Circulatory System Generalities PDF

Gross Anatomy Dr. Esguerra Circulatory Aug. 23, 2012...

Gross Anatomy Dr. Esguerra Circulatory Aug. 23, 2012 System Generalities **we have included notes which are based on the defined objectives (module Systemic circulation given); if you would like to proceed directly with the things discussed by Dr. part of the cardiovascular system which carries oxygenated Esguerra only, please see Vessels of the Thorax on page 3.  blood away from the heart to the body, and returns deoxygenated blood back to the heart. GENERAL FEATURES OF VESSEL WALLS physiologic theory of circulation was first described by William - Blood vessels, irrespective of size, and with the exception of Harvey capillaries and venules The main trunks belonging to the systemic circulation 3 concentric layers (tunicae) o Celiac trunk intima (tunica intima) - innermost layer, main component, the o Superior mesenteric artery endothelium, lines the entire vascular tree o Inferior mesenteric artery o Common liacs media (tunica media) - made of muscle tissue, elastic fibers and Pulmonary circulation collagen, thickest layer in arteries, the media is absent in portion of the cardiovascular system which carries oxygen- capillaries and is comparatively thin in veins depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart adventitia (tunica adventitia) - outer coat of the vessel, and first proposed by Ibn al-Nafis, an Arab physician consists of connective tissue, nerves and vessel capillaries Blood flow of pulmonary circulation: superior and inferior vena cava  RA  tricuspid valve  RV  semilunar ARTERIES vs VEINS valve  pulmonary artery/trunk  lungs  pulmonary capillaries  pulmonary vein  LA  mitral valve  LV  aortic valve  aorta  Ateries Veins systemic circulation Deeply located Superficially located Portal circulation Thicker walls Thinner walls the pathway of blood flow from the GI tract and spleen to the Light Colored Collapsed liver via the portal vein and its tributaries Carries oxygenated blood Carries deoxygenated blood system of veins comprising the hepatic portal vein and its (except pulmonary arteries) (except pulmonary veins) tributaries. away from the heart towards the heart also called the hepatic portal circulation. Tunica media- thickest layer Tunica adventitia/externa - thickest layer POINTS OF PALPATION Blood spurts during injury Blood flows freely - Areas of the body where pulse can be palpated and counted Lumen: rounded Lumen: collapse Absence of clotted blood (in Clotted blood present (in cadavers) cadavers) CLASSIFICATION OF ARTERIES Large arteries aorta, brachiocephalic, common carotid, subclavian and common iliac arteries conduct blood to the medium-sized distributing arteries during systole, their elastic laminae are stretched and reduce blood pressure during diastole, the elastic rebound helps maintain arterial Apical pulse pressure. Medium-sized arteries Internal & external carotid, axillary, internal & external iliacs have less elastic tissue than large arteries the predominant constituent of the tunica media is smooth muscle Small-sized arteries general construction of small arteries is very similar to that of muscular arteries media is still muscular and has up to 8-10 layers of smooth muscle cells adventitia becomes thinner and the external elastic membrane disappears intima becomes smaller and the internal elastic membrane also eventually disappears Small arteries also maintain their shape, and tend to be round or oval. DEFINITION OF TERMS End artery artery that is the only supply of oxygenated blood to a portion of BLOOD VESSELS OF THE HEAD AND NECK tissue EXTERNAL CAROTID ARTERY also known as terminal arteries. One of the terminal branches of the common carotid artery Does not anastomose supplies structures in the neck, face, and scalp; it also supplies E.g. arteries in the brain, retina and kidneys the tongue and the maxilla. Collateral Circulation The artery begins at the level of the upper border of the thyroid Secondary or accessory circulation cartilage and terminates in the substance of the parotid gland when an area of tissue or an organ has a number of different behind the neck of the mandible by dividing into the superficial pathways for blood to reach it. temporal and maxillary arteries. often as a result of anastamoses - branches formed between Close to its origin, the artery emerges from undercover of the adjacent blood vessels. sternocleidomastoid muscle, where its pulsations can be felt. E.g. scapular anastomoses At first, it lies medial to the internal carotid artery, but as it Tributary Vein ascends in the neck, it passes backward and lateral to it. It is A vessel that feeds or flows into or joins a larger vessel crossed by the posterior belly