Skeletal System: Part 1 Overview and Skull Bones PDF

Skeletal System: Part 1 Overview and Skull Bones To accompany Illustrated Anatomy of the Head and Neck 5th Edition Production Margaret J. Fehrenbach, RDH, MS Copyright © 2017, Elsevier Inc. All Rights Reserved. 1  Skeletal Syst...

Skeletal System: Part 1 Overview and Skull Bones To accompany Illustrated Anatomy of the Head and Neck 5th Edition Production Margaret J. Fehrenbach, RDH, MS Copyright © 2017, Elsevier Inc. All Rights Reserved. 1  Skeletal System Overview: Bone Features The bony prominences and depressions on the bony surface are landmarks that serve as muscle, tendons and ligaments attachments. Another feature of a bone are the openings called : Foramen (Foramina) where various nerves and blood vessels travel through. A flat bony structure is called a Plate. Bones of the skeleton join together at sutures and/or articulations Copyright © 2017, Elsevier Inc. All Rights Reserved. 2  Head and Neck Bones The bones of the head and neck serve as a base for palpation of the soft tissue during both an intraoral and extraoral examination of a patient. A dental professional must not only locate each of the head and neck bones but also recognize any abnormalities in the bony surface structure. In order to recognize any bony abnormalities, the dental professional must understand the anatomy of the bones of the head and neck. This includes locating the surface bony prominences, depressions, and articulations as well as the openings in these bones and the nerves and blood vessels that travel through those openings. Copyright © 2017, Elsevier Inc. All Rights Reserved. 3  Skull Bones The bones of the skull can be divided into cranial bone, and the face by the facial bones. The bones of the skull can be single or paired. The skull has 22 bones, not including the six auditory ossicles of the middle ear. Copyright © 2017, Elsevier Inc. All Rights Reserved. 4 Copyright © 2017, Elsevier Inc. All Rights Reserved. 5  Bony Prominences: Process A general term for any prominence on a bony surface is a process. Example: Alveolar process * of the mandible Figure 3-51: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 6  Condyle One specific type of prominence located on a bony surface is a condyle, an oval prominence usually involved in joints. Examples: * * Occipital condyles Figure 3-22, A: Inferior View of External Skull Copyright © 2017, Elsevier Inc. All Rights Reserved. 7  Head A rounded surface projecting from a bony surface by a neck is a head. Example: * Head of the Articulating surface of the Figure 3-54, A: Medial View condyle Copyright © 2017, Elsevier Inc. All Rights Reserved. 8  Tuberosity A large, often rough prominence on a bony surface is a tuberosity. Example: * Maxillary tuberosity Figure 3-48: Posteroinferior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 9  Arch An arch is a prominence shaped on a bony surface like a bridge with a bowlike outline. * * Example: Zygomatic arch Figure 3-14: Lateral View Copyright © 2017, Elsevier Inc. All Rights Reserved. 10  Cornu A cornu is a small hornlike prominence on a bony surface. * Examples: Greater cornu * and Lesser cornu of hyoid bone Figure 3-65: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 11  Tubercle/Eminence A tubercle or eminence is a small * rounded elevation on a bony surface. Figure 3-54, A: Medial View Examples: Genial tubercles of mandible and Frontal eminence * * Figure 3-24: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 12  Crest A crest is a prominent, often roughened border or ridge on a bony surface. Example: * Infratemporal crest Figure 3-34, A: Lateral Cutaway View Copyright © 2017, Elsevier Inc. All Rights Reserved. 13  Line A line is a straight, small ridge on a bony surface. ** Examples: Superior temporal line and Inferior temporal line Figure 3-23: Lateral View Copyright © 2017, Elsevier Inc. All Rights Reserved. 14  Spine An abrupt small prominence on a bony surface that may be a blunt or sharply pointed projection is a spine. * Example: Spine of the Figure 3-34, A: Lateral sphenoid bone Cutaway View Copyright © 2017, Elsevier Inc. All Rights Reserved. 