Axial Skeleton Flashcards
What is the axial skeleton?
The central axis that keeps the body upright
What organs does the axial skeleton protect?
Brain Sense organs Spinal cord Heart Lungs
What does the axial skeleton consist of?
Skull
Vertebral column
Rib cage
What is a lateral view?
A view from the side
What does the skull consist of?
Tow groups of bones
What are the two groups of bones which make up the skull?
Facial
Cranial
What does the cranium consist of?
Eight flat bones
How are the cranial bones joined?
By serrated sutures
These are immovable
What is the function of the cranium?
To enclose the brain and protect it
How does the spinal cord pass through the cranium?
Through the foremen magnum
What is the foremen magnum?
The hole at the base of the skull through which the spinal cord passes
What structures exist on either side of the foremen magnum?
Articular condyles
What do the articular condyles do?
Articulate with the first cervical vertebra
What does it mean to articulate?
To move at or around a joint
What does the facial part of the skull consist of?
Fifteen irregular bones
What do the facial bones form?
Forehead Cheeks Nose Temples Jaws (upper and lower)
Can the facial bones move?
No, except for the lower jaw
What is another name for the upper jaw?
Maxilla
What is another name for the lower jaw?
Mandible
What is another for the cheekbones?
The zygomatic bones
What structures occur on the edges of the mandible and maxilla?
Teeth
How many permanent teeth does an adult human have?
Thirty-two
What is a dental formula?
The number, type and arrangement of teeth of a specific animal
What is the human dental formula?
- 1.2.3
- —— - 1.2.3
How does a dental formula work?
The top sequence of numbers represents half of the upper jaw
The bottom sequence of numbers represents half of the lower jaw
How do you work out how many teeth an animal has from the dental formula?
Add up the numbers in the upper half of the jaw (numbers on top)
Multiply this total by four
What does the dental formula of a human mean?
2.1.2.3 2 incisors 1 canine 2 premolars 3 molars
What does the vertebral column consist of?
Vertebrae joined together by ligaments
What is another name for the vertebral column?
Spine
How many vertebrae are there?
Thirty-three
Is the spine flexible?
To some extent, yes
How many types of vertebrae are there?
Five
What are the five types of vertebrae? (Name them from top to bottom)
Cervical Thoracic Lumbar Sacral Coccyx
How many vertebrae are in the cervical area?
Seven
How many vertebrae are in the thoracic section?
Twelve
How many vertebrae are in the lumbar section?
Five
How many vertebrae are in the sacral section?
Five
How many vertebrae are in the coccyx?
Four
What does an individual vertebra consist of?
Centrum Neural arch Processes Spinal canal Articular surfaces
What is the centrum?
The body of the vertebra
What is the neural arch?
The part of the vertebra that connects the centrum to the neural spine
What is a process? (On the vertebra)
An outgrowth
How many processes does a vertebra have?
Three
What is a neural spine?
One of the processes of a vertebra
What are the other two processes? (Of a vertebra)
Transverse processes
What does the neural spine look like?
An outgrowth which protrudes towards the back and slightly downwards
What do the transverse processes look like?
They extend to the sides
What is another name for the spinal canal?
The foramen
Where can the spinal canal be found?
Between the neural arch and the centrum
What does the foramen do?
Provides a pathway for the spinal cord
What do the articular surfaces do?
Articulate with the previous and successive vertebrae
In the case of the thoracic vertebrae, they also articulate with the ribs
What occurs between the vertebrae?
Cartilage discs
What kind of cartilage exists between the vertebrae?
Fibrous
What is the function of the fibrous cartilage discs?
To prevent friction and absorb shock
How do spinal nerves connect to the spinal cord?
Through small openings between consecutive vertebrae
What are true vertebrae?
Vertebral bones which are separate from one another
What are false vertebrae?
Vertebrae which are fused
Which vertebrae are true?
Cervical
Thoracic
Lumbar
Which vertebrae are false?
Sacral
Coccyx
What is visible when the spine is viewed from the side?
Four curvatures
How do the cervical vertebrae curve?
Towards the front
How do the thoracic vertebrae curve?
Towards the back
How do the lumbar vertebrae curve?
Towards the front
How do the sacral vertebrae curve?
Towards the back
How does the spine appear when viewed from the side?
S-shaped
Why is the spine s-shaped?
For flexibility
For shock absorption
For balance
What is the first cervical vertebra?
The atlas
What kind of movement does the atlas allow for?
The nodding motion of the head
What is the second cervical vertebra?
The axis
What kind of movement does the axis allows for?
The rotation of the skull
What are the functions of the vertebral column?
Supports the skull
Surrounds and protects the spinal cord
Provides a place of attachment for most of the appendicular skeleton
Provides a place of attachment for the back muscles
Provides flexibility and absorbs shock
What does the rib cage consist of?
Thoracic vertebrae
Ribs
Sternum
How many ribs are there?
Twelve pairs
So twenty four
What is the sternum?
A long, flat, dagger-shaped bone
Where can the sternum be found?
At the front of the rib cage
What are the ribs?
Narrow, flat, arched bones
What are all of the ribs attached to?
The thoracic vertebrae
What are the three types of ribs?
True
False
Floating
What are true ribs?
Ribs that attach directly to the sternum through cartilage
What are false ribs?
Ribs that are attached to the proceeding rib by cartilage
What are floating ribs?
They are not attached to anything in the front
Which ribs are true?
The first seven pairs
Which ribs are false?
The second three pairs
Which ribs are floating?
The remaining two pairs
What kind of cartilage exists in the rib cage?
Hyaline
What is the function of the rib cage?
Protects the organs in the thoracic cavity
Plays a role in breathing
What is the thoracic cavity?
The space created between the rib cage and the spine
Which organs exist in the thoracic cavity?
Lungs
Heart
How does the rib cage assist with breathing?
The movement of the rib cage increases the volume of the thoracic cavity
They provide a place of attachment for the intercostal muscles, which play a major role in this process
How does the skull rotate on the atlas?
The atlas rotates around a bony projection of the axis