of the digastric and the stylohyoid 1 6 Chi, Khalid, Nikki  BRANCHES OF THE EXTERNAL CAROTID ARTERY SUBCLAVIAN ARTERIES (Some Actors Like Fame Others Prefer Sex and Money) Right Subclavian Artery Superior thyroid artery upper pole thyroid gland - arises from the brachiocephalic/innominate artery, behind the Ascending pharyngeal artery pharyngeal wall right sternoclavicular joint Lingual artery tongue - arches upward and laterally over the pleura and between the Facial artery tonsils, submandibular gland, scalenus anterior and medius muscles. face - At the outer border of the first rib, it becomes the axillary artery. Occipital artery back of scalp Left Subclavian Artery Posterior auricular artery auricle, scalp - arises from the arch of the aorta in the thorax. Superficial temporal artery scalp - ascends to the root of the neck and then arches laterally in a Maxillary artery upper & lower jaws the muscles manner similar to that of the right subclavian artery scalenus of mastication, the nose, the anterior muscle passes anterior to the artery on each side and divides it into three parts. palate, and the meninges inside the skull *Not all branches of subclavian artery suppy the head and neck; branches in bold are those which specifically have supply to the head & neck.  Part Branches Course Supply FIRST Vertebral Runs cranially in deep neck, PART artery the transverse cervical spinal From its foramina of the cervical cord, hindbrain origin to the vertebrae, joins the medial vertebral artery on the border of contralateral side, scalenus forming the basilar artery anterior and joins the circle of Willis. Internal Runs caudally behind the anterior chest thoracic artery ribs, giving off anterior wall, anterior intercostal branches, portion of perforating vessels to the intercostal breast and terminating in spaces the superior epigastric artery and the musculophrenic artery; "internal mammary" Thyrocervical Very short, thick trunk. lower neck, trunk Divides into 3: posterior 1. inferior thyroid artery shoulder, 2. suprascapular artery thyroid gland 3. transverse cervical artery (also called cervicodorsal trunk) SECOND Costocervical Splits into superior muscles of PART trunk intercostal artery neck Lying (supplies the first and the posteriorly; INTERNAL CAROTID ARTERY behind second intercostal first 2 posterior begins at the bifurcation of the common carotid artery at the level scalenus spaces) and deep intercostal of the upper border of the thyroid anterior cervical artery (supplies spaces supplies the brain, the eye, the forehead, and part of the nose. the deep muscles of the The artery ascends in the neck embedded in the carotid sheath neck) with the internal jugular vein and vagus nerve. THIRD Dorsal From either second or levator PART scapular third part. Passes scapulae, At first it lies superficially; it then passes deep to the parotid Between artery backwards to rhomboideus salivary gland. the lateral supply levator major & minor leaves the neck by passing into the cranial cavity through the border of scapulae and rhomboids. mm. carotid canal in the petrous part of the temporal bone. scalenus It then passes upward and forward in the cavernous venous sinus anterior and (without communicating with it). the outer The artery then leaves the sinus and passes upward again medial border of to the anterior clinoid process of the sphenoid bone. the first rib The internal carotid artery then inclines backward, lateral to the Extra: VIT C & D   mnemonic for subclavian artery branches optic chiasma, and terminates by dividing into the anterior and the middle cerebral arteries. BRANCHES OF THE INTERNAL CAROTID ARTERY Ophthalmic artery Posterior communicating artery Anterior cerebral artery Middle cerebral artery Circle of Willis VEINS OF THE FACE AND THE NECK Facial Vein - formed at the medial angle of the eye by the union of the supraorbital and supratrochlear veins - connected through the ophthalmic veins with the cavernous sinus - descends down the face with the facial artery and passes around the lateral side of the mouth - crosses the mandible, is joined by the anterior division of the retromandibular vein, and drains into the internal jugular vein 2 9 Chi, Khalid, Nikki Superficial Temporal Vein BLOOD VESSELS OF THE THORAX - formed on the side of the scalp ARTERIES - follows the superficial temporal artery and the auriculotemporal 1. Thoracic aorta nerve and then enters the parotid salivary gland, where it joins Descending thoracic aorta the maxillary vein to form the retromandibular vein Commences at the vertebral level T4 Maxillary Vein Terminates at vertebral level T12 - formed in the infratemporal fossa from the pterygoid venous Continuation of the arch of the aorta plexus. Joins the