AnatomicalAnatomical Terms Used In Description of BonesTerms Used In Description of Bones

1.1. Foramen: an opening or a hole in a boneForamen: an opening or a hole in a bone

2.2. Canal: Bony tunnel (foramen of some length)Canal: Bony tunnel (foramen of some length)

3.3. Canaliculus: a very narrow canalCanaliculus: a very narrow canal

4.4. Meatus: a narrow passageMeatus: a narrow passage

5.5. Sulcus: a groove or furrowSulcus: a groove or furrow

6.6. Pit or fovea: a small depressionPit or fovea: a small depression

7.7. Fossa: a large depression (may be articular or non Fossa: a large depression (may be articular or non articulararticular

• Facet : a small, smooth articular area of a boneFacet : a small, smooth articular area of a bone

• Ridge: a linear elevation, usually roughRidge: a linear elevation, usually rough

• Crest: a ridge of some breadthCrest: a ridge of some breadth

• Lip: the raised margin of a crestLip: the raised margin of a crest

• Process: localized elevation or projection of large sizeProcess: localized elevation or projection of large size

• Tubercle: a small localized rounded thickeningTubercle: a small localized rounded thickening

• Tuberosity: same as tubercle but larger in sizeTuberosity: same as tubercle but larger in size

• Head: a round articular area of boneHead: a round articular area of bone

• Spine: a sharp pointed projectionSpine: a sharp pointed projection

• lamina: a thin plate of bonelamina: a thin plate of bone

• Sinus: cavity inside a bone eg. Air sinuses of skull.Sinus: cavity inside a bone eg. Air sinuses of skull.

Bones of SkullBones of Skull

• A. The calvaria/Brain case A. The calvaria/Brain case consists of 8 bonesconsists of 8 bones

• Paired:- 1.parietal 2.TemporalPaired:- 1.parietal 2.Temporal

• Unpaired:- Frontal, occipital, Unpaired:- Frontal, occipital, sphenoid, ethmoidsphenoid, ethmoid

• B. The facial skeleton consists B. The facial skeleton consists of 14 bonesof 14 bones

• Paired: Maxilla, Zygomatic, Paired: Maxilla, Zygomatic, Nasal, lacrimal, Palatine, Inf Nasal, lacrimal, Palatine, Inf Nasal ConchaNasal Concha

• Unpaired: Mandible, VomerUnpaired: Mandible, Vomer

MandibleMandible• Largest & strongest bone of the face and forms the lower Largest & strongest bone of the face and forms the lower

jaw.jaw.

• Parts:Parts:• 1. Body: horse shoe (u) shaped, horizontal and convex 1. Body: horse shoe (u) shaped, horizontal and convex

forwardforward

• 2. Rami: one ramus on each side, projecting upwards from 2. Rami: one ramus on each side, projecting upwards from the posterior ends of the body.the posterior ends of the body.

• Body Body • Possesses: 2 surfaces- 1. external 2. internalPossesses: 2 surfaces- 1. external 2. internal

2 borders- 1.upper(Alveolar), 2. Lower (base)2 borders- 1.upper(Alveolar), 2. Lower (base)

Surfaces:Surfaces:

• A. A. external surfaceexternal surface:: Convex in outline Convex in outline

• Presents:Presents: Symphisis mentiSymphisis menti: a faint ridge in the midline in the upper part of the body : a faint ridge in the midline in the upper part of the body

(indicates fusion of two halves of foetal bone)(indicates fusion of two halves of foetal bone) Mental protuberenceMental protuberence: triangular raised area below sym menti, & forms the : triangular raised area below sym menti, & forms the

prominence of chin.prominence of chin. Mental tuberclesMental tubercles: small tubercle at each lateral angle of the mental : small tubercle at each lateral angle of the mental

protuberence.protuberence. Mental foramenMental foramen: a foramen below the interval between the 1: a foramen below the interval between the 1stst & 2 & 2ndnd premolar premolar

teeth. It leads into the mandibular canal. It gives exit to mental nerve and teeth. It leads into the mandibular canal. It gives exit to mental nerve and vessels.vessels.

Ext oblique lineExt oblique line: a faint line running upward & backward on each side from the : a faint line running upward & backward on each side from the mental tubercle, very prominent behind and continuous with the ant border of mental tubercle, very prominent behind and continuous with the ant border of ramus.ramus.

