3947435 musculoskeletal system

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MUSCULOSKELETAMUSCULOSKELETA

L SYSTEML SYSTEM

EMERITA C. MENDOZA,EMERITA C. MENDOZA,

R.N., M.D.R.N., M.D.



FUNCTIONS OF THE SKELETALFUNCTIONS OF THE SKELETAL

SYSTEMSYSTEM

1. Bony framework for the body

2. Protects delicate vital organs

3. Levers that transmit muscular forces

tendons

ligaments

4. Bone marrow produces blood cells

5. Storage for calcium and phosphorus



Structure of a BoneStructure of a Bone

� periosteum

� Diaphysis

� Epiphysis

� Metaphysis mature

to epiphyseal lines

� Marrow cavity withyellow bone marrow

� endosteum



PARTS OF

A BONE



Types of BoneTypes of Bone

� According to location:

� Axial ± found along our midline axis

� Appendicular ± found in our extremities

� According to shape:

� flat & irregular bones ± many axial bones

� long and short bones ± in our limbs

� pneumatic bones ± have air spaces, e.g., skull

� sesamoid ± in tendons, e.g., patella



Types of BoneTypes of Bone

� According to structure:

� C ompact or dense bone ± outer casing

� S pongy or cancellou s bone ± interior marrow

� According to development:

� E ndochondral ± during fetal development,

ossifies from a cartilage stage, e.g., long bones

� M embranou s ± develop from non-cartilageconnective tissue, e.g., flat, irregular bones



Bone OssificationBone Ossification

OSTEOBLASTS

� bone-building cells

� Secrete the protein collagen� Apatite ± CaPO4 that crystallizes around

collagen fibers, forming hard bone matrix

� Osteoblasts become isolated/trapped inthe lacunae osteocytes



Bone ResorptionBone Resorption

OSTEOCLASTS

� Cells that break down or collapse bone

� Large cells that move about secretingenzymes that digest bone

*Osteoclasts & osteoblasts work together to

shape bones and to form the precise grainneeded in the finished bone



How many bonesHow many bones

are in our skeleton?are in our skeleton?� Axial:

� skull� cranium 22

& face

� auditory oss 6

� hyoid 1� vertebrae 26

� Ribs 24

� sternum 1

� Appendicular:

� upper limb girdle 64� lower limb girdle 62

� Axial = 80

� Appendicular = 126

� Total = 206



The SkullThe Skull

� 8 cranial bones

� 14 facial bones� 6 small bones in the

middle ear



The CraniumThe Cranium

� protects the brain� 4 major divisions:

� f rontal bone - anterior

� parietal s ± central

� temporal s - lateral

� occipital ± posterior

� Plus the:

� s phenoid - base

� ethmoid ± roof of nostrils

� frontal bone also known asthe ³forehead bone´



The FacialThe Facial

bonesbones� 2 nasal bones

� 2 inferior nasal conchae

� 1 vomer ± floor of nasal cavity

� 2 palatine ± roof of oral cavity

� 2 zygomatic ³cheekbones´

� 2 maxillae for upper jaw

� 1 mandible for lower jaw

� 2 lacrimal, where tears flow

� Mandible articulates with thecranium at the temporomandibula joint (TMJ)



The Auditory OssiclesThe Auditory Ossicles

� sense vibration

� 3 inner ear bones:

� malleu s or hammer ±

articulates with

eardrum

� incu s or anvil ± articulates

with malleus & stapes

� stapes or stirrup ±articulates with oval

window



Cranial SuturesCranial Sutures

� Sagittal ± joint bet the

two parietal bones

� Coronal ± joins the

parietal bones to thefrontal bone

� Lambdoidal ± joint bet

the parietal bones

and the occipital bone



Fontanelles or soft spotsFontanelles or soft spots

� Fibrous connective

tissue or cartilage that

occur at the angles of the parietal bone

� Anterior ± closes at 12-

18 months

� Posterior ± closes at 3-

4 months



SinusesSinuses

� Air spaces lined w/mucous membranefound in some cranial

bones� The paranasal

sinuses (located inthe frontal, maxillary,sphenoid, & ethmoidbones) arecontinuous w/ thenose and throat



The Vertebral Column or SpineThe Vertebral Column or Spine

� Supports the body & bearsits weight

� Regions:

± 7 cervical

± 12 thoracic

± 5 lumbar

± Sacrum

± Coccygeal

� S-shaped

� Vertebrae are attached toeach other via synovial joints & by intervertebraldiscs



