Skeletal System: Bones and Joints

A born baby has about 276 bones while an adult has 206 bones, this is because as you grow some bones join together in a single bone. * Bones are 20% of your weight. * The Skeletal System consist of: * Bones * Cartilages * Tendons * Ligaments * Joints * Functions of the skeletal system -bones perform various anatomic (mechanical) & physiologic function. They: 1. Stabilize, provide shape & support the body 2. Protect internal tissues & organs 3. Allows body movements 4. Stores minerals & fats -hydroxyapatite-calcium phosphate crystals 5. Site of blood cell production

Blood supply * Blood reaches the bones through three paths: * Haversian canals- minute channels that lie parallel to the axis of the bone, that are passages for arterioles. * Volkmann’s canals- contain vessels that connect to the outer bone * Vessels in the bone ends & within the marrow Types of Bones according to shape: 1. Long Bone -longer than they are wide -most of the upper & lower limbs are long bones except the wrist & ankle. 2. Short Bones -approximately as broad as they are long -Cube-shaped -mostly spongy Ex. Bones of the wrist & ankle 3. Flat Bones -relatively thin, flattened shape Ex. certain skull bones *ribs *scapulae *sternum 4. Irregular Bones -include the vertebrae & facial bones -with shapes that do not fit readily into the other 3 categories Parts of the Long Bone: 1. Diaphysis- shaft 2. Epiphysis- end of long bones 3. Articular cartilage- covers the epiphyses 4. Epiphyseal plate/growth plate -made up of cartilage in between the epiphyses & diaphysis -site of growth in bone length 5. Epiphyseal line -replaces the epiphyseal plate when growth ceases -bone that replaces the cartilage of each epiphyseal plate Medullary Cavity * cavity within the bone (diaphysis) * contains the marrow

Marrow- soft tissue within the cavity a. Yellow marrow * Mainly fat b. Red marrow * Consist of blood forming cells * Is the only site of blood formation in an adult * Children’s bones: * More red marrow than adults * As a person ages, red marrow is mostly replaced by yellow marrow * In adults, red marrow is confined to the bones in the central axis of the body & in the most proximal epiphyses of the limbs Layers of a Bone: (cross-sectional) 1. Periosteum * Outermost layer * Surrounds the diaphysis * Contains blood vessels, nerves & osteoblasts 2. Bone Substance- made up of matriz & cells. 3.

Endosteum * Innermost layer * Thin connective tissue membrane * Lines the medullary cavity Note: both periosteum & endosteum contains osteoblasts Histologic Structures: A. Lamellae * Thin sheets of extracellular matrix which forms the bones * Contains osteocytes(mature bone cells) located between the lamellae B. Lacunae * Spaces that contains the osteocytes found between the lamellae C. Canaliculi (tiny canals) * Channels between adjacent central canal * Connects on osteocyte to another osteocyte * Nutrition & Communication 2 Major Types of Bones According to Histological Feature: 1. Compact Bone Mostly solid matrix and cells 2. Cancellous Bone * Consist of lacy network of bone with many small, marrow filled spaces 1. Compact/Cortical Bone * Forms the diaphysis of long bones & the thinner surfaces of short, flat & irregular bones. * Consists of layers of calcified solid matrix containing spaces occupied by osteocytes (bone cells); * Tightly packed; smooth * Osteocytes * Bone cells located in the lacunae * Lamellae (bone layers) * Arranged/organized into concentric rings around central canals (haversian canals) * Haversian canals * Contains the blood vessels that run parallel to the long axis of the bone. “bull’s eye” upon cross-section of the bone * Haversian system/osteon * Each haversian canal, with lamellae & osteocytes surrounding it * Canaliculi (tiny canals) * Connect the osteocytes, forming the structural units of the bones. * Provide nutrients to bone tissue and function for communication * Gives the osteon the appearance of having tiny cracks in the lamellae 2. Cancellous Bone/ Spongy Bone * Located mainly in the epiphysis of long bones * Forms the interior of all other bones * Consists of the trabeculae * Delicate interconnecting rods or plates In the bone * Add strength to a bone Spaces between are filled with marrow * Each consists of several lamellae with osteocytes between the lamellae * Usually no blood vessels * No central canals * Nutrients exit vessels in the marrow & pass by diffusion through the canaliculi to the osteocytes of the trabeculae Bones * The human skeleton contains 206 bones; Two divisions of the skeletal system 1. Axial skeleton- called axial because it lies along the central line, or axis of the body (contains 80 bones) 2. Appendicular skeleton- relating to the limbs, or appendages of the body (contains 126 bones) 1. Axial skeleton * 80 bones -22 skull bones 1 hyoid bone -6 auditory ossicles -26 vertebrae -25 rib cage bones * Bones of the Axial Skeleton include: a. Skull b. Auditory Ossicles c. Hyoid bone d. Vertebral Column e. Thoracic Cage A. Skull/Cranium A. 1. Braincase (8) A. 2. Facial bones (14) A. 1. Braincases (8 bones) * Houses the brain * Frontal (1) * Parietal (2) * Temporal (2) * Ethmoid (1) * Sphenoid (1) * Foramen Magnum -where in the posterior fossa -where the spinal cord exists * Sella Turcica -located at the sphenoid bone -where the pituitary gland rests Sutures -joint uniting bones of the skull * Coronal (f-p) * Sagittal (p-p) * Squamous (p-t) * Lambdoid External occipital protuberance- site of attachment for ligamentum nuchae * Auditory meatus- transmit sound waves toward the ear drum * Mastoid process- filled with cavities “mastoid air cells”- connected to the middle ear *neck muscles involved in head rotation attach to this A. 2. Facial Bones (14 bones) a. Mandible (1) * Lower jaw * Coronoid process * Houses the inferior set of teeth (alveolar process) * Freely movable * 2 parts: body and ramus b. Maxilla (2) * Upper jaw * Houses the superior set of teeth (alveolar process) c. Zygomatic (2) * Cheek bones * Zygomatic arch d. Nasal bones (2) * Bridge of the nose e.

