4 The Skeletal System Lesson 4 1 Bone

4 The Skeletal System Lesson 4. 1: Bone as a Living Tissue Lesson 4. 2: The Axial Skeleton Lesson 4. 3: The Appendicular Skeleton Lesson 4. 4: Joints Lesson 4. 5: Common Injuries and Disorders of the Skeletal System © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Chapter 4: The Skeletal System Lesson 4. 1 Bone as a Living Tissue © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Bone as a Living Tissue • • functions of the skeletal system structures and classifications of bones growth and development of bones remodeling of bones © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Functions of the Skeletal System- ALL 206! • support – body framework • protection – surround organs • movement – muscles pull bones • storage – Minerals ( Ca, P) • Neuromuscular and clotting vs bone strength and chemical release of fat stores • Homeostatic/negative feedback! • blood cell formation = Hematopoiesis – red bone marrow in medullary cavity ( flat and short bones, vertebrae and long bone ends) – Yellow cavity stores fat © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Structures and Classifications of Bones- ALL 206! • composition of bones – osteocytes–mature bone cells – Minerals • 60 -70% minerals (Ca carbonate and Ca phosphate) • 30 -40% Collagen and water (higher in kids- stronger and more flexible) • organization of bones – Cortical ( outer)= dense, stiff, strong • Mineralized – Trabecular=honeycomb • Porous and flexible • adds lightness • Birds? © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

