1 Skeletal system
2 rationale Healthcare professionals must have a comprehensive medical vocabulary in order to communicate effectively with other health professionals. They should be able to use terminology of the skeletal system to discuss common conditions and diseases.
3 objective Upon completion of this lesson you will be able to:Define and decipher common medical terms associated with the skeletal system Identify the basic anatomy of the skeletal system Analyze unfamiliar terms using the knowledge of root words, suffixes and prefixes gained in this course Research diseases which involve the skeletal system
4 engage A 78-year-old, female patient is admitted to the ortho floor with a broken hip; her physician said that her hip broke while she was walking and caused her to fall. The family members are asking you if that is really possible or if they should be looking for another doctor. Should they look for another doctor?
5 introduction There are 206 bones in the human adult body
6 functions 1. Support of the body structure and shape 2. Protection of the vital organs 3. Movement and Anchorage of the muscles (levers for muscular action) a. Tendons – attach muscle to bone b. Ligaments – attach bone to bone 4. Mineral storage – calcium and phosphorus 5. Blood cell formation – hematopoiesis
7 Bone composition A. Collagen – a chief organic constituent (protein) B. Inorganic calcium salts (Vitamin D is essential for the absorption of minerals, i.e. calcium) C. Cells 1. Osteoblasts – bone-building, bone-repairing cells in the periosteum 2. Osteocytes – mature bone cells within the bone matrix 3. Osteoclast – causes the reabsorption of bone D. Periosteum 1. A dense, fibrous membrane covering bone 2. Contains blood vessels 3. Essential for bone cell survival and bone formation
8 Types of bone By composition
9 Compact bone 1. Very dense, stress bearing 2. Haversian systems - the functional unit of compact bone a. Lamellae – a concentric cylinder-shaped calcified structure b. Lacunae – small spaces containing tissue fluid c. Osteocytes – facilitate the exchange of calcium between blood and bone d. Canaliculi – canals connecting the lacunae to each other and to the Haversian canal which carries nutrients and wastes to and from the osteocytes
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11 Cancellous bone 1. Light and spongy 2. Low stress areas where the weight of bone would be a problem 3. Found at the ends of the long bones, ribs, sternum, hips, vertebrae, and cranium 4. No Haversian systems 5. Web-like arrangement
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13 Classification of bones By shape
14 Long bones Found in the extremities and usually have levers 1. Epiphysis – at the ends, covered with hyaline cartilage for articulating bones; cancellous bone 2. Diaphysis – shaft, covered with periosteum; medullary canal with yellow and red marrow (lined with endosteum); covered with periosteum for bone growth, repair, and nutrition; compact bone 3. Femur, tibia, fibula, humerus, ulna, radius, and clavicle
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16 Short bones Cube-shaped; allows flexible movement 1. Cancellous bone covered by compact bone 2. Carpals, tarsals, metacarpals, metatarsals, and phalanges
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18 Flat bones Flat plates- protect the vital organs and provide a broad surface area for muscle attachment 1. Cranial bones, facial bones, scapula, and sternum
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20 irregular Irregular – peculiarly shaped to provide support and protection, yet allow flexibility 1. Vertebrae, ribs, ear, hip, and hyoid
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22 Sesamoid bones Extra bones found in certain tendons, i.e., the patella
23 Bone formation
24 Formation of bones A. Initially collagen fibers secreted by fibroblasts B. Cartilage deposited between the fibers C. The skeleton is fully formed by the second month of fetal development (all cartilage) D. After the eighth week of fetal development, ossification begins (the mineral matter deposited replaces the cartilage) E. Childhood and adolescence – ossification exceeds bone loss F. Early adulthood thru middle age – ossification equals bone loss G. After age 35 – bone loss exceed ossification
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26 H. The skull 1. Begins as a fibrous membrane 2H. The skull 1. Begins as a fibrous membrane 2. The ossification center is in the middle of the membrane – begins in the middle and radiates outward 3. Ossification is not complete at birth – the fontanels (soft spots) on an infant’s head allow molding of the skull during birth and, with the open joints, allows for growth of the brain
27 I. Other bones 1. Begin as hyaline cartilage 2I. Other bones 1. Begin as hyaline cartilage 2. Short bones – there is one ossification center in middle that proceeds toward the periphery 3. Long bones – there are three ossification centers (one at each end and one in the center of the shaft); ossification goes from the center toward each end and from each end toward the center
28 Bone growth
29 Bone growth A. Grow in length at the epiphyseal line B. Grow in width by the addition of bone to the surface C. Controlled by the anterior pituitary (growth hormone) 1. Dwarfism – hypofunction 2. Gigantism – hyperfunction 3. Acromegaly – hyperfunction after puberty; enlarges bones of the hands, feet, and face
