ARTERIES (ARTERIAE) Arteries carry blood from the heart. Arteries have firm and elastic walls adapted to hits of blood ejected from the heart. The pressure wave dilates the vascular wall and it is palpated as a pulse. During systole blood is ejected from the left ventricle into the aorta. Having traversed numerous successive branchings of the aorta, the blood eventually enters a capillary bed in the tissues. There are many progressive changes in the structural and functional properties of arteries with increasing distance from the heart. The largest are elastic arteries, smaller are muscular arteries, the smallest arterioles continue to capillaries. However, lining the interior of the whole system from the finest capillaries up to and including heart is a smooth, continuous single-layered endothelium. In the systemic circulation arteries carry oxygenated blood and veins carry deoxygenated blood. In the pulmonary circulation deoxygenated blood flows through the arteries into lungs and oxygenated through the veins to the heart. The arterial branches accompanying the main trunk are called collaterals. The collaterals may be important during the blockage of the main artery by a trombus to ensure blood supply of an organ. Branches of various arteries may be connected by anastomoses that allow overrunning of blood between adjacent regions. Anastomoses may be missing or functionally insufficient in some organs (heart, retina, and kidney). Arteries that have no or very small anastomoses are termed as terminal arteries. Pulmonary trunk (Truncus pulmonalis) – arises from the right ventricle – ascends towards the aortic arch below which divides into the right and left pulmonary arteries Right pulmonary artery (A. pulmonalis dx.) – behind the ascending aorta and superior vena cava – enters the hilum of the right lung below the right bronchus Left pulmonary artery (A. pulmonalis sin.) – connected to the inferior margin of the aortic arch by the ligamentum arteriosum (the remnant of the ductus arteriosus from the fetal period) – enters the left hilum above the left bronchus Both arteries accompany the bronchial tree in the lungs to capillary plexusses which surround alveoli where exchange of gasses takes place. Two pulmonary veins leave each lung in the hilum and enter the left atrium. They convey oxygenated blood to the left half of the heart. Aorta (Aorta; Fig. 42; Table 2) – the largest and longest artery of the human body – emerges from the left ventricle – distributes blood to all organs and tissues of the body – has 3 segments: Ascending aorta (Aorta ascendens) – 3-5 cm long – passes through the pericardium from the level of the 3^rd right sternocostal junction to the level of the 2^nd right sternocostal junction where it fluently continues to the aortic arch – first located behind the pulmonary trunk, then on its right side – bulbus aortae – widening at the origin formed by aortic sinuses Aortic arch (Arcus aortae; Fig. 43) – from the 2^nd right sternocostal junction obliquely backwards to the left side of T3 vertebra – the convexity of the arch is oriented upwards, the uppermost point reaches the level of the 1^st right sternocostal junction – located first anterior to the tracheal bifurcation, then it runs above the left pulmonary root and then it apposes to the left side of the oesophagus – gives off 3 branches that supply the head, neck and upper limbs – the brachiocephalic trunk, the left common carotid artery and left subclavian artery Descending aorta (Aorta descendens) – continuation of the aortic arch – descends in the thoracic cavity (Aorta thoracica) and in the abdominal cavity (Aorta abdominalis) – ends at the level of the L4 vertebra dividing into the common iliac arteries Artery Branches Truncus pulmonalis A. pulmonalis dx. A. pulmonalis sin. Aorta ascendens A. coronaria dx. A. coronaria sin. Arcus aortae Truncus brachiocephalicus A. carotis communis sin. A. subclavia sin. Aorta thoracica Rr. bronchiales Rr. oesophageales Rr. pericardiaci Rr. mediastinales Aa. phrenicae sup. Aa. intercostales post. Aa. subcostales Aorta abdominalis Aa. phrenicae inf. Aa. lumbales Truncus coeliacus A. mesenterica sup A. mesenterica inf. Aa. suprarenales mediae Aa. renales Aa. testiculares/ovaricae Aa. iliacae communes A. sacralis mediana Table 2. Pulmonary trunk and aorta - survey Brachiocephalic trunk (Truncus brachiocephalicus) – the