Lacrimal (2) * Tunnel that passes from the orbit into the nasal cavity f. Inferior Nasal Conchae (2) * “shelves” inside the nasal cavity * Increases surface area of cavity (moisten and warmth air; remove particles) g. Vomer (1) * Inside the nose; in between the nostrils forms most of the posterior portion of nasal septum * One of the parts of bony part of septum h. Palatine bones (2) * Separates the nasal cavity & nasopharynx from the mouth * Enabling us to chew & breath at the same time Parts: A. Hard Palate- forms the floor of the nasal cavity and the roof of the mouth B. Soft Palate- connective tissue & muscle

Facial Bones * Support the organs of smell, taste and vision * Provide attachment points for muscles involved in mastication, facial expression and eye movement The Paranasal Sinuses -named according to location * Frontal sinus * Maxillary sinus * Sphenoidal sinus Functions: * Decrease the weight of the skull * Resonating chambers during voice production B. Hyoid Bone * Unpaired; U-shape * Located at the anterior neck area * No direct bony attachment to the skull, instead muscles and ligaments attach it to the skull * Attachment for tongue muscles and for important neck muscles that elevate larynx during speech or swallowing

C. Auditory Ossicles * Located at the middle ear * Smallest bones in the body * Malleus/ Hammer * Incus/ Anvil * Stapes/ Stirrup D. Vertebral Column (26 bones) * The human spine is a flexible chain of 26 bones which let you move with flexibility * Central axis, extending from the base of the skull to slightly past the end of pelvis * The spine’s S-shpaed curve supports the weight of the head, keeping it in upright position. * Back bone * All irregular DIVISIONS OF THE VERTEBRAL COLUMN (from superior to inferior) * Cervical – (7) * Thoracic – (12) * Lumbar – (5) * Sacrum – (1) * Coccyx – (1) FUNCTIONS: Supports the weight of the head & trunk * Protects the spinal cord * Allows spinal nerves to exit the spinal cord * Site for muscle attachment * Movement of head & trunk PARTS OF THE VERTEBRAL COLUMN: * BODY – weight bearing portion * VERTEBRAL FORAMES -opening where the Spinal cord is located -VERTEBRAL CANAL – contains the cord and cauda equina * SPINOUS PROCESS -serves as lumps down the midline of the back * VERTEBRAL ARCH – projects posteriorly from the body -(2)Pedicles and (2)lamina * TRANSVERSE PROCESSES – extend laterally from each side of the arch between the lamina and pedicle * Spinous process – muscle attachment sites Articular facet – 2 superior and 2 inferior articular processes DISORDERS OF THE VERTEBRAL COLUMN: * 1. Kyphosis -abnormal posterior curvature of the thoracic spine – “Hunch-back” * 2. Lordosis -abnormal anterior curvature of the lumbar spine * 3. Scoliosis -abnormal lateral curvature of the spine REGIONAL DIFFERENCES IN VERTEBRA * All cervical vertebra have transverse foramen in each transverse process through which the vertebral arteries extend to head * Atlas – has no body; no spinous process * Large superior articular facets – joins the occipital condyles * Axis Thoracic vertebra – attachment site for ribs * T1 – T10 – articular facets on transverse process – articulate with tubercles of ribs * Lumbar vertebra – large, thick bodies, and heavy rectangular transverse and spinous process * Sacral vertebra – sacrum * Sacral promontory – separates abdominal from pelvic cavity * Coccyx – tail bone * INVERTEBRAL FORAMEN -where spinal nerves exit * Atlas – C1 (1st cervical vertebrae) -ring-like vertebra that supports the skull by forming a joint -no body -“yes” motion * Axis – C2 (2nd cervical vertebrae) -acts like a pivot for the rotation of C1 & the skull “No” motion E. THORACIC CAGE – protects the heart & lungs -T-vertebrae, ribs, sternum, costal cartilage * 2 BONES C. 1. Ribs – 24 bones C. 2. Sternum – 1 bone TYPES OF RIBS 1. True Ribs -1st 7 pairs – attached directly to the sternum via costal cartilages (between sternum & ribs) 2. FalseRibs -last 5 pairs -NOT attached directly to the sternum 8th-10th – share a common cartilage 11th&12th – are not attached to the sternum -“Floating Ribs” STERNUM/BREASTBONE Parts: (Superior to inferior) 1. Manubrium -Jugular notch – depression located at superior end of the sternum, between the ends of clavicle 2.

Body -sternal angle -identifies the location of the second rib -important in identifying the location of the apex of the heart (between 5th and 6th ribs) 3. Xiphoid Process -important landmark when doing CPR -only bone in the thoracic cage without any other bones attached to it 2. APPENDICULAR SKELETON -composed of 126 non-axial bones Upper region (64) – pectoral/shoulder Girdle (4) & upper limbs (60) Lower region (62) – hips/pelvic Girdle (2) & lower limbs (60) DIVISIONS: A. Pectoral Girdle (4) B. Upper Limbs (60) C. Pelvic Girdle (2) D. Lower Limbs (60) Total: 126

