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The Axial Skeleton:
General Characteristics
The axial skeleton it that part of the skeletal system that is at the ____ of the body’s vertical axis. It includes the ___, _____ _____, _____ and _____.
As already discussed, the skull and vertebral column _____ the central nervous system, the brain and spinal cord.
In addition, the vertebral column is important to _____ and ____. Thus, it has many attachments to _____.
The skull has too many functions to recount, but a short list includes: feeding, breathing, seeing, hearing, smelling, and tasting.
The Axial Skeleton:
General Characteristics
The ribs and sternum are also protective to the organs of the _____ cavity. Through their movements they also play an important role in _____ the lungs.
There are 5 regions that consist of anatomically distinct vertebrae: _____, _____, ____, ____, and ______.
Notice, vertebral column is has several curves. The cervical and lumbar curvatures are ____ from a posterior perspective, while the thoracic and sacral curvatures are _____.
The Vertebral Column: General Characteristics
The vertebral column is composed of about __ vertebrae and the intervertebral discs that are found between them.
There are _ regions that consist of anatomically distinct vertebrae: cervical, thoracic, lumbar, sacral, and coccygeal. Notice, vertebral column is has several curves.
The cervical and lumbar curvatures are ___ from a posterior perspective, while the thoracic and sacral curvatures are ____.
The Vertebral Column: General Characteristics
Vertebrae:
_____: the weight bearing region of the vertebra. They become ____ in the lower regions of the vertebral column and bear more of the body’s weight.
______ ______: location of the spinal cord
_____ and _____ processes: sites of muscle attachments.
_____ _____: form joints with articular processes of adjacent vertebrae. ____ movement of vertebral column.
________ ______: above and below the pedicles of each vertebra a notch is carved out that allows for the passage of a _____ _____
The Vertebral Column: General Characteristics
GUTS
Vertebra or vertebrae?
Pedicle
Lamina
Articular
Process
The Vertebral Column: Cervical Vertebrae
____ cervical vertebra allow great flexibility in the ____.
A ____ _____ easily identifies these vertebrae and allows passage of the vertebral artery, a significant blood supply to the brain.
The Vertebral Column: Cervical Vertebrae
The Atlas and Axis:
The first cervical vertebrae (C1) is the ___. It has no vertebral ____, and serves to articulate with the skull. Movement between the skull and C1 is in the sagittal plane (move your head as ___ ____ __).
The ___ below (C2) is also unique among cervical vertebrae. It has a projection called the ___ (also called the odontoid process) that fits into the large vertebral foramen of ___. The dens prevents C1 from ____ posteriorly, and allows ____ (shaking your head ‘no’) between C1 and C2.
The Vertebral Column: Cervical Vertebrae
C3-C7:
The remaining cervical vertebrae are similar to one another. C7 is often called ‘vertebra _____’ because of its long ____ process. In most people this can be easily identified by palpation.
The Vertebral Column: Cervical Vertebrae
GUTs
dens
Atlas
The Vertebral Column: Thoracic and Lumbar Vertebrae
Thoracic Vertebrae:
The most distinguishing characteristic of the __ thoracic vertebrae is their articulation with ___.
Small costovertebral joints are formed on the body of the vertebra and on the transverse process.
Small cartilaginous pads, ____, mark the articulations. Also distinguishing are the very long ____ sloping ___ _____.
The Vertebral Column: Thoracic and Lumbar Vertebrae
Lumbar Vertebrae:
The ____ vertebral bodies are found on the lumbar vertebrae. __ in number, these vertebrae support a large amount of your body’s weight.
As such, they have the largest vertebral bodies. They have __ articulation with ribs and have strong, ___, and ___ transverse and spinous processes.
The Vertebral Column: Sacral and Coccygeal Vertebrae
The Sacrum:
___ sacral vertebral bodies ___ during development. The superior aspect of the sacrum contains articular processes that connect the sacrum to L5.
The spinous processes likewise fuse to form the ___ ____ ___.
The transverse processes also fuse producing a pair of large “wings,” the ___.
The spinal nerve (cauda equina) travel through the vertebral canal, here called the ___ canal. Anteriorly and posteriorly, the ventral and dorsal rami exit through the 5 pairs of anterior and posterior sacral foramina.