superficial temporal vein to form the Terminates as the abdominal aorta retromandibular vein called the abdominal aorta as it pierces the diaphragm Retromandibular Vein - formed by the union of the superficial temporal and the maxillary veins; On leaving the parotid salivary gland, it divides into an anterior branch, which joins the facial vein, and a posterior branch, which joins the posterior auricular vein to form the external jugular vein. External Jugular Vein - formed behind the angle of the jaw by the union of the posterior auricular vein with the posterior division of the retromandibular vein. Descends across the sternocleidomastoid muscle and beneath the platysma muscle, and it drains into the subclavian vein behind the middle of the clavicle Tributaries a. Posterior external jugular vein from the back of the scalp b. Transverse cervical vein from the skin and the fascia over the posterior triangle c. Suprascapular vein from the back of the scapula Anterior Jugular Vein - The anterior jugular vein descends in the front of the neck close to the midline. Just above the sternum, it is joined to the opposite vein by the jugular arch. Joins the external jugular vein deep to the sternocleidomastoid muscle Internal Jugular Vein - large vein that receives blood from the brain, face, and neck - Starts as a continuation of the sigmoid sinus and leaves the skull through the jugular foramen. Descends through the neck in the carotid sheath lateral to the vagus nerve and the internal and common carotid arteries - Ends by joining the subclavian vein behind the medial end of the clavicle to form the brachiocephalic vein - closely related to the deep cervical lymph nodes - has a dilatation at its upper end called the superior bulb and another near its termination called the inferior bulb - Directly above the inferior bulb is a bicuspid valve. Tributaries: a. Inferior petrosal sinus b. Facial vein c. Pharyngeal veins d. Lingual vein e. Superior thyroid vein f. Middle thyroid vein SUBCLAVIAN VEIN - continuation of the axillary vein at the outer border of the first rib - joins the internal jugular vein to form the brachiocephalic vein - receives the external jugular vein - often receives the thoracic duct on the left side and the right lymphatic duct on the right Relations Anteriorly: clavicle Branches of the Thoracic Aorta Posteriorly: scalenus anterior muscle and the phrenic nerve Inferiorly: The upper surface of the first rib A. Visceral branches Pericardial branches Bronchial branches – supplies trachea, bronchi and lungs Mediastinal branches- supplies lymph nodes in the posterior mediastinum Esophageal artery – supplies middle third of esophagus B. Parietal branches Thoracic wall (phrenic branches, Posterior dintercostal arteries, Subcostal arteries ) Parietal branch supplies the posterior wall of thorax and diaphragm Supplies the 3rd- 11th posterior intercostals arteries o 1st and 2nd intercostals arteries are supplied by subclavian artery Supplies the superior phrenic and subcostal arteries 2. Subclavian Artery Branches of the subclavian artery that supply the thorax  Pericardiacophrenic  Intercostal  Anterior Mediastinal  Perforating  Pericardial  Musculophrenic  Sternal  Superior Epigastric 3 9 Chi, Khalid, Nikki Branches that supply thoracic wall Internal Mammary artery/ Thoracic artery o Gives rise to the anterior intercostals arteries to the upper 6 o intercostal spaces o Gives rise to superior epigastric and musculophrenic arteries o Musculophrenic gives rise to anterior intercostals arteries to the 7th – 11th anterior intercostals arteries Costocervical artery o Gives off the upper 2 posterior intercostal arteries VEINS OF THE THORAX AZYGOS VENOUS SYSTEM 1. Azygos Vein  will serve as an alternate pathway if ever the superior vena cava (or inferior) is blocked  lies on the right side  posterior aspect of the inferior vena cava  below the level of the renal veins  origin is not constant  vein running up the right side of the thoracic vertebral column  It can provide an alternate path for blood to the right atrium by allowing the blood to flow between the venae cavae when one vena cava is blocked.  formed by the union of the ascending lumbar veins with the right subcostal veins at the level of the 12th thoracic vertebra, ascending in the posterior mediastinum  arching over the right main bronchus posteriorly at the root of the right lung to join the superior vena cava  "arch of the azygos vein" (arcus venae azygos) is an important anatomic landmark  As a rare anatomical variation, the arch can be displaced Arteries that Supply the External Surface of the laterally, thereby creating a pleural septum separating an Anterior Thoracic Wall azygos lobe from the upper lobe of the right lung Internal thoracic artery  The azygos vein is unpaired in that there is only one in the Gives rise to two anterior intercostal arteries in each of the body, mostly on the right side upper six intercostal spaces and terminates at the sixth  While there is the hemiazygos vein and its accessory on the intercostal space by dividing into the musculophrenic and left side of the body, they are considered tributaries of the superior epigastric arteries. azygos vein rather than its left-side equivalent.  