15 Re Cap: Bony Prominences or Process. Condyle Tuberosity Head Arch Cornu Tubercle/eminence Crest Line Spine  Bony Depressions: Incisura/Notch One type of depression on a bony surface is an incisura or notch, which is an indentation at the * edge of a bone. Example: Coronoid notch Figure 3-52, A: Slightly Oblique Lateral View Copyright © 2017, Elsevier Inc. All Rights Reserved. 17  Sulcus/Sulci Another depression(s) on a bony surface is a sulcus (plural, sulci), which is a shallow depression or groove that usually marks the course of blood * vessels or nerves. Example: Infraorbital sulcus Figure 3-45: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 18  Fossa/Fossae A generally deeper depression(s) or concavity on a bony surface is a fossa (plural, fossae). Fossae can be parts of * joints, be attachment sites for muscles, or have other functions. Example: Figure 3-13: Lateral View Temporal fossa Copyright © 2017, Elsevier Inc. All Rights Reserved. 19  Plate Area on bony surfaces that is not a prominence nor depression such as a plate, which is a * flat bony structure of a bone. Example: Figure 3-37: Oblique View Cribriform plate Copyright © 2017, Elsevier Inc. All Rights Reserved. 20 Re Cap: Bony Depressions Incisura or Notch Sulcus Fossa A bony surface that is neither a prominence nor a depression is called a plate, which is a flat bony structure.  Bone Openings: Foramen/Foramina A foramen (plural, foramina) is a short windowlike opening(s) in a bone. Examples: * * Mental foramen, Mental foramina Figure 3-51: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 22  Canal A canal is a longer, narrow tubelike opening in a bone. Example: Hypoglossal canal * Figure 3-22, A: Inferior View of External Skull Copyright © 2017, Elsevier Inc. All Rights Reserved. 23  Meatus A meatus is a type of canal in a bone. Example: Internal acoustic meatus * Figure 3-19: Superior View of Internal Skull Copyright © 2017, Elsevier Inc. All Rights Reserved. 24  Fissure A narrow cleftlike opening in a bone is a fissure. Examples: Superior orbital * fissure and Inferior * orbital fissure of orbit Figure 3-7: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 25  Ostium/Ostia A smaller opening(s), especially as an entrance into a hollow organ or canal in a bone, is an ostium * * (plural, ostia). Examples: Ostium or ostia of the Maxillary sinus of Figure 3-56, A: Coronal maxillae Magnetic Resonance Imaging From Reynolds PA, Abrahams PH: McMinn’s interactive clinical anatomy: head and neck, ed 2, London, 2001, Elsevier. Copyright © 2017, Elsevier Inc. All Rights Reserved. 26  Aperture A narrow opening in a bone is an aperture. Example: Piriform aperture of * nasal cavity Figure 3-8: Anterior View Copyright © 2017, Elsevier Inc. All Rights Reserved. 27 Re Cap: Bony Openings Foramen Canal Meatus Fissure Ostium Aperture Copyright © 2017, Elsevier Inc. All Rights Reserved. 28  Articulation An articulation is an area of the skeleton where the * bones are joined to each other. Example: Articulation at Figure 3-26: Posterior View Sagittal suture between paired parietal bones Copyright © 2017, Elsevier Inc. All Rights Reserved. 29  Joint A joint is a site of a junction or union between two or more bones. Example: * Temporomandibular joint Figure 3-14: Lateral View Copyright © 2017, Elsevier Inc. All Rights Reserved. 30  Suture A suture is the union of bones joined by fibrous * tissue that appears on the dry skull as a jagged line. * Examples: * Coronal suture and Figure 3-2: Superior View Sagittal suture and of Skull Lambdoidal suture Copyright © 2017, Elsevier Inc. All Rights Reserved. 31  Skull Bones: Growth Growth continues to take place in all bones of the skull during early childhood. Growth of the upper face also occurs at the sutures between the maxillae and other bones, as well as at bony surfaces. Growth in the lower face takes place at the bony surfaces of the mandible and at the head of its condyle. Copyright © 2017, Elsevier Inc. All Rights Reserved. 32 Infant’s Skull Fontanelle  Skull Bones: Articulation All skull bones are immovable, except the mandible with its temporomandibular joint (TMJ). Instead, the articulation of many of the bones in the skull is by sutures. In addition, the skull also has a movable articulation with the bony vertebral column in the cervical region. Copyright © 2017, Elsevier Inc. All Rights Reserved. 