Blood supply Flashcards
What is arterial blood supply to the brain
What proportion is provided by each
What does the main supplier divide into
where do they supplies
The ophthalmic artery is a branch of what
What supplies the posterior portion
What do they unite to form
What is formed by anastomosis
What links anterior cerebral and posterior arter
The arterial blood supply to the brain is provided by the two internal carotid arteries (two thirds) and the two vertebral arteries (one third).
The internal carotid artery divides into the anterior and middle cerebral arteries that supply the anterior two thirds of the cerebral hemispheres. The ophthalmic artery is a branch of the internal carotid artery (not anterior cerebral artery).
The vertebral arteries unite to form the basilar artery, which supplies the brain stem and cerebellum. The basilar artery then divides into the two posterior cerebral arteries that supply the posterior one third of the cerebral hemispheres.
The circle of Willis is formed by anastomoses linking the carotid arterial system to the vertebrobasilar system.
The anterior communicating artery links the anterior cerebral arteries and the posterior communicating arteries link the vertebrobasilar system to the carotid system. This provides a collateral blood supply should one or more of the four extracranial arteries supplying the brain become diseased.
The arterial blood supply to the brain is provided by the two internal carotid arteries (two thirds) and the two vertebral arteries (one third).
The internal carotid artery divides into the anterior and middle cerebral arteries that supply the anterior two thirds of the cerebral hemispheres. The ophthalmic artery is a branch of the internal carotid artery (not anterior cerebral artery).
The vertebral arteries unite to form the basilar artery, which supplies the brain stem and cerebellum. The basilar artery then divides into the two posterior cerebral arteries that supply the posterior one third of the cerebral hemispheres.
The circle of Willis is formed by anastomoses linking the carotid arterial system to the vertebrobasilar system.
The anterior communicating artery links the anterior cerebral arteries and the posterior communicating arteries link the vertebrobasilar system to the carotid system. This provides a collateral blood supply should one or more of the four extracranial arteries supplying the brain become diseased.
Bronchial supply
BA branch what
BV comm with what
What delivers deoxy blood to alveoi
The bronchial arteries are branches of the descending aorta (not pulmonary arteries) and supply the bronchi, the lung connective tissue and the visceral pleura.
The bronchial veins communicate with the pulmonary veins and drain into the azygos and hemiazygos veins.
The terminal branches of the pulmonary arteries deliver deoxygenated blood to the alveoli (not oxygenated).
Following oxygenation the blood leaves the alveolar capillaries and drains into the tributaries of the pulmonary veins, which follow the intersegmental connective tissue septa to the lung root, thus there are a total of four (not two).
How many pair spinal roots
Wht is SC supply by
do they direct anastomosis
how many of each
what supply each side
There are 31 pairs of spinal roots from the spinal cord:
Eight cervical Twelve thoracic Five lumbar Five sacral and One coccygeal. The spinal cord is supplied by two posterior and one anterior spinal arteries which do not form a direct anastomosis at each spinal level. However caudally, at the conus medullaris, the anterior spinal artery anastomoses with both posterior spinal arteries.
The anterior spinal artery supplies the anterior two-thirds of the spinal cord and medulla. Disruption of the anterior spinal artery supply is characterised by ischaemia or infarction of motor tracts (corticospinal) and loss of pain and temperature sensation below the level of the lesion.
The posterior spinal arteries supply the posterior columns (posterior third of the spinal cord). Infarction of the posterior columns results in the loss of proprioceptive, vibration and two-point discrimination.
The spinal cord normally ends at the level of L1 or L2 in an adult and L3 in a newborn.
Vertebral arery
The vertebral artery winds around the superior part of the lateral mass of the atlas and pierces the posterior atlanto-occipital membrane, the dura mater and the arachnoid.
The right and left vertebral arteries unite at the caudal border of the pons to form the basilar artery.
Passes medially behind the lateral mass of the atlas
Is crossed anteriorly by the inferior thyroid artery
Pierces the dura mater
Most likely to be inj SC V CVC
The subclavian artery lies posterior to and partly above the subclavian vein and may be inadvertently cannulated in an attempt to cannulate the subclavian vein (3-4%).
