The skull (also known as cranium) consists of 22 bones which can be subdivided into 8 cranial bones and 14 facial bones.
Skull - Physiopedia Search Search Search Toggle navigation pPhysiopedia pPhysiopedia About News Contribute Courses Resources Contact Donate Login pPhysiopedia About News Contribute Courses Resources Shop Contact Donate p o + Contents Editors Categories Share Cite Contents 1 Introduction 2 Blood Supply 3 Nerve Supply 4 Resources 5 References Original Editor - Yasmina Hossam Top Contributors - Kim Jackson, Yasmina Hossam, Mande Jooste, Admin, Naomi O'Reilly, Lucinda hampton, Rachael Lowe, Tony Lowe, Tarina van der Stockt, Simisola Ajeyalemi, Uchechukwu Chukwuemeka, Nicole Hills and George Prudden CategoriesAnatomyHead - BonesCourse Pages AddThis Sharing ButtonsShare to MoreAddThisShare to LinkedInLinkedInShare to TwitterTwitterShare to FacebookFacebook When refering to evidence in academic writing, you should always try to reference the primary (original) source. That is usually the journal article where the information was first stated. 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Cite article Skull Jump to:navigation, search Original Editor - Yasmina Hossam Top Contributors - Kim Jackson, Yasmina Hossam, Mande Jooste, Admin, Naomi O'Reilly, Lucinda hampton, Rachael Lowe, Tony Lowe, Tarina van der Stockt, Simisola Ajeyalemi, Uchechukwu Chukwuemeka, Nicole Hills and George Prudden Contents 1 Introduction 2 Blood Supply 3 Nerve Supply 4 Resources 5 References Related online courses on +Physiopedia Plus Online Course: Introduction to Myofascial Pain Introduction to Myofascial Pain Become familiar with the myofascia and learn how it can cause your patient's pain Start course 1-1.5 hours - - - - Powered by Physiopedia Course instructor Rina Pandya Dr. Rina is an excellent course presenter and has experience with a range of conditions in various • Online Course: Male Pelvic Anatomy Pelvic Anatomy Understanding pelvic floor anatomy and physiology is the first step toward clinical competency Start course 2-2.5 hours - - - - Powered by Physiopedia Course instructor Pierre Roscher Pierre is a physiotherapist with a passion for educating others about men's health physiotherapy • Online Course: Overview of Female Pelvic Floor Muscle Anatomy and Physiology Overview of Female Pelvic Floor Muscle Anatomy and Physiology Gain insight into the synergistic relationship between the pelvic floor and other parts of the body Start course 1-1.5 hours - - - - Powered by Physiopedia Course instructor Ibukun Afolabi Ibukun is an experienced physiotherapist serving • Related online courses on +Physiopedia Plus Online Course: Introduction to Myofascial Pain Introduction to Myofascial Pain Become familiar with the myofascia and learn how it can cause your patient's pain Start course 1-1.5 hours - - - - Powered by Physiopedia Course instructor Rina Pandya Dr. Rina is an excellent course presenter and has experience with a range of conditions in various • Online Course: Male Pelvic Anatomy Pelvic Anatomy Understanding pelvic floor anatomy and physiology is the first step toward clinical competency Start course 2-2.5 hours - - - - Powered by Physiopedia Course instructor Pierre Roscher Pierre is a physiotherapist with a passion for educating others about men's health physiotherapy • Online Course: Overview of Female Pelvic Floor Muscle Anatomy and Physiology Overview of Female Pelvic Floor Muscle Anatomy and Physiology Gain insight into the synergistic relationship between the pelvic floor and other parts of the body Start course 1-1.5 hours - - - - Powered by Physiopedia Course instructor Ibukun Afolabi Ibukun is an experienced physiotherapist serving • Online Course: Women’s Pelvic Health Programme Women’s Pelvic Health Programme Gain the skills to help female clients restore their pelvic health and function Start course 11-13 hours - - - - Powered by Physiopedia Course instructor Ibukun Afolabi Ibukun is an experienced physiotherapist serving in the space where pelvic floor health, childbirth • Online Course: Considerations for Working with Survivors of Torture Considerations for Working with Survivors of Torture Eye-opening accounts from rehabilitation professionals working with torture survivors Start course 2.5-3 hours - - - - Powered by Physiopedia Course instructor ReLAB-HS Learning, Acting and Building for Rehabilitation in Health Systems Summarising • Introduction[edit | edit source] The skull (also known as cranium) consists of 22 bones which can be subdivided into 8 cranial bones and 14 facial bones. The main function of the bones of the skull along with the surrounded meninges, is to provide protection and structure.