34 Copyright © 2017, Elsevier Inc. All Rights Reserved. 35 Copyright © 2017, Elsevier Inc. All Rights Reserved. 36  Most Important Openings that you need to know. Foramen Ovale: Sphenoid bone. Mandibular nerve of third division of Trigeminal nerve. Foramen Rotunda: Sphenoid bone. Maxillary nerve of the 2nd division of the Trigeminal nerve. Superior Orbital Fissure: Sphenoid bone. Ophthalmic nerve of the 1st division of the Trigeminal nerve. Mandibular Foramen: Mandible. Inferior Alveolar nerve and blood vessels. Mental Foramen: Mandible. Mental nerves and blood vessels. Incisive Foramen: Maxilla. Nasopalatine nerves and Sphenopalatine artery. Infraorbital Foramen: Maxilla. Infraorbital nerve and blood vessels. Posterior Superior Alveolar Foramen: Maxilla. Posterior Superior Alveolar nerve and blood vessels. Copyright © 2017, Elsevier Inc. All Rights Reserved. 38  Superior View of External Skull: Cranial Bones When the skull is viewed from a superior aspect, four cranial bones are noted. At the anterior part of the skull is the single frontal bone. At each lateral part is the paired parietal bone. At the posterior part of the skull is the single occipital bone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 39 Cranial Bones From Superior View Figure 3-1 Copyright © 2017, Elsevier Inc. All Rights Reserved. 40 Skull Sutures From Superior View The suture extending across the skull, between the frontal bone and each parietal bone, is the paired coronal suture. Figure 3-2 Copyright © 2017, Elsevier Inc. All Rights Reserved. 41 Skull Sutures From Superior View A single suture, the sagittal suture, extends from the anterior to posterior of the skull at the midline between the parietal bones. Figure 3-2 Copyright © 2017, Elsevier Inc. All Rights Reserved. 42 Skull Sutures From Superior View Another single suture, located between the occipital bone and the parietal bone, is the lambdoidal suture. Figure 3-2 Copyright © 2017, Elsevier Inc. All Rights Reserved. 43 Skull Sutures Drake RL, et al. Gray’s Anatomy for Students, ed 2, London, 2010, Churchill Livingstone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 44  Anterior View of External Skull When the external skull is viewed from the anterior aspect, certain bones of the skull (or parts of these bones) are noted. These bones include the single frontal bone, ethmoid bone, vomer, sphenoid bone, and mandible and also the paired lacrimal bones, nasal bones, inferior nasal conchae, and zygomatic bones as well as the maxillae. The facial bones as a group that form the facial features, the orbit, and the nasal cavity are also noted from this view. Copyright © 2017, Elsevier Inc. All Rights Reserved. 45 Anterior View of External Skull Figure 3-3 Copyright © 2017, Elsevier Inc. All Rights Reserved. 46  Facial Bones From Anterior View The facial bones visible from an anterior view of the skull include the lacrimal bone, nasal bone, vomer, inferior nasal concha (plural, conchae), zygomatic bone, maxilla, and mandible. However, the paired palatine bone is not noted from this view. In fact, the palatine bone is not considered to be a facial bone by anatomists, but for ease of learning it is included under the general heading of facial bones. Copyright © 2017, Elsevier Inc. All Rights Reserved. 47 Facial Bones From Anterior View Figure 3-4 Copyright © 2017, Elsevier Inc. All Rights Reserved. 48  Orbit and Associated Structures From Anterior View The orbit, which contains and protects the eyeballs, is a prominent feature of the anterior part of skull. Certain skull bones form both the walls and apex of each of the orbits. Figure 3-5 Copyright © 2017, Elsevier Inc. All Rights Reserved. 49 Copyright © 2017, Elsevier Inc. All Rights Reserved. 50  Orbit and Associated Structures From Anterior View The larger orbital walls are composed of the orbital plates of the frontal bone (the roof or superior wall), the ethmoid bone (the greatest part of medial wall), the lacrimal bone (at the anterior medial corner of the orbit) orbital surfaces of the maxilla, the floor or inferior wall, and the zygomatic bone (the anterior part of the lateral wall). Copyright © 2017, Elsevier Inc. All Rights Reserved. 