4. 2 - comparison © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Shape Categories of Bones-ALL 206! • Long – – Cylindrical with bulbs trabecular bone inside Cortical outside Hollow medullary canal • Arms and legs • Short – Cube shaped – Mostly trabecular • Cortical outside • wrists and ankles © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Shape Categories of Bones • Flat – Thin, elongated – Curved, large surface area – Two thin layers of cortical • Small amount of trabecular – Protection and muscle attachment • Skull, ribs, sternum • Irregular – Don’t fit in a category – Shape based on function • Vertebrae and pelvis © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Anatomical Structure of Long Bones © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Anatomical Structure of Long Bones • Made of three parts: • Periosteum • Fibrous CT • Contains vessels, lymph and nerves • Involved in growth, repair and nutrition • Diaphysis- cortical bone shaft • Surrounded by periosteum • Contains hollow medullary canal • All begins as yellow marrow • Blood vessels and fat stores • Lined by CT called endosteum • Epiphysis- ends of long bones • Mostly trabecular bone and red marrow • Hematopoiesis =blood cell formation (mostly RBC) • Covered by articular cartilage © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Anatomical Structure of Long Bones © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Anatomical Structure of Bones • Bone nourishment and waste elimination • Passageways through the mineralized bone (Subway) • Contains nerves and blood vessels for nutrient and signal transfer • Haversian Canals- Major lengthwise canals • Contain Lacunae (cavities in lamella) • Lacunae make little circles around HCs called Lamella (“tree trunks”) • Lacunae are where the osteocytes are located • Osteons OR Haversian System • Each Haversian Canal and parts • Canaliculi • Travel sideways between lacunae to connect different osteons • Volkmann’s or perforating canals connect multiple systems © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Growth and Development of Bones • osteoblasts – build bone tissue • osteoclasts – break down bone tissue (damaged, old or weak) • bone formation – Modeling- Building new bone tissue • Usually from hyaline cartilage (in vitro) – Ossification • 2 phase process prior to birth • Matrix covers cartilage, clasts resorb to form medullary cavities • Balanced in healthy adults – Osteoblast=osteoclast- Homeostatic mechanisms © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Growth and Development of Bones • longitudinal growth- long bones – epiphyseal plates- location of growth during childhood – Ends when plates dissolve and bone fuses ( mid to late adolescence) • circumferential growth- maintains Healthy, strong, lightweight bones – change in diameter- all throughout life • Blasts build from the periosteum • Clasts resorb from the endosteum • Lifelong process= SLOW • adult bone development – aging causes loss of bone mass, mineral content, collagen (elasticity) – Increased risk of fractures ( also… hormonal issues? ) – 25 -28 W, 30 -35 M smaller bones=more density issues © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Remodeling of Bones at the MICROSCOPIC level • Remodeling is due to Blast/clast activity – Result of forces acting on the bone – Converts forces into changes in density, size or shape • hypertrophy of bones still 15% – stronger bones + increased density – Large forces, usually at attachment sites (including mass) – Active lifestyles or heavier/ High impact • Dynamic activity=fluid movement in the matrix) • atrophy of bones still 15% – weaker bones, decreased density or mineral content – Reduced forces (bedridden, swimmers and astronauts? ) © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Chapter 4: The Skeletal System Lesson 4. 2 The Axial Skeleton © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Axial Skeleton • the skull • the vertebral column • Thoracic cage © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Axial Skeleton © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Skull • the cranium – surround the brain – Protects (mostly) • the facial bones – – protect the front of the head Produce face shape Protect and orient eyes Mastication © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Cranium • Joined by interlocking, immovable joints (Sutures) • Sutures allow tiny amounts of movement • Babies are different. Why? – Big heads (1/8 v 1/4) – Fontanels – Soft sutures • Birth trauma and brain development • 22 -24 M © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Cranial Bones and Facial Bones • frontal bone • Forehead • parietal bones (2) • Top/sides of skull • Temporal bones (2) • Surround ears • occipital bone • Back of head • ethmoid bone • Nasal septum • sphenoid bone • Base of brain/eyes • maxillary bones (2) – Upper jaw • palatine bones (2) – Hard palate • zygomatic bones (2) – Cheeks/eye sockets • lacrimal bones (2) – Eyes and tears • nasal bones (2) – nose • vomer – Nasal septum • inferior concha bones (2) – Sides of nasal cavity • mandible – Lower jaw. Only mover © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Cranial and Facial Bones © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Vertebral Column • 33 bones • regions of the spine – – – Cervical (7) Atlas and axis, yes and no Thoracic (12) Lumbar (5) Sacrum (5) Fused. Form posterior p girdle Coccyx (4) Fused. “Tailbone” • curves of the spine= stronger and resists injuries. Present at birth or with development. – – cervical curve – concave secondary thoracic curve convex primary lumbar curve- concave primary sacral curve convex secondary © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Structures of the Vertebrae • the vertebral body – Thick and disc shaped • Bears weight and forms anterior vertebra • the vertebral arch – Round projection surrounding the foramen • Where the spinal cord passes • the transverse processes – Projections on either side of the arch • the spinous process – Extends posteriorly • the superior and inferior articular processes – Facets of articulation © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Structures of the Vertebrae © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Abnormal Spinal Curvatures • Due to genetic or congenital abnormalities • Lordosis – Exaggerated lumbar curve • Kyphosis – Exaggerated thoracic curve • Scoliosis – Lateral deviation © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Intervertebral Discs • located between vertebrae • shock absorbers – Made of fibrocartilage – cushioning • allow flexibility • Change in height – Nutrients – Sleep vs waking © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Thoracic Cage • sternum – Manubrium • Clavicle and upper 2 p ribs – body of the sternum – xiphoid process • projection • ribs – true ribs (7 p) • Attached to sternum – false ribs (3 p) • Cartilage connections – floating ribs (2 p) • No connection but spine © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Chapter 4: The Skeletal System Lesson 4. 3 The Appendicular Skeleton © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

2 Divisions Upper Extremity= arms Lower Extremity= Legs © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Upper Extremity • the shoulder complex/pectoral girdle – Mobility vs stability • Attachment sites for the arm – Scapula - posterior • Acromion- superior and posterior • Coracoid – inferior and anterior • Meets humerus at the glenoid fossa (shoulder joint) – Clavicle anterior • • Attaches to scapula and sternum Acromioclavicular joint – arm raises Sternoclavicular joint –shrugging Positions shoulder away from trunk © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Upper Extremity © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Upper Extremity • Humerus – Second largest bone in the body. Attaches to radius and ulna • Radius – Rotational ( thumb and wrist) – radiocarpal joint with wrist • Ulna – Larger and stronger than radius – Olecranon process of ulna=elbow • Connections – Interosseus membrane, styloid processes – Proximal and distal radioulnar joints © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Upper Extremity • the wrist and hand (54 bones) – precision and grasp – carpals (8) • Two rows connected by ligaments. Base of hands. – metacarpals (5) • Articulate with carpals, “hands” – phalanges (14) • • Fingers and thumb 3 -3 -2 Numbering system Opposable thumb = more motion © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Upper Extremity © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Lower Extremity (weight bearing and gait) • the pelvic girdle • Reproductive organs, bladder, colon – Two coxal bones • M Vs F – Childhood 3 separate bones that fuse • Ilium- superior and posterior, sacroilliac joint, “wings”, illiac crest • Ischium- inferior portion, supports upper body weight, acetabular joint • Pubis- anterior, pubic symphysis ( hyaline) © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Lower Extremity (weight bearing and gait) © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Leg – Femur • Longest and largest • Head to acetabulum=stability • Neck vulnerability – Tibia • Strong- shin, bears weight – Fibula • Muscle attachment only, not part of knee – Lateral malleolus=ankle outside – I. O. membrane – patella • Small flat and triangular, protects the front of the knee © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