This may be of serious consequence, as it is not possible to put pressure on the subclavian artery to arrest bleeding, given its anatomical position.
The apical pleura is inferior and caudal to the subclavian vein. Pleural puncture causing a pneumothorax is a recognised consequence of subclavian vein cannulation (1%).
Anterior spinal artery
arise where
unite where
what it supply
where does it anastamose and with what
Post spinal - arise where
where pass
what supply
How is this blood supply augmented
Atery adamkiewicz supply what
where does it arise
The anterior spinal arteries arise from the vertebral arteries (not carotids) and unite below the foramen magnum to form a single artery. This single artery (not paired) then supplies the pia matter and anterior two thirds of the spinal cord including the anterior and lateral columns (major motor tracts). It anastomoses with the posterior artery over the conus medullaris.
The posterior spinal arteries arise from the posterior inferior cerebellar arteries, which pass down the spinal cord but they do not unite. They supply the posterior one third of the spinal cord (including the major sensory tracts).
The blood supplied by the anterior and posterior spinal arteries is augmented by collateral radicular arteries, the most important being the branches of the posterior intercostals arteries at the sites of the cervical and lumbar cord enlargements.
The artery of Adamkiewicz (greater radicular artery) supplies blood to the anterior spinal artery and distal cord. It usually arises from an intercostals branch between T9 and T12 in 75% of patients
Subclavian vein relationships for injury
artery where
pleural
nerve?
ansa cervicalis
The subclavian artery lies inferior to the subclavian vein and may be inadvertently cannulated in an attempt to cannulate the subclavian vein.
This may be of serious consequence as it is not possible to put pressure on the subclavian artery to arrest bleeding given its anatomical position.
The apical pleura is inferior and caudal to the subclavian vein and pleural puncture, with or without pneumothorax, is a recognised consequence of subclavian vein cannulation.
The phrenic nerve passess posterior to the subclavian vein and phrenic nerve palsy is a rare complication of its cannulation.
The Ansa cervicalis is a network of nerve fibres originating from the cervical plexus (C1-C3) supplying geniohyoid and the infra hyoid muscles. its immediate anatomical relationship is with the internal jugular vein and common carotid artery in the anterior triangle of the neck.
IJV
Contin what
where begin
Trib from where
Course
RElations
which is shorter left or right
The internal jugular veins (IJV) are a continuation of the transverse sinuses (running in a groovealong the interior surface of the occipital bone) and then the sigmoid sinus (beneath the temporal bone), beginning in the jugular foramen, in the posterior compartment of the skull.
Tributaries:
The inferior petrosal sinus, the common facial, lingual, pharyngeal, superior and middle thyroid veins, and sometimes the occipital vein drain into the IJVs. The thoracic duct on the left side and the right lymphatic duct on the right side open into the angle of union of the internal jugular and subclavian veins.
Course:
At its origin it is somewhat dilated, the superior bulb. It runs down the side of the neck in a vertical direction, lying at first lateral to the internal carotid artery, and then lateral to the common carotid, and at the root of the neck unites with the subclavian vein to form the brachiocephalic (innominate vein). A little above its termination is a second dilatation, the inferior bulb.
Relations:
Above, it lies upon the rectus capitis lateralis, behind the internal carotid artery and the nerves passing through the jugular foramen. The vein and artery lie upon the same plane, the glossopharyngeal and hypoglossal nerves passing forward between them; the vagus descends between and behind the vein and the artery in the same sheath, and the accessory runs obliquely backward, superficial or deep to the vein.
The left IJV is generally shorter than the right, and each contains a pair of valves, which are placed about 2.5 cm above the termination of the vessel.
how is IJ sep from -sympathetic chain
What is IJ spatial relationship - symp chain
IJ commences where
What seperates IJ from inferior pterosal sinus
Does ant jug vein drain into EJV
The prevertebral fascia separates these structures. It lies anterolateral to the sympathetic chain.
The internal jugular vein commences at the jugular foramen in the posterior cranial fossa as the direct continuation of the sigmoid sinus.
The anterior jugular vein drains into the external jugular vein.
The 9th, 10th, and 11th cranial nerves separate the internal jugular vein from the inferior petrosal sinus.