A. Pectoral/Shoulder Girdle -attaches the upper limb to the body Parts: 1. Scapula (shoulder blade) 2. Clavicle (collar bone) -easily dislocated -reason: * There is only 1 point of attachment between the shoulder girdle & the axial skeleton (sterno-clavicular joint) * Sternoclavicular joint – joint where clavicle and sternum meet B. Upper Limbs * ARM B. 1. Humerus: arm bone * FOREARM B. 2. Ulna: medial forearm bone B. 3. Radius: lateral forearm bone * WRIST B. 4. Carpals – wrist bones * HAND B. 5. Metacarpals – palm bones B. 6. Phalanges – digits/fingers HUMERUS Humerus – with smooth rounded head which is attached to the scapula by glenoid cavity * Deltoid tuberosity – where the deltoid muscle is attached * Epicondyles – provide attachment sites for forearm muscles. FOREARM * Radius * Located on the lateral (thumb side) * Radial Tuberosity – where the biceps brachii attaches. * Ulna * Located on the medial (little finger side) * Semilunar notch – located at the proximal end of ulna, that fits tightly over the end of the humerus, forming most of the elbow joint. * Olecranon process – extension of ulna, which can be felt as the point of elbow. Note : Radial and ulnar styloid processes provides attachment for ligaments of the wrist CARPALS * Wrist bones * Eight carpal bones * Proximal row – Scaphoid (boat like), lunate (moon), triquetrum (three-cornered), pisiform (pea-shaped) * Distal row- trapezium (table), trapezoid (resembling like a table), capitates (head), hamate (Hook) HAND * Metacarpals * Attached to the carpal bones * Numbered 1 to 5 (from thumb to little finger) * Knuckles – formed by the head of metacarpals * Phalanges * Consists of three small bones (proximal, middle and distal) except for thumb (proximal and distal only) C. PELVIC GIRDLE place of attachment for lower limbs -protects internal organs PELVIS –r ing of bones -formed by the: * Sacrum * Coccyx * Two Coxae (hipbones) Parts of Coxae: * Ilium -most superior * Ischium -inferior posterior * Pubis -inferior anterior * Symphysis Pubis -joins 2 coxae together anteriorly * Sacroiliac joint -posteriorly * Acetabulum -lateral -where femur articulates DIFFERENCE BETWEEN MALES & FEMALE PELVIS * MALE : * Heavier * Narrower * Heart shaped pelvic inlet * Suprapubic angle less than 90o * Ischial spines are nearer to each other * FEMALE : * Lighter * Widely laterally * Oval shaped pelvic inlet Suprapubic angle more than 90o * Ischial spines are further apart D. LOWER LIMBS D. 1. Femur * Thigh bone * Articulates with the acetabulum of the coxa * Longest & heaviest bone in the body * Condyles – articulate with tibia * Epicondyles – points of ligament attachment * Trochanters – points of muscle attachment D. 2. Patella – knee cap D. 3. Tibia * Shin bone * Medial leg bone * Larger than the fibula * Major weight – bearing bone of the leg * Tibial tuberosity (attachment for anterior thigh muscles) D. 4. Fibula * Lateral leg bone * Thinner than the tibia D. 5. Tarsals * Ankle bones (seven) * Talus (ankle bone), alcaneus (heel), cuboid (cube-shaped), navicular (boat-shaped), medial, intermediate, lateral cuneiforms (wedge-shape) D. 6. Metatarsals * Sole * Longer than metacarpals D. 7. Phalanges * Digits/toes * Shorter than the phalanges of the hand * Same with fingers PART II CARTILAGE * 3 Types * Hyaline- most intimately associated with bones * Growth in length and bone repair * ChondroBLASTS * ChondroCYTES * Avascular * Perichondrium- cover cartilage (2 layers) * Articular Cartilage- cover ends of long bones GROWTH OF CARTILAGE * Appositional Growth – addition of new cartilage on the surface of cartilage. Interstitial Growth – addition of new cartilage matrix within cartilage. -Chondrocytes undergo mitosis and add more matrix -This increases the thickness of cartilage BONE HISTOLOGY * Bone matrix- 35% organic, 65% inorganic material * Organic – collagen and proteoglycans -Collagen- flexible strength to matrix -Decreased? -> brittle bones * Inorganic – Calcium phosphate crystals ->HYDROXYAPPATITE -Compression strength -Decreased? -> overly flexible * Ossification- osteogenesis – formation of bone by osteoblasts. * Appositional growth on the surface of previously