These veins drain the back, thoracic and abdominal walls Anterior intercostal arteries provide another means of venous drainage from the abdomen Are 12 small arteries , 2 in each of the upper six intercostal and thorax. spaces that run laterally, 1 each at the upper and lower borders  These 3 will drain the back, thoracic and abdominal walls to of each space. provide another means of venous drainage from the The upper artery in each intercostal space anastomoses with abdomen, back the posterior intercostal artery, and the lower one joins the  connects the superior and inferior venae cavae, either directly collateral branch of the posterior intercostal artery. by joining the IVC or indirectly by the hemiazygos and Provide muscular branches to the intercostal, serratus anterior, accessory hemiazygos veins and pectoral muscle  It ascends in the posterior mediastinum, passing close to the right sides of the bodies of the inferior eight thoracic vertebrae Anterior perforating branches (T4-T12) Perforate the internal intercostal muscles in the upper six  covered anteriorly by the oesophagus as it passes posterior intercostal spaces, course with the anterior cutaneous branches to the root of the right lung of the intercostal nerves, and supply the pectoralis major muscle  In addition to the posterior intercostal veins, the azygos vein and the skin and subcutaneous tissue over it communicates with the vertebral venous plexuses. Provide the medial mammary branches (second, third, and  This vein also receives the mediastinal, esophageal, and fourth branches). bronchial veins. Musculophrenic artery 2. The Hemiazygous Vein Follows the costal arch on the inner surface of the costal  mimics the azygos vein (left) cartilages.  same purpose as the right azygos vein Gives rise to two anterior arteries in the seventh, eighth, and  This vein arises on the left side of the junction of the left ninth spaces; perforates the diaphragm; and ends in the tenth subcostal and ascending lumbar veins. intercostal space, where it anastomoses with the deep circumflex iliac artery  It ascends on the left side of the vertebral column, posterior to Supplies the pericardium, diaphragm, and muscles of the the thoracic aorta, as far as T9 vertebra abdominal wall.  it crosses to the right, posterior to the aorta, thoracic duct, and oesophagus, and joins the azygos vein. THORACOEPIGASTRIC VEIN  receives the inferior three intercostal veins, the inferior oesophageal veins, and several small mediastinal branches.  alternate pathway to connect axillary and femoral veins  Is a venous connection between the lateral thoracic vein and the 3. The Accessory Hemiazygos Vein superficial epigastric vein.  a tributary of the hemiazygous vein  establishes an important communication between the femoral  does not have the same purpose as the other 2 vein and axillary vein  This vein begins at the medial end of the 4th or 5th intercostal  especially important vein when the inferior vena cava (IVC) space and descends on the left side of the vertebral column becomes obstructed, by providing a means of collateral venous from T5 to T8. return.  It receives tributaries from veins in the 4th to 8th intercostal Clinical significance: spaces and sometimes from the left bronchial veins.  Mondor’s disease  It crosses over T7 or T8 vertebrae, posterior to the thoracic o tenderness at the breast area with cord-like structure upon aorta and thoracic duct, where it joins the azygos vein. palpation (thoracoepigastric vein which is inflammed)  Sometimes the accessory hemiazygos vein joins the o Phlebitis of the Thoracoepigastric Vein hemiazygos vein and opens with it in the azygos.  