Axial Skeleton

SKULL
Cranium: encloses and protects the fragile brain tissue and is composed of eight large, flat bones 
Facial Bones: hold the eyes in an anterior position and allow the facial muscles to show our feelings through smiles or frowns 
Frontal Bone: the frontal bone forms the forehead, the bony projections under the eyebrows, and the superior part of each eye's orbit
Parietal Bones: the paired parietal bones form most of the superior and lateral walls of the cranium (they meet in the midline of the skull at the sagittal suture and for the coronal suture where they meet at the frontal bone) 
Temporal Bones: the temporal bones lie inferior to the parietal bones; they join them at the squamous sutures
~~~ External Acoustic (Auditory) Meatus: the canal that leads to the eardrum and the middle ear
~~~ Styloid Process: a sharp, needlelike projection just inferior to the external auditory meatus ~ this serves as an attachment point for many neck muscles 
~~~ Zygomatic Process: a thin bridge of bone that joins with the cheekbone (zygomatic bone) anteriorly
~~~ Mastoid Process: a rough progression posterior and inferior to the external acoustic meatus, which is full of air cavities (mastoid sinuses); providing an attachment site for some muscles of the neck
~~~ Jugular Foramen: located at the junction of the occipital and temporal bones, this allows passage of the jugular vein, the largest vein of the head, which drains the brain
~~~ Internal Acoustic Meatus: transmits cranial nerves VII and VIII (the facial and vestibulocochlear nerves)
~~~ Carotid Canal: located anterior to the jugular foramen on the skull's inferior aspect, this canal in which the internal carotid artery runs, supplies blood to most of the brain
Occipital Bone: the most posterior bone of the cranium in which forms the floor and back wall of the skull
~~~ Foramen Magnum: large opening that surrounds the lower part of the brain and allows the spinal cord to connect with the brain
~~~ Occipital Condyles: structures that rest on the first vertebra of the spinal column
Sphenoid Bone: the butterfly shaped bone that spans the width of the skull and forms part of the floor of the cranial cavity
Sella Turcica: also called Turk's Saddle this holds the pituitary gland in place
Foramen Ovale: a large oval opening in line with the posterior end of the sella turcica that allows fibers of cranial nerve V (the trigeminal nerve) to pass to the chewing muscles of the lower jaw (mandible) 
Optic Canal: an opening that allows the optic nerve to pass to the eye
Superior Orbital Fissure: a slitlike opening through which the cranial nerves controlling eye movements (III, IV, and VI) pass
Sphenoid Sinuses: air cavities that riddle the central part of the sphenoid bone 
Ethmoid Bone: very irregularly shaped and lies anterior to the sphenoid ~ it forms the roof of the nasal cavity and part of the medial walls of the orbits
Crista Galli: a projection in which the outermost covering of the brain attaches
Cribriform Plates: allow nerve fibers carrying impulses from the olfactory (smell) receptors of the nose to reach the brain
Superior and Middle Nasal Conchae: form part of the lateral walls of the nasal cavity and increase the turbulence of air flowing through the nasal passage 

FACIAL BONES

Maxillary Bones: fuse to form the upper jaw
Alveolar Margin: where the maxillae carry the upper teeth
Palatine Processes: extensions of the maxillae that form the anterior part of  the hard palate of the mouth
Paranasal Sinuses: work to lighten the skull bones and probably act to amplify the sounds we make as we speak
Palatine Bones: form the posterior part of the hard palate ~ failure of these or the palatine processes to fuse medially results in cleft palate
Zygomatic Bones: commonly referred to as the cheekbones and form a good-sized portion of the lateral walls of the orbits or eye sockets 
Lacrimal Bones: fingernail-sized bones forming part of the medial walls of each orbit ~ each lacrimal bone has a groove that serves as a passageway for tears
Nasal Bones: small rectangular bones forming the bridge of the nose
Vomer Bone: the single bone in the median line of the nasal cavity which forms most of the nasal septum
Inferior Nasal Conchae: thin, curved bones projecting  from the lateral walls of the nasal cavity 
