ExperimentalManualofHumanAnatomyformedbyorganic components,such ascells,collagenfiberswhichmakeaboneflexible.Theinorganic components account for almost two-thirds of bone mass which provide bonecompressional strength.Section2ArthrologyArticulation (joint) is the site where two skeletal elements come together.Articulations arecategorized functionally and structurally as followingI.The Synarthroses (ImmovableArticulations)1. Fibrous joints: bones are held together by dense fibrous tissue. (1) sutures are found only incertainbones ofthe skull.(2)gomphoses arefoundonlybetweentheteethand adjacent bone(3)syndesmoses:two adjacent bones are joined bylong strands of dense regular connectivetissue only. Observe the sutures and syndesmoses in the specimen.2Cartilaginous joints: bones are connected by cartilage. (l) synchondrosis: hyaline cartilageplate between bones, such as epiphyseal cartilage. Observe the joint between rib I and thesternum which is a hyaline cartilage connection. (2) symphysis: fibrocartilage pad betweenbones, such as the intervertebral discs, pubic symphysis3.Bony fusion (synostosis): two separate bones actually fuse together to form a solid mass ofbone. Find the sacrum and observe that it is composed of five fused sacral vertebraeII. The Diarthroses (Synovial Joints)Thediarthroses,or synovial joints are connections between skeletal components where the elementsinvolved are separated by a space called an articularcavity. So when the skeletal muscle contractsit pulls an articulating bone move over another articulating bone to cause movement.Essential structures of a synovial joint contain articular surfaces, an articular cavity and anarticular capsule.The articular surfaces are covered by a thin layer of hyaline cartilage calledarticularcartilage.Thearticularcapsule consists of an innersynovialmembraneandanouterfibrousmembrane.11
Experimental Manual of Human Anatomy 11 formed by organic components, such as cells, collagen fibers which make a bone flexible. The inorganic components account for almost two-thirds of bone mass which provide bone compressional strength. Section 2 Arthrology Articulation (joint) is the site where two skeletal elements come together. Articulations are categorized functionally and structurally as following: I. The Synarthroses (Immovable Articulations) 1. Fibrous joints: bones are held together by dense fibrous tissue. (1) sutures are found only in certain bones of the skull. (2) gomphoses are found only between the teeth and adjacent bone. (3) syndesmoses: two adjacent bones are joined by long strands of dense regular connective tissue only. Observe the sutures and syndesmoses in the specimen. 2. Cartilaginous joints: bones are connected by cartilage. (1) synchondrosis: hyaline cartilage plate between bones, such as epiphyseal cartilage. Observe the joint between rib 1 and the sternum which is a hyaline cartilage connection. (2) symphysis: fibrocartilage pad between bones, such as the intervertebral discs, pubic symphysis. 3. Bony fusion (synostosis): two separate bones actually fuse together to form a solid mass of bone. Find the sacrum and observe that it is composed of five fused sacral vertebrae. II. The Diarthroses (Synovial Joints) The diarthroses, or synovial joints are connections between skeletal components where the elements involved are separated by a space called an articular cavity. So when the skeletal muscle contracts it pulls an articulating bone move over another articulating bone to cause movement. Essential structures of a synovial joint contain articular surfaces, an articular cavity and an articular capsule. The articular surfaces are covered by a thin layer of hyaline cartilage called articular cartilage. The articular capsule consists of an inner synovial membrane and an outer fibrous membrane
ExperimentalManualofHumanAnatomyAccessory structures of a synovial joint include ligaments, articularlabrum,articular disc andbursae.Find the following representative joints to study the structure of synovial joint.(I) Should joint: observe the articular cavity, articular cartilage and the two layers of articularcapsule.(2) Sternoclavicular joint: observe the essential structures of a synovial joint first, then find thearticular disc which is located inside the joint cavity and separate the cavity into twocompartments.