existing bone or cartilage. Cell bodies and processes from a “MOLD” around which matrix is formed. * *new layer of bone is then produced osteoCYTES * Mature bone cells that maintain matrix. * Result when osteoblasts become surrounded by bone matrix. * Lacunae – spaces occupied by osteocyte body * Canaliculi – spaces occupied by the osteocyte cell processes (in contact with other bone cells) osteoCLASTS * bone resorption * large cells with several nuclei * release Hydrogen ion ->acidic environment that is necessary for decalcification * Release enzymes that digest CHON components of matrix. * Endocytosis Origin of the Cells Osteochondral Progenitor Cell – stem cells that become osteoblasts or chondroblasts. * Located in the inner layer of the perochondrium, periosteum and endosteum. Classification accdg to organization of Collagen fibers in matrix * Woven Bone- collagen fibers are randomly oriented in many directions. * Forms at fetal development and during repair of fracture. * Remodelling- removing old bone and adding new bone. * Lamellar Bone * Mature bone that is organized into thin sheets or layers (3-7 micrometers) LAMELLAE * Collagen fibers lie parallel to one another. OSSIFICATION * Formation of bone by osteoblasts. Involves the synthesis of organic matrix containing collagen and proteoglycans and addition of hydroxyapatite crystals to the matrix. * Osteocytes- mature bone cells formed when the osteblast becomes completely surrounded by bone matrix. Types of Bone Development 1. Intramembranous Ossification * Formation of bone within connective tissue membrane. * 8th week of development- tissue membrane forms around developing brain. * Osteochondral progenitor cells become osteoblasts. * Osteoblasts lay down bone matrix on collagen fibers of connective tissue membrane ->trabeculae of woven bone. Center of ossification- locations on the membrane where ossification begins. * They expand to form a bone by gradually ossifying the membrane. * Fontanels- larger membrane-covered spaces between the developing skull bones that have not yet ossified. OSSIFICATION CENTERS * Area where ossification process begins * Trabeculae radiated out from the centers. * Usually 2 or more centers exist in each flat skull bone and the skull bone result from the fusion of these centers as they enlarge. 2. Endochondral Ossification * Formation of bone within cartilage Bones of the base of the skull, part of mandible, epiphysis of clavicles, most of the remaining skeletal system. * Osteochondral progenitor cells ->chondroblasts->hyaline cartilage model * Approximate shape of the bone to be formed. * Perichondrium- surrounds the cartilage model (except areas for joints) * Replacement of cartilage by bones continues until ALL the cartilage except in epiphyseal plate and on articular surfaces has been replaced by bone. * Mature bone 4 Zones of Epiphyseal plate 1. Zone of resting cartilage- nearest the epiphysis and contains chondrocytes that don’t divide rapidly. . Zone of Proliferation- chondrocytes produce new cartilage through interstitial growth. * Chondrocytes divide and form columns resembling stacks of plate or coins. 3. Zone of Hypertrophy- the chondrocytes mature and enlarge. 4. Zone of Calcification- very thin and contains hypertrophied chondrocytes and calcified cartilage matrix. * Enlarged chondrocytes die and are replaced by osteoblasts. Closure of epiphyseal plate- 12-25 years of age. Factors Affecting Bone Growth 1. Genetics 2. Nutrition * Vitamin D * Rickets- decrease Vit. D in children * Osteomalacia 3. Hormones * Growth Hormone * Gigantism Acromegaly * Dwarfism 4. Sex hormones BONE REMODELLING * Removal of existing bone(by osteoclasts) and deposition of new bone (by osteoblasts) * Woven to lamellar * Responsible for: a. ) changes in bone shape b. ) adjustment of bone to stress c. ) bone repair d. ) calcium regulation * Basic Multicellular unit (BMU) – temporary assembly of osteoclasts and osteoblasts that travel through or across the surface of bone. * Removes old bone matrix and replaces them with new one. * Life span is 6 months. * BMU activity renews skeleton every 10 years. FRACTURE * Break in the integrity of bones.