51  Orbit and Associated Structures From Anterior View The orbital surface of the greater wing of the sphenoid bone is also included (the posterior part of the lateral wall). Figure 3-5 Copyright © 2017, Elsevier Inc. All Rights Reserved. 52  Orbit and Associated Structures from Anterior View The orbital apex (plural, apices) is the deepest part of the orbit and is composed of the lesser wing of the sphenoid bone (the base) and the palatine bone (a small inferior part). Figure 3-6 Copyright © 2017, Elsevier Inc. All Rights Reserved. 53  Orbit and Associated Structures From Anterior View The round opening in the orbital apex is the optic canal, which lies between the two roots of the lesser wing of the sphenoid bone. Figure 3-6 Copyright © 2017, Elsevier Inc. All Rights Reserved. 54  Orbit and Associated Structures From Anterior View Lateral to the optic canal is the curved and slitlike superior orbital fissure, located between the greater wing and lesser wing of the sphenoid bone. Figure 3-7 Copyright © 2017, Elsevier Inc. All Rights Reserved. 55  Superior Orbital Fissure The third cranial or oculomotor nerve, the fourth cranial or trochlear nerve, the sixth cranial or abducens nerve, and the ophthalmic nerve (or first division from fifth cranial or trigeminal nerve) and vein travel through the superior orbital fissure. Figure 8-8 Figure 8-9 Copyright © 2017, Elsevier Inc. All Rights Reserved. 56  Orbit Drake RL, et al. Gray’s Anatomy for Students, ed 2, London, 2010, Churchill Livingstone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 57  Nasal Cavity and Associated Structures From Anterior View The nasal cavity or nasal fossa can also be viewed on the skull from the anterior. It has lateral walls and a floor with anterior and posterior openings, and it is mainly composed of bone and cartilage. Figure 3-8 Copyright © 2017, Elsevier Inc. All Rights Reserved. 58  Nasal Cavity and Associated Structures From Anterior View The bridge of the nose is formed from the paired nasal bones. Figure 3-8 Copyright © 2017, Elsevier Inc. All Rights Reserved. 59  Nasal Cavity and Associated Structures From Anterior View The nasion, a cephalometric midpoint landmark, is located at the junction of the frontal and nasal bones. Figure 3-8 Copyright © 2017, Elsevier Inc. All Rights Reserved. 60  Nasal Cavity and Associated Structures From Anterior View The anterior opening of the nasal cavity, the piriform aperture, is large and triangular. And the large deeper posterior openings are the posterior nasal apertures or Figure 3-8 choanae. Copyright © 2017, Elsevier Inc. All Rights Reserved. 61  Nasal Cavity and Associated Structures From Anterior View The floor of the nasal cavity is formed from the two separate bones of the hard palate: the palatine processes of the maxillae anteriorly and the horizontal plates of the palatine bones Figure 3-8 posteriorly. Copyright © 2017, Elsevier Inc. All Rights Reserved. 62  Nasal Cavity and Associated Structures From Anterior View The lateral walls of the nasal cavity are mainly formed by the maxillae. In addition, each lateral wall of the nasal cavity has three projecting structures that extend inward, which are the nasal conchae or turbinates. These are the superior, middle, and inferior nasal conchae; each extends like a scroll into the nasal cavity. Copyright © 2017, Elsevier Inc. All Rights Reserved. 63  Nasal Cavity and Associated Structures From Anterior View The vertical partition or fin of the nasal cavity, the nasal septum, divides the nasal cavity into two parts. Figure 3-9 Copyright © 2017, Elsevier Inc. All Rights Reserved. 