Unit 1.5 Flashcards
Axial skeleton include
Skull, thoracic cage (sternum and ribs), vertebral column
Appendicular skeleton includes
Shoulder girdle (clavicle and scapula), upper limb, pelvis girdle (ilium, ishium, pubis), lower limb
The axial skeleton bones form the
Provides
Protects
The central axis of the skeleton
Main support of the body
The CNS - brain and spinal cord
The skull can be divided into
Includes
2 regions - Cranial and facial bones
Cranial- frontal, parietal, occipital, temporal, sphenoid, ethmoid
Facial- mandible, maxilla, palatine, nasal, vomer, inf.nasal concha, zygomatic, lacrimal
Cranial sutures
Areas where one cranial plate meets another
Sagittarius, coronal, lambdoidal, squamosal
Fossae’s off the vault
Posterior, middle, and anterior
Frontal bone is positioned at
Forms
Creates
Features
Th anterior and superior region of the cranial vault
Forms the anterior cranial fossa with the ethmoid and sphenoid
Creates the superior orbit of the eye
Supraorbital notch, supraorbital margin, glabella, frontal sinus, frontal sinus, zygomatic process,
Associated structure- coronal suture
Coronal suture
Coronal plane superior surface of cranial vault Forms
Parietal bones are positioned
Creates
Forms
Features
Posterior to the frontal, anterior to the occipital, and superior to the temporal bones
Creates most of the lateral wall of the cranial vault
Contributes to the formation of the middle cranial fossa
Associated structure- squamous suture, coronal suture, lambdoid suture, sagittal suture
Temporal bones are positioned
Forms
Found
Features
Inferior to the parietal, anterior to the occipital, and in general posterior to the facial bones
The floor of the middle cranial fossa with the temporal, parietal, and sphenoid
Found inferior and posterior to the conventionally conceived of temple (pterion)
Squamous and pterosaurs portions, internal and external acoustic meats, mastoid and styloid processes, carotid canal, zygomatic process, mandibular fossa
Associated structures- jugular foramen, squamous suture
Occipital is
Creates
Features
The most posterior bone of the cranial vault
Creates the floor of the posterior cranial vault
External occipital protuberance, occipital condyles, hypoglossal canal, foramen magnum, grooves for transverse and superior sagittal venous sinuses
Associated structures- jugular canal, lambdoid suture
Sphenoid is
Known as
Creates
Features
The most centrally placed bone of the skull
Keystone- all other bones of the skull touch it
Creates the posterior part of the orbit of the eye, and contributes to the formation of the anterior and middle cranial fossa
Sella turcica, body and sphenoid sinus, optic canal, medial and lateral pterygoid processes, foramen ovals, greater and lesser wings, supraorbital fissure
Ethmoid is
Found
Creates
Features
A deep bone of the cranial vault
Found posterior to the nasal bones, anterior to the sphenoid, temporal, parietal, and occipital, and to a certain degree inferior to the frontal
Deep to bones of the face
Creates the floor of the anterior cranial vault with the frontal
Is the medial wall of the orbit of the eye
Its perpendicular plate creates the superior portion of the bony nasal septum, the vomer contributes the inferior portion
Christa galli, cribriform plate and ethmoid foramina, perpendicular plate, ethmoid sinuses, superior and middle nasal conchae
Mandible is
Features
The inferior jaw bone
Mandibular condyle, mandibular notch, coronoid process, ramus, angle of the mandible, alveolar margin, mental protuberance
Maxilla is the
Creates
Features
Upper jaw bone
Creates most of the face, orbits of the eyes, nasal aperture, and oral cavity
Palatine portion, zygomatic process, maxillary sinus, alveolar margin
Palatine is found
Creates
Posterior to the palatine portion of the maxillary bone
The palatine bones and palatine portion of the maxillary bone creates the hard palate
Nasal bones are
Creates
Vomer
Inferior to the frontal, superior to the maxilla, and anterior to the ethmoid
The bridge of the bone
Creates the bony nasal septum with the perpendicular plate of the ethmoid and the vomer
The vomer is a single bone that is inferior and posterior to the nasal bones
The vomer is inferior to the perpendicular plate of the ethmoid bone
The inferior nasal conchae are
Found
Bilateral turbinate bones
Within the nasal cavities and are inferior to the superior and middle nasal conchae portions of the ethmoid bone
Zygomatic bones are
creates
Arch
Paired and are located inferior to the frontal, posterior to the maxilla
Creates the corner of the cheek
Zygomatic arch is the curvature of bone tissue that is lateral to the fleshy bit of the cheek
The arch is created from the centrally placed zygomatic bone, the temporal process of the zygomatic bone and the zygomatic process of the temporal bone
