Skeletal SystemObjectives: List five functions of bones

Label the main parts of a bone on a diagram of a bone

Name two division of the skeletal system and the main groups of bones in each

divisionCompare the three classifications of joints

by describing the type allowed by eachDescribe at least four disease of the skeletal

system

Skeletal system

• Made of organs called bones

• In adult there are 206 bones

Functions

• Frame work- support muscles, fat and skin• Protection- surround vital organsExample- skull surrounds brain, ribs protect heart

and lungs• Levers- attach to muscles to help provide

movement• Produce blood cells- Red and white, platelets, a

process called hemopoiesis or hematopoiesis• Storage- store most of calcium supply in body

Parts of a long bone--

• Long bones are bones of extremities (arms and legs)• Diaphysis- long shaft• Epiphysis- two extremities or ends• Medullary canalCavity in daphysisFilled with yellow marrow• Yellow marrowInside the medullary canalMainly fat cells

Parts of long bone cont

• EndosteumMembrane that lines the medullary canalKeeps the yellow marrow intactProduces some bone growth• Red marrowFound in bones such as vertebrae, ribs, sternum, cranium, and

proximal ends of humerus and femurProduces red blood cells, platelets and some white blood cellsBone marrow is important in the manufacture of blood and is

involved with the body’s immune response--used in diagnosing blood diseases--given as transplants to people with defective immune systems

Parts of a long bone cont

• PeriosteumTough membrane covering outside of bonesContains blood and lymph vesselsContains osteoblasts- special cells that form new bone

growthNecessary for bone growth, repair and nutrition• Articular CartilageThin layler covers the epiphysisActs as a shock absorber when bones meet to form a joint

Two sections of skeleton

• Axial SkeletonForms main trunk of the bodyComposed of the skull spinal column, ribs and

sternum• Appendicular skeletonForms extremities (arms and legs)Composed of shoulder girdle, arm bones, pelvic

girdle, and leg bones

Skull

• Composed of cranial and facial bones• CraniumSpherical structure that surrounds and protects the

brain--made of eight bones- frontal, two parietal, two

temporal, occipital, ethmoid and sphenoidAt birth the cranium is not a solid bone- spaces called

fontanels or soft spot allow for enlargement as brain grows– turns into solid bone about 18 months of age

Skull Cont

• Facial bonesFourteen facial bonesMain bones- Mandible (lower jaw)

- Maxilla- 2 bones forming upper jaw - Zygomatic- 2 cheek bones - Nasal- 5 bones in upper part of nose - Lacrimal- 2 bones at inner aspect of eye - Palatine- two bones of hard palate or

roof of mouth

Skull Cont

• Sutures- aresas where cranial bones have joined

• SinusesAir spaces in bones of the skullProvide strength with less weightAct as a resonating chambers for the voiceLined with mucous membranes

Skull cont

• ForminaOpenings in bonesAllow nerves and blood vessels to enter or leave the bone• VertebraeSpinal column – made up of 26 bones called vertebraeProtect the spinal cordProvide support for head and trunkMain sections- Cervical 7 neck vertebraeThoracic- 12 in back of chest, attach to ribsLumbar- 5 vertebrae on back of pelvic girdleSacrum- 1 large vertebra called a tailbone

Vertebrae cont

• Intervertebral disks• Pads of cartilage tissue that separate

vertebrae• Act as shock absorbers• Permit bending and twisting movements

Ribs or costae

• 12 pairs of long slender bones• Attach to thoracic vertebrae on dorsal surface

of body• True ribs- first 7 pairs of ribsAttach to directly to the sternum on front of body• False ribs- next 5 pair, first 3 attach to cartilage

of rib above and floating ribs – last 2 of false ribs, no attachment on front of body

Sternum

• Breastbone- consists of three partsManubrium or upper regionGladiolus- body or center areaXiphoid process- small piece of cartilage at bottom

(what do we know about this bone?)• Two Clavicles attach to manubrium by ligaments • Ribs attach to sternum with costal cartilages to

form a cage that protects the heart and lungs

Shoulder or pectoral girdle

• Two clavicles or collarbonesS shaped• Two scapulas (scapulae) or shoulderbones• Scapula proides for attachment of upper arm

bone

Bones of the arm

• Humerus- upper arm bone• Radius- lower arm bone on thumb side• Ulna- larger bone of lower arm that contains

projection called the olecranon process at the upper end forming the elbow

• Carpals- 8 wrist bones on each hand• Metacarpals- 5 bones on each hand to form palm• Phalanges- 14 bones on each hand to form thumb

and fingers

Bones of pelvic girdle

• Made of two os coxae- coxal or hip bones• Join with sacrum on dorsal part of body• Join at joint called symphysis pubis on ventral part of body• Each os cox made of three bones that are fused or joined-

