The Arterial and Venous Blood Supply of Head, Neck, and Upper Limbs - Research Paper Example

? 16 November The arterial and venous blood supply of head, neck, and upper limbs: This paper is primarily based on contemplating the phenomenally important arterial and venous blood supply to head, neck, and upper limbs. Mentioning the curving aortic arch here would be a worthwhile effort as it is the aortic arch basically which connects the ascending aorta with the descending aorta and through which three major elastic arteries come off namely brachiocephalic trunk which further divides into the right common carotid and right subclavian arteries, left common carotid artery, and left subclavian artery. These arterial branches are mentioned here to be discussed later in the paper because they are basically responsible for supplying blood to the head, neck, and upper limbs. There is a pair of subclavian arteries in the thoracic region. Each subclavian artery before leaving the thoracic region splits into three other major arteries namely thyrocervical trunk, internal thoracic artery, and vertebral artery. In the head, neck, and upper limbs, there is superficial venous return in addition to the deep venous return as there are superficial veins in addition to the deep veins accompanying deep arteries. Head: Brain stands in contrast to other body parts in respect that it is extremely vulnerable to any shortcomings in its blood supply. In the larger picture, it is the carotid arteries which are responsible for supplying oxygenated blood to the head and brain. As mentioned earlier, the carotid arteries arising from the arch of aorta become the arterial blood supply of head and brain. Just at the bas of ear, each carotid artery gives off branches called internal and external carotid arteries. Both internal and external carotid arteries individually become the arterial blood supply of different body parts. While the external carotid supplies blood to the face, skull, scalp, and meninges, the internal carotid is responsible for supplying arterial blood to the brain. So the brain is supplied blood by the internal carotid and its network of branches while rest of the head is supplied by the external carotid and its branches. The internal carotid typically divides into the intracranial part which gains access to the brain through the base of the skull and the extracranial part which gives off branches to further help in the formation of Circle of Willis. The branches involved in the formation of the Circle of Willis are the middle, anterior, and posterior cerebral arteries. The vertebral arteries not only supply the medulla but they also fuse to form the basilar artery which further splits into the posterior inferior cerebral artery and the superior cerebral artery (Blood Supply). In the head there are superficial veins which drain blood from cerebrum into sinuses and the deep veins draining blood from the brain which also ultimately drain into the dural sinuses. These dural sinuses exist in the dura matter of the brain. The dural sinuses include superior sagittal sinus, transverse sinus, and sigmoid sinus. As the blood collected from the brain drains into the sigmoid sinus, it later travels outside the cranium through the jugular foramen to become the internal jugular vein. The vertebral vein on the other hand accompanies the vertebral artery, collects blood from the rear of the skull, and exits through transverse foramina. The superficial veins draining blood from the superficial tissues of the head include the facial, temporal, and maxillary veins. Now while the temporal and maxillary veins drain into the external jugular vein accompanying the external jugular artery, the facial vein drains into the internal jugular vein. Further the external jugular drains into the subclavian vein while the internal jugular joins the subclavian vein to later drain into the brachiocephalic vein. Neck: The left and right common carotid arteries not only supply the oxygenated blood to the head but they form the arterial blood source of the neck. The right common carotid enters the neck, the starting point of which is the brachiocephalic trunk as already mentioned while the left originates from the aortic arch. These arteries divide in the neck region to form the external and internal carotid arteries and this bifurcation occurs at the level of the fourth cervical vertebra (Manbachi et al.). There are two parts of the left common carotid artery namely the thoracic part and the cervical part which supplies the neck. The cervical parts of both common carotids highly resemble each other. Quite a narrow interval separates the two common carotids at the base of the neck to make a place for the trachea so as to adjust it but at the superior level in the neck these arteries are separated by the thyroid gland, larynx, and pharynx. While both branches namely the external and internal carotid arteries travel upwards in the