) Pubis (Irregular) Ishium (Irregular) Carpals (Short) Metacarpals (Short) Phalanges (Short) Femur (Long) Patella (Sesamoid) Tibia (Long) Fibula (Long) Tarsals (Short) Metatarsals (Short) 19

Function of the Skeletal System Support – your bones give your body shape and provide the supporting framework for the soft tissues of your body Protection – the bones of your skeleton surround and protect vital organs and tissues in your body. Your skull protects your brain, your heart and lungs are protected by your thorax, your vertebral column protects your delicate spinal cord and your pelvis protects your abdominal and reproductive organs. 20

Function of the Skeletal System Attachment for Skeletal Muscle – parts of your skeleton provide a surface for your skeletal muscles to attach to, allowing you to move. Tendons attach muscles to bone, which provides leverage. Muscles pulling on bones act as levers and movement occurs at the joints so you can walk, run, jump, throw etc. You should remember, however, that the type of joint determines the type of movement possible. 21

Function of the Skeletal System Source of Blood Cell Production – your bones are not completely solid, as this would make your skeleton heavy and difficult to move. Blood vessels feed the centre of your bones and stored within them is bone marrow. The marrow of your long bones is continually producing red and white blood cells. This is an essential function as large numbers of blood cells, particularly red, die every minute. 22

Function of the Skeletal System Store of minerals – bone is a reservoir for minerals such as calcium and phosphorus, essential for bone growth and the maintenance of bone health. These minerals are stored and released into the bloodstream as required, facilitating the balance of minerals in your body. 23