The Axial Skeleton. Flashcards
Define a foramina?
The plural of foramen.
Define the thyoid apparatus?
The bones that suspend the tongue and the larynx.
Define the osteoclan?
A product of bones that helps to regulate bone formation and protects against obesity, glucose intolerance and diabetes mellitus.
What are the 6 components of the axial skeleton?
The skull.
The hyoid apparatus.
The cartilage of the larynx.
Vertebral column.
Ribs.
Sternum.
What 3 functions do the bones of the axial skeleton used for?
Movement.
Support.
Protection.
How does the axial skeleton aid with movement?
Many of the skeletal muscles that allow for the movement of the limbs are attached to the axial skeleton.
How does the axial skeleton aid with support?
Many of these bones help to provide the framework that supports the body.
E.g. The ribcage supports the thoracic wall.
How does the axial skeleton aid with protection?
The bones help to protect many important organs within the body.
E.g. The skull protects the brain.
The bones that make up the skull can be divided into what 2 categories?
Those that make up the face and those that make up the cranium.
What are the 5 cranial bones that make up the skull?
The frontal bone.
The inter-parietal bone.
The temporal bone.
The occipital bone.
The parietal bone.
What are the 4 bones that make up the facial region of the skull?
Maxillary bone.
Parts of the frontal bone.
Incisive bones.
Nasal bone.
What is the hyoid apparatus?
A collection of bones that helps to stabilise the tongue and the larynx.
Where is the hyoid apparatus located relative to the skull?
Ventrally to the skull and the tongue.
What are the 5 bones that make up the hyoid apparatus?
The basihyoid.
The epihyoid.
The thyrohyoid.
The keratohyoid.
The stylohyoid.
What is the cartilage of the larynx also known as?
As the laryngeal cartilages.
Where is the cartilage of the larynx located relative to the hyoid apparatus?
Caudally.
What are the 4 different strucutres that make up the cartilage of the larynx?
The unpaired epiglottic cartilage.
The unpaired thyroid cartilage.
The paired arytenoid cartilage.
The unpaired cricoid cartilage.
What is the vocal fold that is located in the larynx used for?
For vocalisation.
What are the 2 folds that are located in the larynx?
The vocal fold.
The vestibular fold.
What is the vestibular fold that is located in the larynx used for?
It allows air to enter the airway, but prevents food and drink from entering the airway.
Where is the laryngeal ventricle located in the larynx?
In the lateral wall (thyroid cartilage) of dogs, pigs and horses.
What can the paralysis of the structures that surround the laryngeal ventricle can lead to?
A clinical condition known as roaring.
How does the vestibular fold of the larynx function in a normal situation?
The structures will open allowing air to pass to the lungs.
How does the vestibular fold of the larynx function when it is paralysed?
The structures will not open as they should and breathing will sound very laboured.
How many bones are found in the vertebral column?
Around 50 irregular vertebrae, however the exact number is species dependent.
What is the function of the vertebral column?
To protect the spinal cord and the root of spinal nerves.
It also aids in supporting the head and as a point of attachment for various muscles.
How many groups are the vertebrae of the spinal column arranged into?
Into 5 different groups.
What are the groups of the vertebral column arranged by?
According to their location within the the vertebral column.
What are the groups in the vertebral column?
Going from cranial to caudal, these groups are;
Cervical.
Thoracic.
Lumbar.
Sacral.
Caudal.
What is the vertebral formula?
It is used to identify how many individual vertebrae are located within a vertebral group.
How is the vertebral formula applied?
The first letter of the group is used, followed by the number of vertebrae in that group.
E.g. If a cervical group consists of 6 vertebrae then it will be represented as C6.
What is the vertebral formula for a dog?
C7, T13, L7, S3 and Cd 20.
What are the 7 strucutres that individual vertebrae can contain?
The body.
The vertebral arch.
Transverse process.
Spinous process.
Articular process.
Accessory process.
Mamillary process.
Of the 7 vertebral features, which one is found on every single vertebra?
The vertebral arch.
What is the body of a vertebra?
The large chunk of bone found on the ventral side of a dogs spine.
Where is the body of the vertebra located relative to the spine?
Below the spinal cord.