neck, the internal carotid takes a deeper or more internal route while the external carotid remains more superficial and stays close to the skin. The subclavian arteries are also visible lying superficially on the right side of the neck. The internal carotid reaches into the skull to supply the brain through the carotid canal while the external carotid gives off myriad branches making a network responsible for supplying both neck and face. There is also internal jugular vein in addition to the carotid artery in the carotid sheath. The superior and middle thyroid veins drain into the internal jugular vein. The common carotid artery in the neck is in relation to many structures like esophagus, trachea, thyroid gland, and the inferior thyroid artery. The superior and middle thyroid veins cross this artery at different levels while anterior jugular vein crosses it just above the clavicle. The inferior thyroid artery also crosses it from behind at the lower level and travels upwards to be in relation with the pharynx and larynx. At the lower part of the neck on the right side, the right internal jugular vein travels away from the common carotid while the left internal jugular vein on the left side approaches towards it and often crosses over the lower part of the artery. The common carotid supplies a lot of muscles and structures. While at the lower part of the neck it is very deeply seated, it becomes more superficial in the upper part of its journey through the neck. In the lower part of the neck, it is covered by the superficial fascia, the platysma muscle, the sternocleidomastoid muscle, and the hyoid muscles. In the upper part of its course, however, it is only covered by the superficial fascia, the platysma, medial part of SCM muscle, and deep cervical fasica. The veins of the neck which drain blood from the head and face are named the external jugular, internal jugular, anterior jugular, and posterior external jugular veins. The ext. jug. receives venous blood from the cranium, the post. ext. jug. drains blood from the skin and superficial muscles in the superior and back part of the neck, the ant. jug. at the lower part of the neck opens into the ext. jug., and the int. jug. drains blood from the brain, face, and the neck. Upper limbs: The main artery of the upper limb in the region of axilla starts off its journey as the axillary artery and is a continuation of the subclavian artery. At the border of the subscapularis muscle, this artery gives off posterior and anterior humeral arteries to supply the posterior muscles in the shoulder part. The humeral arteries later meet at the level of the humerus. The axillary artery then becomes the brachial artery as soon as it moves beyond the axilla and reaches the teres major muscle in the upper arm. Here it also gives off deep seated branches which supply the posterior part of the arm. In the forearm near the distal part of the cubital fossa, the brachial artery divides into the radial and ulnar arteries. While the radial artery is responsible for supplying the posterior region of the forearm, the ulnar supplies the anterior aspect. Together the two arteries later anastamose once having reached the hand region to develop the superficial and deep palmar arches. Most of the arteries supplying the hand lie superficially. The radial artery mainly supplies the thumb and the lateral part of the index finger while the ulnar artery contributes to supplying blood to the rest of the fingers and the medial side of the index finger, the lateral being supplied by the radial artery. In context of venous drainage of the upper limb, the cephalic and basilic veins are worth mentioning as these form the main veins charged with the duty of draining blood from the upper limb. The point to remember is that both of these veins run superficially in the arm. The median cubital vein in the medial cubital fossa lies most superficially in the upper limb region. The antero-lateral aspect of the arm is crosses over by the cephalic vein which travels down it while the basilic vein passes down the arm more on the medial side. The basilica vein is actually deep seated initially and is a continuation of the axillary vein which is seated deep inside the axilla the shoulder part but it emerges and travels down the rest of the arm superficially at the level of the lower border of the teres major. Both cephalic and basilica veins are joined together at the level of the medical cubital fossa by the medial cubital vein (Standring). Works cited: “Blood Supply.” 21 Jan. 2002. Web. 16 Nov. 2012. Manbachi, Amir, Hoi, Yiemeng, Wasserman, Bruce A., Lakatta, Edward G., and Steinman, David A. “On the shape of the common carotid artery with implications for blood velocity profiles.” Physiological Measurement 32.12 (2011): 1885–97. Print. Standring, S. Gray’s anatomy: The anatomical basis of clinical practice. 39th ed. London: Elsevier Churchill Livingstone, 2005. Print. Read More