largest and first branch of the aortic arch – supplies the right half of the head and neck and the right upper extremity – arises from the right part of the aortic arch – ascends behind the manubrium of sternum to the right sternoclavicular joint where it divides into the right common carotid and right subclavian arteries Common carotid artery (A. carotis communis) – supplies the head and upper part of the neck – the left artery (a direct branch of the aortic arch) is 4 cm longer than the right one, which is a branch of the brachiocephalic trunk – ascends lateral to the trachea and larynx – behind the lobe of the thyroid gland – covered by the sternocleidomastoid and omohyoid caudally – in the carotid triangle covered only by the platysma and superficial layer of the cervical fascia (its pulse easily palpated here) – posteriorly related to anterior tubercles of the cervical transverse processes, there is possible compression of the artery by the push against the C6 anterior tubercle (Tuberculum caroticum) – accompanied by the internal jugular vein (laterally) and vagus nerve (posteriorly), all enclosed in the common connective tissue sheath (Vagina carotica) – divides into the external and internal carotid arteries at the level of the upper margin of the thyroid cartilage (Bifurcatio carotidis) – a chemoreceptor that informs about the amount of oxygen in flowing blood (Glomus caroticum) is located in the carotid bifurcation External carotid artery (A. carotis externa; Table 3) – supplies the upper half of the neck and head, except the brain, orbit and inner ear – extends from the carotid triangle to the temporomandibular joint – medial to the stylohyoid and posterior belly of the digastric muscle – enters the submandibular triangle where is crossed by the facial, lingual, and superior thyroid veins, and the hypoglossal nerve – then enters the retromandibular fossa, where it passes through the parenchyma of the parotid gland – lies lateral to the wall of the pharynx, and ventral to the styloid septum – gives off ventral, lateral, dorsal, medial and terminal branches Artery Primary branches Secondary branches A. carotis ext. Ventral branches: A. thyroidea sup. R. infrahyoideus R. sternocleidomastoideus A. laryngea sup. R. cricothyroideus R. glandularis ant., post., lat. A. lingualis R. suprahyoideus Rr. dorsales linguae A. sublingualis A. profunda linguae A. facialis A. palatina ascendens R. tonsillaris A. submentalis Rr. glandulares A. labialis inf. A. labialis sup. R. lateralis nasi A. angularis Lateral branch: A. sternocleidomastoidea Dorsal branches: A. occipitalis R. mastoideus R. auricularis Rr. sternocleidomastoidei Rr. occipitales R. descendens A. auricularis post. A. stylomastoidea A. tympanica post. R. auricularis R. occipitalis Medial branch: A. pharyngea ascendens Rr. pharyngeales A. tympanica inf. A. meningea post. Terminal branches: A. temporalis superficialis Rr. parotidei A. transversa faciei A. zygomaticoorbitalis Rr. auriculares ant. A. temporalis media R. frontalis et r. parietalis A. maxillaris (see below) Table 3. External carotid artery – branches (some details explained in the following text) Superior thyroid artery (A. thyroidea superior) – arises just above the carotid bifurcation – runs ventrocaudally to the thyroid gland – supplies the larynx, adjacent muscles, and superior part of the thyroid gland anastomosing with branches of the inferior thyroid Lingual artery (A. lingualis) – arises at the level of the hyoid bone – runs to the medial side of hyoglossus – then directs between the hyoglossus and genioglossus toward the apex of the tongue – the sublingual artery runs forward below the sublingual gland, supplies the gland, the muscles and mucosa of the mouth floor – the deep lingual artery is the terminal branch of the lingual that enters the tongue and supplies its muscles Facial artery (A. facialis) – arises at the level of the mandibular angle – enters the submandibular triangle – passes below or through the submandibular gland – at the anterior margin of the masseter turns over the mandible to the face (here may be compressed in order to stop bleeding in the face) – then directs towards the mouth angle, nasal wing and medial angle of the eye – the ascending palatine artery supplies the pharynx, isthmus faucium, palate and auditory tube. It anastomoses with descending palatine