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RxPG :: View topic - Artery  
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Author Message

Mahendrakb
Aim AIPGE 2014

artery
oesophagus... inferior thyroid
branch of descendibg thoracic aorta
left gastric

UNANSWERED: Clinical: Which torch to use Bright white or dull yellow

takdumadum
Aim MCh

Blood Supply of Thyroid

The arterial supply to the thyroid gland consists of four main arteries, two superior and two inferior. The superior thyroid artery is the first branch of the external carotid artery and arises immediately above the bifurcation of the common carotid artery. The superior thyroid artery courses medially onto the surface of the inferior pharyngeal constrictor muscle and enters the apex of the superior pole. As the superior thyroid artery proceeds medially, it is adjacent to the external branch of the superior laryngeal nerve, and thus care must be taken to not damage it when controlling the artery.

The inferior thyroid artery takes its origin from the thyrocervical trunk. This artery ascends into the neck on either side behind the carotid sheath and then arches medially and enters the thyroid gland posteriorly, usually near the ligament of Berry. There is generally no direct arterial supply to the thyroid inferiorly. However, a thyroidea ima artery may be present in less than 5% of patients and usually arise directly from the innominate artery or from the aorta.

The inferior thyroid artery has important anatomic relationships. The recurrent laryngeal nerve is usually directly adjacent (in either an anterior or posterior position) to the inferior thyroid artery, within 1 cm of its entrance into the larynx. Careful dissection of the artery in this case is mandatory and cannot be completed until knowledge of the position of the recurrent laryngeal nerve is absolute. Additionally, the inferior thyroid artery almost always supplies both the superior and inferior parathyroid glands, and care must be taken to evaluate the parathyroids after division of the inferior thyroid artery.

Three pairs of venous systems drain the thyroid. Superior venous drainage is immediately adjacent to the superior arteries and joins the internal jugular vein at the level of the carotid bifurcation. Middle thyroid veins exist in more than half of patients and course immediately laterally into the internal jugular vein. The inferior thyroid veins are usually two or three in number and descend directly from the lower pole of the gland into the innominate and brachiocephalic veins. These veins often descend into the tail of the thymus gland.


takdumadum
Aim MCh

Blood Supply of thyroid

The arterial supply to the thyroid gland consists of four main arteries, two superior and two inferior. The superior thyroid artery is the first branch of the external carotid artery and arises immediately above the bifurcation of the common carotid artery. The superior thyroid artery courses medially onto the surface of the inferior pharyngeal constrictor muscle and enters the apex of the superior pole. As the superior thyroid artery proceeds medially, it is adjacent to the external branch of the superior laryngeal nerve, and thus care must be taken to not damage it when controlling the artery.

The inferior thyroid artery takes its origin from the thyrocervical trunk. This artery ascends into the neck on either side behind the carotid sheath and then arches medially and enters the thyroid gland posteriorly, usually near the ligament of Berry. There is generally no direct arterial supply to the thyroid inferiorly. However, a thyroidea ima artery may be present in less than 5% of patients and usually arise directly from the innominate artery or from the aorta.

The inferior thyroid artery has important anatomic relationships. The recurrent laryngeal nerve is usually directly adjacent (in either an anterior or posterior position) to the inferior thyroid artery, within 1 cm of its entrance into the larynx. Careful dissection of the artery in this case is mandatory and cannot be completed until knowledge of the position of the recurrent laryngeal nerve is absolute. Additionally, the inferior thyroid artery almost always supplies both the superior and inferior parathyroid glands, and care must be taken to evaluate the parathyroids after division of the inferior thyroid artery.

Three pairs of venous systems drain the thyroid. Superior venous drainage is immediately adjacent to the superior arteries and joins the internal jugular vein at the level of the carotid bifurcation. Middle thyroid veins exist in more than half of patients and course immediately laterally into the internal jugular vein. The inferior thyroid veins are usually two or three in number and descend directly from the lower pole of the gland into the innominate and brachiocephalic veins. These veins often descend into the tail of the thymus gland.


