gross bright

• Head and Neck

  Anatomically complex areas of the body
• Head

  • Superior part of the body that is attached to the trunk by the neck
• Composition of the head

  • Skull
  • Face (orbits, nasal cavities, and oral cavity)
  • Scalp
  • Teeth
  • The Brain
  • Cranial nerves
  • Meninges
  • Special sense organ
  • Other structures such as blood vessels, lymphatics and fats

  
• Cranium (skull)

  The skeleton of the head

  
• Parts of the cranium

  • Neurocranium (brain box or cranial vault)
  • Viscerocranium (facial skeleton)

  
• Neurocranium

  • Bony covering (case) of the brain and its membranous coverings, the cranial meninges
  • Contains proximal parts of the cranial nerves and the vasculature of the brain
• Parts of the neurocranium

  • Dome-like roof, the calvaria (skullcap)
  • Floor or cranial base (basicranium)

  
• The ethmoid bone is an irregular bone that makes a relatively minor midline contribution to the neurocranium but is primarily part of the viscerocranium

  
• Bones of the neurocranium

  • Frontal
  • Ethmoidal
  • Sphenoidal
  • Occipital
  • Temporal
  • Parietal

  
• The bones of calvaria are primarily flat bones and are formed by intramembranous ossification of the mesenchyme from neural crest while cranial base are primarily irregular bones formed by endochondral ossification of cartilage

  
• During childhood, some bones of the neurocranium are united by hyaline cartilage between the occipital and sphenoid bones

  
• Viscerocranium (facial skeleton)

  • Comprises the facial bones
  • Forms the anterior part of the cranium
  • Consists of the bones surrounding the mouth (upper and lower jaws), nose/nasal cavity, and most of the orbits (orbital cavities)

  
• Bones of the viscerocranium

  • Mandible (1)
  • Ethmoid (1)
  • Vomer (1)
  • Maxillae (2)
  • Inferior nasal conchae (2)
  • Zygomatic (2)
  • Palatine (2)
  • Nasal (2)
  • Lacrimal bones (2)

  
• Aspects of the cranium

  • Anterior aspect
  • Lateral aspect
  • Posterior aspect
  • Superior aspect
• Anterior or facial (frontal) aspect of the Cranium


  • Includes: Frontal bone, Zygomatic bones, Orbits, Nasal region, Maxillae, Mandible

  
• Frontal bone


  • Squamous (flat) part
  • Forms the skeleton of the forehead
  • Articulates inferiorly with the nasal and zygomatic bones
  • Has a supraorbital foramen (notch) for the passage of the supraorbital vessels and nerves
  • Has a superciliary arch, prominence of which is generally greater in males
  • Has a smooth, slightly depressed area called the GLABELLA, the anterior most projecting part of the forehead
  • Intersection of the frontal and nasal bones is called the NASION, a depressed area (bridge of the nose)
  • Horizontal portion forms both the roof of the orbital and part of the floor of the cranial cavity

  
• Zygomatic bones (cheek bones, malar bones)

  • Forms the prominences of the cheeks
  • Lies on the inferolateral sides of the orbits and rest on the maxillae
  • Articulates with the frontal, sphenoid and temporal bones and the maxillae
  • Has a zygomaticofacial foramen which allows for the passage of the zygomaticofacial nerve

  
• Nasal region


  • Made up of a pair of nasal bones joined together at midline by the nasal septum
  • Inferior to these nasal bones is a pear shaped piriform aperture
  • On the lateral wall of each nasal cavity are curved bony plates called the nasal conchae
• Maxillae


  • Form the skeleton of the upper jaw
  • Occur in pairs, united at the intermaxillary suture in the median plane
  • Contain alveolar processes include the tooth sockets (alveoli) and house the maxillary teeth
  • Articulate with the frontal bone anteriorly and zygomatic bones laterally
  • Have an infraorbital foramen for passage of the infraorbital nerve and vessels

  
• Mandible


  • U-shaped bone that forms the skeleton of the lower jaw
  • Consists of a horizontal part (the body) and a vertical part (the ramus)
  • Alveolar process supports the mandibular teeth
  • Has mental foramina inferior to the second premolar teeth for the passage of the mental nerves and vessels
  • Has a midline swelling called the mental protuberance and lateral mental tubercles

  
• Lateral aspect of the skull

  • Includes lateral portions of the neurocranium and viscerocranium (facial skeleton)
  • Bones forming the lateral portion of the neurocranium include: the frontal, parietal, occipital, sphenoid, and temporal bones
  • Bones forming the visible part of the facial skeleton include the nasal, maxilla, and zygomatic bones and the mandible

  
• Pterion

  Junction where the frontal, parietal, sphenoid and temporal bone meet

  
• Asterion


  Star shaped junction of the parietomastoid, occipitomastoid, and lambdoid sutures
• Temporal fossa


  • Bounded superiorly and posteriorly by the temporal lines, anteriorly by the frontal and zygomatic bone and inferiorly by the zygomatic arch
• External acoustic opening

  Entrance to the external acoustic meatus which leads to the tympanic membrane (eardrum)
• Mastoid process


  Bony prominence projecting from the inferior border of the mastoid part of the temporal bone

  
• Styloid process


  Bony projection from the lower border of the temporal bone, medial to the mastoid process

  
• Infratemporal fossa


  Irregular space inferior and deep to the zygomatic arch and the mandible and posterior to the maxilla

  
• Temporal bone


  • Has a squamous part, zygomatic process, tympanic part, and petromastoid part (petrous and mastoid)