artery. – the tonsillar branch supplies the palatine tonsil – the submental artery runs below the mylohyoid towards the chin, supplies suprahyoid muscles – glandular branches supply the submandibular gland – superior and inferior labial arteries anastomose with their fellows to form the inferior and superior labial arches (Arcus labialis sup. et inf.), that constitute the circuit around the mouth (Circulus arteriosus oris) – the lateral nasal branch supplies the wing of the nose – the angular artery supplies the medial angle of the eye, anastomoses with the ophthalmic and infraorbital arteries The ventral branches of the external carotid artery may form common trunks (Truncus thyro-lingualis or tr. linguo-facialis or tr. thyro-linguo-facialis) Sternocleidomastoid artery (A. sternocleidomastoidea) – descends backwards over the hypoglossal nerve and internal jugular vein – enters the sternocleidomastoid – may be a branch of the occipital artery Occipital artery (A. occipitalis) – arises opposite the facial artery – directs dorsocranially along the posterior belly of the digastric to the scalp in the occipital region – the mastoid branch runs through the foramen mastoideum to the cranial cavity – the auricular branch supplies the medial surface of the auricle – the descending branch descends deep to the splenius, anastomosing with the transverse cervical artery (the superficial branch), and between the semispinales capitis and cervicis, anastomosing with both the vertebral and the deep cervical artery (the deep branch) Posterior auricular artery (A. auricularis posterior) – arises above the mandibular angle – directs along the posterior belly of the digastric to the auricle – the stylomastoid artery passes through the stylomastoid foramen to the facial canal to enter the cranial cavity – the posterior tympanic artery supplies the tympanic cavity and mastoid cells Ascending pharyngeal artery (A. pharyngea ascendens) – arises at the same level as the lingual artery – ascends at the pharyngeal wall to the skull base – the inferior tympanic artery passes through the tympanic canal to the tympanic cavity – the posterior meningeal artery passes through the jugular foramen to the posterior cranial fossa and gives off branches for its dura mater Superficial temporal artery (A. temporalis superficialis) – begins behind the mandibular neck – passes through the parotid gland – then ascends superficial to the temporal fascia and anterior to the auricle to the temporal region – the transverse facial artery accompanies the parotid duct to the face – the zygomatico-orbital artery goes to the lateral angle of the eye – anterior auricular branches are for the mandibular joint, external acusticus meatus and the lateral side of the auricle – the middle temporal artery passes through the temporal fascia to the temporalis muscle – the frontal and parietal branch for the scalp in the frontal and parietal regions When the artery runs over the zygomatic arch it may be palpated and compressed. Maxillary artery (A. maxillaris; Table 4) Artery Primary branches Secondary branches A. maxillaris Pars mandibularis: A. auricularis prof. A. tympanica ant. A. meningea media A. tympanica sup. R. frontalis, r. parietalis et r. orbitalis A. alveolaris inf. R. mylohyoideus Rr. dentales et rr. peridentales R. mentalis Pars pterygoidea: A. masseterica Aa. temporales prof. Rr. pterygoidei A. buccalis Pars pterygopalatina: A. alveolaris sup. post. Rr. dentales et rr. peridentales A. infraorbitalis Aa. alveolares sup. anteriores (Rr. dentales et rr. peridentales) A. palatina descendens A. palatina major Aa. palatinae minores A. canalis pterygoidei A. sphenopalatina Aa. nasales posteriores laterales et septi Table 4. Maxillary artery - segments and their branches (some details explained in the following text) Maxillary artery – runs medial to the mandibular neck (Pars mandibularis) – then through the infratemporal fossa (Pars pterygoidea) – then enters the pterygopalatine fossa (Pars pterygopalatina) – the anterior tympanic artery passes through the petrotympanic fissure to the tympanic cavity – the middle meningeal artery passes through the foramen spinosum to the middle cranial fossa, its branches supply the tympanic cavity, dura mater and skull bones – the inferior alveolar artery supplies the mylohyoid muscle, teeth and gingiva of the lower jaw, and mental