takdumadum
Aim MCh

ANATOMY of parathyroid

There are usually four parathyroid glands, which lie on the posterior surface of the thyroid. The superior glands are normally located on the posteromedial aspect of the thyroid near the tracheoesophageal groove, whereas the inferior parathyroids are more widely distributed in the region below the inferior thyroid artery ( Fig. 37-2 ). Common sites for ectopic parathyroids are the thyrothymic ligament, superior thyroid poles, tracheoesophageal groove, retroesophageal space, and carotid sheath ( Fig. 37-3 ).[16] The percentage of individuals with supernumerary glands varies in published series from 2.5% to 22%.[17] The average weight of a normal parathyroid gland is 35 to 40 mg, and in adults its color turns to yellow as the fat content increases. The inferior parathyroids originate from the third branchial pouch, whereas the superior parathyroids descend from the fourth branchial pouch. Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation. The glands are made up of chief and oxyphil cells, as well as fibrovascular stroma and adipose tissue.

Anatomic relationship of a left superior parathyroid adenoma to nearby structures, including the recurrent laryngeal nerve, the carotid sheath, and its blood supply from the inferior thyroid artery. Aberrantly located parathyroid glands can be found behind the esophagus, as well as within the carotid sheath, the thymus, and the mediastinum.

Possible locations of enlarged parathyroid glands in the neck and superior mediastinum with the use of an anteroposterior projection (A) and a lateral projection (B).


Primary HPT can be produced by three different pathologic lesions. A parathyroid adenoma is a benign encapsulated neoplasm that is responsible for 80% to 90% of cases. It usually affects a single gland, but 2% to 5% of patients with primary HPT have adenomas in two glands (double adenomas). Hyperplasia is a proliferation of parenchymal cells that affects all the parathyroid glands; it accounts for 10% to 15% of cases of primary HPT and all cases of secondary HPT. The majority of patients with primary HPT caused by multigland hyperplasia have sporadic disease. It is also associated with multiple endocrine neoplasia (MEN) type 1 (primary HPT combined with lesions of the pancreas and pituitary) and type 2A (primary HPT, medullary thyroid cancer, and pheochromocytoma) syndromes. Parathyroid carcinoma is a slow-growing, invasive neoplasm of parenchymal cells that is responsible for less than 1% of cases of primary HPT. Although fibrosis and mitotic activity are common, they are not specific for malignancy. The diagnosis of carcinoma is restricted to tumors that show invasion of blood vessels, perineural spaces, soft tissues, the thyroid gland or other adjacent structures, or to tumors with documented metastases. It is often difficult for the pathologist to make this diagnosis, especially if there is only a frozen section analysis of a resected parathyroid gland.


takdumadum
Aim MCh

ANATOMY of parathyroid

There are usually four parathyroid glands, which lie on the posterior surface of the thyroid. The superior glands are normally located on the posteromedial aspect of the thyroid near the tracheoesophageal groove, whereas the inferior parathyroids are more widely distributed in the region below the inferior thyroid artery ( Fig. 37-2 ). Common sites for ectopic parathyroids are the thyrothymic ligament, superior thyroid poles, tracheoesophageal groove, retroesophageal space, and carotid sheath ( Fig. 37-3 ).[16] The percentage of individuals with supernumerary glands varies in published series from 2.5% to 22%.[17] The average weight of a normal parathyroid gland is 35 to 40 mg, and in adults its color turns to yellow as the fat content increases. The inferior parathyroids originate from the third branchial pouch, whereas the superior parathyroids descend from the fourth branchial pouch. Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation. The glands are made up of chief and oxyphil cells, as well as fibrovascular stroma and adipose tissue.

Anatomic relationship of a left superior parathyroid adenoma to nearby structures, including the recurrent laryngeal nerve, the carotid sheath, and its blood supply from the inferior thyroid artery. Aberrantly located parathyroid glands can be found behind the esophagus, as well as within the carotid sheath, the thymus, and the mediastinum.

Possible locations of enlarged parathyroid glands in the neck and superior mediastinum with the use of an anteroposterior projection (A) and a lateral projection (B).