64  Lateral View of External Skull When the external skull is viewed from the lateral aspect, the division between the cranial bones and facial bones can be noted. This division between the bones of the skull can be reinforced by making an imaginary diagonal line that passes inferior and posterior from the supraorbital ridge of the frontal bone to the tip of Figure 3-10 the mastoid process of the temporal bone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 65  Cranial Bones From Lateral View Parts of the cranium are noted on the lateral aspect and include the following cranial bones: the occipital, frontal, parietal, temporal bones, as well as the sphenoid bone Figure 3-11 and ethmoid bone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 66  Skull Sutures From Lateral View Also noted on the lateral surface of the skull are the associated sutures of the cranial bones. These sutures include the coronal suture, an articulation between the frontal and parietal bones, and the lambdoidal suture, an articulation between the parietal and occipital bones. Also present is the arched squamosal suture, which is located between the temporal bone and parietal bone on each side. Copyright © 2017, Elsevier Inc. All Rights Reserved. 67 Skull Sutures From Lateral View Figure 3-11 Copyright © 2017, Elsevier Inc. All Rights Reserved. 68  Skull Lines From Lateral View On the lateral external surface of the skull are two separate parallel ridges, the temporal lines, crossing both the frontal and parietal bones. The superior ridge is the superior temporal line. The inferior ridge or inferior temporal line is the superior boundary of Figure 3-12 the temporal fossa. Copyright © 2017, Elsevier Inc. All Rights Reserved. 69  Skull Fossae From Lateral View The temporal fossa is noted on the lateral aspect of the skull. The temporal fossa is formed by parts of several bones of the skull and contains the body of the Figure 3-13 temporalis muscle. Copyright © 2017, Elsevier Inc. All Rights Reserved. 70  Skull Fossae From Lateral View The temporal fossa is formed by several bones of the skull and contains the body of the temporalis muscle. Figure 4-22 Copyright © 2017, Elsevier Inc. All Rights Reserved. 71  Skull Fossae From Lateral View Figure 3-59 Copyright © 2017, Elsevier Inc. All Rights Reserved. 72  Skull Fossae From Lateral View Inferior to the temporal fossa is the infratemporal fossa. Figure 3-59 Copyright © 2017, Elsevier Inc. All Rights Reserved. 73  Skull Fossae From Lateral View Deep to the infratemporal fossa and more difficult to see is the pterygopalatine fossa. Figure 3-61 Copyright © 2017, Elsevier Inc. All Rights Reserved. 74  Zygomatic Arch and TMJ From Lateral View The zygomatic arch or cheekbone is noted farther inferior on the lateral aspect of the skull, which is formed by the union of the slender zygomatic process of the temporal bone and of the broad temporal process of the Figure 3-14 zygomatic bone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 75 Zygomatic Arch and TMJ From Lateral View Figure 2-9 Copyright © 2017, Elsevier Inc. All Rights Reserved. 76  Zygomatic Arch and TMJ From Lateral View The suture between these two bones is the temporozygomatic suture. The zygomatic arch serves as the origin for the prominent masseter muscle. Figure 3-14 Copyright © 2017, Elsevier Inc. All Rights Reserved. 77  Zygomatic Arch and TMJ From Lateral View The temporomandibular joint (TMJ) is also noted, which is a movable articulation between the temporal bone and the mandible. Figure 3-14 Copyright © 2017, Elsevier Inc. All Rights Reserved. 78  Inferior View of External Skull The zygomatic bones, vomer, temporal bones, sphenoid bone, occipital bones, and palatine bones, as well as the maxillae are noted on the inferior view of the skull’s external Figure 3-15 surface. Copyright © 2017, Elsevier Inc. All Rights Reserved. 79  Hard Palate From Inferior View At the anterior part of the skull’s inferior aspect is the hard palate, bordered by the alveolar process of the maxilla with its maxillary teeth. Figure 3-16 Copyright © 2017, Elsevier Inc. All Rights Reserved. 80  Hard Palate From Inferior View The hard palate is formed from two separate bones: the two palatine processes of the maxillae anteriorly and the two horizontal plates of the palatine bones posteriorly, with an articulation at the prominent median palatine suture that underlies the median palatine raphe. The other nearby suture is the transverse palatine suture, an articulation between the two palatine processes of the maxillae and the two horizontal plates of the palatine bones. Copyright © 2017, Elsevier Inc. All Rights Reserved. 81 Hard Palate From Inferior View Figure 2-15 Figure 2-21 Copyright © 2017, Elsevier Inc. All Rights Reserved. 