The NormalThe Normal

SpineS

pine� Has normal curves:

� lordosi s ± cervical, lumbar concaving

� k yphosi s ± thoracic convexity

� intervertebral di sc s ± maintainflexibility, absorb shock; outer annulu s f ibrosi s, inner gelatinous nucleu s pulposu s

� With age, loss of H2O content

causes decrease in disc height



The Thoracic Cage or rib cageThe Thoracic Cage or rib cage

� Bony cage formed bythe sternum, thethoracic vertebrae, &

12 pairs of ribs� Protects the organs of

the chest

� Supports the pectoral

girdle & upper extremities

� Role in respiration



The RibsThe Ribs

� Articulates with thethoracic vertebrae atfacets

� Since there are 12thoracic vertebrae, howmany ribs should wehave?

� 12 pairs or a total of 24

� Spaces in between the

ribs are calledintercostal s paces (ICS)



True, False, & Floating RibsTrue, False, & Floating Ribs

� Ribs 1-7 are ³ true´

ribs, because they

attach directly to the

sternum� Ribs 8-10 are ³ f al se´

ribs, because they

attach to the rib

above

� Ribs 11-12 are

³ f loating´ ribs,

because they have no

anterior attachments



The Pectoral Girdle or shoulder The Pectoral Girdle or shoulder

� Attaches the UE to

the axial skeleton

� Consists of:

± Scapula ± shoulder blade

± Clavicle ± collar

bone

� Articulates with thesternum via the

clavicle but not with

the vertebral

column



The ³Shoulder Blade´: ScapulaThe ³Shoulder Blade´: Scapula

� Major parts of theshoulder blade:

� s pine of scapula, or acromion, withcoronoid

� coracoid process

� glenoid f ossa

� clavicular f acet

� The scapula serves asorigin for many muscles,articulates with theclavicle, and offers thefossa for humeralarticulation (the shoulder

joint).



The ³Collar bone´: ClavicleThe ³Collar bone´: Clavicle

� small, thin, long & flatbone

� articulates with thesternum at the angle of Louis; and with the

shoulder blade by a facetthat accepts the shoulder blade, and by strongligaments to the shoulder blade

� If fractured, the shoulder

falls medially, forward, andslightly downward

� commonly known as a³greenstic k ́ fx in children



The Upper ExtremityThe Upper Extremity

� Consists of 30 bones:

± Humerus ± upper arm

± Ulna - forearm

± Radius - forearm

± Carpal bones - wrist

± Metacarpals - palm

± Phalanges - fingers



Upper Arm: The HumerusUpper Arm: The Humerus� articulates with the

pectoral girdle at theglenoid f ossa of theshoulder joint

� typical long bone

� articulates with theradius & ulna at thehumeral capitulum &olecranon f ossa-trochleaof the elbow joint,

respectively� has radial and ulnar

grooves ± for nerves

� Commonly fractured,described in 1/3¶s



Forearm: Radius & UlnaForearm: Radius & Ulna

� The smaller radius articulateswith the humerus with itshead

� The larger, wrench-shaped

ulna, articulates with thehumerus at the ulnar olecranon

� Both articulate with carpal s of the hand as the carpal or wrist joint via facets and styloid

processes� R adial = thumb side

� U lnar = pinky side



Hand bones, Palm: CarpalsHand bones, Palm: Carpals� 8 short bones in 2 rows

� Proximal: (r-u) scaphoid,lunate, triquetrium,

pi si f orm

� Distal: (r-u) trapezium,

trapezoid, capitate, hamate� ³Scared Lovers TryPositions That They Can¶tHandle´

� If you fall and land on your

hand, which bone is mostlikely to break?

� C olle¶ s f x = dinner forkdeformity of the wrist dueto fx of the radius



More Hand bones:More Hand bones:

� There are 5 pairs of metacarpals, or ³knucklesbones´

� Each finger, or digit, has 3

phalanges� The thumb has 2

phalanges

� metacarpo-phalangeal joints are MCP¶s

� joints between 1st & 2nd

phalanges are PIP¶s

� joints between 2nd & 3rd

phalanges are DIP¶smetacarpals andmetacarpals and

phalangesphalanges



The Pelvic GirdleThe Pelvic Girdle

� Supports the LE &is the site of attachment of major muscles of the

trunk and LE� Supports the weight

of the upper body &protects the organs

that lie within� Two innominate

bones + sacrum &coccyx = pelvic

girdle



Parts of the ´HipParts of the ´Hipboneµboneµ

� Looks like two fish eating abutterfly

� ASIS = anterior superior iliac

spine, important landmark� P SIS ± lies deep to a dimple

� i schial tuberosity ± part we sit on

� symphy si s pubi s ± fibroelasticconnection between two pubicbones

� acetabulum ± depression for thehead of the femur

� greater sciatic notch ± openingfor sciatic nerve

� lesser sciatic notch

� obturator f oramen ± for obturator nerve

� linea terminali s, or pelvic brim ±separates ³false pelvis´ abovefrom ³true pelvis´ below