Hardening and swelling of a veins under the skin of the  The accessory azygos vein is frequently connected to the breast and front chest wall which is caused by a blood superior intercostal vein. clot 4 9 Chi, Khalid, Nikki  BLOOD VESSELS OF THE ABDOMEN BRANCHES OF THE ABDOMINAL AORTA ABDOMINAL AORTA Branches can be classified as:  It begins at the level of the diaphragm, crossing it via the aortic Visceral branches supplying organs hiatus at vertebral level of T12 Posterior/ Parietal branches supplying the diaphragm or body  It travels down the posterior wall of the abdomen, anterior to the wall vertebral column. Terminal branches  It follows the curvature of the lumbar vertebrae, that is, convex A. Visceral branches anteriorly. The peak of this convexity is at the level of the fourth Paired lumbar vertebra (L4) *L4 is the most convex part of the vertebrae  Middle suprarenals and the aorta  Renals  Internal spermatics  Ovarian Unpaired  Celiac  Superior mesenteric  Inferior mesenteric B. Parietal branches Paired  Inferior phrenic  Lumbars Unpaired  Middle sacral C. Terminal Branches  Common iliacs - paired DISTRIBUTION OF THE BRANCHES OF THE ABDOMINAL AORTA RELATIONS OF THE ABDOMINAL AORTA Anteriorly  coeliac trunk and its branches  coeliac plexus  omental bursa  pancreas  left renal vein  ascending part of the duodenum  root of the mesentery  intermesenteric plexus of nerves Posteriorly  bodies of L1 to L4 vertebrae CELIAC ARTERY  intervening intervertebral discs  Left gastric artery (coronary artery)  corresponding part of the anterior longitudinal ligament.  Hepatic artery Right  Splenic artery (lienal artery)  cisterna chyli **Celiac artery - short thick trunk that arises from the front of the  thoracic duct aorta, just below the aortic hiatus of the diaphragm and passing  right crus of the diaphragm nearly horizontally forward. It occasionally gives off one of the Left inferior phrenic arteries.  left crus of the diaphragm  left coeliac ganglion Left gastric artery  branches to the esophagus BRANCHES OF THE ABDOMINAL AORTA  the smallest of the three branches of the celiac artery, Artery Branch Origin Parts supplied  passes upward and to the left, posterior to the omental bursa, Celiac trunk Visceral –up* Immediately inferior to Abdominal foregut to the cardiac orifice of the stomach. the aortic hiatus of the  anastomose with the aortic esophageal arteries diaphragm  supply the cardiac part of the stomach, anastomosing with Superior Viscera l -up Immediately inferior to Abdominal midgut mesenteric the celiac trunk branches of the lienal artery artery  gives branches to both surfaces of the stomach and Inferior Visceral -up Inferior to the renal Abdominal anastomoses with the right gastric artery mesenteric arteries hindgut artery Hepatic Artery Middle Visceral –p* Immediately superior Suprarenal glands  Right Gastric suprarenal to the renal arteries  Gastroduodenal arteries Renal Visceral – p Immediately inferior to Kidneys  Right Gastroepiploic arteries the superior  Superior Pancreaticoduodenal mesenteric artery  Cystic Gonadal Visceral – p Inferior to the renal Testes in male, **The hepatic artery is intermediate in size between left gastric and (testicular/ arteries ovaries in female lienal (adults); it is the largest of 3 branches of the celiac artery ovarian (fetus). arteries Inferior Parietal – p Immediately inferior to Diaphragm Splenic artery phrenic the aortic hiatus arteries  Pancreatic Lumbar Parietal – p Usually four pairs Posterior  Short Gastric arteries abdominal wall  Left Gastroepiploic and spinal cord **The splenic artery is the largest branch of celiac artery. It is Median Parietal –up Superior to the aortic remarkable for the tortuosity of its course. sacral bifurcation,  On arriving near the spleen, it divides into branches: some arteries pass inferiorly across enter the hilus of that organ between the two layers of the lumbar phrenicolienal ligament to be distributed to the tissues of the vertebrae, sacrum and coccyx spleen; some are given to the pancreas; others pass to the Common Terminal Bifurcation usually greater curvature of the stomach between layers of the iliac arteries occurs at the gastrolienal ligament. level of L4 vertebra  branches: Pancreatic. Short Gastric. Left Gastroepiploic 5 9 Chi, Khalid, Nikki  PORTAL CIRCULATION SUPERIOR MESENTERIC ARTERY  The gastric, splenic and mesenteric veins unite to form the portal  Inferior Pancreaticoduodenal vein  Ileocolic  carries to the liver circulated blood through the capillaries of the  Intestinal stomach, spleen, pancreas and intestines laden with nutriment,  Right Colic the products of digestion.  Middle Colic  breaks up into capillaries (after the manner of an artery), and **The superior mesenteric artery is a large vessel distributes this blood by means of them throughout the liver - supplies whole length of small intestine (except: superior part of  mingles with blood supplied by the hepatic artery, and is collected duodenum); supplies cecum, ascending part of colon and 1/2 of again by small veins the transverse part of colon.  