Anatomy and Physiology Chapter 6 DRO Bones, Sutures, Teeth, Processes and Foramina of the Human Skull Name: Period: Bones of the Human Skull Bones of the Cranium: Frontal bone: forms the forehead and the roof of the orbits Parietal bones: (2): Posterior to the frontal bone- forms roof and superior walls of cranium Occipital bone: Occipital Bone: forms the posterior and inferior portions of the cranium Temporal bones: (2): found below the parietal bones- contains many anatomical features such as the external acoustic meatus, eardrum, mandibular fossa, mastoid and styloid processes. Sphenoid bone: (greater and lesser wings) forms the floor of the cranium, braces the sides of the skull and acts like a bridge between the cranial and facial bones. Ethmoid bone: anterior to the sphenoid bone: honeycombed masses of bone. Forms part of the cranial floor, contributes to the medial surface of the orbits and forms the roof and sides of the nasal cavity. Vomer: *Along with the ethmoid bone forms part of the nasal cavity *Articulates with the palatine bones Palatine bone: *forms the posterior portion of the hard palate *contributes to the floor of the naval cavity *forms part of the floor of the orbits
Bones of the Face: Maxilla: upper jaw- forms the floor and medial portion of the orbit, forms the walls of the nasal cavity, and the anterior roof of the mouth. Zygomatic bones: articulates with frontal and maxillary bones. With the temporal bone forms the zygomatic arch. Nasal bones: forms the bridge of the nose Lacrimal bone: located within the orbit, house the lacrimal sacs or the tear ducts. Mandible: lower jaw Sutures of the Human: Sagittal suture: Area of articulation between the two parietal bones- divides the skull from left to right Coronal suture: area of articulation between the frontal bone and the two parietal bones- divides the skull from front to back Lambdoid suture: point of contact between the parietal bones and the flat portion of temporal bone. Squamous suture: point of contact between the occipital bone and the parietal bones. *there are several other sutures on the human skull that will not be covered in class
Teeth of the Human: Teeth totals: Incisors: Total: 32 teeth 8 incisors- 4 upper, 4 lower (2 per quadrant) 4 canines- 1 per quadrant 8 premolars- 2 per quadrant 12 molars- 3 per quadrant *used for cutting- 8 total Canines: *function in tearing flesh- 4 total Premolars: *bicuspids- two cusps- 8 total *come before the molars *guide food to the molars Molars: *cuspids- multiple cusps *have a large surface area for grinding and chewing food *12 total Processes of the Human Skull: Styloid process: attachment for ligaments that support the hyoid bone and muscles that control the tongue and pharynx. Mastoid process: origin or sight of attachment of the sternocleidomastoid that rotates and elevates the head and clavicle Coronoid process: attachment point for the temporalis muscle that closes the jaw Condylar process: process that articulates with the mandibular fossa(mandibular condyle) Mandibular condyle: smooth surface of the condylar process- articulates with mandibular fossa
Occipital condyle: surrounds the anterior portion of the foramen magnum articulates with the first cervical vertebrae- atlas allows for up and down motion of the skull- nodding motion Zygomatic process of the temporal bone: bony bridge extending from the cheek just anterior to the ear External Occipital protuberance: Attachment for the nuchal ligament Pterygoid process: Attachment for muscles used for mastication Superior walls of the orbit Lateral/posterior walls of the nasal cavity Hamulus of the Pterygoid process: Process around which the tendon from muscles of the soft palate passes Foramina and other structures of the Human Skull: Supraorbital (above the orbit)- opening for blood vessels and nerves passing to foramen: and from the eyebrows and eyelids Infraorbital foramen: (below the orbit)- opening for the facial nerves Mental foramen: distal/ lateral opening for the mental nerve and vessels that innervate the lip. Mandibular foramen: Proximal/ medial opening for the mental nerve and vessels that innervate the lip External acoustic meatus: opening that leads to the eardrum(tympanum) Palatine foramen: (anterior and posterior) nerves that innervate the palate
Foramen ovale: Trigeminal nerve Foramen lacerum: Filled with cartilage Foramen spinosum: Arteries that innervate the meninges enters the brain Foramen rotundum: Trigeminal nerve: Jugular foramen: Jugular vein Foramen magnum: Spinal chord Stylomastoid foramen: Facial nerve exits the skull Carotid canal: Carotid artery Other Structure of the Human Skull: Superior Nuchal Attachment site for neck muscles Line: Inferior Nuchal Line: Attachment site for neck muscles Mandibular fossa: Articulation point between the mandible and skull