- Blood Supply to the Heart
- Arterial Supply
- Common carotid Artery Anatomy - Origin , Course , Relations , Branches , Clinical anatomy - USMLE
- Blood supply of head and neck pdf file
- Venous Drainage
- Vishram Singh Anatomy PDF Book
- Head and neck anatomy
- Vishram Singh Anatomy Free PDF Download
- Presentation Description
This article shall explore the anatomy of this arterial system — its anatomical course, branches, and clinical correlations. Fig 1.
Blood Supply to the Heart
Note how the left common carotid and subclavian arteries arise directly from the arch of aorta. We shall start at the origin of the carotid arteries. The right common carotid artery arises from a bifurcation of the brachiocephalic trunk the right subclavian artery is the other branch. This bifurcation occurs roughly at the level of the right sternoclavicular joint.
The left common carotid artery branches directly from the arch of aorta.
The left and right common carotid arteries ascend up the neck, lateral to the trachea and the oesophagus. They do not give off any branches in the neck. This bifurcation occurs in an anatomical area known as the carotid triangle.
The common carotid and internal carotid are slightly dilated here, this area is known as the carotid sinus , and is important in detecting and regulating blood pressure.
Common carotid Artery Anatomy - Origin , Course , Relations , Branches , Clinical anatomy - USMLE
The carotid sinus is a dilated portion of the common carotid and internal carotid arteries. The baroreceptors detect stretch as a measure of blood pressure.
Blood supply of head and neck pdf file
In some people, the baroreceptors are hypersensitive to stretch. In these patients, external pressure on the carotid sinus can cause slowing of the heart rate and a decrease in blood pressure.
The brain becomes underperfused, and syncope results. In such patients, checking the pulse at the carotid triangle is not advised. External to the carotid sinus, there is a cluster of nervous cells , called the carotid body. These act as peripheral chemoreceptors ; detecting the O2 content of the blood, and relaying this information to the brain to regulate breathing rate.
The external carotid artery supplies the areas of the head and neck external to the cranium. The facial, maxillary and superficial temporal arteries are the major branches of note. The maxillary artery supplies the deep structures of the face, while the facial and superficial temporal arteries generally supply superficial areas of the face. Injuries to the scalp can cause excessive bleeding for various reasons:.
Note the maxillary artery before it disappears into the pterygopalatine fossa, to supply the deep structures of the face. The middle meningeal artery is a branch of the maxillary artery. It is unique as it supplies some intracranial structures remember, the external carotid artery and its branches usually supply extra-cranial structures. The middle meningeal artery supplies the skull and the dura mater the outer membranous layer covering the brain. Blood will then collect in between the dura mater and the skull, causing a dangerous increase in intra-cranial pressure.
This is known as an extradural haematoma.
Note the pterion, a weak point of the skull, where the anterior middle meningeal artery is at risk of damage. Within the cranial cavity, the internal carotid artery supplies:.
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The swelling at the bifurcation of the common carotid arteries, the carotid sinus, produces turbulent blood flow. This increases the risk of atheroma formation in this area, with the internal carotid more susceptible than the others. Atherosclerotic thickening of the tunica intima of these arteries will reduce blood flow to the brain , resulting in the variety of neurological symptoms; headache, dizziness, muscular weakness.
If blood flow is completely occluded, a cerebral ischaemia stroke results. If atherosclerosis of the carotid arteries is suspected, a Doppler study can be used to assess the severity of any thickening. In severe cases, the artery can be opened, and the atheromatous tunica intima removed. This procedure is called a carotid endarterectomy.
Head and neck anatomy
The right and left vertebral arteries arise from the subclavian arteries, medial to the anterior scalene muscle. The vertebral arteries enter the cranial cavity via the foramen magnum , and converge. They then give rise to the basilar arteries, which supply the brain. The vertebral arteries supply no branches to the neck, or extra-cranial structures.
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The neck is supplied by arteries other than the carotids. From this trunk, several vessels arise, which go on to supply the neck. Once you've finished editing, click 'Submit for Review', and your changes will be reviewed by our team before publishing on the site. Cookies help us deliver the best experience to all our users. The find out more about our cookies, click here. By TeachMeSeries Ltd Clinical Relevance: Carotid Sinus Hypersensitivity The carotid sinus is a dilated portion of the common carotid and internal carotid arteries.
The numerous anastomoses formed by the arteries produce a very densely vascularised area. Deep lacerations can involve the epicranial aponeurosis , which is worsened by the opposing pulls of the occipital and frontalis muscles. Clinical Relevance: Extradural Haematoma The middle meningeal artery is a branch of the maxillary artery. Clinical Relevance: Atherosclerosis of the Carotid Arteries The swelling at the bifurcation of the common carotid arteries, the carotid sinus, produces turbulent blood flow.
Other Arteries of the Neck The neck is supplied by arteries other than the carotids. This vessel supplies the posterior prevertebral muscles. It crosses the base of the carotid triangle, and supplies the trapezius and rhomboid muscles.