Thursday, March 31, 2011
Blood Supply to the Head and Neck
The Internal Carotid Artery (p. 804)
Click here for a diagram of the external carotid artery and its branches.
Superior Thyroid Artery (p. 805)
The Internal Jugular Vein (pp. 806-7)
Click here for a diagram on the internal jugular vein and its tributaries.
AORTIC ARCH
The arch of the aorta or the transverse aorta is the part of the aorta that begins at the level of the upper border of the second sternocostal articulation
OR
Arch of The Aorta - Cardiovascular System
- Most arteries in the anterior cervical triangle arise from the common carotid artery or one of the branches of the external carotid artery. for blood supply to the brain.
- Most veins in the anterior cervical triangle are tributaries of the large internal jugular vein. for the venous sinuses of the dura mater.
- The right common carotid artery begins at the bifurcation of the brachiocephalic trunk, posterior to the right sternoclavicular joint.
- The left common carotid artery begins arises from the arch of the aorta and ascends into the neck, posterior to the left sternoclavicular joint.
- Each common carotid artery ascends into the neck within the carotid sheath to the level of the superior border of the thyroid cartilage.
- Here it terminates by dividing into the internal and external carotid arteries.
- This is the direct continuation of the common carotid artery and it has no branches in the neck.
- It supplies structures inside the skull.
- The internal carotid arteries are two of the four main arteries that supply blood to the brain.
- Each artery arises from the common carotid at the level of the superior border of the thyroid cartilage.
- It then passes superiorly, almost in a vertical plane, to enter the carotid canal in the petrous part of the temporal bone.
- During its course through the neck, the internal carotid artery lies on the longus capitis muscle and the sympathetic trunk.
- The vagus nerve (CN X) lies posterolateral to it.
- The internal carotid artery enters the middle cranial fossa beside the dorsum sellae of the sphenoid bone.
- Within the cranial cavity, the internal carotid artery and its branches supply the hypophysis cerebri (pituitary gland), the orbit, and most of the supratentorial part of the brain.
Click here for a diagram of the external carotid artery and its branches.
- This vessel begins at the bifurcation of the common carotid, at the level of the superior border of the thyroid cartilage.
- It supplies structures external to the skull.
- The external carotid artery runs posterosuperiorly to the region between the neck of the mandible and the lobule of the auricle.
- It terminates by dividing into two branches, the maxillary and superficial temporal arteries.
- The stems of most of the six branches of the external carotid artery are in the carotid triangle.
- This is the most inferior of the 3 anterior branches of the external carotid.
- It arises close to the origin of the vessel, just inferior to the greater horn of the hyoid.
- The superior thyroid artery runs anteroinferiorly, deep to the infrahyoid muscles and gives off the superior laryngeal artery. This artery pierces the thyrohyoid membrane in company with the internal laryngeal nerve and supplies the larynx.
- This arises from the external carotid artery as it lies on the middle constrictor muscle of the pharynx.
- It arches superoanteriorly, about 5 mm superior to the tip of the greater horn of the hyoid bone, and then passes deep to the hypoglossal nerve, the stylohyoid muscle, and the posterior belly of digastric muscle.
- It disappears deep to the hyoglossus muscle.
- At the anterior border of this muscle, it turns superiorly and ends by becoming the deep lingual artery.
- This arises from the carotid artery either, in common with the lingual artery, or immediately superior to it.
- In the neck the facial artery gives off its important tonsillar branch and branches to the palate and submandibular gland.
- The facial artery then passes superiorly under the cover of the digastric and stylohyoid muscles and the angle of the mandible.
- The facial artery hooks around the inferior border of the mandible and enters the face. Here the pulsation of this artery can be felt (anterior to the masseter muscle).
- Click here to go the facial artery in the face.
- This is the 1st or 2nd branch of the external carotid artery.
- This small vessel ascends on the pharynx, deep to the internal carotid artery.
- It sends branches to the pharynx, prevertebral muscles, middle ear and meninges.
- This arises from the posterior surface of the external carotid near the level of the facial artery.
