+ All Categories
Home > Documents > Circle Willis

Circle Willis

Date post: 04-Apr-2018
Category:
Upload: shazada-khan
View: 253 times
Download: 0 times
Share this document with a friend

of 42

Transcript
  • 7/29/2019 Circle Willis

    1/42

    1www.similima.com

  • 7/29/2019 Circle Willis

    2/42

    2www.similima.com

  • 7/29/2019 Circle Willis

    3/42

    Introduction.Introduction.

    Aorta arise from the left ventricle.

    It has ascending aorta

    -arch of aorta.

    -descending aorta.

    3www.similima.com

  • 7/29/2019 Circle Willis

    4/42

    4www.similima.com

  • 7/29/2019 Circle Willis

    5/42

    Vertebral artery.

    Internal thoracic artery.

    Thyrocervical trunk. Costocervical trunk.

    Dorsal scapular artery.

    5

    www.similima.com

  • 7/29/2019 Circle Willis

    6/42

    6www.similima.com

  • 7/29/2019 Circle Willis

    7/427www.similima.com

  • 7/29/2019 Circle Willis

    8/42

    Left CCA begins in the thorax in front of the

    trachea ,at the center of manubrium sterni.Right begins in the neck starts behind the

    right sternoclavicular joint. It runs upwards with in the carotid sheath.Lies in front of the 4 cervical transverse

    processes.At the level of thyroid cartilage it is divided

    in to ECA,ICA.

    8www.similima.com

  • 7/29/2019 Circle Willis

    9/429www.similima.com

  • 7/29/2019 Circle Willis

    10/42

    Carotid sinus-baroreceptors. Carotid body- chemoreceptors.

    10www.similima.com

  • 7/29/2019 Circle Willis

    11/42

    It begins at the level of theupper border of the thyroid

    cartilage.End in the cranial cavity by

    supplying the brain.

    11www.similima.com

  • 7/29/2019 Circle Willis

    12/42

    Cervical part- no branches. Petrous part-cortico tympanicbranch.

    -Pterigiod branch. cavernous part- cavernous branches

    -superior andinferior hyophyseal branches.

    12www.similima.com

  • 7/29/2019 Circle Willis

    13/42

    Cerebral part.-opthalmic

    branch

    Anterior cerebral.Middle cerebral.

    posterior communicating

    branch.

    Anterior choroidal

    branch.

    13www.similima.com

  • 7/29/2019 Circle Willis

    14/42

    Circle of willis is formedby the

    vertebral artery . internal carotid artery.

    14www.similima.com

  • 7/29/2019 Circle Willis

    15/42

    15www.similima.com

  • 7/29/2019 Circle Willis

    16/42

    It runs forwards to reachthe longitudinal fissures

    separating the cerebralhemisphere.

    The arteries lies in closetogether and united to eachother by ant.

    communicatin branch. 16www.similima.com

  • 7/29/2019 Circle Willis

    17/42

    It lies laterally in thedepth of the stem of the

    lateral sulcus.

    17www.similima.com

  • 7/29/2019 Circle Willis

    18/42

    It runs backwards andanatomies with the

    posterior cerebral artery.

    18www.similima.com

  • 7/29/2019 Circle Willis

    19/42

    Formed by the union ofright and left vertebral

    arteries.It divide in to right and

    left posterior cerebralarteries.

    19www.similima.com

  • 7/29/2019 Circle Willis

    20/42

    Anterior , middle , posterior cerebralarteries give rise to cortical andcentral arteries.

    Cortical supplies the cortex. Central branches antero -medial,antero lateral, postero -medial,postero -lateral dip deep to the

    cerebrum and supplies the structuresdeep to it.

    20www.similima.com

  • 7/29/2019 Circle Willis

    21/42

    21www.similima.com

  • 7/29/2019 Circle Willis

    22/42

    22www.similima.com

  • 7/29/2019 Circle Willis

    23/42

    Anterior, middleposterior cerebralarteries.

    23www.similima.com

  • 7/29/2019 Circle Willis

    24/42

    24www.similima.com

  • 7/29/2019 Circle Willis

    25/42

    Greater part of superolateral surface issupplied by middle cerebral artery.

    A strip of 2cm wide along the

    superomedial border extending fromthe frontal pole to the parito occipitalsulcus is supplied by anterior cerebral

    artery. The area belonging to the occipitallobe, inferior temporal gyrus-

    posterior cerebral artery. 25www.similima.com

  • 7/29/2019 Circle Willis

    26/42

    Medial surface is by anterior cerebralartery.

    Area belonging to occipital lobe

    posterior cerebral artery. Lateral part of the orbital surface middle cerebral artery.

    Tentorial surface PCA. Temporal lobe MCA.

    26www.similima.com

  • 7/29/2019 Circle Willis

    27/42

    Main somatic motor andsensory area-MCA.

    Except leg-ACA.Auditory area-MCA.Visual area-PCA.

    27www.similima.com

  • 7/29/2019 Circle Willis

    28/42

    Due to anastomosis-equalises

    the pressure on both sides.Blood brain barrier.End artery.

    28www.similima.com

  • 7/29/2019 Circle Willis

    29/42

    The concept of the blood brainbarrier was first introduced byPaul Ehrlich.

    The blood- brain barrier islocated in endothelial cells ofcapillaries of the brain.

    29www.similima.com

  • 7/29/2019 Circle Willis

    30/42

    30www.similima.com

  • 7/29/2019 Circle Willis

    31/42

    The mechanism for maintaining thisbarrier function lies in the capillarynetwork supplying blood to the

    brain. Ion concentration levels inplasma may fluctuate abruptly. Theblood- brain barrier protects the

    brain against surging fluctuations inion concentrations.

    31www.similima.com

  • 7/29/2019 Circle Willis

    32/42

    32www.similima.com

  • 7/29/2019 Circle Willis

    33/42

    1. Brain endothelial cells are joined by tightjunctions of high electrical resistanceproviding an effective barrier againstmolecules.

    2. In peripheral endothelial cells there isgood transcellular movement of molecules.There is no such movement in brainendothelial cells.

    3. Brain capillaries are in contact with footprocesses of astrocytes which essentiallyseparate the capillaries from the neurones.

    33www.similima.com

  • 7/29/2019 Circle Willis

    34/42

    34www.similima.com

  • 7/29/2019 Circle Willis

    35/42

    Cerebro vascular disease. Cerebral infarction.

    Intra cerebral hemorrhage.

    35www.similima.com

  • 7/29/2019 Circle Willis

    36/42

    36www.similima.com

  • 7/29/2019 Circle Willis

    37/42

    37www.similima.com

  • 7/29/2019 Circle Willis

    38/42

    38www.similima.com

  • 7/29/2019 Circle Willis

    39/42

    Synthesis repertory. Head apoplexy. Head anoxia , cerebral. Head- anemia, brain of. Head-cerebral hemorrhage. Head-thrombosis. Generalities-paralysis after. Chest aneurysm of arteries.

    39www.similima.com

  • 7/29/2019 Circle Willis

    40/42

    40www.similima.com

  • 7/29/2019 Circle Willis

    41/42

    Brain.

    41www.similima.com

  • 7/29/2019 Circle Willis

    42/42


Recommended