Primary HPT can be produced by three different pathologic lesions. A parathyroid adenoma is a benign encapsulated neoplasm that is responsible for 80% to 90% of cases. It usually affects a single gland, but 2% to 5% of patients with primary HPT have adenomas in two glands (double adenomas). Hyperplasia is a proliferation of parenchymal cells that affects all the parathyroid glands; it accounts for 10% to 15% of cases of primary HPT and all cases of secondary HPT. The majority of patients with primary HPT caused by multigland hyperplasia have sporadic disease. It is also associated with multiple endocrine neoplasia (MEN) type 1 (primary HPT combined with lesions of the pancreas and pituitary) and type 2A (primary HPT, medullary thyroid cancer, and pheochromocytoma) syndromes. Parathyroid carcinoma is a slow-growing, invasive neoplasm of parenchymal cells that is responsible for less than 1% of cases of primary HPT. Although fibrosis and mitotic activity are common, they are not specific for malignancy. The diagnosis of carcinoma is restricted to tumors that show invasion of blood vessels, perineural spaces, soft tissues, the thyroid gland or other adjacent structures, or to tumors with documented metastases. It is often difficult for the pathologist to make this diagnosis, especially if there is only a frozen section analysis of a resected parathyroid gland.


takdumadum
Aim MCh

ANATOMY of parathyroid

There are usually four parathyroid glands, which lie on the posterior surface of the thyroid. The superior glands are normally located on the posteromedial aspect of the thyroid near the tracheoesophageal groove, whereas the inferior parathyroids are more widely distributed in the region below the inferior thyroid artery ( Fig. 37-2 ). Common sites for ectopic parathyroids are the thyrothymic ligament, superior thyroid poles, tracheoesophageal groove, retroesophageal space, and carotid sheath ( Fig. 37-3 ).[16] The percentage of individuals with supernumerary glands varies in published series from 2.5% to 22%.[17] The average weight of a normal parathyroid gland is 35 to 40 mg, and in adults its color turns to yellow as the fat content increases. The inferior parathyroids originate from the third branchial pouch, whereas the superior parathyroids descend from the fourth branchial pouch. Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation. The glands are made up of chief and oxyphil cells, as well as fibrovascular stroma and adipose tissue.

Anatomic relationship of a left superior parathyroid adenoma to nearby structures, including the recurrent laryngeal nerve, the carotid sheath, and its blood supply from the inferior thyroid artery. Aberrantly located parathyroid glands can be found behind the esophagus, as well as within the carotid sheath, the thymus, and the mediastinum.

Possible locations of enlarged parathyroid glands in the neck and superior mediastinum with the use of an anteroposterior projection (A) and a lateral projection (B).


Primary HPT can be produced by three different pathologic lesions. A parathyroid adenoma is a benign encapsulated neoplasm that is responsible for 80% to 90% of cases. It usually affects a single gland, but 2% to 5% of patients with primary HPT have adenomas in two glands (double adenomas). Hyperplasia is a proliferation of parenchymal cells that affects all the parathyroid glands; it accounts for 10% to 15% of cases of primary HPT and all cases of secondary HPT. The majority of patients with primary HPT caused by multigland hyperplasia have sporadic disease. It is also associated with multiple endocrine neoplasia (MEN) type 1 (primary HPT combined with lesions of the pancreas and pituitary) and type 2A (primary HPT, medullary thyroid cancer, and pheochromocytoma) syndromes. Parathyroid carcinoma is a slow-growing, invasive neoplasm of parenchymal cells that is responsible for less than 1% of cases of primary HPT. Although fibrosis and mitotic activity are common, they are not specific for malignancy. The diagnosis of carcinoma is restricted to tumors that show invasion of blood vessels, perineural spaces, soft tissues, the thyroid gland or other adjacent structures, or to tumors with documented metastases. It is often difficult for the pathologist to make this diagnosis, especially if there is only a frozen section analysis of a resected parathyroid gland.


takdumadum
Aim MCh

Blood Supply of Thyroid

The arterial supply to the thyroid gland consists of four main arteries, two superior and two inferior. The superior thyroid artery is the first branch of the external carotid artery and arises immediately above the bifurcation of the common carotid artery. The superior thyroid artery courses medially onto the surface of the inferior pharyngeal constrictor muscle and enters the apex of the superior pole. As the superior thyroid artery proceeds medially, it is adjacent to the external branch of the superior laryngeal nerve, and thus care must be taken to not damage it when controlling the artery.