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31 Bone markings
32 purpose 1. Join one bone to another 2. Provide a surface for the attachment of muscles 3. Create an opening for the passage of blood vessels and nerves 4. Used as landmarks
33 examples 1. Process – a bony prominence or projection 2. Condyle – a rounded, knuckle-like prominence usually at a point of articulation 3. Epicondyle – a small projection 4. Head – a rounded, articulating process at the end of a bone 5. Spine – a sharp, slender projection 6. Tubercle – a small, rounded process 7. Tuberosity – a large, rounded process 8. Trochanter – a large process for muscle attachment 9. Fossa – a depression or hollow 10. Foramen – a hole 11. Crest – a sharp ridge
34 12. Line – a ridge of bone that is less prominent than a crest 1312. Line – a ridge of bone that is less prominent than a crest 13. Meatus – a tube-like passage 14. Sinus/antrum – a cavity within a bone 15. Depression – a hollow region or opening 16. Fissure – a narrow, slit-like opening 17. Sulcus – a groove 18. Facet – a small area on a bone
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36 Bone marrow
37 Yellow bone marrow 1. In the medullary cavity of long bones 2. Fat storage
38 Red bone marrow Hematopoietic tissue 1. In children – in all cancellous bone 2. In adults – in the cancellous bone of the vertebrae, hips, sternum, ribs, cranial bones, proximal ends of femur, and humerus 3. Forms red blood cells (RBCs), platelets, some white blood cells (WBCs), and destroys old RBCs and some foreign materials
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40 Axial skeleton
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42 skull 22 bones A. Houses and protects the brain with eight bones 1. Frontal – forms the forehead and the orbits of eyes; supraorbital margins (a ridge that protects the eyes) 2. Ethmoid – forms the roof of the nasal cavity; a very light bone with a horizontal plate, a perpendicular plate, and two lateral masses 3. Parietal, Right, and Left – form the sides and roof of the skull; the internal surface is rough to accommodate the brain 4. Temporal, Right, and Left – forms the temple, cheek, and ear openings a. Squamous portion – forms the temple b. Zygomatic process – forms the cheek c. Petrous portion – forms the auditory canal d. Mastoid portion – behind the ear e. Tympanic portion – walls of the acoustic meatus 5. Occipital – the back of the skull; the inferior portion has a foramen magnum where the spinal cord passes through; the sides of the foramen have two projections (condyles) that articulate with the first cervical vertebra (atlas)
43 6. Sphenoid – fills the space between the orbital plates; contains the sphenoidal sinuses; the upper surface has a depression called the sella turcica, where the pituitary gland rests 7. Wormian Bones – extra bones formed by irregular connections of cranial sutures 8. Cranial Sutures – unite the bones of the cranium; as a child grows, irregular bands of connective tissue ossify and turn into hard bone a. Coronal suture – between the frontal and parietal bones b. Sagittal suture – between the right and left parietal bones c. Lambdoidal suture – between the parietal and occipital bones d. Squamous suture – between the temporal and parietal bones e. Abnormalities I. Microcephalus – fusion II. Hydrocephalus – delayed fusion (increases intracranial pressure
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45 fontanels Fontanels – fusion of the cranial bones is not complete at birth, so a space between the bones remains a. Anterior (Bregmatic) – the “soft spot”; closes at 18 months b. Posterior (Occipital) – triangular; closes at 2-3 months c. Anteriolateral (Sphenoidal) – at both temples; close at 2-3 months d. Posterolateral (Mastoidal) – behind each ear; close at 1 year
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47 Facial bones guard and support the eyes, ears, nose, and mouth; 14 bones
48 1. Nasal bones (2) – form the bridge of the nose 21.Nasal bones (2) – form the bridge of the nose 2. Vomer – forms the central nasal septum 3. Maxillary (2) – the upper jaw bones; fusion occurs before birth (if not, a cleft palate occurs); forms the roof of the mouth, walls of the nose, and floors of the orbitals; the body has maxillary sinuses, alveolar process; upper teeth, palatine process; anterior palate; the largest bone of the upper face 4. Mandible – the lower jawbone; the largest bone of face; two perpendicular portions called rami (have two processes: condylar process; posterior forms the temporal-mandibular joint; coronoid process; anterior for muscle attachment
49 5. Zygoma (2) – the cheek bones 65. Zygoma (2) – the cheek bones 6. Lacrimal (2) – the small bones the form the medial wall of the eye socket; the tear duct passes through; smallest; fragile 7. Palatine (2) – forms the back roof of the mouth and floor of the nose; L- shaped 8. Inferior turbinate (2) – forms the curved ledge inside the side wall of the nose
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51 Ear bones
52 Ear Bones – tiny bones in the middle ear cavity in the temporal bone 1Ear Bones – tiny bones in the middle ear cavity in the temporal bone 1. Malleus (2) – the hammer 2. Incus (2) – the anvil 3. Stapes (2) – the stirrups E
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54 Hyoid bone
55 A u-shaped bone in the neck at the base of the tongue; the only bone that does not touch another bone