unite to form the hepatic vein, by which it is carried to the inferior - Anastomoses with the ileocolic. vena cava, and by it is poured into the right auricle - Branches: Inferior Pancreaticoduodenal. Ileocolic. Intestinal  Branches or veins that will provide venous return or drain to the Right Colic. Middle Colic portal vein to go to the liver: o Short gastric veins INFERIOR MESENTERIC ARTERY o Left gastric vein  Left Colic o Coronary veins  Sigmoid o Umbilical veins  Superior Hemorrhoidal o Superior hemorrhoidal plexus **The inferior mesenteric artery supplies left half of transverse part o Retroperitoneal communications of colon, whole of the descending and iliac parts of colon, sigmoid  High pressure in the portal vein (syndrome of portal hypertension) colon, and greater part of the rectum. will cause: - smaller than superior mesenteric o esophageal varices o hemorrhoids  esophagus to terminal ileum (celiac artery) o caput medusae (skin near the umbilicus have prominent  terminal ileum to mid transverse (superior mesenteric) veins - parang si medusa) (among others)  mid transverse to first part of rectum (inferior mesenteric) **Dr. Esguerra’s lecture on portal circulation ended up to this part only and then commenced with the Extremities already. Succeeding input on portal vein and porto-caval anastomoses are based on the objectives.  INFERIOR VENA CAVA  receives the blood from the lower limbs and much of the blood Formation of the Portal Vein from the back and from the walls and contents of the abdomen  2.5in (5cm) long and pelvis  Begins at the level of L2 and is formed by the union of the superior  formed by the union of the two common iliac veins at L5, mesenteric and splenic veins ascends to the right of the aorta, traverses the central tendon of  Lies anterior to the inferior vena cava and posterior to the neck of the diaphragm, and empties into the right atrium the pancreas  tributaries are the common iliac, gonadal, renal, suprarenal,  Surrounded by the hepatic nerve plexus and accompanied by inferior phrenic, lumbar and hepatic veins many lymph vessels and some lymph nodes  In some instances the vena cava crosses anterior to (instead of  Ascends to the right, behind the first part of the duodenum, and posterior to) the ureter (pre-ureteric vena cava or postcaval enters the lesser omentum ureter) and may cause ureteric obstruction.  It runs upward in front of the opening into the lesser sac to the  Uncommonly, the embryonic left inferior vena cava may persist. portal hepatitis, where it divides into right and terminal branches Organs/Areas Drained By Tributaries Of The Inferior Vena Cava  Enters the liver and breaks up into sinusoids, from which blood Tributaries Organs/ Regions Drained passes into the hepatic veins that join the inferior vena cava Hepatic vein Liver Suprarenal vein Adrenal glands Renal vein Kidney Gonadal vein Ovaries / testes Inferior phrenic vein Diaphragm Lumbar veins Lumbar portion of the abdomen Internal Iliac vein Muscles of the pelvic region External iliac vein Legs Median sacral vein Pelvis Relations of the Inferior Vena Cava  Posterior to the abdominal cavity  Lateral to abdominal aorta  Medial to right lung  Runs along the side of the vertebral column on its right side  Enters the right atrium at the lower right, back side of the heart 6 9 Chi, Khalid, Nikki Organs Drained by the Portal Vein  Branches: GIT, spleen, pangreas, and gallbladder o Thoracoacromial artery - has clavicular, pectoral, Drains blood from the abdominal part of the gastrointestinal tract deltoid and acromial branches. from the lower third of esophagus to halfway down the anal o Lateral thoracic - runs with long thoracic nerve and canal supplies muscles that it traverses Also drains from the spleen pancreas and gall bladder rd Enters the liver and breaks up into sinusoids, from which blood 3. 3 part passes into the hepatics veins that join the inferior vena cava  Begins after it exits the teres minor and ends after the lower border of teres major. Tributaries of the Portal Vein  Branches: Splenic vein o Subscapular- divides into thoracodorsal and Inferior mesenteric vein circumflex scapular branches. Superior mesenteric vein o Anterior humeral circumflex - Passes around Left gastric vein surgical neck of humerus. Right gastric vein o Posterior humeral circumflex - Runs with axillary Cystic veins nerve through the quadrangular space to anastomose with anterior circumflex branch. PORTO-CAVAL ANASTOMOSIS *The anterior and posterior circumflex will meet at the  is a specific type of anastomosis that occurs between the veins surgical neck of the humerus. of portal circulation and those of systemic circulation  normal conditions: the portal venous blood traverses the liver and drains into the inferior vena cava of the systemic venous circulation by way of the hepatic veins – this is the direct route  if the direct route is blocked: other smaller communications exist between the portal and systemic systems play a role in