Section 3: Axial Skeleton Flashcards
What are the 2 sets of bones that make up the skull?
Cranial and facial bones.
How many bones are in the skull?
22
How many bones make up the cranium?
8 (we will only need to know 7)
What are the functions of the cranium?
Providing protection for the brain.
What are the 7 bones of the cranium that we need to know? (Hint: only 5 names)
Frontal bone (1), temporal bones (2), sphenoid bone (1), parietal bones (2), occipital bones (1)
What is the frontal bone?
It is a single bone and it forms the forehead and roots of the orbits (eye sockets)
What are the temporal bones?
They are paired (2 bones) and form the lateral and inferior walls of the skull. The features of the bone include: zygomatic process, external auditory (acoustic) meatus (ear hole), and mastoid process.
What is the sphenoid bone?
It is a single bone. Known as the “keystone” of the skull as it joints the cranium and facial bones by attaching with almost every other bone of the skull. The shape is similar to a bat with its wings extended.
What are the parietal bones?
They are paired bones (2 bones), and form the superior and lateral surfaces of the skull.
What is the occipital bone?
It is a single bone, that forms the posterior wall and the base of the skull.
What are the two features of the occipital bone?
- Foramen magnum (big hole)
Allows the spinal cord to exit the cranial cavity
- Occipital Condyles
Articulate with the first bone in the neck
What are sutures?
Attachments (articulations) between flat bones of the skull
What is the coronal?
Junction between frontal and parietal bones
What is the sagittal?
Junction between parietal bones
What is lamboid?
junction between the occipital and parietal bones
What is the squamous?
junction between temporal and parietal bones.
What is the cranial vault?
refers to the dome shaped bony roof of the skull that encases the brain. It is formed by the frontal, parietal, and occipital bones which are flat bones. Sometimes called the skullcap.
What us the cranial base?
It is the floor of the cranium, on which the brain sits. It contains 3 fossae.
What is a fossa?
It is a depression in a bone
What are the three fossae on the cranial base?
-the anterior cranial fossa
-the middle cranial fossa
-the posterior cranial fossa
How many bones make up the face?
14 (we will only need to know 7)
What are the 7 facial bones that we need to know?
-maxillary (2 bones)
-nasal (2 bones)
-zygomatic (2 bones)
mandible (1 bone)
Describe the maxillary bones.
it is paired (2 bones) and are the upper jaw bones
Describe the nasal bones.
they are paired (2 bones), articulate with the frontal lobe, and together they form the bridge of the nose.
What does it mean when two bones articulate?
The parts come together at a joint
Describe the zygomatic bones.
They are paired (2 bones) and form the cheekbones.
A feature of these bones is the temporal processes, and this articulates with the zygomatic process of the temporal bone to form the zygomatic arch.
Describe the mandible bone.
it is a single bone and forms the lower jaw.
What is the common name for the vertebral column?
the spine
How many bones is the spine made up of? and how many of each type of bone?
there are 24 bones in total.
-24 vertebrae
-1 sacrum
-1 coccyx
What is a vertebrae?
small bones that form the backbone`
What are the divisions of the vertebral column?
- Cervical (7 vertebrae)
2.Thoracic (12 vertebrae) - Lumbar (5 vertebrae)
*the above 3 account for the 24 verterbrae - Sacrum (5 fused vertebrae)
- Coccyx (4 fused vertebrae)
What are the three basic features of a vertebrae?
- Body (anterior)
- Vertebral arch (posterior). this extends into the spinous and transverse processes)
- Vertebral formen (canal).
What houses the spinal cord?
the vertebral formen. all of the vertebral formen stack together to form the vertebral canal, which houses the spinal cord.
Are all vertebrae the same?
No. there are distinct differences seen in the three regions of the vertebral column.
What are the first and second cervical vertebrae?
C1 (atlas) and C2 (axis)
What are the 2 features of the C1? How are they important for articulation?
The anterior arch and lateral masses are the two features.
The anterior arch provides the surface for articulation with the dens. While the lateral masses provide the surfaces for articulation of the occipital condyles of the occipital bone.
What is the main feature of the C2?
The dens is the main feature, and rests within the anterior arch of C1.
What joint allows the yes movement of the head?
it is the lateral masses of C1 via the occipital condyles, since this is where the skull rests on top of.
What allows for the “no” movement of the head?
underneath the C1, the dens of C2 articulates (attaches) with the anterior arch of C1.
What are vertebral articulations?
Individual vertebrae articulate (join together) to stack on top of one another.
These give rise to the following two structures: intervertebral disc, and intervertebral foramina.
What is the intervertebral disc?
located between two vertebrae, think of them as the “jelly filled donut”. It acts as a shock absorber.
What is the intervertebral foramina?
these are lateral openings between adjacent vertebrae that allow for the passage of spinal nerves.
What is the type of cartilidge that is found between invertebral discs?
fibrocartilidge, since it is tough and inflexible, this is necessary to resist compression on the spine.
What is the sacrum?
It is located inferiorly, and a formed for the fusion of 5 vertebrae
what is the coccyx?
It is located inferiorly and is the fusion of 3-5 vertebrae (typically 4).
How many pairs of ribs are there?
12
What are the 3 types of ribs?
-True Ribs (pair 1-7)
-False Ribs (Pairs 8-10)
-Floating Ribs (pair 11-12)
What is the structure of a typical rib?
long, flat, and twisted containing a head, neck, tubercle, shaft (body), and angle (where the shaft is bent sharply and anteriorly)
What does the typical head of a rib articulate with?
The bodies of two thoracic vertebrae
What is the common name for sternum?
the breastbone
What is the sternum and what are the 3 parts of it?
It makes up the anterior portion of the thoracic cage, and it is made up of the following:
-Manubrium (articulates with rib #1)
-Body (articulates with ribs #2-7)
-The xiphoid process
What is the thoracic cage made up of?
thoracic vertebrae posteriorly, ribs laterally, and the sternum anteriorly
What is scoliosis?
it is a lateral curvature of the spine, forming what appears tto be an “s” shape of the vertebral column. Commonly known as “twisted disease”.
What is a function of the thoracic cage?
To protect the lungs
why would patients with scoliosis have breathing problems?
the lateral curvature places the thoracic cavity in an atypical position. This would cause for abnormal development and placement of the rubs and thoracic cavity. This form could compress the lungs, causing breathing problems.