What feature does the body of the vertebra in the thoracic region contain?
The costal fovea which serves as a point of attachment for the ribs.
Where on the dorsal vertebrae is the costal fovea located?
At the dorsal extremity.
Which vertebrae will attach to the ribs?
Only the thoracic vertebrae.
What does the body on all vertebrae serve as a point of attachment for?
The intervertebral discs.
Are the bodies of the vertebrae the same size all the way down the spine?
As the spine proceeds from a cranial to caudal direction, the bodies of the vertebrae will increase in size.
What are the pedicles of a vertebra?
The region of that attaches the ventral region of the body to the dorsal half of the spine.
What is the function of the pedicles?
To protect each side of the spinal cord.
Where are the lamina located on a vertebra?
The lamina makes up the dorsal half of the vertebral foramen.
It lies on each side of the spinous process and proceeds to the medial side of the 2 facet joints.
What is the function of the lamina in the spinal column?
To protect the dorsal side of the spinal cord.
What is the spinous process that is found on a vertebra?
A single spur of bone that projects out of the middle of the lamina.
How are the spinous processes of different vertebrae attached to each other?
Each spinous process is attached by ligaments to the spinous process that is above and below.
What is the transverse process on a vertebral bone?
2 spurs of bone that lie on each side of the spinous process and project out at 90 degrees to the spinous process.
How do the transverse processes attach to the vertebrae?
They attach ventrally to their respective pedicle and dorsally they attach to the facet joint.
What is the function of the transverse processes in vertebral bones?
It is used as a point of attachment for the muscles of the back.
What vertebrae will lack transverse processes?
The vertebrae of the neck.
Where are the 2 facet joints of each vertebrae located?
They lie laterally to each lamina and medially to each transverse process.
What is the job of the transverse process in the vertebrae?
To serve as a point of attachment for each vertebrae to attach to the vertebrae above and below it.
What is the facet that lies on the cranial side of the vertebra?
The superior articular facet.
What is the facet that lies on the caudal side of the vertebra?
The inferior articular facet.
Where is the articula process of the vertebrae located?
At the junction between the pedicle and the lamina.
What is the function of the articula process of the vertebrae?
To link 2 vertebrae together.
On the dog there is a cranial articular process and a caudal articular process on each vertebrae.
What vertebrae will the costal fovea feature on?
Only on the thoracic vertebrae.
What is the costal fovea of the vertebrae?
It is a small depression that is created by the articulation of the costal fovea with the ribs.
What is the vertebral foramen on a vertebrae?
It is where the spinal cord will run through the vertebra.
What surrounds the vertebral foramen?
The vertebral arch.
What is the difference between the vertebral canal and the vertebral foramen?
The vertebral foramen is where the spinal cord passes through single vertebra.
The vertebral canal is where the spinal cord passes through the length of the spine.
What is the intervertebral foramen?
An opening between the 2 pedicles and allows for nerves and blood vessels to exit the vertebral canal and travel to other areas of the body.
What is the difference between the accessory process and the mamillary process that may be located on some vertebrae?
The accessory process projects caudally in some vertebrae.
The mamillary process projects in the dorsal direction.
What is the accessory process on a vertebra?
A small spur of bone on the caudal region of each transverse process.
What vertebrae are the accessory processes located on?
From the vertebrae of the mid thoracic region to the 5th or 6th lumbar vertebrae.
What is the mamillary process?
A projection of bone that lies on the dorsal aspect of the transverse processes.
What vertebrae are the mamillary processes located on?
On the 2nd to 10th thoracic vertebrae where it serves as a point of muscle attachment.
How many cervical vertebrae are there on most mammals?
7.
What is the name of the 1st cervical vertebra?
The atlas.
What is the most notable feature of the atlas?
It does not contain a spinous process.
What are the 6 notable features that are located on the atlas vertebrae?
A modified articular process.
No spinous process.
A very small body.
A shelflike transverse process.
Transverse foramina.
Lateral and vertebral foramen.
What is the transverse foramina of the atlas?
A small opening that passes through the transverse process.
What is the transverse foramina of the atlas used for?
For nerves and blood vessels to pass through.
What aspect of the articular fovea will the atlas articulate with the occipital condyle of the skull?