[1] Protection to the brain (cerebellum, cerebrum, brainstem) and orbits of the eyes. Structurally it provides an anchor for tendinous and muscular attachments of the muscles of the scalp and face. The skull also protects various nerves and vessels that feed and innervate the brain, facial muscles, and skin. Cranial Bones Sutures Facial Bones Fontal Bone Parietal Bone (2) Temporal Bone (2) Occipital Bone Sphenoid Bone Ethmoid Bone [1] Strong, fibrous, elastic bands of tissues that binds/connect the cranial bones together. Coronal Suture: Junction between the frontal and two parietal bones. The coronal suture lies in the coronal plane. Sagittal Suture: Junction between two parietal bones. The sagittal suture lies in the sagittal plane. Squamous Suture: Junction between the temporal and parietal bones. Lambdoid Suture: Junction between the parietal bones and the occipital bones. Pterion: Junction of the frontal, parietal and temporal bones in the lateral aspect of the skull. Nasal Conchae (2) Nasal Bones (2) Maxilla Bones (2) Palatine Bones (2) Lacrimal Bones (2) Zygomatic Bones (2) Mandible Vomer [2] Blood Supply[edit | edit source] The skull and its contents are mainly supplied with oxygenated blood from the common carotid artery. The remainder of blood supply comes from the vertebral artery. Nerve Supply[edit | edit source] The base of skull has numerous foramina that allow the entry lot of vessels and nerves, including the cranial nerves. The Optic Nerve and Ophthalmic Artery passes through the Optic Nerve Canal. Superior orbital fissure transmits the Oculomotor Nerve, Trochlear Nerve, Ophthalmic branch of the Trigeminal Nerve and the Abducens Nerve. Internal Carotid Artery enters through the Carotid Canal. The Mandibular Branch of the Trigeminal Nerve exits the skull through the Foramen Rotunda. The Middle Meningeal Artery passes through the Foramina Spinosum. Foramina Magnum: allows the Spinal Cord through the base of skull into the Spinal Canal of the Vertebral Column.[2] Resources[edit | edit source] [3] [4] Practical Assessment and Treatment of Cervicogenic HeadachesAn online course by Ari KaplanLearn more on this topic Related articles Equine Spine and Head Anatomy - Physiopedia Introduction Equine anatomy refers to the gross and microscopic anatomy of horses and other equids (donkeys, and zebras). This page introduces the Anatomy of Equine Spine and Head. Axial Skeleton[edit | edit source] The axial skeleton consists of the skull, vertebral column, sternum, and ribs. Multiple sternebrae fuse to form one bone, attached to the 8 "true" pairs of ribs, out of a total of 18.[1] The vertebral column contains 54 bones: 7 cervical vertebrae: includes the atlas (C1) and axis (C2) 18-19 thoracic vertebrae 5-6 lumbar vertebrae 5 sacral vertebrae 15-25 caudal vertebrae[2] In certain breeds, there may be variations in these numbers.[3] Skull[edit | edit source] The skull contains the brain and the most important organs of sense. Cranium[edit | edit source] The Roof of the cranium is made up of frontal and parietal bones. The Floor is made up of sphenoid bone. The cranium consists of 5 orbital regions: Frontal Lacrimal Palatine Sphenoid Zygomatic Interparietal bone: only found in horse and cat. The orbit is complete in horse and ruminants while it is incomplete in carnivores but completed by the orbital ligament. The lacrimal fossa collects tears and sends them through lacrimal canal into the nasal cavity. Bones in the Equine Skull[edit | edit source] There are 34 bones and most of them are flat. During the birth process, these bones overlap and allow the skull to compress as much as possible to allow for parturition. The 14 major bones are:[1] Incisive bone (premaxillary): part of the upper jaw; where the incisors attach Nasal bone: covers the nasal cavity Maxillary bone: a large bone that contains the roots of the molars Mandible: lower portion of the jaw; largest bone in the skull Lacrimal bone: contains the nasolacrimal duct, which carries fluid from the surface of the eye, to the nose Frontal bone: creates the forehead of the horse Parietal bone: extends from the forehead to the back of the skull Occipital bone: forms the joint between the skull and the first vertebrae of the neck (the atlas) Temporal bone: contains the eternal acoustic meatus, which transmits sound from the ear to the cochlea (eardrum) Zygomatic bone: attaches to the temporal bone to form the zygomatic arch (cheekbone) Palatine bone: forms the back of the hard palate Sphenoid: formed by fusion of the foetal basisphenoid and presphenoid bones, at the base of the skull. Can become fractured in horses that rear over backwards Vomer: forms the top of the inside of the nasal cavity Pterygoid: small bone attached to the sphenoid that extends downward Cavities[edit | edit source] The equine skull consists of 4 cavities: The cranial cavity: Protects and encloses the brain, supports sense organs. The cranium consists of a roof made up of the frontal and parietal bones and a floor made up of the sphenoid bone The orbital cavity: Has 5 orbits: frontal, lacrimal, palatine, sphenoid and zygomatic. It protects and surrounds the eye.