SKELETAL SYSTEM SKELETAL SYSTEM

Karen LancourKaren Lancour Patty PalmiettoPatty PalmiettoNational Bio Rules National Bio Rules National Event National EventCommittee Chairman Committee Chairman Supervisor – Health Supervisor – Healthkarenlancour@charter.net ScienceScience

Skeletal System - Functions

Support & shape to bodySupport & shape to body Protection of internal organsProtection of internal organs Movement in union with Movement in union with

musclesmuscles Storage of minerals (calcium, Storage of minerals (calcium,

phosphorus) & lipidsphosphorus) & lipids Blood cell productionBlood cell production

The Skeletal System

Know the Skeletal AnatomyKnow the Skeletal Anatomy Axial SkeletonAxial Skeleton Appendicular SkeletonAppendicular Skeleton Surface Anatomy of the boneSurface Anatomy of the bone

By x-ray or diagramBy x-ray or diagram Structure/function of joints, muscle Structure/function of joints, muscle

and ligament attachmentsand ligament attachments Including range of motionIncluding range of motion

Human Skeleton

206 Bones206 Bones Axial skeletonAxial skeleton: (80 : (80

bones) in skull, bones) in skull, vertebrae, ribs, vertebrae, ribs, sternum, hyoid bone sternum, hyoid bone

Appendicular Appendicular SkeletonSkeleton: (126 : (126 bones)- upper & bones)- upper & lower extremities lower extremities plus two girdles plus two girdles

Half of bones in Half of bones in hands & feet hands & feet

Axial Skeleton (80)

Skull Skull Ossicles of the Ossicles of the

middle earmiddle ear Hyoid bone Hyoid bone Thorax or Thorax or

chest chest Vertebral Vertebral

columncolumn

AppendicularSkeleton (126)

Upper Extremity (64)Upper Extremity (64) Shoulder GirdleShoulder Girdle ArmsArms HandsHands

Lower Extremity (62)Lower Extremity (62) Pelvic GirdlePelvic Girdle LegsLegs Feet Feet

Types of Bone Long bonesLong bones: : longer than they are wide; shaft & longer than they are wide; shaft &

2 ends (e.g.: bones of arms & legs,except wrist, 2 ends (e.g.: bones of arms & legs,except wrist, ankle & patella)ankle & patella)

Short bonesShort bones: : roughly cube-shaped (e.g.: ankle roughly cube-shaped (e.g.: ankle & wrist bones)& wrist bones)

Sesamoid bonesSesamoid bones: : short bones within tendons short bones within tendons (e.g.: patella)(e.g.: patella)

Flat bonesFlat bones: : thin, flat & often curved (e.g.,: thin, flat & often curved (e.g.,: sternum, scapulae, ribs & most skullbones)sternum, scapulae, ribs & most skullbones)

Irregular bonesIrregular bones: : odd shapes; don't fit into other odd shapes; don't fit into other classes (e.g.: hip bones & vertebrae)classes (e.g.: hip bones & vertebrae)

Types of Vertebrae

Cevical (7)Cevical (7) AtlasAtlas Axis Axis

Thoracic (12)Thoracic (12) Lumbar (5)Lumbar (5)

• Atlas – 1st; supports head• Axis – 2nd; dens pivots to turn head

Cervical Vertebrae

• long spinousprocesses

• rib facets

Thoracic Vertebrae

• large bodies

• thick, short spinous processes

Lumbar Vertebrae

Joints Ball & SocketBall & Socket Pivot Pivot Saddle Saddle HingeHinge Elipsoid Elipsoid

(Condyloid)(Condyloid) Plane or Gliding Plane or Gliding

- vertebrae- vertebrae

Bones – Cellular & Physiology

Cross section structures

Cellular composition

Bone marrow Cartilage Fractures

Bone Cells

OsteoblastsOsteoblasts – bone forming cells synthesize and secrete – bone forming cells synthesize and secrete unmineralized ground substance and are found in areas unmineralized ground substance and are found in areas of high metabolism within the bone of high metabolism within the bone

OsteocytesOsteocytes – mature bone cells made from osteoblasts – mature bone cells made from osteoblasts that have made bone tissue around themselves. They that have made bone tissue around themselves. They maintain healthy bone tissue by secreting enzymes and maintain healthy bone tissue by secreting enzymes and controlling the bone mineral content; they also control controlling the bone mineral content; they also control the calcium release from the bone tissue to the blood. the calcium release from the bone tissue to the blood.

