The framework of bones and cartilage which protect organs, and provides a lever system that allows locomotion.
The SKELETAL System
SupportProtectionMovement FacilitationMineral Storage and HomeostasisHematopoiesisStorage of Energy
Functions of the Skeletal System
Osteoprogenitor Osteoblasts OsteocytesOsteoclasts
Types of Bone Cells
Bone Cells
the process by which bones form in the body – 2 types
Intramembranous OssificationMembranes ----> Bone
Endochondral OssificationCartilage ----> Bone
Ossification/ Osteogenesis
Intramembranous Ossification
Endochondral Ossification
Bones are constantly undergoing ossification and remodeling
Replacing old bone matrix with new bone matrixbone reabsorption (osteoclasts)bone deposition (osteoblasts)
Allows injured or worn out bone to be replaced
Compact bone tissue is formed by the reorganization of spongy bone tissue
Homeostasis and Bone Remodeling
Periosteum – the outer covering Diaphysis - shaft of a long boneEpiphysis - ends of a long boneMedullary Cavity – contains marrowRed Marrow – where blood cells are
produced.Yellow Marrow – where fat is stored
Long Bone Structure
Long Bone Structure
Compact Bone (Dense Bone)little space between the solid components of
boneSpongy Bone (Trabecular Bone)
made up of an irregular network of thin plates of bone with many intercellular spaces called trabeculae (spicules)spaces between trabeculae filled with red bone
marrow- responsible for reducing weight of boneresponsible for hematopoiesis
Classification of Bones
Compact Bone
Compact BoneYou Tube Video: Osteon Model found at http://www.youtube.com/watch?v=CQhUINnTdZI
Proximal End of a Long Bone
EpiphysealPlate
Spongy Bone Structure
Long BonesShort BonesFlat BonesIrregular BonesSesamoid Bones (not a classification used by
all anatomists)
Types of Bones
Types of Bones
Greater length than widthHave a distinct diaphysis and a variable
number of epiphysisSlightly curved for strengthExamples: humerus, ulna, radius, femur,
tibia, fibula, metacarpals, metatarsals, phalanges
Long Bones
Cube-shaped bonesNearly equal in length and widthSpongy texture on inside of the boneExamples: carpal and tarsal bones
Short Bones
Generally thin and flatCompact bone on anterior and posterior
surfaces with spongy bone in the middleProvides protection to organsLarge surface area for muscle attachmentExamples: cranial bones, sternum,
scapula, ribs
Flat Bones
Complex shaped bonesCannot be classified into other categoriesVary in the amount of spongy and compact
boneExamples: vertebrae, facial bones, patella
Irregular Bones
Foramen - an opening or hole in a bone.Bone Markings
Source: Mcstrother. (2010). File:Skull foramina labeled.svg Wikimedia Commons. Retrieved on October 16, 2011 from http://en.wikipedia.org/wiki/File:Skull_foramina_labeled.svg.
Meatus - a tube-like passageway within a bone
Bone Markings
Source: Pngnot. (2007). File:Gray908.png. Wikimedia Commons. Retrieved on October 16, 2011 from http://en.wikipedia.org/wiki/File:Gray908.png.
Sinus - a space within a bone lined with mucus membrane that reduces the weight of a bone
Bone Markings
Source: Arcadian. (2007). File:Illu09 sinuses.jpg. Wikimedia Commons. Retrieved on October 16, 2011 from http://en.wikipedia.org/wiki/File:Illu09_sinuses.jpg
Fossa - a depression or groove on a boneBone Markings
Source: Hughes, P. Shoulder Anatomy. Upper Limb Centre.Retrieved on October 16, 2011 from:http://www.upperlimbcentre.com/anatomy.htm
Source: Uwe Gille. (2007). File:Scapula ant numbered.png.Wikimedia Commons. Retrieved on October 16, 2011 from:http://en.wikipedia.org/wiki/File:Scapula_ant_numbered.png
Condyle - “Knuckle” - a large rounded
prominence on a bone
Bone Markings
Source: Pngbot. (2007). File:SFile:Gray347.png.Wikimedia Commons. Retrieved on October 16, 2011 from:http://en.wikipedia.org/wiki/File:Gray347.png
Tuberosity - an elevated, rounded, usually roughened area of a bone
Bone Markings
Source: Johnuniq. (2010). File: HumerusFront.png.Wikimedia Commons. Retrieved on October16, 2011 from http://en.wikipedia.org/wiki/File:HumerusFront.png
Trochanter - a large blunt process found only on the femur
Bone Markings
Source: Pngbot. (2010). File:Gray343.png.Wikimedia Commons. Retrieved on October16, 2011 from http://en.wikipedia.org/wiki/File:Gray343.png
Tubercle - a small rounded process
Bone Markings
Source: Bot. (2006). File:Gray122.png.Wikimedia Commons. Retrieved on October16, 2011 from http://en.wikipedia.org/wiki/File:Gray122.png.
Process - any projection from the surface of abone
Bone Markings
Source: Engusz. (2007). File:Processusmastoideusossistemporalis.PNGWikimedia Commons. Retrieved on October16, 2011 from hhttp://en.wikipedia.org/wiki/File:Processusmastoideusossistemporalis.PNG
Sutures are the joints between the skull bones. They fuse together between the ages of 18 months old and 3 years.
Fontanels are the soft, membranous spots of a baby’s skull that allows for brain growth and the delivery of the fetus through the birth canal.