The inferior thyroid artery takes its origin from the thyrocervical trunk. This artery ascends into the neck on either side behind the carotid sheath and then arches medially and enters the thyroid gland posteriorly, usually near the ligament of Berry. There is generally no direct arterial supply to the thyroid inferiorly. However, a thyroidea ima artery may be present in less than 5% of patients and usually arise directly from the innominate artery or from the aorta.

The inferior thyroid artery has important anatomic relationships. The recurrent laryngeal nerve is usually directly adjacent (in either an anterior or posterior position) to the inferior thyroid artery, within 1 cm of its entrance into the larynx. Careful dissection of the artery in this case is mandatory and cannot be completed until knowledge of the position of the recurrent laryngeal nerve is absolute. Additionally, the inferior thyroid artery almost always supplies both the superior and inferior parathyroid glands, and care must be taken to evaluate the parathyroids after division of the inferior thyroid artery.

Three pairs of venous systems drain the thyroid. Superior venous drainage is immediately adjacent to the superior arteries and joins the internal jugular vein at the level of the carotid bifurcation. Middle thyroid veins exist in more than half of patients and course immediately laterally into the internal jugular vein. The inferior thyroid veins are usually two or three in number and descend directly from the lower pole of the gland into the innominate and brachiocephalic veins. These veins often descend into the tail of the thymus gland.


takdumadum
Aim MCh

Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation.


takdumadum
Aim MCh

Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation.


takdumadum
Aim MCh

Vasculature of adrenal gland

Knowledge of the macroscopic vascular anatomy of the adrenal glands is essential for proper surgical management. It is important to conceptualize that although the arterial supply is diffuse, the venous drainage of each gland is usually solitary. The arterial supply arises from three distinct vessels: the superior adrenal arteries from the inferior phrenic arteries, the small middle adrenal arteries from the juxtaceliac aorta, and the inferior adrenal arteries from the renal arteries. Of these, the inferior is the most prominent and is commonly a single identifiable vessel. The left adrenal vein is approximately 2 cm long and drains into the left renal vein after joining the inferior phrenic vein. The right adrenal vein is typically as short as it is wide (0.5 cm) and drains directly into the vena cava. This configuration presents a surgical challenge that will be revisited in the technical section of this chapter. In up to 20% of individuals, the right adrenal vein may drain into an accessory right hepatic vein or into the vena cava at or near the confluence of such a vein.[4] Vigilance toward this variant and others ( Fig. 39-3 ) may reduce the likelihood of intraoperative venous hemorrhage during right adrenalectomy.


takdumadum
Aim MCh

Vasculature of adrenal gland

Knowledge of the macroscopic vascular anatomy of the adrenal glands is essential for proper surgical management. It is important to conceptualize that although the arterial supply is diffuse, the venous drainage of each gland is usually solitary. The arterial supply arises from three distinct vessels: the superior adrenal arteries from the inferior phrenic arteries, the small middle adrenal arteries from the juxtaceliac aorta, and the inferior adrenal arteries from the renal arteries. Of these, the inferior is the most prominent and is commonly a single identifiable vessel. The left adrenal vein is approximately 2 cm long and drains into the left renal vein after joining the inferior phrenic vein. The right adrenal vein is typically as short as it is wide (0.5 cm) and drains directly into the vena cava. This configuration presents a surgical challenge that will be revisited in the technical section of this chapter. In up to 20% of individuals, the right adrenal vein may drain into an accessory right hepatic vein or into the vena cava at or near the confluence of such a vein.[4] Vigilance toward this variant and others ( Fig. 39-3 ) may reduce the likelihood of intraoperative venous hemorrhage during right adrenalectomy.
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,,


takdumadum
Aim MCh

ANATOMY of parathyroid

There are usually four parathyroid glands, which lie on the posterior surface of the thyroid. The superior glands are normally located on the posteromedial aspect of the thyroid near the tracheoesophageal groove, whereas the inferior parathyroids are more widely distributed in the region below the inferior thyroid artery ( Fig. 37-2 ). Common sites for ectopic parathyroids are the thyrothymic ligament, superior thyroid poles, tracheoesophageal groove, retroesophageal space, and carotid sheath ( Fig. 37-3 ).[16] The percentage of individuals with supernumerary glands varies in published series from 2.5% to 22%.[17] The average weight of a normal parathyroid gland is 35 to 40 mg, and in adults its color turns to yellow as the fat content increases. The inferior parathyroids originate from the third branchial pouch, whereas the superior parathyroids descend from the fourth branchial pouch. Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation. The glands are made up of chief and oxyphil cells, as well as fibrovascular stroma and adipose tissue.

