Functions of the Skeletal System
Protect vital organsSupport and maintain postureProvide attachment points for musclesStorage and release of minerals such as calcium and phosphorusBlood cell productionStorage of energy
Axial Skeleton
Skull - protects brain, eyes, and earsVertebral Column -Cervical - 7-Thoracic - 12-Lumbar - 5- Sacral - 5 (fused)-Coccygeal - 4 (fused)
Ribs
First 7 - True ribs that attach to the sternum8-10 - False ribs that attach indirectly to the sternum
Appendicular - Upper Body
Pectoral girdlesClavicleScapulaeHumerusUlnaRadiusRadicular jointCarpalMetacarplesPhalanges
Appendicular - Lower
Pelvis (illium, ishium, pubis)FemurTibiaKnee jointFibulaPatellaTarsalsMetatarsels
What is a long bone
Length greater than widthMost important for movementie. Femur
What is a short bone
small and cube-shapedie. carpals and tarsels
What is a flat bone
Curved surfacesThick and thinProtection and areas for muscle attachmentie. sternum, scapula
What is an irregular bone
specialized shapes and functionsie. vertebrae
Diaphysis
Mid section of long boneCompact boneProtection and support
Proximal and Distal Epiphysis
Top and end of long bonesCancellous/spongy bone
Cancellous bone
Irregular latticework structureShort, flat, long, and irregular bonesRed bone marrow stored hereBlood cells produced here
Articular cartilage
Covers end of boneReduce friction between bonesAbsorbs shock
Periosteum
Outer lining of the boneThin, shiny membraneBone growth, repair, nutrition, attachment of ligaments and tendons
Medullary Cavity
Space in diaphysis where yellow marrow is stored
Nutrient Foramen
Small opening in diaphysisBlood vessels pass through which provide bone marrow and compact bone with blood and nutrients
What is a joint
Two or more bones come into contact or articulate with each other
Main function of jones
Increase mobility of body and limbs
Joint classification
gap between articulating bonesShape of bonesType of tissue that connects bones together
Factors that affect stability around the joints
Shape of the bones and whether they interlockArea over which the bones are in contactFlexibility of ligamentsInfluence of other soft tissue structures
What are ligaments?
Strong, flexible tissues that connect bone to boneProvide stability and help maintain normal body arrangementsNot very elastic
Three types of joints
FibrousCartilaginousSynovial
Fibrous joints
No cavityThin layer of fibrous tissue connecting edges of two bonesNo movement is allowedie. with the skull
Cartilaginous joints
Bones separated by fibrocartilage disc or by thick layer of hyaline cartilageie. vertebrae discsLimited movement
Synovial joints
Most common jointsMost important for mobility
Distinct features of Synovial joints
-Articular cavity (space between joints)-Articular Cartilage-Articular capsule cation, some fibers arranged in parallel bundles-Synovial membrane-Menisci-Bursae
Articular Carilage (Synovial Joint)
Smooth, white layerCovers articulating surfacesUsually Hyaline cartilage or fibrocartilageProtects bonesReduces frictionAbsorbs shock
Articular capsule (Synovial Joint)
Sleeve-like structureAllows momementTensile strength protects from dilocationSome fibers arranged in parallel bumdles
Synovial membrane (Synovial joint)
Secretes synovial fluidMore fluid with movementLubricates joint cavity
Menisci
Semi-lunar discs of fibrocartilage Found between some articulating bonesAllow bones to fit together more tightlyGreater cushioning and stability
Bursae
Small fluid filled sacsBetween structures that rub against each otherLined with synovial membraneReduce friction
Types of Synovial Joints
GlidingHingePivotCondyloidSaddleBall and socket
Gliding joints
Least amount of movementFlat or slightly curvedSlide back and forthFound between carples
Hinge Joints
Bend or straiten in one directionConvex usually fits into concaveLike elbow
Pivot joint
One bone forms ring that other bone rolls in Radius around ulna
Condyloid Joints
Oval or egg-shaped convex fits into reciprocally shaped concaveRadius and carpal bonesMovement in two directions
Saddle Joint
Bones shaped like saddle and riding sitting in itMetacarpals and thumbMove in two directions
Ball and socket
Move in all directionsGreatest amount of movementsphere shaped head fits into round cavityShoulder and hip
Three types of muscle
Skeletal CardiacSmooth
Skeletal Muscle
Voluntary controlStriated appearanceAlternating dark and light bandsTendons that attach mostly to boneMove the skeleton
Cardiac Muscle
StriatedInvoluntary controlContracts without consciously thinking
Smooth Muscles
Lines walls of blood vessels and hollow organsInvoluntaryNot striated
Main Functions of Muscle
-Joint movement (muscle, tendon, bone, joint)-Move substances (ie blood, food)-Stabalize and maintain body positions (postural muscles)-Generate up to 85% of body heat
Properties of Muscles
ContractilityExtensibilityElasticity
Contractility
Ability of muscle to contractGenerate force when it is stimulated by nerveOne muscle is contracted, other is stretched
Extensibility
Muscle to stretch beyond its normal resting length
Elasticity
Return to original resting length after stretch is removed
Fascia