Female pelvisFemale pelvis

� Broader and more

shallow

� Pelvic inlet is larger &

more circular

� Ischial spines are shorter

with greater relative

distance bet them

� Greater angle bet the

pubic bones

� Adapted for a developing

baby & its delivery



The Lower ExtremityThe Lower Extremity

� Consists of 30bones: ± Femur ± upper leg

or thigh

± Patella ± or kneecap

± Tibia & fibula ±

lower leg or shin ± Tarsal bones ± back

part of foot & heel

± Metatarsals ± mainpart of the foot

± Phalanges - toes



The ³thigh bone´: Femur The ³thigh bone´: Femur

� longest bone of the body� acetabular head articulates withthe pelvic acetabulum

� nec k ± commonly fractured, esp.in postmenopausal women withosteoporosi s (excessive boneresorption)

� greater trochanter ± for attachments, e.g., gluteus m

� lesser trochanter ± for theiliopsoas m.

� shaf t

� epicondyles ± for attachment of medial & lateral collateralligaments of the knee joint to theleg bones, and articulation withthe tibia

� trochlea ± facet for patella



The ³knee cap´: PatellaThe ³knee cap´: Patella

� sesamoid bone

� articulates with the femoraltrochlea above and thetibial head below

� surrounded byligaments,e.g., anterior &posterior cruciates, medial(tibial) & lateral (fibular)collateral s

� prepatellar bur sa isassociated with gouty arthritis when excess uricacid is produced, causingarthritic pain



The leg bones: Tibia & FibulaThe leg bones: Tibia & Fibula� leg also known as cru s,

� anterior leg as shin

� articulates with the femur via thelarger, medial tibia

� the smaller, lateral fibula ismostly for attachment of mm

� tibia-fibula joined together by aninterosseou s membrane

� medial ( tibial ) malleolu s = inner ankle, area prone to sprain

� lateral (f ibular ) malleolu s = outer ankle, prone to fracture

� lower quadrangular surface of tibia bears much weight on thefoot



TheThe

AnkleAnkleBonesBones

tibia

fibula

talus



The Foot bones,S

ole: TarsalsThe Foot bones,S

ole: Tarsals� the tall talu s receives

the weight from the

tibia

� rests on a ³calcifiedrock,´ the calcaneu s

� mid-sole are the

navicular, cuboid , and

three cunei f orms� cuboid and

cuneiforms articulate

with the metatarsals



Joints (Articulations)Joints (Articulations)

� Point of contact bet

two bones

� For flexibility and

movement



Synovial JointsSynovial Joints

� Most of body¶s joints

� Joint capsule lined w/ a smoothsynovial membrane that secretes alubricating synovial fluid

� Fluid-filled sacs called bursaecushion the movement of bone over other tissues



Types of MovableTypes of Movable

JointsJoints

� E narthrosi s ± ball-and-socket

of shoulder, hip

� G inglymu s ± hinge of

elbow, digits, ankle,mandible

� C ondyloid ± knee, MCP, wrist

� T rochoid ± pivot of atlas,

radioulnar

� Arthrodial ± sliding of acromioclavicular jt, CMC,

knee, ribs, sternoclavicular,

subtalar, tibiofibular

� S addle - vertebra



MUSCULARMUSCULAR

SYSTEMSYSTEM

� ORIGIN:

± The attachment of

muscle to the less

movable bone

� INSERTION

± The attachment of

the muscle to the

more movable bone



Flexion Decreasing the angle between twobones; bending a limb

Extension Increasing the angle between two bones;straightening out a limb

Abduction Movement away from the midline of the

bodyAdduction Movement toward the midline of the body

Rotation Circular movement around an axis

Dorsiflexion Backward (upward) bending of the foot

Plantar flexion Bending the sole of the foot downwardtoward the ground; toe pointing

Supination As applied to the hand, the act of turningthe palm forward, or up

Pronation As applied to the hand, the act of turningthe palm backward, or down

3947435 musculoskeletal system

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