Accdg to severity of injury to surrounding soft tissue: * Open-compound- occurs when open wounds extend to site of fracture or when fragment of bone protrudes to the skin. * Closed-simple- if the skin is not perforated. * Complicated- occurs if soft tissues around a closed fracture are damaged. * Incomplete- fracture does not extend completely across the bone. -Greenstick fracture- occurs in the convex side of the curve of the bone. * Complete- bone is broken into at least 2 fragments. * Comminuted- complete; breaks down into more than 2 pieces. * Impacted- one fragment is driven into the cancellous portion of the other fragment. Linear- runs parallel to the long axis. * Transverse- at right angle to the long axis. * Oblique BONE HEALING FORMATION (Repair) Steps in Bone Repair: 1. Clot Formation 2. Callus Formation Bone Repair * Hematoma/Clot Formation * Is a localized mass of blood released from blood vessels but confined within an organ or space. * Clot formation ->disruption of blood vessels in central canal->decrease O2 delivery to osteocytes and bone tissue adjacent to site ->cells die * Inflammatory response * Callus formation * Callus is a mass of tissue that forms at a fracture site, connecting the broken ends of bones. Callus forms as the clots dissolves and is removed by macrophages. * It helps stabilize the ends of broken bones * Cast/metal plates * Callus ossification * The fibers and cartilage of calluses are ossified produce woven, cancellous bone. * The ossification process is similar to that which occurs during fetal bone development. * Cancellous bone formation in the callus is done in 4-6 weeks after injury * IMMOBILIZE BONE!! Bone remodeling-A cancellous bone is slowly remodeled to form compact and cancellous bone . Remember: If bone occurs properly, the healed region can be even stronger than the adjacent bone.

Bone and Calcium Homeostasis The bones are the major storage area for calcium in the body. Movement in Ca in and out of the bone helps to determine blood Ca levels. (Critical for normal muscles and nervous system functions) Ca moves into the bones as osteoblasts builds a new bone. Ca moves out of the bones as osteoclasts breaks down the bones. Parathyroid Hormone Increases Blood calcium (Ca ++ ) level Mechanisms: 1. Increases osteoclastic activity 2. Increases Ca reabsorption from urine. 3. Increases Ca absorption from small intestines by stimulating the kidneys to form active Vit. D

CALCITONIN Decreases blood Ca level Decreases osteoclastic activity Increases osteoblastic activity. Articulation/Joint Places where 2 or more bones come together/connected Functions: 1. Holds bones together securely 2. Mobility Functional Classification: Based on degree of motion /amount of movement allowed by a joint. 1. Synarthrosis- non movable. Ex: Structures of the skull 2. Amphiarthrosis -slightl;y movable 3. Diarthrosis –freely movable. Three majorstructural classes of joints 1. Fibrous joints Joined by a fibrous tissue. Little or no movement. Classification: 1. Sutures 2.