Ant part gives origin to:Ant part gives origin to: Depressor labii inferioris: infrontDepressor labii inferioris: infront Depressor angulioris: behind. Depressor angulioris: behind.

Its post part and the adjoining area gives origin of buccinator.Its post part and the adjoining area gives origin of buccinator. Platysma is inserted below the oblique line.Platysma is inserted below the oblique line.

Incisive fossaIncisive fossa: shallow depression below the incisor teeth.: shallow depression below the incisor teeth.Gives origin to:-1. Mentalis 2. Parts of orbicularis oris.Gives origin to:-1. Mentalis 2. Parts of orbicularis oris.

B. Internal Surface: Concave in outline.B. Internal Surface: Concave in outline.

Presents:Presents:•Mylohyoid ridgeMylohyoid ridge: (int oblique line): an oblique ridge running forward and : (int oblique line): an oblique ridge running forward and downwards on each side from 3downwards on each side from 3rdrd Molar tooth to the symphysis menti; very Molar tooth to the symphysis menti; very prominent behind. It divides the int surface in to 2 areas.prominent behind. It divides the int surface in to 2 areas.a. Submandibular fossa below the linea. Submandibular fossa below the lineb. Sublingual fossa above the lineb. Sublingual fossa above the line•Gives origin to :Gives origin to : mylohyoid muscle: throughout its whole length.mylohyoid muscle: throughout its whole length.Sup constrictor muscle of pharynx: from its post end.Sup constrictor muscle of pharynx: from its post end.

•Groove for lingual nerveGroove for lingual nerve: a groove above the mylohyoid line but below the : a groove above the mylohyoid line but below the last molar tooth. It lodges lingual nerve. Above this groove sup constrictor last molar tooth. It lodges lingual nerve. Above this groove sup constrictor muscle is attached.muscle is attached.

•Sub-Mandibular fossaSub-Mandibular fossa: a triangular hollow area below the : a triangular hollow area below the

mylohyoid linemylohyoid lineLodges- 1. submandibular glandLodges- 1. submandibular gland

2. submandibular lymph nodes2. submandibular lymph nodes 3. facial artery 3. facial artery

• Sublingual fossaSublingual fossa: a triangular concave area above the : a triangular concave area above the mylohyoid line.mylohyoid line. lodges- sublingual salivary glandlodges- sublingual salivary gland

• Genial tuberclesGenial tubercles: 4 in numbers, just above the ant ends of : 4 in numbers, just above the ant ends of mylohoid lines. They lie in pairs- 2 upper & 2 lowermylohoid lines. They lie in pairs- 2 upper & 2 lower

upper tubercle- gives origin to genioglossus muscles, one on upper tubercle- gives origin to genioglossus muscles, one on each side.each side.

lower tubercle- gives origin to geniohyoid muscles, on each lower tubercle- gives origin to geniohyoid muscles, on each side.side.

• Mylohyoid groove: runs downwards and forwards from the Mylohyoid groove: runs downwards and forwards from the ramus on to the body below the post end of mylohyoid lineramus on to the body below the post end of mylohyoid line

transmits- mylohyoid vessels and nerves.transmits- mylohyoid vessels and nerves.

BordersBorders– Upper border (alveolar part):Upper border (alveolar part):

presents: 16 sockets, 8 on each side for lodging the presents: 16 sockets, 8 on each side for lodging the roots of teeth.roots of teeth.

Dental formulae: ICPM/2123Dental formulae: ICPM/2123

• Lower border (base of mandible):Lower border (base of mandible): -thick and rounded-thick and rounded

-continuous with lower border of ramus behind 3-continuous with lower border of ramus behind 3rdrd molar molar teeth.teeth.

Presents:-Presents:-#Digastric fossa: a shallow depression on either side of mid-#Digastric fossa: a shallow depression on either side of mid-

line. It gives origin to ant belly of digastric.line. It gives origin to ant belly of digastric.#Insertion of platysma: lower border & extending anteriorly #Insertion of platysma: lower border & extending anteriorly

on to the adjoining ext surface.on to the adjoining ext surface.

RamusRamus• Flattened, quadrilateral part projecting upwards from the post Flattened, quadrilateral part projecting upwards from the post

end of the body on each side, gives insertion to all muscles of end of the body on each side, gives insertion to all muscles of mastication.mastication.