[4] Horses have both monocular and binocular vision: Monocular vision: The horse can see objects with one eye. This means that the brain receives two images simultaneously Binocular vision: The horse can focus with both eyes just like humans and the brain receives only one signal The oral cavity: A passage into the respiratory and digestive system The nasal cavity: Contains bone that protects the mucous membrane from inspired warm air Foramina of the Skull and the Structures Passing Through[edit | edit source] Foramina Structures passing through Infra-orbital foramen Infra-orbital nerve. CNV Maxillary foramen Cribriform foramen Olfactory nerve. CNI Optic canal Optic nerve. CNII Orbital fissure CNVII, IV, V and VI (ophthalmic division) Round foramen CNV (maxillary division) Oval foramen CNV (mandibular division) Foramen lacerum Internal carotid artery CN V3 (horse and pig) Internal acoustic meatus CNVIII Jugular foramen CNIX, X, XI Stylomastoid foramen CNVII Mandibular foramen CNV (mandibular alveolar nerve) Mental foramen Joints and Ligaments[edit | edit source] Joints and Ligaments of the Skull[edit | edit source] The temporo-mandibular joint - a condylar joint between the mandibular condyles and the mandibular fossae of the temporal bones. It has a loose joint capsule with thickenings that form a lateral ligament, as well as an articular disc[1] Mandibular symphysis Hyoid apparatus - consists of three joints: Tympanohyoid cartilage- skull (syndesmosis) Interhyoid joints (synovial) Thyrohyoid bone- cranial cornu of thyroid cartilage (synovial)[1] [5] Cervical Spine[edit | edit source] Joints[edit | edit source] Atlanto-Occipital Joint[edit | edit source] A condylar, modified synovial hinge joint. The articulating surfaces are the occipital condyles and the cranial articular surfaces of the atlas (C1). There are three thickenings that strengthen the spacious joint capsule: Dorsal, Ventral, Lateral. The transverse atlantal ligament holds the dens of the axis against the ventral arch of the atlas.[1] Atlanto-Axial Joint[edit | edit source] A pivot joint between the atlas and the saddle shaped surface of the axis (C2), which extends upon the dens. It has a loose joint capsule. The apical ligament of dens connects the apex of the dens to the occipital bone. Motion at this joint includes rotation of the atlas and head upon the axis and some accessory lateral flexion.[1] Rotation at this joint makes up 73 percent of cervical rotation.[6] Cervical Spine C3-C4[edit | edit source] A planar, extensive, oval shaped joint that is obliquely oriented in transverse plane. The cranial articular processes face dorsomedially and the caudal articular processes face ventrolaterally. Spinous process height increases caudally from C6. Lateral flexion is the primary motion at these joints (25-45 degrees each joint - C1/C2 only has 3.9 degrees of lateral flexion).[6] Ligaments[edit | edit source] Dorsal longitudinal ligament Ventral longitudinal ligament Ligamentum flavum Nuchal ligament: This ligament connects the thoracic vertebra to the head and assists in supporting its weight. It consists of two paired parts:[1] Funicular (cord) part - extends from the poll to +/- the second to the fourth thoracic spinous process Lamellar part - arises from the second and third thoracic spinous processes and the funicular part, and inserts on the C2-C6 spinous processes. The first digitation going to the axis is very strong, but it decreases in strength caudally Thoracic Spine (T1-T18)[edit | edit source] Articular processes[edit | edit source] Caudal articular processes face ventrally and are positioned at the base of the spinous process. The cranial articular processes are oval facets on the arch of the vertebra and face dorsally. Each thoracic vertebrae has a pair of costal facets on the dorsal body (except the last) forming the costal fovea.[1] Anticlinal vertebrae: This is the point in the caudal thoracic vertebral column at which the anatomic features of the vertebra start to change.[7] This usually occurs at the 13th vertebra in horses. Motion: Flexion - most flexion occurs at T17/T18; least flexion occurs at T3-T9 Extension - most extension occurs at T14-T18; least extension occurs at T2-9[1] Rib Neck[edit | edit source] Has 2 converse facets: Cranial and Caudal Rib 1 attaches to C7, T1 and the associated IV disc Motion: rotation of the rib, which is greater caudally Costovertebral Joint[edit | edit source] Joints[edit | edit source] The costovertebral joints have two distinct articulations between most ribs and the vertebral column:[1] Head of the rib: Cranial and caudal costal facets of adjacent vertebrae; a ball and socket synovial joint Tubercle of the rib: Transverse process of vertebrae; a plane synovial joint Ligaments[edit | edit source] Radiate longitudinal ligament Intercapital ligament Costotransverse ligament Ligament of the neck Lumbar Spine[edit | edit source] Joints[edit | edit source] Horses usually have 6 lumbar vertebrae (L1-L6), but some arabian horses only have 5 (L1-L5).