Syndesmoses 3. Gomphoses Classification of Fibrous joints 1. Sutures – Fibrous joints between the bone of the skull. In a new born sutures are quite wide and are called fontanels or soft spots. Functions of Fontanels 1. Allow flexibility of skull during childbirth 2. Growth of the head after birth. Synostosis – Results when two bones grow together across a joint to form single bone. 2. Syndesmoses Fibrous joints in which bones are separated by some distance and are held together by ligaments. e. g. Fibrous membrane connecting most of the distal part of the radius and ulna . 3. Gomphoses

Consist of pegs fitted into the socket and held in place by ligaments. e. g. joint between a tooth and its socket . II. CARTILAGINOUS JOINTS -joint by a cartilage. -Slight movement Ex. ribs,sternum,vertebrae epiphyseal plates of long bones . Sychondroses- consist of 2 bones joint by hyaline cartilage where little or no movement occurs. e. g. joints between ilium , ischium and pubis before they fused together. -Epiphyseal plates of growing bones -Temporary Symphyses Fibrocartilage uniting two bones Junction between the manubrium and body of sternum , symphysis pubis and intervetebral disks. III.

SYNOVIAL JOINTS -joints containing synovial fluid surrounding the ends of articulating bones. -freely movable. -mostly synovial joints of appendicular skeleton are large Structures of Synovial Joints Articular cartilage – provides a smooth surface where bones meet . Articular disks – flat plate or pad of fibrocartilage. Absorb and distribute forces between articular cartilage as bone moves. Joint cavity –filled with synovial fluid. Joint capsule- encloses the joint cavity, hold bones together and allows movement. Synovial membrane – lines the joint cavity except on articular cartilage -Forms synovial fluid. May extend as a tendon sheath Bursa – pocket or saclike structures ,which reduces friction on structures that rub together -Bursitis inflammation of bursa. Types of Synovial Joints Types: A. Plane/Gliding B. Saddle C. Hinge D. Pivot E. Ball and Socket F. Ellipsoid/Condyloid Plane or Gliding Joints -Two opposed flat surfaces glide over each other -e. g. Articular facets between vertebrae Saddle Joints -Two saddle shaped articulating joints oriented at right angles to each other -movement can occur in two planes -e. g. joints between metacarpal and carpal (trapezium of thumb) Hinge Joints Consist of a convex cylinder of one bone applied corresponding conactivity of the other bone. -Movement in one plane only -e. g Elbow, knee and finger prints| Pivot Joints -Restrict movement to rotation around a single axis -Composed of cylindrical bony process that rotates within a ring composed partly of bone and partly ligament -e. g. The rotation between the axis and atlas when shaking the head “no” Ball and Socket -Consists of a ball (head) at the end of bone and a socket in an adjacent bone into which a portion of the balls fits. -Allows wide range of movement in all most any direction e. g. Shoulder and hip joints Ellipsoid/Condyloid Joints -Elongated ball and socket joints -e. g. Joint between the occipital condyle and atlas of vertebral column Movement 1. FLEXION -“bend” -moves body part anterior or ventral to the coronal plane 2. EXTENSION – “straighten” -moves the body part posterior or dorsal to the coronal plane 3. ABDUCTION -movement away from the median 4. ADDUCTION -moves towards the median 5. PRONATION -palms down 6. SUPINATION -palms up 7. ROTATION -turning the structure along its long axis such as shaking the hand “no” 8. PLANTAR FLEXION -standing on toes 9.

DORSIFLEXION -walking on heels 10. EVERSION -turning the foot to face laterally 11. INVERSION -turning the foot to face medially 12. PROTRACTION -structures glides anteriorly 13. RETRACTION -structures glides posteriorly 14. ELEVATION -movement in a superior direction 15. DEPRESSION -movement in an inferior direction 16. EXCURSION -movement to one side or the other 17. OPPOSITION -tips of thumb and little finger are brought to each other across the palms of the hands 18. REPOSITION -returns the digit to anatomic position 19. CIRCUMDUCTION -occurs at freely movable joints such as the shoulder