• Possesses:Possesses: 2 surfaces: 1. external (lateral) 2. internal (medial)2 surfaces: 1. external (lateral) 2. internal (medial)

4 borders: anterior, posterior, upper, lower4 borders: anterior, posterior, upper, lower

• 2 processes: 1. coronoid 2. condyloid 2 processes: 1. coronoid 2. condyloid

• Surfaces:Surfaces: a. lateral (ext) surface: flat surface, rough throughout a. lateral (ext) surface: flat surface, rough throughout

except in upper & post part which is smoothexcept in upper & post part which is smoothPresents:-Presents:-

1.1. Insertion of masseter muscle: to a rough areaInsertion of masseter muscle: to a rough area2.2. Parotid gland lies in smooth upper & post part.Parotid gland lies in smooth upper & post part.

B. B. Medial (int surface)Medial (int surface)Presents:-Presents:-• Mandibular foramen- near the center,leads into a mandible Mandibular foramen- near the center,leads into a mandible

canal and finally into mental foramen.canal and finally into mental foramen.• Lingula- a sharp thin process of bone projection from medial Lingula- a sharp thin process of bone projection from medial

margin of mandibular foramen. Gives attachment to margin of mandibular foramen. Gives attachment to sphenomandibular ligaments.sphenomandibular ligaments.

• Mylohyoid groove- begins just behind linguala and runs Mylohyoid groove- begins just behind linguala and runs downwards & forwards to fade out at the post end of downwards & forwards to fade out at the post end of submandibular fossa.submandibular fossa.

Lodges- mylohyoid vessels & nervesLodges- mylohyoid vessels & nerves

4. Medial pterigoid is inserted below & behind the mylohyoid 4. Medial pterigoid is inserted below & behind the mylohyoid groove.groove.

• Borders:-Borders:-• Ant borderAnt border: sharp/ prominent. Continuous above to the anterior border : sharp/ prominent. Continuous above to the anterior border

of coronoid process & below the oblique line.of coronoid process & below the oblique line.• Post border: thick/ rounded, concave in the middlePost border: thick/ rounded, concave in the middle• Upper (superior) borderUpper (superior) border::• Presents:Presents:• Mandibular notch- in the middleMandibular notch- in the middle• Coronoid process- in frontCoronoid process- in front• Condyloid process- behindCondyloid process- behind• Mandibular notch transmit- masseteric vessels & nervesMandibular notch transmit- masseteric vessels & nerves• Lower (inferior) borderLower (inferior) border: continuous in front with the base of : continuous in front with the base of

mandible.mandible.• Processes:Processes:

• Coronoid processCoronoid process: flat & traingular with the apex pointing upwards while : flat & traingular with the apex pointing upwards while the base is fused with upper & ant part of ramus. Its ant border is the base is fused with upper & ant part of ramus. Its ant border is continuous with ant border of the ramus & the post border forms the ant continuous with ant border of the ramus & the post border forms the ant boundary of mandibular notch.boundary of mandibular notch.

14.14. Insertion of temporalis muscle: to the apex, margins, whole of medial Insertion of temporalis muscle: to the apex, margins, whole of medial surface and a part of lat surface close to the apex.surface and a part of lat surface close to the apex.

15.15. Masseter covers lateral surface.Masseter covers lateral surface.

• Condyloid processCondyloid process: projects upwards from the upper & post : projects upwards from the upper & post

part of ramus. part of ramus.

• Presents:-Presents:-

5.5. Head of Mandible: thick and expanded upper part. Articulates Head of Mandible: thick and expanded upper part. Articulates with the articular part of mandibular fossa of temporal bone with the articular part of mandibular fossa of temporal bone to form TMJ.to form TMJ.

6.6. Neck of Mandible: the constricted part just below the head. It Neck of Mandible: the constricted part just below the head. It gives attachment to lat. Ligament of TMJ.gives attachment to lat. Ligament of TMJ.