-Connective tissue that is located in between and surrounding other tissues of the body-Fibrous tissue, adipose (fatty) tissue, and fluidSuperficial or deep-Each muscle compartment surrounded by fascia
Three layers of Fascia in each individual skeletal muscle
EpimysiumPerimysiumEndomysium
Epimysium
Outer layer of fascia that covers the entire muscle
Perimysium
Fascia hat surrounds bundles of muscle fibers or fascicles that are long, cylindrical and very in length and width
Endomysium
Layer of fascia that surrounds individual muscle fibres
Myofibrils
Within the perimysiumLight and dark bandsStriated appearanceArranged into series of functional units called sarcomeresCauses muscle to get bigger when trainer - increase number of myofibrils
Sacromeres
Series of functional unitesBands of contractile proteins: actin and myosinImportant for muscle contraction
Hypertrophy
Increase in number of myofibrilsMuscle will get bigger when muscle is trained through exercise or increased activity
Atrophy
Myofibrils will decreaseWaste away or atrophyWhen muscle isn't used
Tendons
-Tough, flexible bands of fibrous connective tissue connecting muscle to bone-Round cord or flat sheet-Could be enclosed in tendon sheaths that contain synovial fluid-Strong and transmit forces generated by muscle to bone-Muscle contraction and joint movement-Muscle belly is the fleshy middle that is prominent when the muscle contracts
Structure of the muscle
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Origin and intersection
-Two ends of the muscle-One stays fixed and one moves-Closest to center of body is usually fixed
Rectus Abdominus
Most superficial muscle in anterior trunkUpwards from pubis to ribs on either side of midline"six pack" appearancePull trunk forward when they contract
External obliques
Side and front of the trunkUnder rectus abdominusLower 8 ribs to iliumSideways and bending movement and rotation
Erector Spinae
-Overlapping muscles that run alongside most of the spine-Originate in ribs, cervical, thoracic and lumbar verebrae, illiym-Different insertion points-Pull trunk into extension when contract for person to lean back
Muscles of upper extremity
DeltoidPectoralisMajor and biceps brachiiTrapeziuzLatissimus dorsiTriceps brachii
Deltoid
-Most prominent and useful shoulder muscles-Origionates on scapula and clavicle-Inserts onto lateral humerus-Involved in shoulder movements
Pectoralis Major
-Originates on clavicle, ternum, and anterior ribs-Covers entire anterior chest region-Tendon forms front of armpit-Insets to the inside of the humerusShoulder movements where arm is brought forward or up
Biceps Brachii
-Two muscle heads that originate on scapula-Inserts onto radius and ulna-Shoulder and elbow movementFlexes or brings the arm upwards at shoulder and flexes at the elbow
Trapezius
-Triangular muscle on posterior neck and upper back-Origin is base of skill and along cervical and thoracic vertebrae-Inserts onto clavicle and scapula-Main action is to raise shoulders-Controls movements of the scapula (important for powerful shoulder movement)
Latissimus dorsi
-Large muscle located on the back-Sacrum and illium along lumbar and thoracic vertebrae-Tendon forms posterior border of armpit-INserts onto inside of humerous close to insertion of the pectoralis-Brings arm backwards-Rotates arm inwards
Triceps Brachii
-Upper arm-Origin has three heads on scapula and humerus-Insertion is on bony prominence on proximal and posterior ulna-Shoulder and elbow movement-Extends of moves arm backwards at the shoulder-Straitens at the elbow`
Illiopsoas
-Originates on the lumbar vertebrae and illium-Attaches to inner femur-Brings thigh upwards at hip
Satorius
-Ilium to medial tibia-Crosses knee and hop joints-Brings thigh upwards at the hip-Also bends the knee
Four muscles in quadricep Muscle group
Rector femorisVastus medialisVastus lateralisVastus intermediusForm quadriceps tendon that insert into the patellaInserts also onto the anterior and upper tibiaStraighten the knee joint
Rectus Femoris
Part of quadriceporigionates at illium
Vastus lateralis
Located on lateral thighoriginates on illium
Vastus medialis
Medial thighOriginates on illium
Vastus intermedius
Between lateralis and medialisUnder rectus femoris
Tibialis anterior
Front of lower legRuns between tibia and fibulaInserts onto first metatarsal and tarsal bonesContracts, pulls toes towards shin
Gluteus maximus
Large muscleCovers posterior hip and buttocksOriginates on the sacrum, ilium, and coccyxInserts to the upper part of the lateral femurContracts and moves thigh backwards at the hip into extension
Three muscles in hamstring group
Biceps femorisSemitendinosusSemimembranosuslocated on posterior thigh
Bicept Femoris
Part of hamstringOriginates on ischiumInserts on head of fibula and lateral tibiaExtend hip and flex the knee
Semitendinosus
Originates on ischiumInserts on medial tibia
Semimembranosus
Originates on ischiumInserts on medial tibia
Gastrocnemius
Most superficial calf muscleTwo headsOriginate on the posterior femurMuscle crosses knee and ankle joint
Soleus
Origionates on the posterior tibia and fibulaLocaed underneath the gastrocnemius
Gastrocnemius and Soleus
Form the calfTendons join to form the achilles tendonAttaches to the calcaneus (heel)