Axial Skeleton Flashcards
46- Structure
Hint: Cranial Bones
46. frontal - the “forehead”
Cranial bones - these contribute to the cranium, which encloses & protects the brain; note they are
separated by jagged boundaries called sutures; there are 8 cranial bones (note there is a right & left parietal
& temporal)
#51- **Ethmoid** - Only a horizontal cut skull (transverse section) will reveal this well; you can also find part of this bone forming the superior part of the nasal septum, and most of the side walls of the nasal cavity.
51- Structure
Hint: Facial Bones
Facial bones - fourteen facial bones form the face (note most of the following bones come in pairs)
51- nasal - These from the bridge of the nose.
52- lacrimal - These are within the orbits (eye sockets).
53- zygomatic - the “cheek bones”
54- maxilla - the upper jaw bones
55- palatine - These from the posterior two thirds of the hard palate.
56- vomer - This single bone is the inferior half of the nasal septum (the nasal septum divides the nose into left and right passageways).
- inferior nasal conchae - One of these thin curved bones projects into each nasal passage from its inferior-lateral wall.
- mandible - This single bone forms the lower jaw; it is the largest & strongest facial bone.
59- Structure
HINT: Projections and parts
59- zygomatic arch – Each (right and left) ring is composed of extensions of the zygomatic and temporal bones which meet.
Parts of the zygomatic arch:
60- temporal process – this is the name for the zygomatic bone’s contribution.
61- zygomatic process – This is the name for the temporal bone’s contribution; it is the
longer one.
64-. perpendicular plate – this part of the ethmoid bone forms the superior portion of the nasal
septum.
66.external acoustic meatus – this is the opening of the auditory canal; it is found in the temporal
bone
-
mastoid process – this projection from the temporal bone is located just posterior to the
external acoustic meatus
Parts of the mandible:
- alveoli – sockets for the lower teeth
- condylar process – Each one of these *articulates with a temporal bone.
63- Structure
HINT: Parts and projections
- sella turcica - This is the saddle-like depression in the mid-superior portion of the sphenoid bone. It can only be seen in a transverse (horizontally) sectioned skull. It is a protective housing for the pituitary gland (the “master gland” of the endocrine system)
-
crista galli – this is the median ridge of the ethmoid bone. It can be seen by looking into a
horizontally sectioned skull
62- Stucture & articulation
HINT: Parts and Projections
62- occipital condyles – These oval smooth projections. Articulate with the atlas (the first vertebra).
70- Structure
Hint: FORAMINA
70- magnum - the largest one through which the spinal cord and brain meet
Foramina (singular is foramen)-these are openings for blood vessels, nerves, and ligaments (often the foramen is named for the artery, vein, or nerve that passes through it).
#72- **jugular** – These are large but rather hidden; looking down into the skull form the inside may help. This is a passageway for the major vein (jugular vein) that drains blood from the brain.
74- Structure
Hint: FORAMINA
74) mandibular – There are two of these on the inside of the mandible, near the base of the condylar and coronoid processes. These holes contain sensory nerves and are often used by dentists as a route to inject anesthetics.
Foramina (singular is foramen)-these are openings for blood vessels, nerves, and ligaments (often the foramen is named for the artery, vein, or nerve that passes through it).
76- Structure
HINT: General structure
76- Body
HINT: General structure
81- Structure
HINT: Specializations of cervical vertebrae
81- transverse foramen; all cervical vertebrae have this pair of openings in their transverse processes
84-Structure
Specializations of the Cervical Vertebrae
84-The axis is the second vertebra, which has a unique structure to permit it to rotate the atlas and skull
86- Structures & articulation
HINT: Specializations of thoracic vertebrae
86- costal facets - All thoracic vertebrae (and only thoracic vertebrae) have costal facets (“costal” means “rib”). These special articular processes are *for articulation with the ribs
87- Vertebre type
HINT: Vertebrae dinstinction
87- Cervical - Smallest of the group that have the transverse foramen. 7 bones total
88- Vertebrae type
HINT: Vertebrae dinstinction
88- Thoracic vertebrae- larger than cervical but smaller than lumber. Have the costal facets. 12 bones total.
89- Vertebrae type
HINT: Vertebrae dinstinction
89- Lumbar -note that lumbar vertebrae are the largest, strongest, and lack transverse foramen & costal facets. 5 total bones
90- Structure
90- sacrum – During development, this bone is formed from the fusion of five separate fetal vertebrae.
92- Structure
92- hyoid bone – supports the larynx
93- Bone
HINT: Thorax
93- sternum – the “breast bone” consists of 3 parts
94- Structure
Bone
94- head – bulbous vertebral end, which *articulates with the body of the costal facet of the toracic vertebrae
Bone: ribs – all ribs have the following structures