Ant surface of the neck is hollowed out into a depression Ant surface of the neck is hollowed out into a depression called pterygoid fovea or pit which gives insertion to lat called pterygoid fovea or pit which gives insertion to lat pterygoid muscle.pterygoid muscle.

cervical vertebraecervical vertebrae

Vertebral column consists of a Vertebral column consists of a number of separate irregular number of separate irregular bones called vertebrae. Forms bones called vertebrae. Forms the central axis of the bodythe central axis of the body

• Functions:Functions:3.3. Protects spinal cordProtects spinal cord4.4. Supports and transmits body Supports and transmits body

weightweight5.5. Provides attachment to axial Provides attachment to axial

musclesmuscles6.6. Provides movement of the Provides movement of the

trunktrunk There are 33 vertebrae & 31 pairs of There are 33 vertebrae & 31 pairs of

spinal nervesspinal nerves

12thoracic12thoracic

1coccyx4coccyx

5sacral5sacral

5lumber5lumber

8cervical7Cervical

numberSpinalNumberVertebrae

Characteristics of vertebrae:Characteristics of vertebrae:A typical vertebrae has 2 partsA typical vertebrae has 2 parts2.2. Body – Ant or ventralBody – Ant or ventral3.3. Neural arch- post or dorsalNeural arch- post or dorsal

Vertebral foramen: lies between body and arch. In between vertebrae there are Vertebral foramen: lies between body and arch. In between vertebrae there are intervertebral discs. Vertebral foramen lodges spinal cord with its meninges & intervertebral discs. Vertebral foramen lodges spinal cord with its meninges & blood vessels.blood vessels.

Body of vertebrae:Body of vertebrae:• Shape and size: nearly cylindrical and shape varies in different regions.Shape and size: nearly cylindrical and shape varies in different regions.• 6 surfaces: Ant/post, upper/lower, 2 lateral6 surfaces: Ant/post, upper/lower, 2 lateral

Vertebral (neural ) arch: Vertebral (neural ) arch: 11.11. Pairs of pediclesPairs of pedicles12.12. Pairs of laminaPairs of lamina13.13. Seven processes-Seven processes-

• Spinous-1Spinous-1• Articular-4Articular-4• Transverse-2Transverse-2

Arch is connected to the body by the pedicles.Arch is connected to the body by the pedicles.

1.1. pedicles- short, thick & passes backwards from the junction of lat & pedicles- short, thick & passes backwards from the junction of lat &

post surface of the body.post surface of the body.

2.2. Laminae- broad plates lying behind & medial to pedicles. They fuse Laminae- broad plates lying behind & medial to pedicles. They fuse behind in a median plane into the spinous process.behind in a median plane into the spinous process.

3.3. Spinous process- passes backward and downward from the junction Spinous process- passes backward and downward from the junction of the 2 laminae.of the 2 laminae.

4.4. Articular processes- 4 in number, 2 superior, 2 inferior. Arises from Articular processes- 4 in number, 2 superior, 2 inferior. Arises from junction of pedicles & laminae.junction of pedicles & laminae.

5.5. Transverse processes- 2 in number projects lat from the junction of Transverse processes- 2 in number projects lat from the junction of pedicle and laminae. In thoracic region they articulates with ribs.pedicle and laminae. In thoracic region they articulates with ribs.

• Distinguishing features of vertebrae:Distinguishing features of vertebrae:

• Cervical- presence of foramen in transverse process called foramen Cervical- presence of foramen in transverse process called foramen transversarium.transversarium.

• Thoracic- presence of costal facet on the bodyThoracic- presence of costal facet on the body

• Lumber- no foramen no costal facets on the body.Lumber- no foramen no costal facets on the body.

Cervical vertebraeCervical vertebrae

• 7 in numbers7 in numbers• Identification: presence of foramen transversarium in the transverse Identification: presence of foramen transversarium in the transverse

processprocess• Typical c.v: 3,4,5,6Typical c.v: 3,4,5,6• Atypical c.v: 1,2,7Atypical c.v: 1,2,7• 11stst c.v – atlas c.v – atlas• 22ndnd c.v- axis c.v- axis• 77thth c.v- vertebra prominens c.v- vertebra prominens

Characteristics of typical vertebrae:Characteristics of typical vertebrae:• BodyBody::• Smallest of all vertebraeSmallest of all vertebrae• Transverse> AP measurementTransverse> AP measurement• Post surface has 2 vascular foramen, to transmit basi vertebral vein Post surface has 2 vascular foramen, to transmit basi vertebral vein

& NA.& NA.• Ant. & post surfaces are flat.Ant. & post surfaces are flat.