Mandible: the largest and strongest bone of the face that joins the temporal bones on each side of the face (forming the only freely movable joints in the skull) 
Hyoid Bone: the only bone of the body that does not articulate directly with any other bone, and is instead suspended in the mid-neck region where it is anchored by ligaments to the styloid processes of the temporal bones (is not technically part of the skull) 
Fetal Skull: the skull of a fetus or newborn infant that contains a small face, large total size in comparison to the rest of the body, and a lot of cartilage
Fontanels: the fibrous regions connecting the cranial bones

VERTEBRAL COLUMN (SPINE)

Vertebral Column/Spine: the axial support of the body that extends from the skull, which it supports, to the pelvis, where it transmits the weight of the body to the lower limbs
Vertebrae: the bones of the spine that are categorized under cervical, thoracic, and lumbar vertebrae 
Intervertebral Discs: pads of flexible fibrocartilage that cushion the vertebrae and absorb shocks while allowing the spine flexibility 
Primary Curvatures: the spinal curvatures in the thoracic and sacral regions
Secondary Curvatures: curvatures that develop when a baby begins to raise its head, and the lumbar curvatures begin to develop when the baby begins to walk
~~~ Body/Centrum: disclike, weight-bearing part of the vertebra facing anteriorly in the vertebral column
~~~ Vertebral Arch: arch formed from the joining of all posterior extensions from the vertebral body
~~~ Laminae/Pedicles: all posterior extensions
~~~ Vertebral Foramen: canal through which the spinal cord passes
~~~ Transverse Processes: two lateral projections from the vertebral arch
~~~ Spinous Process: single projection arising from the posterior aspect of the vertebral arch (actually the fused laminae) 
~~~ Superior and Inferior Articular Processes: paired projections lateral to the vertebral foramen, allowing a vertebra to form joints with adjacent vertebrae
Cervical Vertebrae: the seven vertebrae (C1-C7) that form the neck region of the spine
Atlas (C1): this joint allows you to nod "yes" 
Axis (C2): acts as a pivot for the rotation of the atlas (and skull) above (allows you to rotate your head from side to side indicating "no")
Dens/Odontoid Process: acts as the actual pivot point
Thoracic Vertebrae: the twelve vertebrae (T1-T12) that are larger than the cervical vertebrae (where the ribs are located) 
Lumbar Vertebrae: the five vertebrae (L1-L5) that have massive, blocklike bodies ~ their short, hatchet-shaped spinous processes make them look like a moose head from the lateral aspect
Sacrum: is formed by the fusion of five vertebrae ~ superiorly, it articulates with L5, and inferiorly, it connects with the coccyx
Alae: a winglike structure that articulates laterally with the hip bones, forming the sacroiliac joints
Median Sacral Crest: the fused spinous processes of the sacral vertebrae ~ this is flanked laterally by the posterior sacral foramina 
Sacral Canal: the vertebral canal that continues inside the sacrum
Sacral Hiatus: a large inferior opening that terminates the sacral canal
Coccyx: the fusion of three to five tiny, irregularly shaped vertebrae ~ it is the human "tailbone," a remnant of the tail that other vertebrate animals have
Bony Thorax: the sternum, ribs, and thoracic vertebrae
Thoracic Cage: a protective, cone-shaped cage of slender bones around the organs of the thoracic cavity (heart, lungs, and major blood vessels)
Sternum: a typical flat bone that is the result of the fusion of the three bones manubrium, body, and xiphoid process
~~~ Jugular Notch: the concave upper border of the manubrium that can be palpated easily
~~~ Sternal Angle: a transverse ridge that is formed by the manubrium and body meeting at a slight angle
~~~ Xiphisternal Joint: the point where the sternal body and xiphoid process fuse
Ribs: twelve pairs of bones that form the walls of the bony thorax ~ all the ribs articulate with the vertebral column posteriorly and then curve downward and toward the anterior body surface
True Ribs: the first seven pairs that attach directly to the sternum by costal cartilages
False Ribs: the next five pairs, either attached directly to the sternum or are not attached to the sternum at all
Floating Ribs: the last two pairs of false ribs that do not connect to the sternum at all

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s