Zygomatic bone has a superior projection, frontal process, that stabilizes the zygomatic bone
Aides in creation of the orbit of the eye
The lacrimal bones are
Paired bones positioned in the medial aspect of the orbit of the eye Its perpendicular
Sagittal suture
Located between the two parietal bones. It is on the median plane
Coronal suture
Posterior to the frontal bone and anterior to the parietals. It is in the frontal/coronal plane
Lambdoid suture
Appears on the posterior vault as the Greek letter lambda. It is at the superior boundary of the occipital bones and is posterior to the parietal and temporal bones
Squamosal suture
Between the parietal and temporal. The inferior parietal edge compresses the superior temporal edge at approximately 80 degrees in the transverse plane
Hyoid
Suspends the larynx (voice box)
Only bone in the body not directly attached to another bone
The thoracic rib cage
Comprised posteriorly of the bodies of thoracic vertebrae
It is bound laterally by bilateral (right and left sides) costae 1-12 and anteriorly by associated costal cartilages and the sternum
Sternum
Has three regions- looks like a sword
Manubrium- the uppermost portion
Body- central portion
Xiphoid process- inferior portions or tip of the sword
Costae
Features
2 types- true and false
True ribs are 1-7. These costae directly attached to the sternum by their costochondral cartilages
False ribs are 8-12. They are not directly attached to the sternum. Attach to cartilage of the next superior rib
Floating ribs are 11-12. The cartilage of these costae do not attach to the inferior border of the thoracic rib cartilage
Hea, neck, tubercle
Primary curvatures
Known as
Thoracic and sacral regions
Known as accommodation curvatures because they develop to accommodate internal organs
Curvature is present at birth
Secondary curvature
Known as
Cervical and lumbar regions
Known as compensation curvatures because they develop in response to motor (movement) needs
Curvature develops during early life
Regions of the vertebral column
Cervical- found in the neck. There are 7 (C1-C7) of them and is secondary curvature
Thoracic- associated with the thorax (chest). There are 12 of them (T1-T12) and articulate with the 12 pairs of ribs. Primary curvature
Lumbar- posterior to the abdominal region. There are 5 of them (L1-L5) and is secondary curvature
Sacral- posterior wall of the pelvis. There are 5 (S1-S5) that have fused together. Primary curvature
Coccygeal- tailbone. There are 3-4 coccygeal (Co1-Co4) vertebrae that fuse into one post puberty
Features of typical vertebra
Body-central anterior facing bone mass
Pedicure- footing and wall of the vertebral arch
Lamina- the roof top of the vertebral arch
Transverse process- bilateral projections between pedicle and lamina
Spinous process- posterior projection between bilateral laminae
Superior and inferior articulating facets- smooth faces that provide articulation between vertebrae
Superior and inferior articulating processes- muscle attachments sited
Vertebral arch -bone arch created by bilateral pedicles and lamina
Vertebral foramen- hole anterior or laminae and posterior to the body
Vertebral canal- canal create by articulated vertebrae and their foramen transmits the spinal cord
Intervertebral foramen- aperature created between pedicles of articulated vertebrae and transmits the spinal nerves
The cervical vertebrae
Brigid spinous process found on C2-C6
Transverse processes have transverse foramen
Superior and articulating facets are oriented to articulate in a transverse plane which allows for increase motion
C1- atlas
C2-axis
Atlanto- occipital joint
Found between the occipital condyles and superior articulation facets of the atla
Known as the yes joint
Atlantoaxial Joint
Found between the anterior arch of the atlas and the dens process of the axis
Known as the no joint
Special features of the thoracic vertebrae
Costal facets and Demi facets
The costal facet articulates with the tubercle of the rib
The Demi facets articulates with the head of the rib
Spinous processes are long
Special features of the lumbar vertebrae
Robust body
Spinous processes are short and blunt
Superior and inferior articulating facets increasing orient themselves into the sagittal plane as we move down the column- begins to limit the action of rotation
Sacrum
Fusion of 5 sacral vertebrae
Spinous processes transformed into the median sacral crest- posterior surface
Transverse processes transformed into the transverse ridges- posterior surface
Accepts and transmits force to and from the vertebral column and legs- lateral surfaces and superior surface
Coccyx
Tail bone
Fusion of 3-4 coccygeal vertebrae
Vestigial skeletal remains of a tail; retained and useful for other mammals
