Chapter 7 Skeleton Flashcards
How do you identify the appendicular skeleton?
These bones are appended to the axial skeleton. They allow us to interact with and manipulate our environment.
What are the interlocking joints of the adult skull bones?
Sutures
How many bones in cranium?
8
What are the divisions of the cranium?
1 - Cranial Vault - forms superior, lateral, and posterior aspects (includes forehead) 2 - Cranial Base - includes three fossae - anterior, middle, and posterior. These house the brain which is then enclosed by the vault.
What are the eight cranial bones?
1 - Parietal (paired) 2 - Temporal (paired) 3 - Frontal 4 - Occipital 5 - Sphenoid 6 - Ethmoid
What are some landmarks and neighbors of the frontal bone?
Posterior articulation with parietal bones via coronal suture. Its most anterior region, the forehead, is vertical squamous. Ends inferiorly at supraorbital margin. Supraorbital margins contain supraorbital foramen (notch) which allow for artery and nerve passage. The Glabella is the spot “right between the eyes” between orbits and meets the sinuses inferiorly at the frontonasal suture Lateral of glabella are sinuses.
Where are the parietal bones? Which sutures are they relevant for?
The superior and lateral parts of the cranial vault. Coronoal suture - parietal bone meet frontal bone anteriorly sagittal suture - between the parietal bones superior region of skull lambdoid suture - parietal bones meet the occipital bone posteriorly squamous suture - where the parietal bones meet the temporal bones at lateral aspect
What are the features of the occipital bone?
Its the most posterior wall and base. In addition to parietal articulation is the occipitomastoid suture with the tmeporal bone, it also joins to the sphenoid via the basilar. It forms the posterior cranial fossa which supports the cerebellum. In the base is the foramen magnum which allows the brain and spinal cord connection. This structure is flanked by the occipital condyles that articulate with 1st vertebrae. Medial and superior to condyles is hypoglossal canal for nerve passage.
What is the external occipital protuberance?
It is a bulge which is the tree trunk of the nuchal lines a superior and inferior line. ligamentum nucha
Temporal bones
Three parts: 1 - Squamous part ends at suture superiorly. Zygomatic process meets zygomatic bone anteriorly (creates zygomatic arch when joined to temporal process). On the inferior surface of zygomatic process is the mandibular fossa which receives condylar process of mandible to form temporomandibular joint. 2 - Tympanic part surounds the external acoustic meatus (ear canal) 3 - Petrous part houses the middle and internal ear cavities containing receptors for hearing and balance. Its a mountain ridge that runs posteriorly from occipital bone anteriorly to sphenoid bone. Along with the sphenoid bone these construct the middle cranial fossa which houses the temporal lobes of the brain.
What are the foramina of the petrous region of the temporal bone?
Jugular foramen - allows passage of the internal jugular vein Carotid canal - supply blood to over 80% of the cerebral hemisphere Internal acoustic meatus - superolateral to jugular foramen.
What are the two inferior processes in the inferioposterior region of the temporal bone and what is found between them?
Mastoid Process - A process on the posterior part of the temporal bone for neck muscle attachment. Styloid Porcess - The needle like projection on the inferior anterior region of temporal bone. Stylomastoid foramen - allows nerve to leave skull.
What are the landmarks of the sphenoid bone?
It spans the width of the middle cranial fossa. It articulates with all other cranial bones. The greater wings project laterally and form parts of: middle cranial fossa, posterior walls of orbits, external wall of skull. Lesser wings form part of the floor of the anterior cranial fossa and medial walls of the orbits. The pterygoid process projects inferiorly from the junction of body and greater wings
What is the sella turcica?
“Turk’s saddle” - the seat of the saddle, the ephyseal fossa, is the sight for the pituitary gland.
What are the openings of the sphenoid bone?
Optic canals - anterior to sella turcica. Superior orbital fissure - a long slit that allows cranial nerves which control the eyes. Foramen rotundum and ovale - also allow for cranial nerve passage. Formamen spinosum - transmits the middle meningeal artery.
What are the major features of the ethmoid bone?
Crista galli - superior projection to which the dura matter attaches. Lateral Masses (left and right) riddled with emthoidal air cells
What are sutural bones?
Bones that actually form within the sutures the lambdoid sometimes has these but not everyone grows them.
What are the features of the mandible?
Body is the inferior chunk - lower jawline and chin, holds teetch Ramus - are the more vertical sections that terminate with the condylar and coronoid processes. The anterior condylar process articulates with temporal fossa to form the temporomandibular joint. Mandibular formania allow for nerve to teeth these are on the medial aspects of the ramus. Mental foramina allow vessels and nerves to pass - these are on lateral aspects of the body.
Features of the maxillary bone?
The upper jaw. Carries the upper teeth in alveolar processes.
Where is the palatine bone located?
It is anterior to the maxilla and forms forms the anterior two-thirds of the hard palate. It is two boney plates which are joined at the median palatine suture.