(3) Knee joint: besides the essential structures of a joint, note that the knee joint is the largest andmost complex joint which has many accessory structures.Inside the articular cavity find the C-shaped cartilages interposed between articular surfaceswhich are called menisci, then identify the intracapsular ligaments which hold the articulatingbones firmly. On the medial side of the joint observe the articular capsule is strengthened toformmedial collateral ligament,whereas on the lateral side of the joint finda lateral collateralligament located outside the joint capsule.Based on the location the ligaments can be dividedinto extracapsular, capsular and intracapular ligaments.Notethat theintracapsular ligamentsareenclosed withinthefibrousmembranebutlocated outsidethesynovial membraneIII. Types of movements at synovial jointsAll movements aredescribed with referenceto afigure intheanatomical position and specializedterms are used to describe the movements.The following table shows the four types ofmovementsoccuratsynovial joints:gliding,angular,rotational,andspecial movementsMovementDescriptionGlidingmotionTwo opposing surfaces slide past one anotherAngularmotionThe angle between articulating bones increases or decreasesFlexionDecrease the angle between articulating bones, usually occurs in thesagittal plane12
Experimental Manual of Human Anatomy 12 Accessory structures of a synovial joint include ligaments, articular labrum, articular disc and bursae. Find the following representative joints to study the structure of synovial joint. (1) Should joint: observe the articular cavity, articular cartilage and the two layers of articular capsule. (2) Sternoclavicular joint: observe the essential structures of a synovial joint first, then find the articular disc which is located inside the joint cavity and separate the cavity into two compartments. (3) Knee joint: besides the essential structures of a joint, note that the knee joint is the largest and most complex joint which has many accessory structures. Inside the articular cavity find the C-shaped cartilages interposed between articular surfaces which are called menisci, then identify the intracapsular ligaments which hold the articulating bones firmly. On the medial side of the joint observe the articular capsule is strengthened to form medial collateral ligament, whereas on the lateral side of the joint find a lateral collateral ligament located outside the joint capsule. Based on the location the ligaments can be divided into extracapsular, capsular and intracapular ligaments. Note that the intracapsular ligaments are enclosed within the fibrous membrane but located outside the synovial membrane. III. Types of movements at synovial joints All movements are described with reference to a figure in the anatomical position and specialized terms are used to describe the movements. The following table shows the four types of movements occur at synovial joints: gliding, angular, rotational, and special movements. Movement Description Gliding motion Two opposing surfaces slide past one another Angular motion The angle between articulating bones increases or decreases Flexion Decrease the angle between articulating bones, usually occurs in the sagittal plane
ExperimentalManualofHumanAnatomyExtensionIncrease the angle between articulating bones, usually occurs in thesagittal planeAbductionMovement away from the midline of the bodyAdductionMovement toward the midline of the bodyCircumductionAcontinuousmovementthatcombinesflexion,abduction,extensionandadduction in succession,thedistal endof the limbordigitmovesina circleRotationalmotionAbone spins around its own longitudinal axisPronationRotation of theforearm wherebythepalm is turned posteriorlySupinationRotation of theforearm wherebythe palm is turned anteriorlySpecialmovementsDorsiflexionAnkle joint movementwhereby thedorsum of thefoot is broughtcloser to the anterior surface of the legPlantarflexionAnklejointmovementwherebythe soleofthefootisbroughtcloserto the posterior surface of the legInversionTurn the sole of thefoot inwardEversionTurn the sole of the foot outwardOppositionSpecial movement of the thumb across the palm toward the fingers topermit grasping and holding of an object(Jin Xu)Chapter2BonesandarticulationsoftrunkLearning Objectives:1.Identifythegeneralfeatures of atypical vertebra and comparethevertebraefrom eachregion2.Describetheformation,divisionsandfunctionofthevertebral column3.Comprehendtheformation,general structureandfunctionofthethoraciccage13