• Attachments:Attachments:A. Anterior surface:A. Anterior surface:

• Ant long ligament: to upper and lower bordersAnt long ligament: to upper and lower borders

B. Posterior surface:B. Posterior surface:

• Post long ligament: to upper and lower bordersPost long ligament: to upper and lower borders

2. Vertebral foramen:2. Vertebral foramen:

• Larger than the bodyLarger than the body

• Triangular Triangular

3. Pedicles:3. Pedicles:

• Projects laterally and backwardsProjects laterally and backwards

4. Laminae: 4. Laminae:

• Long and narrowLong and narrow

• Ligamentum flava attached to upper and lower part of anterior surface.Ligamentum flava attached to upper and lower part of anterior surface.

5. Spine:5. Spine:

• short and bifidshort and bifid

• Ligmentum nuchae is attached to itLigmentum nuchae is attached to it

6. Articular processes:6. Articular processes:

• Form an articular pillar which projects laterally at the junction Form an articular pillar which projects laterally at the junction of pedicles and laminae.of pedicles and laminae.

• Articular facets are flat and ovalArticular facets are flat and oval

7. Transverse process:7. Transverse process:

• pierced by foramen called foramen transversariumpierced by foramen called foramen transversarium

• Transmits: vertebral artery & veinTransmits: vertebral artery & veinAttachment:Attachment:

AtlasAtlas• Distinguishing points:Distinguishing points:• No bodyNo body• No spineNo spine• It has 2 arches: ant & postIt has 2 arches: ant & post• 2 lateral masses2 lateral masses

7.7. Lateral masses:Lateral masses:• Lie obliquly between 2 archesLie obliquly between 2 archesI.I. Superior articular facets:Superior articular facets:• Faces upwards and mediallyFaces upwards and medially• Concave and elongated (kidney shaped)Concave and elongated (kidney shaped)B. Inferior articular facet:B. Inferior articular facet:• Faces downwards and backwards.Faces downwards and backwards.• Round, slightly concave and flatRound, slightly concave and flat

2. Anterior arch:2. Anterior arch:• Short, curved anteriorly Short, curved anteriorly • Connects to lateral massesConnects to lateral masses• There is a rough tubercle on the anterior aspect called the rough tubercleThere is a rough tubercle on the anterior aspect called the rough tubercle

3. Posterior arch:3. Posterior arch:

• Upper surface has a wide groove behind the lateral massesUpper surface has a wide groove behind the lateral masses

• Posterior tubercle: small tubercle at the posterior part. It Posterior tubercle: small tubercle at the posterior part. It represents spinous process.represents spinous process.

Attachments:Attachments:

4. Transverse processes:4. Transverse processes:

• Quite long and strongQuite long and strong

• Ends laterally in a tubercleEnds laterally in a tubercleAttachments:Attachments:

Axis (2Axis (2ndnd cervical vertebrae) cervical vertebrae)

• Distinguishing point:Distinguishing point:

• Presence of odontoid process (dens)Presence of odontoid process (dens)

4.4. Odontoid process:Odontoid process:

• Strong tooth like process projecting from superior surface of the body.Strong tooth like process projecting from superior surface of the body.

• Half inch longHalf inch long

• Represents the body of the atlasRepresents the body of the atlas

• Acts as a pivot around which atlas rotatesActs as a pivot around which atlas rotatesAttachment:Attachment:

2. Body:2. Body:

• the odontoid process arises from the superior surfacethe odontoid process arises from the superior surface

• On the lateral side of the upper surace a large circular facet is present On the lateral side of the upper surace a large circular facet is present which articulates with the inferior facet of the lateral mass of atlaswhich articulates with the inferior facet of the lateral mass of atlas

3. 3. laminae:laminae:• Thickest and strongest of all c.vThickest and strongest of all c.v

• Gives attachment to ligamentum flavaGives attachment to ligamentum flava

4. spine:4. spine:

• Large and very strongLarge and very strong

Attachment:Attachment:

5. Transverse process:5. Transverse process:

• Very smallVery smallAttachment:Attachment:

seventh cervical vertebraeseventh cervical vertebrae• Called vertebra prominence because of its long and thick Called vertebra prominence because of its long and thick

prominent spinous processprominent spinous process

3.3. spine:spine:• Long, thick, horizontalLong, thick, horizontal• Not bifurcated, ends behind in a tubercleNot bifurcated, ends behind in a tubercleAttachment:Attachment:

2. Transverse process:2. Transverse process:• Big sizeBig size• Foramen transversarium is relatively smallForamen transversarium is relatively small• F.T may be double or absentF.T may be double or absent• Transversed by accessory vertebral veinTransversed by accessory vertebral veinAttachment:Attachment: