Neurovascular Structures of the Neck 1 Flashcards
What can think of the neck as?
We can think of the neck as a tube through which structures pass through to get to the trunk.
The upper parts of which passageways pass through the neck?
The upper parts of the respiratory and digestive passageways pass through the neck.
What direction do arterial and venous blood travel in in the neck?
Arterial blood travels upwards towards the head and the neck and venous blood travels downwards through the veins.
Aside from arteries and veins what else travels through the neck?
Cranial nerves that leave the brain will pass through foramina in the base of the skull and then they will also run down the neck.
What are 2 important functions of the neck?
Stability and mobility. Neck needs a strong musculoskeletal framework and it also has to be mobile.
How is stability and mobility of the neck achieved?
It is achieved by the 7 cervical vertebrae.
How do pairs of spinal nerves leave the cervical vertebrae?
They leave through the intervertebral foramen.
How many pairs of cervical spinal nerves do we have?
There are 8 pairs instead of 7.
Why are there 8 and not 7 pairs of cervical vertebrae?
Because the first of these pairs leaves leaves the column above the 1st cervical vertebrae.
What do the first 4 cervical spinal nerves supply?
They supply several neck muscles and are involved in cutaneous sensation in the neck.
What do the lower pairs of cervical spinal nerves supply?
They join the brachial plexus and run into the axilla and onwards to supply the upper limb.
Posteriorly what is the cervical vertebral column surrounded by?
There is a thick extensor mass.
Why must the extensor mass on the back of the neck be particularly powerful?
Because in the upright position the head falls against the chest at rest therefore you need a strong extensor mass to maintain the upright position of the head.
What are the prevertebral flexor muscles on the front of the cervical column like?
They are rather weak because in the upright position they are aided by gravity.
Aside from the flexor and extensor muscles what other sets of muscles does the cervical column give rise to?
It gives rise to muscles that suspend the scapula on the back of the rib cage and to another set of muscles that run down the first 2 ribs at the thoracic ribs – these are the scalene muscles.
What are all of the muscle groups of the cervical column surrounded by?
They are covered by fascia which is especially well defined over the prevertebral muscles. In front of the prevertebral muscles it is called prevertebral fascia.
What is the ligamentum nuchae?
This is a thick bit of the prevertebral fascia in the midline posteriorly between the extensor muscles.
How many major compartments are there in the neck?
2 - the anterior compartment and the posterior compartment.
What does the anterior compartment consist of?
It transmits the upper parts of the respiratory and digestive tracts which are the trachea and the oesophagus as well as other neurovascular structures.
What does the posterior compartment consist of?
It consists of the cervical vertebral column and its surrounding musculature.
What are the anterior and posterior compartments enclosed by on the outside of the sheath?
They are enclosed by a sheath of investing or deep cervical fascia which covers the anterior and posterior compartments like a stocking.
Where do neurovascular structures and lymph nodes lie?
They lie on either side of the structures in the anterior compartment
What type of gland is the thyroid gland?
It is an endocrine gland.
Where does the thyroid lie?
The thyroid gland straddles the neurovascular structures and the lymph nodes that lie on either side of the anterior compartment. The thyroid gland lies across the root of the neck.
What are the foramina that are present in the cranial base from front to back?
- foramen ovale
- smaller foramen spinosum
- neat round entrance to the carotid canal
- irregular jugular foramen between the temporal and occipital bones
- stylomastoid foramen between the styloid and mastoid process
- anterior condylar foramen
Where is anterior condylar foramen?
In line with the 1st cervical vertebrae in the base of the skull, just above the occipital condyle.
What is the anterior condylar foramen also called?
It is also called the hypoglossal canal.
What is the hole at the root of the neck?
This is the superior aperture of the thorax or the thoracic inlet.
What are the boundaries of the superior aperture of the thorax?
- first thoracic vertebrae
- first 2 ribs
- manubrium
What passes through the superior aperture of the thorax?
- airway
- oesophagus
- vessels
- nerves
What are 2 of the branches of the aorta?
- brachiocephalic artery – RIGHT
- common carotid artery – LEFT
What happens to the brachiocephalic artery before it ascends through the superior aperture of the thorax?
It divides.
What is one of the branches of the brachiocephalic artery?
The right common carotid artery.
How do the left and the right common carotid arteries ascend the neck?
They ascend on the side of the midline tubes.
What happens to the common carotid arteries at the level of the upper border of the thyroid cartilage?
They bifurcate into the interal and external carotid arteries.
What ist he internal carotid artery destined to supply?
It is destined to supply the brain.
On its way to the base of the skull, does the internal carotid artery give off any branch?
No it doesnt give off any branches to the neck on the way to the skull.
How does the internal carotid artery enter the cranial cavity?
It enters the cranial cavity by passing through the carotid canal.
Where does the internal carotid artery emerge?
It emerges close to the pituitary fossa.
What does the external carotid artery supply?
It supplies much of the neck, face and scalp.