The Lower Extremity • the ankle and foot : walking and balance – tarsals (7) • Calcaneus • talus – metatarsals (5) • “Foot” – Phalanges (14) • 33332 • Stability • Weight area • 2 arches – Longitudinal and transverse • Spring © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Chapter 4: The Skeletal System Lesson 4. 4 Joints © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Categories of Joints • immovable joints–synarthroses – Fibrous joints. Little to no movement • slightly movable joints–amphiarthroses – Cartilage. Absorb shock • freely movable joints–diarthroses – Synovial joints(encapsulated) © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Immovable Joints • TWO types • Sutures – Ossified fibrous tissues – Skull only • Syndesmoses (held by bands) – Fibrous tissue bands prevent movement – coracoacromial joint – distal tibiofibular joint © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Slightly Movable Joints • Synchondroses (held by cartilage) – hyaline – sternocostal joint – epiphyseal plates • Symphyses – Hyaline cartilage plates and fibrocartilage disc – vertebral joints – pubic symphysis © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Freely Movable Joints • Gliding – Articulating surfaces flat. • Saddle • Hinge – planar movement (door) • Pivot – Around 1 axis – Multidirectional movement – > ROM than condyloid • Ball and Socket – Mobility vs stability • Condyloid © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Freely Movable Joints © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Freely Movable Joint Structures • Bursae – Cushioning structures filled with synovial fluid • tendon sheaths – Surround tendons subject to friction. Secrete synovial fluid (wrists and fingers) • articular tissues – articular fibrocartilage • meniscus – Tendons • Muscle to bone – Ligaments • Bone to bone © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Chapter 4: The Skeletal System Lesson 4. 5 Common Injuries and Disorders of the Skeletal System © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Common Injuries and Disorders of the Skeletal System • • common bone injuries osteoporosis common joint injuries arthritis © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Fractures= a break or crack in the bone • Force – Size, Direction, duration – Bone health and maturity • Types – – Simple (closed) Compound (open) Communited (splinter) Avulsion (tendon or ligament) • Bone chip – Spiral (twisting) © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Fractures= a break or crack in the bone • Greenstick – Incomplete break – Found in children – Higher collagen • Stress – – Tiny cracks Overuse Repetitive motion injuries “playing injured” © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Epiphyseal Injuries • epiphyseal plate – Premature closure • articular cartilage – Osteochondrosis (Osgood-schlatter) • Young athletes, usually male • Quadriceps to tibia attachment • Pain and swelling at attachment site • Apophysis – Tendon attachment site © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Osteoporosis- demineralized bones • low strength bones easily break • Trabecular bone mostly • age-related osteoporosis – Women, most elderly – Osteopenia first- reduced mass without fracture – Type 1 - postmenopausal: 15 yr. femur, vertebrae, wrist – Type 2 - age related: 60 -70 yrs femoral neck – Common sign back pain • Vertebral crush injuries • kyphosis © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Osteoporosis- demineralized bones • the female athlete triad – disordered eating • Anorexia nervosa • Bulimia nervosa – amenorrhea – Osteoporosis • irreversible © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Common Joint Injuries- usually to freely moveable joints • sprains – Torn/overstretched ligament or tendon – Ankle most common – Pain and swelling = ice and elevation • dislocations – bone displaced from socket – Falls or collisions – Joint deformity, pain and swelling= replace and splint • bursitis – inflammation of bursae © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.

Arthritis >100 types • rheumatoid arthritis – – immune system attacks joints Usually adults Thickening of synovial membranes, breakdown of cartilage Loss of motion, fusing of bones • osteoarthritis – degeneration of articular cartilage – Pain swelling and stiffness – Pain improved by rest and stiffness by use. © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.