Axial Skeleton Flashcards
How many bones are in the skull?
22 bones
Facial bones
Protect sensory organs
Attachment sites
Alveolar processes and sockets
What are the six cavities of the skull?
Cranial cavity - holds the brain Orbits - eye sockets Nasal Cavity Oral cavity Middle and inner-ear cavities Paranasal sinuses - air filled spaces connected to nasal cavity. Named after the bones in which they are found
What are the functions of the paranasal sinuses?
Decrease skull weight
Resonating chambers
What makes something a cranial bone?
Bones that have direct contact with membranes that enclose that brain.
What are the three parts of the cranial base?
Anterior cranial fossa - Frontal lobe
Middle cranial fossa - Temporal lobes
Posterior cranial fossa - Cerabellum
What are the four parts of the temporal bones?
Squamous, tympanic, mastoid, and petrous
Describe the differences between the lesser and greater wings of the sphenoid bone?
Lesser wing - posterior margin of anterior cranial fossa. Posterior wall of orbit. Optic canal.
Greater wing - About half middle cranial fossa. Lateral surface
What parts of the skull does the ethmoid bone contribute to?
Roof/walls of nasal cavity
Medial wall of orbit
Nasal septum
What kind of bones have no contact with meninges?
Facial bones
What bones make up the facial bones?
2 maxillae, palatine, zygomatic, lacrimal, nasal, and inferior nasal conchea
1 vomer and mandible
What bone makes up the majority of the hard palate? What does this allow us to do?
The maxillae
Chew and breath at the same time.
What is the largest sinus?
Maxillary sinus
What makes up the rest of the hard palate?
Palatine bone
That three facial features are made up of the palatine bone?
Hard palate, nasal cavity wall, and floor of the orbit
What is the smallest skull bone?
Lacrimal bone which is found in the medial wall of each orbit. (think lacrimal fossa collecting the tears from eyes)
What is the largest conchae in the nasal cavity?
Inferior nasal conchae. This is not a part of the ethmoid bone
How many bones form the orbit?
7 bone
What part of the orbit does the frontal bone form?
Roof
What bone forms the roof and the posterolateral wall?
Sphenoid
What bone forms the lateral wall of the orbit?
Zygomatic
True or false -
The maxilla forms the medial wall of the orbit
False the maxilla forms the floor of the orbit
What three bones form the medial wall of the orbit?
Lacrimal bone, Ethmoid bone, Palatine bone
Nasal cavity
Pear shaped, open anteriorly
What divides the nasal cavity?
Nasal septum made up of the vomer and perpendicular plate of the ethmoid bone
What is the purpose of the nasal conchae?
Increases surface area, covered in mucus membrane, and used to moisten, warm and filter air
How many bones form the nasal cavity?
9
True or false -
There are four bones that form the roof of the nasal cavity
True, the frontal bone, nasal bone, sphenoid bone, and ethmoid bone.
What three surfaces are formed by the ethmoid bone in the nasal cavity?
Roof, septum, and lateral wall
What forms the lateral wall of the nasal cavity?
Inferior nasal concha and lacrimal bone
What forms the septum?
Vomer
What two bones form the floor of the nasal cavity?
Maxilla and palatine bone
What does the palatine bone form in the nasal cavity?
Floor and lateral wall
What is a fontanelles?
The space between unfused cranial bones, contains fibrous membrane. This helps with child birth allowing for shifting of the skull bones.
What is the only bone in the body with no articulation?
Hyoid bone that is found between the chin and larynx
What bones are associated with the auditory ossicles?
Malleus, incus, stapes
What are the four functions of the vertebral column?
Support of the skull and trunk
Protects spinal cord
Absorbs stress from movement
Attachment for limbs, thoracic cage, and postural muscles
How many vertebrae are in the vertebral column?
33
How many groups of vertebrae are there?
What are the names and amount in each group?
Cervical - 7 very top
Therasic - 12 middle of back
Lumbar - 5 lower back
Sacral - 5 Fused into a single bone called the sacrum
Coccygeal - 4 fused as a single called the coccyx
Explain the functions of the body of the vertabrae and its rough surfaces.
The body is used for weight bearing and the rough surfaces are attachment for intervertebral discs
What are the two places on the vertabrea that are used for attachment of ligaments and bones?
Spinous process - extends from the apex of arch
Transverse process - extends laterally from arch
What makes the C1 (atlas) special?
Very large vertebral foramen
Has no body
Supports the head
Allows for “yes” nodding
What makes the C2 (axis) special?
Allows for rotation of the head
It is the first vertebrae with a spinous process.
What vertebrae support the ribs?
Thoracic vertebrae
What are the four functions of the intervertebral discs?
Binds adjacent vertebrae together
Allows for flexibility for the spine
Supports weight of body
Absorbs shock from movement
What makes up the thoracic cage and what are its functions?
Made up of thoracic vertebrae, sternum, and ribs
Encloses lungs, heart, spleen, liver, and kidneys
Attachment for pectoral griddle and upper limbs
What are the three regions of the sternum?
Manubrium - Broad superior portion
Body (gladiolus) - longest part and where the ribs attach
Xiphoid process - inferior point, attachment for abdominal muscles
Where does the head of the ribs articulate?
The head attaches to the thoracic vertebrae.
What are true ribs and how many are there?
Ribs that are directly connected to the sternum
True or false -
There are 5 false ribs that do not connect to anything on the distal end.
False there are 5 false ribs that do not independently connect to the sternum. This also includes floating ribs (2) that have no cartilage connection on the distal end.
What makes the C1 rib different from the rest?
It is short, flat and C- shaped
Articulates with the T1
What is different about T11-12?
No tubercles to the transverse process
What four bones articulate with the left parietal bone?
Parietal, temporal, occipital, frontal
True or false -
True ribs attach directly to the sternum with costal cartilage.
True
True or false -
There are five pairs of floating ribs.
False - there are 5 pairs of false ribs
True or false -
the head of the rib attaches to the transverse process of the vertabea.
True
True or false -
Ribs 8-10 are classified as true ribs.
False - 8-10 are false ribs
True ribs are 1-7
True or false -
Floating ribs do not attach to the vertabrea.
False - Floating ribs are attached to the vertabrea but they are not attached to the sternum.
The _______ can be easily palpated between the clavicles.
Jugular notch
The nasal septum is composed partly of the same bone as _______
The cribriform plate