blood First part supply Areas of porto-caval anastomoses At the lower third of the esophagus, the esophageal branches of the left gastric vein (portal tributary) anastomoses with the Second part esophageal veins draining the middle third of the esophagus into the azygos veins (systemic tributary) Halfway down the anal canal, the superior rectal veins (portal tributary) draining the upper half of the anal canal anastomose with the middle and inferior rectal veins (systemic tributaries) Third part which are tributaries of the internal iliac and internal pudendal veins, respectively The paraumbilical veins connect to the left branch of the portal vein with the superficial veins of the anterior abdominal wall (systemic tributaries) The veins of the ascending colon, descending colon, duodenum, pancreas, and liver (portal tributary) anastomose SCAPULAR ARTERIAL ANASTOMOSIS with the renal, lumbar, and phrenic veins (systemic tributaries)  Anastomosis - group of vessels that will unite form a collateral circulation. Importance of porto-caval anastomosis  A system connecting each subclavian artery and the Portal hypertension – hypertension in the portal vein and its corresponding axillary artery, forming an anastomosis around tributaries the scapula. it causes the blood being forced down alternate channels by the  It allows blood to flow past the joint regardless of the position of increased resistance to flow through the portal system the arm. Enlargement of the portal-systemic connections is frequently  Blood vessels involved: accompanied by congestive enlargement of the spleen 1. Transverse cervical artery Porta-caval shunts for the treatment of portal hypertension 2. Transverse scapular artery may involve the anastomosis of the portal vein, because it lies 3. Branches of subscapular artery within the lesser omentum, to the anterior wall of the inferior 4. Branches of thoracic aorta vena cava behind the entrance into the lesser sac. The splenic  All these vessels anastamose or join to connect the first part of vein may be anastomosed to the left renal vein after removing the subclavian with the third part of the axillary, providing a the spleen. collateral circulation  This collateral circulation allows for blood to continue circulating UPPER EXTRIMITY BLOOD VESSELS if the subclavian is obstructed. AXILLARY ARTERY  conveys oxygenated blood to the lateral aspect of the thorax, BRACHIAL ARTERY the axilla (armpit) and the upper limb  Continuation of the axillary artery beyond the lower margin of  st Begins at the lateral border of the 1 rib and ends in the lower teres major muscle border of teres major.  Continues down the ventral surface of the arm until it reaches  st Before it reaches the 1 rib, the vessel is called the subclavian the cubital fossa at the elbow artery; after the teres major, the vessel is called the brachial  Divides into the radial and ulnar arteries which run down the artery. forearm.  3 parts of the axillary artery: st  Branches: 1. 1 part 1. Profunda brachii artery (deep brachial artery)  from the lateral border of the 1 rib before penetring st 2. Superior ulnar collateral artery pectoralis minor 3. Inferior ulnar collateral artery  Branches: 4. Radial artery (a terminal branch) o Superior thoracic artery – supplies the first two 5. Ulnar artery (a terminal branch) intercostals. 6. Nutrient branches to the humerus nd 2. 2 part  lies behind the pectoralis minor muscle (before entering pectoralis minor and before it exits pectoralis minor).  reference for the locational descriptions of the cords in the brachial plexus. o E.g., the posterior cord of the brachial plexus is so named because it lies posterior to the second part of the artery. If it’s located laterally t is named lateral cord; medially= medial cord. 7 9 Chi, Khalid, Nikki  SUPERFICIAL VEINS OF THE UPPER EXTRIMITY  Cephalic vein o Ascends in the superficial fascia on the lateral side of the biceps and, on reaching the infraclavicular fossa, drains into the axillary vein.  Basilic vein o Ascends in the superficial fascia on the medial side of the biceps. Halfway up the arm it pierces the deep fascia and at the lower border of the teres major joins the venae comitantes of the brachial artery to form the axillary v.  Median cubital vein o Communication between the cephalic and basilica veins o Located in the cubital fossa o Separated from the underlying brachial artery by the bicipital aponeurosis PALMAR ARTERIAL ANASTOMOSIS  Arterial supply to the man’s hand, his most important earning tool is derived from two anastomotic arches (superficial and deep).  superficial and deep formed by the anastomosis between two main arteries of forearm.  