Suture and Fontanel
Axial Skeleton - bones that lie along the long axis of the body. Includes the skull, hyoid bone, sternum, ribs, and vertebrae. There are 80 bones.
Appendicular Skeleton - bones of the extremities. There are 126 bones.
Divisions of the Skeleton
Bones of the Skeletal System
Skull – Anterior View- Identify Bones
Skull – Lateral View- Identify Bones
Skull – Posterior View- Identify Bones
SkullYou Tube Video: Skull Bones at http://www.youtube.com/watch?v=Nc5IRj3OJhE
Bones of the vertebral columnCervical vertebrae (7) - neckThoracic vertebrae (12) - ribsLumbar vertebrae (5) - lower backSacral vertebrae (5) - pelvic bonesCoccygeal vertebrae (4) - tail boneIntervertebral Foramina - openings
between the vertebrae for nerve exit
Vertebrae
Vertebral Column
Anatomy of the spine
You Tube Video: Anatomy of the spinal http://www.youtube.com/watch?v=qigpRFN5o04&feature=related
The points of contact between bones, between bones and cartilage, or between teeth and bones.
Joints (Articulations)
Classification of joints based upon how they are held together
Fibrous Jointsheld together by fibrous connective tissue-
skull suturesCartilaginous Joints
held together by cartilage-holds rib and sternum together
Synovial Jointsjoint enclosed within a synovial or joint
capsule- knee cap
Structural Classification of Joints
JointsYou Tube Video: Joints of the skeleton found at http://www.youtube.com/watch?v=VsBJ4oUff10&feature=related
Enclosed within a joint or synovial capsulefibrous capsule - outer layer
attaches to periosteum of bonesynovial membrane - inner layer
secretes synovial fluidSpace between the ends of articulating
bones called a synovial spaceEnd of articulating bones are covered with
hyaline (articular) cartilage
Synovial Joints
Typical Synovial Joint
Pads of fibrocartilagenous discs found between bony surfaces in some joints
Allows the bones to fit together betterMaintains the stability of the jointAbsorbs shockDirects the flow of synovial fluid to areas of
greatest friction
Menisci
Sac-like structures that resemble joint capsules situated within body tissues
Function like ball-bearingsReduces friction between bones and soft
tissuesReduces friction between bones and skin
Bursae
Knee Joint
Shoulder Joint
Shoulder Joint
Hip Joint
Joint VideoYou Tube Video called Joint XL TM found at http://www.youtube.com/watch?v=-hZ8OGpWBrY
Tendons - connect muscle to boneA band or cord of dense fibrous connective
tissue extending from a muscle to a bone for attachment
Ligaments - connect bone to boneA band or cord of dense fibrous connective
tissue extending from one bone to another bone to provide a joint with structural stability
Tendons and Ligaments
Degenerative joint disease associated with aging
Usually preceded by traumatic joint injury
Characteristics:degeneration of articular cartilagedevelopment of bone spursusually effects large joints (knees, hips, etc)
Treatment:rest - removal of bone spursjoint replacement
Osteoarthritis
OsteoarthritisYou Tube video called osteoarthritis found at http://www.youtube.com/watch?v=0dUSmaev5b0
Rupture of the fibrocartilage discsUsually caused by compression forcesUsually occurs between L4 and L5 or
L5 and the 1st Sacral VertebraeDisc protrudes and exerts pressure on
spinal nervesTo decrease risk of herniated discs:
1. maintain optimal body weight2. strengthen abdominal muscles3. increase lower back flexibility
Herniated Discs(Slipped Discs)
Herniated Disc
Herniated DiscYou Tube Video called Disc Protrusion found at http://www.youtube.com/watch?v=zEOlXmUeK7o&feature=related
congenital defect where the neural arch fails to unit
usually involves the lumbar vertebraesymptoms may be mild to severe
usually results in paralysispartial or complete loss of bladder controlabsence of reflexes
can be diagnosed during pregnancy by sonography, amniocentesis, blood tests
Spina Bifida
Spina BifidaYou Tube Video called Spina Bifida Animation can be found at http://www.youtube.com/watch?v=ouMi5z1vwbE
Increases strength of the spineHelps maintain balanceDissipates vertical shockProtects spinal column from fractureAnterior Curves (Secondary Curves)
Cervical Vertebrae -Lumbar VertebraePosterior Curves (Primary Curves)
Thoracic Vertebrae -Sacral Vertebrae
Curvature of the Spine
Curvature of the Spine
Scoliosis - lateral curvature of the spineusually in thoracic and lumbar region
Kyphosis - hunchback/humpbackexaggeration of thoracic curvature
Lordosis - swayback (sprinters butt)exaggeration of lumbar curvature
Abnormal Curvatures of the Spine
Abnormal Curvatures
Curvature of the SpineYou Tube Video called Scoliosis Spinal Fusion Animation can be found at http://www.youtube.com/watch?v=WBIf4AQj5s0&feature=related
Decrease in bone mass and increased susceptibility to fractures.
Osteoporosis
Decreased estrogen productionPoor nutritional statusLow activity levelsWeightSmoking Drugs and alcohol consumptionGender/race/hereditary factors
OsteoporosisContributing Factors
Calcium supplementationEstrogen Replacement TherapyWeight-bearing exerciseSteroid treatment therapy
Osteoporosis - Treatment
Osteoporosis
You Tube video called Osteoporosis can be found at http://www.youtube.com/watch?v=5uAXX5GvGrI&feature=related