82 Hard Palate From Inferior View Figure 3-44 Copyright © 2017, Elsevier Inc. All Rights Reserved. 83  Middle Part of Skull From Inferior View The lateral borders of the posterior nasal apertures are formed on each side by the pterygoid process of the sphenoid bone. Figure 3-17 Copyright © 2017, Elsevier Inc. All Rights Reserved. 84  Middle Part of Skull From Inferior View Each pterygoid process consists of a thin medial pterygoid plate and a flattened lateral pterygoid plate. The depression between the medial and lateral plates is the pterygoid fossa. At the inferior part of the medial plate of the pterygoid process is a thin curved process, the hamulus. Copyright © 2017, Elsevier Inc. All Rights Reserved. 85 Middle Part of Skull From Inferior View Figure 3-17 Copyright © 2017, Elsevier Inc. All Rights Reserved. 86  External Skull Foramina From Inferior View The inferior surface of the external skull has a large number of foramina. These openings provide entrances and exits for the arteries and veins that supply the brain and facial tissue. Figure 3-18 Copyright © 2017, Elsevier Inc. All Rights Reserved. 87  External Skull Foramina From Inferior View Also on the external surface of the skull is the large, irregularly shaped foramen lacerum. Posterolateral to the foramen lacerum is a round opening in the petrous part of the temporal bone, the carotid canal. Figure 3-18 Copyright © 2017, Elsevier Inc. All Rights Reserved. 88  External Skull Foramina From Inferior View A pointed bony projection, the styloid process, is noted lateral and posterior to the carotid canal. Immediately posterior to the styloid process is the stylomastoid foramen, an opening through which the seventh cranial or facial nerve exits from the skull to the face. Figure 3-18 Copyright © 2017, Elsevier Inc. All Rights Reserved. 89  External Skull Foramina From Inferior View The jugular foramen, just medial to the styloid process, is the opening through which pass the internal jugular vein and three cranial nerves: the ninth cranial or glossopharyngeal nerve, the tenth cranial or vagus nerve, and the eleventh cranial or accessory nerve. Figure 3-18 Copyright © 2017, Elsevier Inc. All Rights Reserved. 90  External Skull Foramina from Inferior View The largest opening is the foramen magnum of the occipital bone, through which the spinal cord, vertebral arteries, and eleventh cranial or accessory nerve pass. Figure 3-18 Copyright © 2017, Elsevier Inc. All Rights Reserved. 91 External Skull From Inferior View Drake RL, et al. Gray’s Anatomy for Students, ed 2, London, 2010, Churchill Livingstone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 92  Superior View of Internal Skull The frontal bone, ethmoid bone, sphenoid bone, temporal bones, occipital bone, and parietal bones are noted from this view of the internal surface of the skull. Figure 3-19 Copyright © 2017, Elsevier Inc. All Rights Reserved. 93  Internal Skull Foramina From Superior View Also present on the superior surface of the internal skull are the inside openings of the optic canal, superior orbital fissure, foramen ovale, foramen spinosum, foramen lacerum, jugular foramen, and foramen magnum, as discussed before when viewing the external skull surface. Figure 3-19 Copyright © 2017, Elsevier Inc. All Rights Reserved. 94  Internal Skull Foramina From Superior View The perforated cribriform plate, with foramina for the first cranial or olfactory nerve, and the foramen rotundum for the maxillary nerve (or division) of the fifth cranial or trigeminal nerve are also seen from this view. Figure 3-19 Copyright © 2017, Elsevier Inc. All Rights Reserved. 95  Internal Skull Foramina From Superior View Finally, also present are the hypoglossal canal for the twelfth cranial or hypoglossal nerve and the internal acoustic meatus for the seventh cranial or facial nerve and the eighth cranial or vestibulocochlear nerve. Figure 3-19 Copyright © 2017, Elsevier Inc. All Rights Reserved. 96 Internal Skull Foramina From Superior View Figure 3-19 Copyright © 2017, Elsevier Inc. All Rights Reserved. 97 Internal Skull From Superior View Drake RL, et al. Gray’s Anatomy for Students, ed 2, London, 2010, Churchill Livingstone. Copyright © 2017, Elsevier Inc. All Rights Reserved. 98