Osteogenic cellsOsteogenic cells respond to traumas, such as fractures, respond to traumas, such as fractures, by giving rise to bone-forming cells and bone-destroying by giving rise to bone-forming cells and bone-destroying cells cells

OsteoclastsOsteoclasts – bone absorbing cell – large cells that break – bone absorbing cell – large cells that break down bone tissue – important to growth, healing, down bone tissue – important to growth, healing, remodeling remodeling

Bone lining cellsBone lining cells - made from osteoblasts along the - made from osteoblasts along the surface of most bones in an adult. Bone-lining cells are surface of most bones in an adult. Bone-lining cells are thought to regulate the movement of calcium and thought to regulate the movement of calcium and phosphate into and out of the bonephosphate into and out of the bone

Long Bone Structure

Compact BoneCompact Bone Outer LayerOuter Layer Haversian Haversian

SystemSystem Spongy BoneSpongy Bone

Ends of long Ends of long bonesbones

Cartilage Cartilage

Red and Yellow Bone Marrow

The formation of blood cells, The formation of blood cells, ((hematopoiesishematopoiesis), takes place mainly in the ), takes place mainly in the red marrow of the bones. red marrow of the bones.

In infantsIn infants, , red marrowred marrow is found in the bone is found in the bone cavities. With age, it is largely replaced by cavities. With age, it is largely replaced by yellow marrowyellow marrow for fat storage. for fat storage.

In adultsIn adults, , red marrowred marrow is limited to the is limited to the spongy bone in the skull, ribs, sternum, spongy bone in the skull, ribs, sternum, clavicles, vertebrae and pelvis. Red marrow clavicles, vertebrae and pelvis. Red marrow functions in the formation of red blood functions in the formation of red blood cells, white blood cells and blood platelets.cells, white blood cells and blood platelets.

Cartilage – Characteristics

Mostly water; no blood Mostly water; no blood vessels or nervesvessels or nerves

Tough, resilientTough, resilient New cartilage forms from New cartilage forms from

chondroblastschondroblasts Heal poorlyHeal poorly

Types of Skeletal Cartilage

Hyaline Cartilages: fine collagen fiber matrix- most abundant type- found in articular (movable joint) cartilages, costal cartilages (connect ribs tosternum), respiratory cartilages (in larynx & upper respiratory passageways) & nasal cartilages

Elastic Cartilages: similar to hyaline cartilage, more elastic fibers (very flexible) – found in external ear & epiglottis (larynx covering)

Fibrocartilage: rows of chondrocytes with thick collagen fibers; highly compressible with great tensile strength- found in menisci of knee, intervertebral discs & pubic symphysis

Fractures of the Bone

Know fractures based on diagrams or by x-ray recognitionKnow fractures based on diagrams or by x-ray recognition

Bone Repair Sequence Injury – broken blood vessels, Injury – broken blood vessels,

hematomahematoma Invasion of blood vessels & generalized Invasion of blood vessels & generalized

cells (2-3 days)cells (2-3 days) Fibroblasts develop (1 week)Fibroblasts develop (1 week) Chondroblasts develop Chondroblasts develop Callus forms (4 weeks)Callus forms (4 weeks) Remodeling with osteoclasts (8 weeks)Remodeling with osteoclasts (8 weeks)

Disease/Injury Levels

OsteoarthritisOsteoarthritis OsteoporosisOsteoporosis Fractures (via pictures and x-rays)Fractures (via pictures and x-rays) Disc herniationDisc herniation ScoliosisScoliosis ACL and MCL injuriesACL and MCL injuries