The cranial aspect.
What is the atlanto-occiptal joint?
Where the occipital condyle of the skull articulates with the atlas vertebrae.
What kind of joint is the atlanto occipital joint?
A synovial joint.
What range of movement does the atlanto occipital joint have?
Flexion and extension.
Nodding of the head.
What articulation occurs at the caudal aspect of the atlas joint?
The atlantoaxial joint which joins the atlas and the axis together.
How does the atlas articulate with the 2nd cervical vertebrae?
It contains 2 shallow Glenoid cavities that articulate with the 2nd cervical vertebrae.
What is 2nd cranial vertebra known as?
The axis.
What kind of joint is the atlantoaxial joint?
A pivot joint which allows for a large range of movement.
What are the 2 major features of the axis?
An elongated spinous process.
The dens.
What kind of spinous process does the axis have?
An elongated spinous process
What is the dens of the axis?
A protrusion of bone that emerges cranially and is sometimes known as the ordontoid process.
What movements can be performed by the atlantoaxial joint?
Rotation.
Protraction.
Retraction.
Twisting.
Flexion.
Extension.
Abduction.
Adduction.
What are the middle 3 cervial vertebrae?
C3, C4 and C5.
What similarities do vertebrae C3-5 share?
A spinous process which increases in size from 3 to 5.
What direction does the spinous process proceed from the dog?
Dorsally.
Which vertebra contains the largest spinous process of all the cervical vertebrae?
The 7th.
How can the tranvserse process on cervical vertebrae C3-C5 be recognised?
By the fact that they have a 2 pronged transverse process.
What is the most recognisable aspect on cervical vertebrae C3-C5?
The presence of a transverse foramina which is a small hole that run through the base of the transverse process.
How many thoracic vertebrae are there?
13.
How can the throacic vertebrae be differentiated from the 7th cervical vertebrae?
By the fact that they have a much shorter body.
Which thoracic vertebrae contain a costal fovea?
1-10.
How do the spinous processes vary on the thoracic vertebrae?
The first 8 thoracic vertebrae have very long spinous processes.
After the 8th vertebrae these spinous processes will get progressively shorter.
What feature distinguishes the lumbar vertebrae from the thoracic vertebrae?
The lumbar vertebrae have a longer body.
How is the spinous process shaped on the lumbar vertebrae?
They have a broad, blunt spinous process.
How is the sacrum of the spinal cord formed?
From the fusion of the bodies of 3 separate vertebrae.
What vertebrae form the tail?
The caudal vertebrae.
What joints are formed between vertebrae in the spinal column?
Cartilaginous joints.
What movements do the cartiliginous joints of the spine allow for?
Small ranges of movement such as compression and stretching.
What joints are formed between the ribs and the sternum?
Cartilaginous joints.
What is the vertebral disc of the spinal cord?
A shock absorber that lies between each vertebra.
What are the 2 features that are found on the spinal disc?
The nucleus pulposus (middle).
The annulus fibrosis (exterior).
What is the nuchal ligament?
It runs caudally from the spinous process of the axis to the tip of the 1st thoracic vertebra.
What is the job of the nuchal ligament?
To hold the head onto the spine.
What is the supraspinous ligament?
It runs from the spinous process of the 1st thoracic vertebra to the spinous process on the 3rd coccygeal vertebra.
What is the job of the supraspinous ligament?
To prevent the abnormal separation of the spine during flexion of the vertebral column.
How many pairs of ribs do dogs have?
13 pairs.
What are the 2 regions on a rib?
A bony dorsal region and a cartilaginous ventral region
What are the 4 features found on the bony section of a rib?
The head.
The neck.
The tuberculum.
The body.
What section of the rib projects out of the spinal column?
The bony segment.
What section of the rib joins up with the sternum?
The cartilaginous section.
What is the location of the rib where the cartiliginous and bony sections of the rib meet?
The costal contrail junction.
How many segments is the sternum made up of?
8 individual segments called sternebrae.
What links the individual sternebrae together?
Intersernebral cartilage.
What is the 1st sternebra of the sternum known as?
The manubriam.
What is the most caudal sternebra of the sternum known as?
Xiphoid cartilage.
