(2.1) Vasculatures Flashcards
What are the branches of External Carotid Arteries? Where do they largely supply?
- Superior Thyroid
- Ascending Pharyngeal
- Lingual
- Facial
- Occipital
- Posterior Auricular
- Maxillary
- Superficial Temporal
- Supply face & extracranial structures
What is the largest blood supply to the Skull? Through which foramen does it travel through? Where is this artery most at risk of injury?
- Middle Meningeal Artery, a br. of Maxillary
- Through Foramen Spinosum in Sphenoid Bone
- Pterion, may lead to Extradural Haematoma
What is an Extradural Haematoma? How may it occur?
- Collection of blood between the cranium & periosteal layer of dura mater
- Laceration to Middle meningeal artery, e.g. fracture at Pterion
What are the supplies to intracranial structures? Through which foramina these arteries go through?
- Internal Carotid Artery via Carotid Canal in Temporal bone
- Vertebral A via Foramen Transversaria -> Basilar Artery via Foramen Magnum in Occipital Bone
What are the blood supplies to the Scalp?
- External Carotid -> Occipital & Posterior Auricular & Superficial Temporal
- Internal Carotid -> Opthalmic -> Supra-trochlear & Supra-orbital
Where is the Carotid pulse taken?
- Between larynx & middle 1/3 sternocleidomastoid
Where does the Right and Left Common Carotid Arteries each arise from? Where do they split?
- R: from Brachiocephalic Trunk
- L: from Aortic Arch
- Split at C4, within Carotid Sheath, only the Internal Carotid A carries on within the sheath
Where can Temporal pulse be felt?
Superior to Zygomatic Arch of Temporal Bone
Why is the Left common carotid artery longer than the right one?
Left originates from Aortic Arch, whereas Right originates from Brachiocephalic Trunk
Where is the Carotid Sinus? What structure is located at it? What is their function?
- Dilated area of Internal Carotid Artery, just above the common carotid artery splits
- Baroreceptors detect pressure within it
Through which nerve does the Baroreceptor sends its feedback?
Glossopharyngeal Nerve
Where is the Carotid Body? What structure is located at it? What is their function?
- Deep in medial side of Bifurication
- Peripheral chemoreceptors detect pO2 & pCO2 here
What structures travel through the Parotid Gland?
- Maxillary & Superficial Temporal A
- Facial N
- Retromandibular V
Where does the Vertebral Artery arise? Through which foramina does it travel through?
- Subclavian artery
- Foramen Transversaria in Transverse processes of Cervical vertebrae -> becomes Basilar artery -> Foramen Magnum of Occipital bone
Where do Internal, External and Anterior Jugular veins arise from?
Subclavian veins which is arised from Brachiocephalic veins
Where does the veins in neck drain into?
Anterior Jugular Veins
What are Dural Venous Sinuses? Name some of them.
- Endothelial lined spaces between Epiosteal & Meningeal layers of Dura Mater, they are valveless
- Superior Sagittal
- Inferior Sagittal
- Cavernous
- Transverse
- Sigmoid
Where is a common site of the Carotid Artery to form Atheroma? What can it result in?
- Bifurcation of the Carotid Artery due to turbulent flow
- Stenosis or Thrombosis can cause stroke/transient ischaemic shock
How might you be able to differentiate the Internal & External arteries from an x ray?
Internal artery is lack of branches in the neck, as it ascends into supply intracranial structures
What do the Facial & Superior Opthalmic Veins drain into at the medial angle of the eye?
Cavernous Sinus
What structure do the deep facial veins drain into?
Pterygoid Plexus
Suggest why an infection in deep Pterygoid region be dangerous to the eye?
- Pterygoid plexus infected -> pus accumulation -> direct increase in pressure of Opthalmic V
- Pterygoid -> Deep V -> Cavernous sinus Thrombophlebitis
- Both cause paralysis of Extraocular muscles
What nerves may be in danger during a carotid arteriogram puncture?
- Vagus & its branches
- Sympathetic chain
Suggest some possible causes of an infection of Cavernous sinus (3). What may be the complications (2)?
- Laceration of dangerous area (upper lip to nasal bridge)
- Laceration underneath the orbit area
- Both result in Thrombophlebitis of Facial Vein -> Superior Opthalmic V -> Cavernous Sinus
Complications
- Infections spread to surrounding nerves (NC III, IV, Vi, Vii, VI)
- Thrombophlebitis of Cavernous DURAL sinus -> intracranium -> Meningitis
Where is the Sternal Angle, and what anatomical landmarks does it make?
- Anteriorly: Manubriosternal joint (2nd rib)
- Posteriorly: T4/5 Intervertebral disc
- Separates Ascending Aorta, Aortic Arch, Descending Aorta
- Separates superior & inferior Mediasternum
- Marks Tracheal bifurcation
- Marks end of Azygous system
- Marks Thymus gland