- It passes posteriorly along the inferior border of the posterior belly of digastric.
- It ends in the posterior part of the scalp.
- During its course, it is superficial to the internal carotid artery and three cranial nerves (CN IX, CN X and CN XI).
- This is a small posterior branch of the external carotid artery.
- It arises from it at the superior border of the posterior belly of the digastric muscle.
- It ascends posteriorly to the external acoustic meatus and supplies adjacent muscles, the parotid gland, the facial nerve, structures in the temporal bone, the auricle, and thescalp.
Click here for a diagram on the internal jugular vein and its tributaries.
- This is usually the largest vein in the neck.
- The internal jugular vein drains blood from the brain and superficial parts of the face and neck.
- Its course corresponds to a line drawn from a point immediately inferior to the external acoustic meatus to the medial end of the clavicle.
- The dilation at its origin is called the superior bulb of the internal jugular vein.
- From here it runs inferiorly through the neck in the carotid sheath.
- The internal jugular vein leaves the anterior triangle of the neck by passing deep to the SCM muscle.
- Posterior to the sternal end of the clavicle, it unites with the subclavian vein to form the brachiocephalic vein.
- Near its termination is the inferior bulb of the jugular vein contains a bicuspid valve similar to that of the subclavian vein.
AORTIC ARCH
The arch of the aorta or the transverse aorta is the part of the aorta that begins at the level of the upper border of the second sternocostal articulation
OR
Arch of The Aorta - Cardiovascular System
Chris Coons: The Bearded Marxist
by Stephan Tawney on September 18, 2010
I’ve spent some time slamming Christine O’Donnell so it’s only fair I point out the biggest problem with her opponent: He once proudly admitted to being a Marxist. Yes, really.
An article Democrat Chris Coons wrote for his college newspaper may not go over so well in corporation-friendly Delaware, where he already faces an uphill battle for Vice President Joe Biden’s old Senate seat.The title? “Chris Coons: The Making of a Bearded Marxist.”
Again, that’s the title that Coons himself gave the article.
In the article, Coons, then 21 years old and about to graduate from Amherst College, chronicled his transformation from a sheltered, conservative-minded college student who had worked for former GOP Delaware Sen. William Roth and had campaigned for Ronald Reagan in 1980 into a cynical young adult who was distrustful of American power and willing to question the American notion of free enterprise.
What happened? He visited Kenya — coincidentally Obama’s fatherland.
The source of his conversion, Coons wrote, was a trip to Kenya he took during the spring semester of his junior year—a time away from America, he wrote, that served as a “catalyst” in altering a conservative political outlook that he was growing increasingly uncomfortable with.“My friends now joke that something about Kenya, maybe the strange diet, or the tropical sun, changed my personality; Africa to them seems a catalytic converter that takes in clean-shaven, clear-thinking Americans and sends back bearded Marxists,” Coons wrote, noting that at one time he had been a “proud founding member of the Amherst College Republicans.”“[I]t is only too easy to return from Africa glad to be American and smugly thankful for our wealth and freedom,” added Coons. “Instead, Amherst had taught me to question, so in turn I questioned Amherst, and America.”
Coons went on:
In one passage of the article, Coons explains how in the months leading up to the trip abroad “leftists” on campus and college professors had begun to “challenge the basic assumptions” he had formed about America.A course on cultural anthropology, noted Coons, had “undermined the accepted value of progress and the cultural superiority of the West,” while a class on the Vietnam War led him to “suspect…that the ideal of America as a ‘beacon of freedom and justice, providing hope for the world’ was not exactly based in reality.”
And this is why, no matter how nutty Christine O’Donnell may have sounded in her past, I’ll still support her over Chris Coons.
I’d rather have a somewhat-nutty defender of the free market and America than a far-leftist guy who proudly admitted to being a “bearded Marxist” who says he discovered that America is not a beacon of freedom and justice.
3 Responses to “Chris Coons: The Bearded Marxist”
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20. September 2010 at 9:21 pm
14. October 2010 at 9:17 am
14. October 2010 at 9:23 am