radial, ulnar & their branches; in the palm.  2 arches: 1. Superficial Palmar arch  fed mainly by the ulnar artery, entering the palm with the ulnar nerve, anterior to the flexor retinaculum and lateral to the pisiform  Passing medial to the hamate’s hook, then curving laterally to form an arch, convex distally across the middle 1/3 of the palm  in level with a transverse line through the distal border of the fully extended pollicial base. AXILLARY VEIN  Formed at the lower border of the teres major muscle by the union of the venae comitantes of the brachial artery and basilic vein.  Runs upward on the medial side of the axillary artery and ends on the medial side of the first rib by becoming the subclavian vein.  Receives tributaries which correspond to the branches of the axillary artery and the cephalic vein. 2. Deep Palmar arch  formed by anastomosis of the end of the radial with the deep palmar branch of the ulnar artery  forms a flatter curve than the superficial arch  lies across the metacarpal bones just distal to their bases  gives rise to 3 common palmar digital arteries. BLOOD VESSELS OF THE LOWER EXTRIMITIES FEMORAL ARTERY  Begins at the inguinal ligament (femoral head)  Ends just above the knee at adductor canal or Hunter's canal traversing the extent of the femur.  Continuation of the external iliac.  Becomes the popliteal artery as it passes through an opening in adductor magnus near the junction of the middle and distal thirds of the thigh.  Branches: o superficial and deep external pudendal o superficial epigastric o superficial circumflex iliac, profunda femoris o descending genicular (saphenous) arteries 8 9 Chi, Khalid, Nikki   descends medially in the flexor compartment and divides under abductor hallucis  posterior to tibialis posterior, flexor digitorum longus, the tibia and the ankle joint  Terminal Branches: 1. circumflex fibular 2. fibular 3. medial plantar 4. lateral plantar DORSALIS PEDIS  dorsal artery of the foot  continuation of the anterior tibial artery distal to the ankle  passes to the proximal end of the first intermetatarsal space, where it turns into the sole between the heads of the first dorsal interosseous to complete the plantar arch  Superficial in position and is crossed by the inferior extensor POPLITEAL ARTERY retinaculum and the first tendon of the extensor digitorum  extension of the "superficial" femoral artery after passing brevis. through the adductor canal and adductor hiatus above the knee  Pulsations are easily palpated.  The termination of the popliteal artery is its bifurcation into the anterior tibial artery and posterior tibial artery.  knee joint and muscles in the thigh and calf  Branches: o anterior tibial artery o posterior tibial artery o sural artery medial o superior genicular artery o lateral superior genicular artery o middle genicular artery o lateral inferior genicular artery o medial inferior genicular artery SUPERFICIAL VEINS OF THE LOWER EXTRIMITY 1. Small Saphenous Vein From its origin, it courses around the lateral aspect of the foot (inferior and posterior to the lateral malleolus) runs along the posterior aspect of the leg (with the sural nerve) passes between the heads of the gastrocnemius muscle drains into the popliteal vein, approximately at or above the level of the knee joint. 2. Great Saphenous Vein originates from where the dorsal vein of the first digit (the large toe) merges with the dorsal venous arch of the foot After passing anterior to the medial malleolus (where it often can be visualized and palpated), it runs up the medial side of the leg. At the knee, it runs over the posterior border of the medial epicondyle of the femur bone.  Relation: o Front (from above downward)  Popliteal surface of the femur  The back of the knee-joint  Fascia covering the Popliteus o Back (covered by)  Semimembranosus (above)  Gastrocnemius and Plantaris (below) ANTERIOR TIBIAL ARTERY  terminal branch of the popliteal artery  arises at the distal border of popliteus  At first in the flexor compartment, it passes between the heads of tibialis posterior and through the oval aperture in the proximal part of the interosseous membrane to reach the extensor region.  passing medial to the fibular neck  vulnerable here during tibial osteotomy  Descending anteriorly on the membrane it approaches the tibia and, distally, lies anterior to it.  At the ankle it is midway between the malleoli, and continues on "There is one quality which one must possess to win, and that is definiteness the dorsum of the foot as the dorsalis pedis artery. of purpose, the knowledge of what one wants, and a burning desire to POSTERIOR TIBIAL ARTERY possess it. Your big opportunity may be right where you are now."  begins at the distal border of popliteus, between the tibia and - Napoleon Hill fibula  9 9 Chi, Khalid, Nikki