The Coccyx
__ to __ tail vertebrae fuse to form the ___, the coccyx.
The Thoracic Cage: Sternum and Ribs
The thoracic cage forms a ____ yet rigid structure that is important to the ____ of the lungs and essential in anchoring the borders of the _____.
The Sternum:
__ components comprise the sternum, the ____, ___, and ____ ____ Most of the ribs attach directly or indirectly to the sternum.
The sternal ___ is the line of fusion between the ____ and ____, and can be palpated easily in most people. The xiphoid process can also be felt, although it can be best noted upon inspiration.
The Thoracic Cage: Sternum and Ribs
Ribs:
Posteriorly, each rib has a ___ for articulation with the costal ___ of a ____ vertebral body.
The head tapers to a ___. In this region, a ____ is present that articulates with the costal facet of a thoracic vertebra’s ____ process. Anteriorly, the ribs terminate in a costal ____ that spans the gap to the sternum.
Classification of Ribs:
___ ribs: ribs _-_ articulate directly (via their own costal cartilage)
with the sternum.
__ ribs: ribs _-_ do not directly attach to the sternum. Some connect to other costal cartilages while others do not connect to the sternum at all.
The later are often referred to as ____ ribs (ribs _ & _).
The Thoracic Cage: Sternum and Ribs
GUTSs
Tubercle?
The Cranium: Overview of Major Structures
One aspect of the skull that we will not spend much time on is the cranial foramina.
Should be able to identify:
Supraorbital, infraorbital, and mental foramina: CN?
Optic canal: CN?
Superior orbital fissure: CN?
Foramen magnum: ?
Internal acoustic meatus: CN?
The Cranium:
Overview of Bones and Major Structures
Broadly defined, the cranium consists of the bones surrounding the ___, forming the face, the jaws, the middle ear bones, and the ___ bone and laryngeal cartilages.
The ___ is that portion of the cranium concerned with protecting the brain and forming the face and jaws.
The Cranium:
Overview of Bones and Major Structures
Cranial ____ form where adjacent bones fuse during development. In adults, only some of these sutures remain visible.
In the fetus, large voids exist at these sutures to allow _____ of the skull, even the overlapping of bones, during parturition.
Locate the squamous, coronal, sagittal, and lambdoid sutures.
The Cranium:
Overview of Bones and Major Structures
Cranial cavity:
The brain is housed within the large ___ cavity.
Several important structures are worth noting within the cavity:
_____ ____: part of the ethmoid bone that allows the passage of CN I from the nasal cavity to the olfactory bulb
____ ____: sitting at the center of the skull, it houses the pituitary gland and the sphenoid sinus, forms the ____ processes for attachment of jaw muscles, and borders the orbit, cranial, and nasal cavities.
*It is visible from nearly any internal or external view of the skull!*
_____ ____: the part of the sphenoid bone that houses the pituitary gland. Its name means “Turkish saddle”
_____ ____: the brainstem exits the skull at this largest foramen (= hole) of the skull
____ _____ _____: a passage for CN VIII from the inner ear to the brain
The Cranium:
Specific Regions of the Skull
The Orbit:
The eye, extraocular muscles, and associated neurovascular structures are housed in the boney structure known as the ____.
Note the 6 bones that form the orbit.
Oral cavity:
The roof of the oral cavity’s hard palate is formed by the ____ and ____ bones.
The Cranium:
Specific Regions of the Skull
Nasal cavity:
The __ nasal cavities are located beneath the cranial cavity, and above the oral cavity. They are separated from each other by a median nasal septum (____ & _____).
Nasal ____ are bony spirals that project into the nasal cavities from their ethmoid bone. As air passes through and over these coils during ventilation, it is humidified and ____ by the ample mucous membranes.
______ _____: small cavities within the bones surrounding the nasal cavity. __-filled and lined with mucous membranes, the sinuses are connected to the nasal cavities.
The Hyoid Bone
The hyoid bone is a horseshoe-shaped bone that is ___ articulated with any other bone, but instead ____ below the _____.
It is held with ligamentous attachments to the ____ ____ of the skull and to the ____. It is also the attachment of well over a dozen muscles including those of the ____.
It’s purpose is to allow for muscular control of ______, _____, and ____ processes.
