Skeletal System. Supplementary Information

Transcription

1 Skeletal System Supplementary Information

2 COMMON ANATOMICAL TERMS Planes run through the body side to side and front to back eg. median plane Surfaces of the body are also named eg. anterior surface This person is standing in the anatomical position with palms facing forward - 1 -

3 SKELETAL SYSTEM FUNCTION 1. Protection 2. Locomotion 3. Support and rigidity 4. Production of red blood cells 5. Attachment of muscles, tendons and ligaments 6. Storage (minerals) ANATOMY 206 skeletal bones Bones are dense dry connective tissue o Mixture of organic and inorganic material o Inorganic material mainly magnesium and calcium salts o Living bone has plastic quality ie. its shape can change o Bone has good blood and nerve supply OSSIFICATION Fetal skeleton is a cartilage model becoming bone by process know as ossification Ossification is carried out by cells called osteoblasts - 2 -

4 Ossification completed by age 25 but osteoblasts continue to make new bone eg. repairing fractures SKELETAL SYSTEM TYPICAL BONE 2 main types of bone tissue: COMPACT: CANCELLOUS: which is solid, smooth and forms the shafts and ends of bone which has latticework structure and forms the insides of the ends of bones. This is where red bone marrow is found MEDULLARY CAVITY It is a narrow cavity in the shaft of bones containing yellow bone marrow PERIOSTEUM It is a strong covering over the whole bone. It has a rich blood supply and osteoblasts here are stimulated to work by action of muscle attachments CARTILAGE - 3 -

5 It is found on joint surfaces and is a smooth connective tissue. It has no blood supply - 4 -

6 DIAGRAM OF A TYPICAL BONE Label the diagram below using the descriptions from the previous page. Colour in the diagram if you think it will help you - 5 -

7 CLASSIFICATION OF BONES Long Bones greater dimension in one direction Short Bones same dimension in all directions Flat Bones sandwich of compact/cancellous/compact bone Irregular Bones do not fit above definitions Sesamoid Bones held inside tendons. Protective function BONE GROWTH AND DEVELOPMENT Like skin, bone replaces itself throughout adult life. When old bone tissue is replaced by new bones tissue this is called remodeling. In long bones, new bone is formed externally and the diameter of the bone increases Bone growth and development depend on: o Sufficient quantities of calcium and phosphorus (makes bones hard) o Vitamin D (for the absorption of calcium from the diet) o Vitamin C (to help maintain the matrix of bone) o Vitamin A (to help regulate the number of osteoblasts) o Perhaps Vitamin B12 o The right hormones - 6 -

8 KNOW YOUR BONES CRANIUM UPPER LIMB Parietal Humerus Frontal Ulna Ethmoid Radius Sphenoid Carpals: Scaphoid Occipital Lunate Temporal Triquetral Pisiform FACIAL Trapezium Nasal Trapezoid Zygomatic Capitate Maxilla Hamate Lacrimal Metacarpals (5) x2 Turbinator Phalanges - Hand (14) x28 Palatine Mandible LOWER LIMB Vomer Femur Hyoid Tibia Fibula VERTEBRAE Tarsals: Cuneiforms Cervical (7) lateral) Thoracic (12) Lumbar (5) Sacrum (5) Coccyx (4) SHOULDER GIRDLE Scapula Clavicle PELVIC GIRDLE Innominate bones: Ischium Ilium Pubis (medial, intermediate, Navicular Cuboid Talus Calcaneus Metatarsals (5) x5 Phalanges - Foot (14) x2 Patella THORAX Sternum Ribs (12 pairs)

9 JOINT MOVEMENTS Flexion / Extension Abduction / Adduction Medial rotation / Lateral rotation Pronation / Supination Elevation / Depression Retraction / Protraction Side flexion Rotation Dorsiflexion / Plantarflexion Eversion / Inversion Accessory movements Circumduction Opposition Hyperextension Some specific joints also have special movements exclusive to them: Spine - Lateral flexion Scapula and jaw - Protraction / retraction elevation / depression Forearm / wrist - Pronation / supination - radial deviation / ulnar deviation Thumbs - Opposition - 8 -

10 3 types: JOINTS FIXED (Fibrous) held together by fibrous ligament. No movement SLIGHTLY MOVEABLE (Cartilaginous) - cartilage pad between bone ends. Some movement FREELY MOVEABLE wide range of movement. Also known as synovial joints SYNOVIAL JOINTS see diagrams Section Through A Typical Synovial Joint and Types of Synovial Joints Freely moveable Ends of bones covered with cartilage Joint surrounded by synovial membrane Joint space filled with synovial fluid. This is secreted by synovial membrane and has the consistency of egg white. It provides nutrients to the cartilage and lubrication for joint Capsular ligament forms a sleeve of dense fibrous tissue around the joint Bursae found between muscle tendons and ligaments are small pouches of synovial membrane. Protective function

11 SECTION THROUGH A TYPICAL SYNOVIAL JOINT Label the diagram below. Colouring in the components may help you

12 TYPES OF SYNOVIAL JOINTS

13 TYPES OF SYNOVIAL JOINTS BALL & SOCKET The ball-like head of one bone fits into the socket-like head of another, permitting all movements. Eg. shoulder and hip joints SADDLE The concave surfaces of two bones articulate with one another. Forward and back and side-to-side movements are possible. Eg. The trapezium and metacarpal bones of the thumb PIVOT A ring of bone rotates about a process of bone. Movement is limited to rotation. Eg. skull on its atlas (1 st cervical vertebra) rotates about the odontoid process of the axis (2 nd cervical vertebra) HINGE The C-shaped surface of one bone swings about the rounded surface of another. Movement is limited to flexion/extension. Eg. elbow, interphalangeal joints ELLIPSOID This is a reduced ball and socket configuration in which rotation is not permitted. Found between radius and ulna of the forearm where they articulate with the scaphoid and lunate carpals of the wrist GLIDING Bones glide across one another. Eg. intercarpal joints