Experimental Manual of Human Anatomy 13 Extension Increase the angle between articulating bones, usually occurs in the sagittal plane Abduction Movement away from the midline of the body Adduction Movement toward the midline of the body Circumduction A continuous movement that combines flexion, abduction, extension and adduction in succession; the distal end of the limb or digit moves in a circle Rotational motion A bone spins around its own longitudinal axis Pronation Rotation of the forearm whereby the palm is turned posteriorly Supination Rotation of the forearm whereby the palm is turned anteriorly Special movements Dorsiflexion Ankle joint movement whereby the dorsum of the foot is brought closer to the anterior surface of the leg Plantar flexion Ankle joint movement whereby the sole of the foot is brought closer to the posterior surface of the leg Inversion Turn the sole of the foot inward Eversion Turn the sole of the foot outward Opposition Special movement of the thumb across the palm toward the fingers to permit grasping and holding of an object (Jin Xu) Chapter 2 Bones and articulations of trunk Learning Objectives: 1. Identify the general features of a typical vertebra and compare the vertebrae from each region. 2. Describe the formation, divisions and function of the vertebral column. 3. Comprehend the formation, general structure and function of the thoracic cage
ExperimentalManualofHumanAnatomyBones and articulations ofthe trunk include the vertebral column and the thoracic cage.Section 1 Vertebral columnLying in the middle of the back, the vertebral column is composed of 26 bones including 24vertebrae, the sacrum and the coccyx. Each vertebra (except the first and the second) articulateswith one another via the intervertebral discs, ligaments and synovial joints to form the vertebralcolumn.IBonesofthevertebralcolumnUsing theillustrationsasareference,find thefollowingbones to observe.Thevertebral column isdivided into regions. From superior to inferior, in adults the number of vertebrae are: cervical (7)thoracic (12), lumbar (5), sacral (1),andcoccygeal (1)1.Typical vertebrae:finda thoracicvertebrafrom theBONEBOX andobserve.Atypical vertebrahas following components.(1)AVertebral body:located anteriorly.It is rounded or cylindrical and relatively thick(2) A Vertebral arch: located posteriorly. The arch and the body enclose a circular opening calledthevertebral foramen.Thevertebral foramina ofall thevertebrae togetherform thevertebralcanal.Thevertebral arch iscomposedoftwopedicles andtwolaminae.Eachpedicleisnotchedon its superior and inferior surfaces. These notches participate in forming the intervertebralforamina through which spinal nerves travel.(3) Seven processes:arise from the vertebral arch.A spinous process projects posteriorly andinferiorly in themidline.Twotransverse processes extend laterally from the junction of thepedicle and lamina. Two pairs of articular processes (superior and inferior articular processes)also arise at the junction of the pedicles and laminae2.Cervical vertebraeTypical cervical vertebra (C3-C6):the most distinctive feature is the transverse foramina in thetransverse processes. The transverse processes end laterally in two projections: an anterior tubercle14
Experimental Manual of Human Anatomy 14 Bones and articulations of the trunk include the vertebral column and the thoracic cage. Section 1 Vertebral column Lying in the middle of the back, the vertebral column is composed of 26 bones including 24 vertebrae, the sacrum and the coccyx. Each vertebra (except the first and the second) articulates with one another via the intervertebral discs, ligaments and synovial joints to form the vertebral column. I. Bones of the vertebral column Using the illustrations as a reference, find the following bones to observe. The vertebral column is divided into regions. From superior to inferior, in adults the number of vertebrae are: cervical (7), thoracic (12), lumbar (5), sacral (1), and coccygeal (1). 1. Typical vertebrae: find a thoracic vertebra from the BONE BOX and observe. A typical vertebra has following components. (1) A Vertebral body: located anteriorly. It is rounded or cylindrical and relatively thick. (2) A Vertebral arch: located posteriorly. The arch and the body enclose a circular opening called the vertebral foramen. The vertebral foramina of all the vertebrae together form the vertebral canal. The vertebral arch is composed of two pedicles and two laminae. Each pedicle is notched on its superior and inferior surfaces. These notches participate in forming the intervertebral foramina through which spinal nerves travel. (3) Seven processes: arise from the vertebral arch. A spinous process projects posteriorly and inferiorly in the midline. Two transverse processes extend laterally from the junction of the pedicle and lamina. Two pairs of articular processes (superior and inferior articular processes) also arise at the junction of the pedicles and laminae. 2. Cervical vertebrae Typical cervical vertebra (C3-C6): the most distinctive feature is the transverse foramina in the transverse processes. The transverse processes end laterally in two projections: an anterior tubercle
