Axial Skeleton Flashcards
How many bones are in the axial sskeleton?
80
Where does the axial skeleton form?
Along the long axis of the body (up and down)
What does the axial skeleton consist of?
Bones of the skull, vertebral column, and rib cage
What are sutures?
Interlocking joints that firmly unite all the bones of the adult skull
What do the suture lines look like?
They have a saw tooth or serrated appearance
What are the four major skull sutures?
Coronal, sagittal, squamous, and lambdoid
What is the frontal bone?
The forehead, the bony projection under the eyebrows, the superior part of each eye’s orbit
What is the foramen magnum and what does it mean?
The base of the occipital bone, meaning large hole
Where is the foramen magnum?
Surrounds the lower part of the brain
What does the foramen magnum do?
Allows the spinal cord to connect with the brain
How do the occipital condyles work?
Rocker like and lateral (on each side of) to the foramen
Where are the occipital condyles located?
They rest on the vertebra of the spinal column
What is the sphenoid bone?
Has a butterfly shape that spans the width of the skull
What does the sphenoid bone do?
Forms part of the floor of the cranial cavity
What is the sella turcica?
A small depression in the middle of the sphenoid bone
What is the sella turcica also called?
Turk’s saddle
What does the sella turcica do?
It holds the pituitary gland in place
What is the crista galli latin for?
Cock’s comb
What does the crista galli look like?
The outer most covering of the brain attaches to this projection
What does the crista galli look like?
It projects from its superior surface
What are the cribiform plates?
The small holes on each side of the crista galli
What do the cribiform plates do?
Allow nerve fibers carrying impulses from the olfactory (smell) receptors of the nose to reach the brain
How many bones comprise the facial bone?
14
How many bones in the facial bone are paired?
12
What are the two single bones of the face?
The mandible and the vomer
What do the two maxillae do?
Fuse together to form the upper jaw
What bones join the maxillae and what do they make the maxillae?
All facial bones except for the mandible, the main bone of the face
What does the maxillae carry and where?
The upper teeth in the aveolar margin
Where are the paired palatine bones located?
They lie posterior to the palatine processes of the maxillae
What do the palatine bones form?
The posterior part of the hard palate
What is a cleft palate?
Failure of these or the palatine processes to fuse medially results in a cleft palate
What are the nasal bones?
Small rectangular bones that form the bridge of the nose
What is the inferior conchae?
Thin curved bones projecting from the lateral walls of the nasal cavity
What is the inferior conchae a part of?
The ethmoid bone
What is the hyoid bone not a part of?
The skull
What is the hyoid bone closely related to?
The mandible and the temporal bones
What does the hyoid bone do?
Doesn’t articulate with any other bones
During fetal development, what does the spine consist of?
33 separate bones called vertebrae
What do the vertebrae do after birth?
Nine of these vertebrae will fuse forming the two composite bones, the sacrum and the coccyx
What do the sacrum and coccyx do?
They construct the inferior portion of the vertebral column
What are the intervertebral discs?
Pads of flexible fibrocartilage which separate the single vertebrae
What do the intervertebral discs do?
The discs along the s shaped structure of the vertebral column work together to prevent shock to the head while walking and running, make the body trunk flexible
What does the body or centrum of the vertebrae look like?
Disc like
What does the body or centrum of the vertebrae do?
It is the weight bearing part of the vertebrae facing anteriorly in the vertebral column
What is the vertebral arch?
An arch formed from the joining of all posterior extentions
What forms the vertebral body?
The laminae and the pedicles
What is the vertebral foramen?
Canal through which the spinal cord passes
What are the transverse processes?
Two lateral projections from the vertebral arch
What do the cervical vertebrae form?
The neck region of the spine
What are the first two vertebrae?
C1 (the atlas) and C2 (the axis)
What does the atlas do?
Recieves the occipital condyles of the skull
What does the atlas allow for?
To nod “yes”
What does the axis do?
Acts as a pivot for the rotation of the atlas and skull
The thoracic vertebrae are all…
typical and larger than the cervical vertebrae
What do the thoracic vertebrae look like?
The body is somewhat heart shaped
What do the thoracic vertebrae have?
Two costal demifacets (articulating surfaces) on each side
What do the costal demifacets of the thoracic vertebrae do?
Recieve the heads of the ribs
What do the lumbar vertebrae look like?
Have massive block like bodies, short, hatchet shaped spinous processes
What do the spinous processes of the lumbar vertebrae do?
Make them look like a moose head from the lateral aspect
What do the alae of the sacrum look like?
Wing like in shape
What do the alae of the sacrum do?
Articulates laterally with the hip bones, forming the sacroiliac joints
What does the sacrum do?
Forms the posterior wall of the pelvis
What is the sacral canal?
The vertebral canal continuing inside the sacrum
What is the coccyx?
The human “tailbone”, a remnant of the tail that other vertebrae animals have
What does the coccyx consist of?
Formed from the fusion of three to five tiny, irregular shaped vertebrae
What kind of bone is the sternum?
A typical flat bone
What does the sternum consist of?
The result of the fusion of three bones- the manubrium, the body, the xiphoid process
What is the sternum attached to?
The first seven pairs of the ribs
What is the jugular notch?
The concave upper border of the manubrium
The jugular notch can be…
palpated (examined by touch) easily
What are the true ribs and what do they do?
The first seven pairs, they attach directly to the sternum by costal cartilage
What are false ribs and what do they do?
The next five pairs, either attach indirectly to the sternum or are not attached to the sternum at all
What are the floating ribs?
The last two pairs of false ribs that do not attach to the sternum
What do the intercostal spaces between the ribs do?
Are filled with intercostal muscles that aid in breathing