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57 CRANIAL SINUSES Cavities within the cranium; function as resonance chambers in the production of the voice; the decrease weight of the skull; lined with mucous membranes
58 1. Frontal sinuses (2) – above the eyebrows; open into the nasal cavity 2. Ethmoid sinuses (2) – between the eyes 3. Sphenoidal sinus (1) – posterior to the ethmoidal sinuses; opens into the nasopharynx 4. Maxillary sinuses (2) – on either side of the nose; opens on the lateral wall of the nasal cavity
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60 Vertebral column
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62 functions a. Supports the trunk and neck b. Protects the spinal cord c. Multiple joint spaces allow for bending and twisting
63 curves Allow for resilience and spring for walking a. Thoracic – present at birth b. Sacral – bow back c. Cervical – begins at 3 months when the infant first begins to lift his or her head d. Lumbar – begins when the child first walks
64 vertebrae 26 bones separated by intervertebral disks to cushion the joints for movement
65 cervical Smallest, oblong bodies; wide transverse processes I. Atlas – the first cervical vertebra; supports the head by articulating with the condyles of the occipital bone; a bony ring with no body; has a short wing-like transverse process; allows for forward and backward motion
66 II. Axis – the second vertebra; a small body with a projection called the odontoid process that acts as the axis of rotation for the skull
67 III. The 3rd, 4th, 5th, and 6th vertebrae are forked to cradle the strong ligaments of head
68 IV. The 7th vertebra has a very prominent spinous process, called the vertebral prominence, that can be felt at the base of the neck
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70 thoracic (12) – progressively increase in size from the neck down; have a long spinous process (pointed downward) and six articular facets for rib attachment
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72 lumbar (5) – the largest and strongest; have short projections for muscle attachment
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74 sacral Sacral – five fused bones; triangular; form the dorsal part of the pelvis; join the ileum bone at the iliosacral joint
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76 coccyx 3-4 fused bones; articulates with the tip of the sacrum; slightly movable (to assist in childbirth)
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78 Injuries and diseases
79 a. Kyphosis – hunchback; the posterior thoracic is exaggerated ba. Kyphosis – hunchback; the posterior thoracic is exaggerated b. Lordosis – swayback; an exaggerated anterior curve of the lumbar region c. Scoliosis – a lateral curvature of the spine d. Fractures and dislocations – most often a fracture of the lamina; can cause spinal cord damage and paralysis e. Intervertebral disk herniation – causes pressure on the spinal nerve and pain f. Tuberculosis of the spine – by tubercle bacillus; destroys body of vertebrae
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82 Thorax 25 bones and cartilage; walls covered by skin and muscles; the floor is formed by the diaphragm
83 sternum The breast bone; sword and handle shape a. Manubrium – the handle; notched for the first 7 costal cartilages; articulates with the acromium end of the clavicle and the first rib b. Body – the blade; notched for first 7 costal cartilages c. Xiphoid process – the tip; attachment site for the diaphragm
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85 Costal cartilage Hyaline cartilage connecting the ribs to the sternum in 1-7 and to the anterior ribs in 8-10
86 ribs Ribs (12 pairs) – attached posteriorly to the vertebrae and anteriorly to the costal cartilage a. True ribs – the first 7 pairs b. False ribs – pairs 8-12 (11 & 12 are floating)
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88 Appendicular skeleton126 bones
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90 Shoulder girdle 1. Clavicles (2) – the collarbones 2. Scapulas (2) – the shoulder blades
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92 Upper extremities 1. Humerus – upper arm 2. Radius – thumb side of the forearm 3. Ulna – little finger side of the forearm 4. Carpals (8) – wrist bones 5. Metacarpals (5) – hand bones 6. Phalanges (14) – finger bones
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94 Pelvic girdle 1. Os coxae (2) – contains the acetabulum (hip socket) a. Ilium b. Ischium c. Pubis
95 functions a. Protect and support the heart and lungs b. Support the bones of the pectoral girdle c. Plays a leading role in respiration d. The ribs and sternum aid in RBC formation
96 Lower extremities 1. Femur – thigh bone 2. Patella – kneecap 3. Tibia – shin bone 4. Fibula – lateral bone of the lower leg 5. Tarsals (7) – ankle bones a. Talus b. Calcaneus 6. Metatarsals (5) – foot bones 7. Phalanges (14) – toe bones
97 articulations a joint (an area where two bones are attached for the purpose of motion of body parts).
98 A. Synarthrotic – immovable B. Amphiarthrotic – limited movement, i. eA. Synarthrotic – immovable B. Amphiarthrotic – limited movement, i.e. the pubic symphysis, vertebral joints, and sacroiliac joint C. Diarthrotic – freely movable 1. Gliding – wrist 2. Pivot – between the radius and ulna 3. Ball and socket – hip 4. Hinge – elbow
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