Anatomic relationship of a left superior parathyroid adenoma to nearby structures, including the recurrent laryngeal nerve, the carotid sheath, and its blood supply from the inferior thyroid artery. Aberrantly located parathyroid glands can be found behind the esophagus, as well as within the carotid sheath, the thymus, and the mediastinum.

Possible locations of enlarged parathyroid glands in the neck and superior mediastinum with the use of an anteroposterior projection (A) and a lateral projection (B).


Primary HPT can be produced by three different pathologic lesions. A parathyroid adenoma is a benign encapsulated neoplasm that is responsible for 80% to 90% of cases. It usually affects a single gland, but 2% to 5% of patients with primary HPT have adenomas in two glands (double adenomas). Hyperplasia is a proliferation of parenchymal cells that affects all the parathyroid glands; it accounts for 10% to 15% of cases of primary HPT and all cases of secondary HPT. The majority of patients with primary HPT caused by multigland hyperplasia have sporadic disease. It is also associated with multiple endocrine neoplasia (MEN) type 1 (primary HPT combined with lesions of the pancreas and pituitary) and type 2A (primary HPT, medullary thyroid cancer, and pheochromocytoma) syndromes. Parathyroid carcinoma is a slow-growing, invasive neoplasm of parenchymal cells that is responsible for less than 1% of cases of primary HPT. Although fibrosis and mitotic activity are common, they are not specific for malignancy. The diagnosis of carcinoma is restricted to tumors that show invasion of blood vessels, perineural spaces, soft tissues, the thyroid gland or other adjacent structures, or to tumors with documented metastases. It is often difficult for the pathologist to make this diagnosis, especially if there is only a frozen section analysis of a resected parathyroid gland.


takdumadum
Aim MCh

Blood Supply of thyroid

The arterial supply to the thyroid gland consists of four main arteries, two superior and two inferior. The superior thyroid artery is the first branch of the external carotid artery and arises immediately above the bifurcation of the common carotid artery. The superior thyroid artery courses medially onto the surface of the inferior pharyngeal constrictor muscle and enters the apex of the superior pole. As the superior thyroid artery proceeds medially, it is adjacent to the external branch of the superior laryngeal nerve, and thus care must be taken to not damage it when controlling the artery.

The inferior thyroid artery takes its origin from the thyrocervical trunk. This artery ascends into the neck on either side behind the carotid sheath and then arches medially and enters the thyroid gland posteriorly, usually near the ligament of Berry. There is generally no direct arterial supply to the thyroid inferiorly. However, a thyroidea ima artery may be present in less than 5% of patients and usually arise directly from the innominate artery or from the aorta.

The inferior thyroid artery has important anatomic relationships. The recurrent laryngeal nerve is usually directly adjacent (in either an anterior or posterior position) to the inferior thyroid artery, within 1 cm of its entrance into the larynx. Careful dissection of the artery in this case is mandatory and cannot be completed until knowledge of the position of the recurrent laryngeal nerve is absolute. Additionally, the inferior thyroid artery almost always supplies both the superior and inferior parathyroid glands, and care must be taken to evaluate the parathyroids after division of the inferior thyroid artery.

Three pairs of venous systems drain the thyroid. Superior venous drainage is immediately adjacent to the superior arteries and joins the internal jugular vein at the level of the carotid bifurcation. Middle thyroid veins exist in more than half of patients and course immediately laterally into the internal jugular vein. The inferior thyroid veins are usually two or three in number and descend directly from the lower pole of the gland into the innominate and brachiocephalic veins. These veins often descend into the tail of the thymus gland.


takdumadum
Aim MCh

Both the superior and inferior parathyroid glands receive their blood supply from the inferior thyroid artery in 80% of cases. Each parathyroid gland generally receives a single end-artery blood supply that is vulnerable to injury during surgical manipulation.

Essentials of Medical Pharmacology By KD Tripathi
Extensively revised and updated chapters to include recently introduced drugs, published information and therapeutic practices.
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