Ilium, Ischium, and Pubis• Contains two recessed areas or sockets called acetabulums

that provide attachment of bones of the leg• Obturator foramen-opening between the ischium and

pubis, allows for passage of nerves and blood vessels to and from the legs

Bones of the legs

• Femur- thigh bone• Patella- kneecap• Tibia- long supporting bone of lower leg, medical

surface• Fibula- smaller bone of lower leg, lateral surface• Tarsals- 7 bones of ankles, calcaneous is heel

bone• Metatarsals- 5 bones forming instep of foot• Phalanges- 14 bones of each foot, form toes

Joints

• Area where two or more bones join together• Ligaments- connective tissue bands that hold long

bones together• 3 types of jointsDiarthrosis- free movable, ball and socket of shoulder

and hip, hinge joints of the elbow and kneeAmphiarthosis- slightly movable, attachment of ribs

to the thoracic vertebraeSynarthrosis- immovable, example is cranium

Disease and abnormal conditions

• Arthritis- group of diseases involving an inflammation of the joints

• Two main types- Osteoarthritis and rheumatoid arthritis

Osteoarthritis- chronic disease that occurs with agingSymptoms- joint pain, stiffness, aching, limited range

of motion (ROM)Treatment- rest, heat/cold applications, aspirin, anti-

inflammatory medications, steroid injections, special exercises

Disease and abnormal conditions cont

• Rheumatoid arthritisChronic inflammatory disease of connective tissues and jointsThree more times common in womenOften begins between ages 35-45Progressive attacks cause scar tissue formation and atrophy of

bone and muscle tissue, which results in permanent deformity and immobility

Treatment- Rest and prescribed exerciseAnti-inflammatory medications- steriods and aspirinSurgery or arthroplasty to replace damaged joints such as

knees or hips

Bursitis

• Inflammation of bursae, small fluid-filled sacs surround joints

• Frequently affects shoulders, elbows, hips or knees• Symptoms- sever pain, limited movement,

accumulation of fluid in joint• Treatment- pain medications and rest, injections of

steroids and anesthetics into joint, aspiration (withdrawal of fluid with a needle) of joint

• Physical therapy to perserve joint motion

Fractures

• Involve a crack or break in a boneTypes- Green stick- bone is bent and splits causing

a crack or incomplete break- common in children

Simple- complete break with no damage to skinCompound- break in bone that ruptures through

skin; increased chance of infectionImpacted- broken bone ends jam into each other

Fractures cont• Comminuted- bone fragments or splinters into more than two pieces• Spiral- severe twisting of a bone causes one or more breaks;

common in skiing and skating accidents• Depressed- broken piece of skull bone moves inward- common with

severe head injuries• Colles- breaking and dislocation of the distal radius that causes a

characteristic bulge at the wrist- caused by falling on an outstretched hand

• Reduction- process by which bone is put back into proper alignmentClosed reduction- position bone in alignment usually with traction and

apply cast or splint to maintain positionOpen reduction- surgical repair of bone and at times insertion of pins,

plates and other devices.

Dislocation

• Bone is forcibly displaced from a joint• Frequently occurs in shoulders, fingers, knees

and hips• Reduced and immobilized with a splint, cast or

traction

Sprain

• Twisting action tears ligaments at a joint• Common sites are wrists and ankles• Symptoms: pain, swelling, discoloration,

limited movement• Treatment: Rest and elevation, immobilization

with elastic bandage or splint, cold applications

Osteomyelitis

• Inflammation of bone usually caused by pathogenic organism

• Pathogen causes formations of abscess within bone and accumulation of pus in medullary canal

• Symptoms: pain at site, swelling, chills, fever• Treatment: antibiotics for infections

Osteoporosis

• Metabolic disorder with increased porosity or softening of bones

• Etiology- Deficiency of hormones, especially estrogen in females, Prolonged lack of calcium in diet, Sedentary life

• Loss of calcium and phosphate caused bones to become porous, brittle and prone to fracture.

• Treatment- increased calcium and vitamin D, Exercise, Medications to increase bone mass, Estrogen replacement

Ruptured disk

• Also called a herniated or slipped disk• Intervertebral disk ruptures or protrudes out of place and causes pressure

on the spinal nerve.• Most common site is the lumbar-sacral area: can occur anywhere on

spinal column• Symptoms: severe pain, muscle spasm, impaired movement, and/or

numbness• Treatment- Pain, anti-inflammatory, and muscle relaxant medications• Rest and transaction• Physical therapy and massage therapy• Chiropractic treatment• Heat or cold treatment• Laminectomy- Surgical removal of the protruding disk for severe cases

Abnormal curvatures of spinal comlumn

• Kyphosis: “hunchback: or rounded bowing of the back at the thoracic area

• Scoliosis: side-to side or lateral curvature of spine• Lordosis: “swayback” or abnormal inward cruvature of

lumbar vertebrae.• Causes- poor posture, congenital defects, structural

defects of vertebrae, malnutrition, degeneration of vertebrae

• Treatment- Therapeutic exercises, firm mattresses, and braces, Surgical repair for severe deformities