Chapter 2 Blood vessels of Head and Neck Flashcards
Describe features of arteries
- Oxygenated blood
- Arteries usually have a smaller diameter than veins
- Thicker wall means arteries are paler in colour (dark colour of veins is due to contained blood being partly visible through thin wall).
- Blood flows in arteries under pressure from the heart
- Apart from the origins of aorta & pulmonary artery, arteries do not have & do not need valves.
- Large and medium sized arteries are named
- Smaller arteries are usually described as “branches of…”
- Arteries are often accompanied by a vein or veins.
- Veins are usually more superficial so that slow venous return is not compressed by overlying artery.
- Artery & accompanying vein oftne have similar veins
Describe the two types of nerves associated with arteries
Muscle contraction (vasomotor) - penetrate wall, mostly sympathetic (accompanied by sensory fibres)
Hitchhikers
- Remain outside adventitia (outer layer of wall)
- Can be parasympathetic, sympathetic, sensory or a combination
Small lymph vessels form a plexus on the walls of many large arteries.
True
Define anastomosis
Anastomosis is a join between two vessels that allows by passing of the usual route - means that they can influence/feed into each others territories.
Describe arterial anastomosis
Connection between two arteries rather than the usual pattern of arteries of decreasing size emptying into network of capillaries & from there into a network or veins of increasing size.
What can arterial anastomosis mean?
- One artery opening directly into another
- Two arteries coming together to form a single artery e.g. Vertebral arteries forming the basilar artery inside skull
- Two arteries linked by a small connecting artery
Define ‘arterio-venous anastomosis’
E.g. in skin where the capillary bed may be partly bypassed. Play a role in thermoregulation
Define ‘veno-venous anastomosis’
Dorsal venous arch of the foot (improved venous return under gravity)
‘Lymph vessels’ have numerous anastomoses - facilitate return of lymph.
True
Define ‘endothelium’
A single layer of flattened epithelial cells which forms the innermost lining of all vessels - blood and lymph.
Arch of the aorta is at the level of ?
Manubriosternal joint
Define manubriosternal joint
This is the joint between the upper two bones of the three which form the sternum. The upper is the manubrium & the middle one is the body of the manubrium.
Why is manubriosternal joint useful?
This joint is an useful surface landmark as it can be usually be palpated externally as a horizontal ridge - called the sternal angle.
Which branches and arteries branch/arise from the arch of aorta?
Braciocephalic trunk, left common carotid and left subclavian artery
Brachiocephalic trunk divides at level of right sternoclavicular joint into _____________________.
Right common carotid and subclavian.
Both common carotids divide at level of top of thyroid cartilage of larynx into __________________.
Internal and external carotids.
Carotids are on either side of trachea, thyroid gland, larynx, pharynx and deep to sternocleidomastoid.
True
What is the carotid sheath?
It encloses both common and internal carotids (medial) along with internal jugular (anterior or anterolateral) and vagus (posterior).
What is ansa cervicalis?
A nerve loop arising from cervical spinal nerves and supplying muscles of anterolateral neck is in or just anterior to the carotid sheath.
Sympathetic trunk is anterior to carotid sheath and ansa cervicalis.
False, it is posterior to ansa cervicalis and carotid sheath.
Carotid sheath consists of?
A sheet of dense fascia enclosed in looser adjacent fascia.
List branches of external carotid artery
- Superior thyroid artery
- Lingual artery
- Facial artery
- Ascending pharangeal artery
- Occipital artery
- Posterior auricular artery
Which landmarks to use to identify branches of external carotid artery?
- Sternocleidomastoid
- Infrahyoid muscles
- Digastric
- Styloid muscles
- Submandibular gland
- Thyroid gland
Superior thyroid artery arises ___ to SCM, crosses the anterior triangle (______), and runs ___ to infrahyoid muscles (________) to supply thyroid gland (thyroid gland is also supplied with a pair of _______________ - a branch of subclavian artery).
Deep, anterior to SCM, deep, attached to inferior surface of hyoid bone, inferior thyroid arteries from thyrocervical trunk
Lingual artery passes deep to ______________ and to submandibular gland. Then medial to posterior border of ________ (a muscle at the side of the root of the tongue ) and into _______.
intermediate tendon of digastric muscle, hyoglossus, postero-inferior tongue.
Facial artery loops posterior to _____ and crosses ________ to run obliquely across face to ________.
Submandibular gland, body of mandible, medial corner of eye.
Branches of facial artery include?
Tonsilar artery, submental artery and inferior and superior labial arteries.
Facial artery supplies?
Soft palate, tonsils, submandibular and sublingual glands plus adjacent muscles and superficial face.
Variations of facial artery include:
Lingual and facial arteries often arising as a common trunk with the superior thyroid artery.
Describe ascending pharangeal artery
Small posterior branch arising near origin of external carotid.
Ascending pharyngeal artery passes deep to?
Styloid msucles
Ascending pharyngeal artery has an extracranial branch that supplies?
Upper pharynx, temporomandibular joint, tympanic cavity
Ascending pharyngeal artery also has an intracranial branch which passes through _____ to supply ____.
foramen mangum, meninges
Occipital artery runs deep to ________, passes behind mastoid to supply _______ and ____________.
Posterior belly of digastric, sternocleidomastoid, muscles of skin of occiput
Occipital artery grooves ______________ medial to mastoid/digastric notch.
Temporal bone
Posterior auricular artery has a posterior branch which arises above ___________ and supplies __________.
posterior belly of digastric, auricle and occipital region
How do you distinguish ascending pharyngeal artery?
Arises well below posterior belly of digastric and close to origin of external carotid.
How do you distinguish occipital branch/artery?
Passes deep to posterior belly of digastric, usually has a branch to SCM (usually a stump), can also be located posterior to external ear where it is fairly superficial.
How do you distinguish posterior auricular artery
Above level of posterior belly of digastric
External carotid divides in parotid gland to form?
Two terminal branches - superficial temporal and maxillary arteries.
What other structures pass through the parotid?
Retromandibular vein and facial nerve.
Which landmark muscles to help you identify branches of the superficial temporal artery:
Orbicularis oculi - extensive thin muscle surrounding eye, temporalis
Important branches of superficial temporal artery?
- Transverse facial artery
- Zygomatico-orbital artery
Transverse facial artery arises from ________ and passes ______.
Superficial temporal artery, passes below zygomatic arch and passes anteriorly to parotid and duct.
Zygomatico-orbital artery arises from ________ and passes to __________ (________).
Arises from the superficial temporal artery above zygomatic arch, passes to orbicularis oculi (muscle of facial expression)