ExperimentalManualofHumanAnatomyand a posterior tubercle.The anterior tubercles of vertebra C6 are called carotid tubercles.Thespinous processes of C3-C6 vertebrae are short and bifid.Atlas(Cl):ithasneithera bodynoraspinousprocess.It is composed of twolateral massesinterconnected by an anterior arch and a posterior arch. It possesses the bean-shaped, concavesuperior articular surfaces which articulate with the occipital condyles. It also has the circularinferior articular surfaces that articulate with the AxisAxis (C2): the distinguishing feature is the large tooth-like dens (odontoid process) which projectssuperiorly from its body. The dens is held in position against the articular facet for dens of the Clby the transverse ligament. The dens serves as a pivot that allows the atlas and attached head torotate ontheaxisVertebra Prominens (C7): it is characterized by a large and long spinous process which can bepalpated beneath the skin at the base of the neck3.Thoracic vertebrae:theyprovide attachment for the ribs.Thus the primary feature is the costalfacets (or costaldemifacets)whichare locatedonthelateral sideofthebodyandon thesidesof the transverse processes for rib articulation. The costal facets on the bodies articulate withthehead oftherib whilethetransversecostal facets articulatewiththetubercle of the rib.Sincethe eleventh and twelfth ribs do not have the tubercles, the T1l and T12 lack the transversecostal facets. Besides, the costal facets on the bodies also has variations: (1) the body ofT1 hasa full superior facet and an inferior demifacet. (2) the bodies of T2-T8 have a superior demifacetand an inferiordemifacet.(3)thebody ofT9 has onlya superiordemifacet.(4)thebodies ofT10-T12havea singlefull facet4. Lumbar vertebrae: the largest vertebrae. They have massive bodies and small, triangularvertebral foramina. The spinous process is thick and projects dorsally.5.Sacrum: in adults it is usually composed of five fused sacral vertebrae. It is triangular-shapedwith the apex pointed inferiorly. The anterosuperior edge protrudes anteriorly to form thepromontory. On each lateral surface it has L-shaped facet called auricular surface for15
Experimental Manual of Human Anatomy 15 and a posterior tubercle. The anterior tubercles of vertebra C6 are called carotid tubercles. The spinous processes of C3-C6 vertebrae are short and bifid. Atlas (C1): it has neither a body nor a spinous process. It is composed of two lateral masses interconnected by an anterior arch and a posterior arch. It possesses the bean-shaped, concave superior articular surfaces which articulate with the occipital condyles. It also has the circular inferior articular surfaces that articulate with the Axis. Axis (C2): the distinguishing feature is the large tooth-like dens (odontoid process) which projects superiorly from its body. The dens is held in position against the articular facet for dens of the C1 by the transverse ligament. The dens serves as a pivot that allows the atlas and attached head to rotate on the axis. Vertebra Prominens (C7): it is characterized by a large and long spinous process which can be palpated beneath the skin at the base of the neck. 3. Thoracic vertebrae: they provide attachment for the ribs. Thus the primary feature is the costal facets (or costal demifacets) which are located on the lateral side of the body and on the sides of the transverse processes for rib articulation. The costal facets on the bodies articulate with the head of the rib while the transverse costal facets articulate with the tubercle of the rib. Since the eleventh and twelfth ribs do not have the tubercles, the T11 and T12 lack the transverse costal facets. Besides, the costal facets on the bodies also has variations: (1) the body of T1 has a full superior facet and an inferior demifacet. (2) the bodies of T2-T8 have a superior demifacet and an inferior demifacet. (3) the body of T9 has only a superior demifacet. (4) the bodies of T10-T12 have a single full facet. 4. Lumbar vertebrae: the largest vertebrae. They have massive bodies and small, triangular vertebral foramina. The spinous process is thick and projects dorsally. 5. Sacrum: in adults it is usually composed of five fused sacral vertebrae. It is triangular-shaped with the apex pointed inferiorly. The anterosuperior edge protrudes anteriorly to form the promontory. On each lateral surface it has L-shaped facet called auricular surface for