[1] Articular processes[edit | edit source] Cranial articular processes are fused with mammillary processes. They are concave dorsally and mostly in sagittal alignment. Caudal processes are convex ventrally and correspond with the convexity of the cranial articular processes. They are differentiated from the last thoracic vertebra by the lack of costal facets.[1] Motion: The lumbar spine and caudal thoracic spine are the least mobile regions of a horse's back.[8] Lateral flexion and rotation is very limited especially at L4-L6 due to intertransverse joints.[1] Ligaments of Thoraco-Lumbar Spine[edit | edit source] Supraspinous ligament: A heavy band of connective tissue running over the top of spinous processes ( T2/T3 caudally). It prevents abnormal separation of spinous processes during flexion Ventral longitudinal ligament: Marks the ventral surface of vertebrae from the axis to the sacrum. It is strongest and widest caudally. It plays a major role in preventing overextension of the spine Dorsal longitudinal ligament: Extends from the floor of the vertebral canal from the axis to sacrum and helps to prevent spine hyper-flexion Annulus fibrosis of IVD: Thick ventrally Intertransverse ligament Interarcuate ligament/ yellow ligament/ ligamentum flavum: An elastic ligament that fills the dorsal space between the arch of the adjacent vertebra[1] Lumbosacral Joint[edit | edit source] The cranial articular process of the first sacral vertebra are concave and face dorsomedially. Motion: Flexion and Extension - 23.4 degrees[9] Sacrum[edit | edit source] The sacrum consists of fused sacral vertebrae and has dorsal and ventral sacral foramina. [10] Myology and Neurology[edit | edit source] Muscles of the Head[edit | edit source] Muscles of the Face[edit | edit source] The muscles of facial expressions are innervated by the motor fibers of CNVII (facial nerve).[1] Muscle Origin Insertion Action M. Levator labii maxillaris Lacrimal, Zygomatic and Maxillary bones The maxillary lip Elevates the Maxillary lip M. Levator nasolabialis Nasal and Frontal bones The lateral wing of nostril The maxillary lip Elevates and retracts the angle of the mouth M. Zygomaticus The fascia covering the Masseter The commissure of the lips M. Buccinator Maxilla and Mandible Flattens the cheeks and thus presses food between the teeth M. Depressor labii mandibulars The alveolar border of the Mandible The mandibular lip Depresses and retracts the mandibular lip M. Orbicularis oris The sphincter muscle of the skin and the muscles of the lips Corner of the mouth Into the lips as it surrounds the mouth Closes the mouth M. Risorius Part of M. cutaneous faciei The angle of the mouth Retracts the angle of the mouth M. Dilator naris Alar cartillage Alar cartillage Dilates the nostril M. Lateralis nasi Dorsal part Nasal bone Parietal cartilage Dilates the nostril and nasal vestibule Ventral part Nasal process of Incisive bone Lateral wall of the Nasal vestibule M. Caninus Maxilla close to the rostral extremity of the facial crest Lateral wing of the nostril Dilates the nostril laterally M. Levator nasolabialis Frontal and Nasal bones Lateral wing of the nostril Elevates the maxillary lip and the commissure of the mouth Dilates the nostril Ear[edit | edit source] The ear is an organ of hearing and balance. It consists of the outer, middle, and inner ear. Outer Ear[edit | edit source] The outer ear includes:[1] Pinna: mobile and can move independently - can hear multiple sounds at the same time[11] Ear canal Cartilage: Cartilages of the ear collect and transmit sound to the essential organ of hearing within the temporal bone. In order to achieve this, they (especially the concha) need to move.[1] The muscles of outer ear:[1] Rostral Dorsal Caudal Ventral There are 3 cartilages:[1] Conchal: Forms the framework of the portion of the ear which stands erect. It has a large vertical opening on one side to receive sound, and is attached below to the annular cartilage Annular: A small ring of gristle connected to the auditory process of the petrous temporal bone Scutiform: A small, flat and somewhat triangular cartilaginous plate situated in front of the base of concha, to which it is attached Middle Ear[edit | edit source] The middle ear includes:[1] Eardrum Small, air-filled chamber containing 3 tiny bones: the hammer, anvil, and stirrup. It also includes 2 muscles: the oval window, and the eustachian tube. Inner Ear[edit | edit source] The inner ear is a complex structure that includes the cochlea and the vestibular system.[11] Muscles of Mastication[edit | edit source] The muscles of mastication are innervated by the mandibular branch of trigeminal nerve CNV.[1] Muscle Origin In… truncated (73,668 more characters in archive)