region. – branches of the pterygoid part supply mainly masticatory muscles – the posterior superior alveolar artery passes through alveolar foramina of the maxillary tuberosity for upper molars – the infraorbital artery passes through the inferior orbital fissure to the infraorbital sulcus and canal, where it gives off branches for upper premolars, canine, and incisors and enters the face – the descending palatine artery gives off the greater palatine artery for the hard palate and lesser palatine artery for the soft palate – the artery of pterygoid canal runs to the nasal part of the pharynx – the sphenopalatine artery supplies the dorsal part of the nasal cavity Internal carotid artery (A. carotis interna; Table 5) Artery Primary branches Secondary branches A. carotis int. Pars petrosa: Aa. caroticotympanicae Pars cavernosa: R. sinus cavernosi R. meningeus A. hypophysialis inf. Pars cerebralis: A. ophthalmica A. centralis retinae A. lacrimalis R. meningeus recurrens Aa. ciliares posteriores Aa. musculares A. supraorbitalis A. ethmoidalis post. A. ethmoidalis ant. Aa. palpebrales med. A. supratrochlearis A. dorsalis nasi A. hypophysialis sup. A. communicans post. R. meningeus A. choroidea ant. A. cerebri ant. et media (for more see blood supply of the central nervous system) Table 5. Internal carotid artery - segments and their branches (some details explained in the following text) Internal carotid artery – supplies most of the brain and the contents of the orbit – its widened origin (Sinus caroticus) contains numerous baroreceptors (register changes of the tension of the vascular wall) – the cervical part ascends first dorsally and laterally from the external carotid artery, then through the retrostyloid space to the skull base (separated from the external carotid artery by the styloid septum), this part has no branches – the petrosal part enters the external opening of carotid canal and runs through the carotid canal – the cavernous part passes through the cavernous sinus, where is sigmoidally curved, convex first medially and then laterally – the carotid syphon (Siphon caroticum) – the cerebral part is on the base of the brain – caroticotympanic arteries pass through the caroticotympanic canals to the tympanic cavity – the cavernous branch supplies the trigeminal ganglion and nerves passing through the cavernous sinus – the meningeal branch for the dura mater of the anterior cranial fossa – the ophthalmic artery supplies the orbital region, sphenoid and ethmoid sinuses, dura mater of the anterior cranial fossa, anterior part of the nasal cavity, scalp in the frontal region and anastomoses with the branches of the facial and infraorbital arteries (for more see the visual system) Arteries of the cerebral part supply the bigger anterior part of the brain. Subclavian artery (A. subclavia; Table 6) – the left artery (a direct branch of the aortic arch) is 4 cm longer than the right one which is a branch of the brachiocephalic trunk – runs over the dome of pleura and produces an impression on the apex of the lung (the first/ intrascalenic part) – enters the fissura scalenorum (the second/interscalenic part) – goes below the clavicle (the third/extrascalenic part) – at the lateral border of the clavicle it becomes the axillary artery Artery Primary branches Secondary branches A. subclavia A. vertebralis Rr. spinales Rr. musculares Rr. meningei A. spinalis post. A. spinalis ant. A. inferior posterior cerebelli A. basilaris (for more see blood supply of the central nervous system) A. thoracica int. Rr. mediastinales Rr. thymici Rr. tracheales Rr. bronchiales Rr. sternales A. pericardiacophrenica Rr. perforantes Rr. intercostales anteriores A. musculophrenica A. epigastrica sup. Truncus thyrocervicalis A. thyroidea inf. A. cervicalis ascendens A. suprascapularis A. cervicalis spf. A. transversa colli Truncus costocervicalis A. cervicalis profunda A. intercostalis suprema Table 6. Subclavian artery - branches (some details explained in the following text) Vertebral artery (A. vertebralis) – arises from the first part of the subclavian artery – directs cranially, enters the transverse foramen of the C6 vertebra and passes through transverse foramina of upper cervical vertebrae – after leaving the transverse foramen of the atlas it lies in the grove for the vertebral artery of the atlas, then it penetrates the posterior atlantooccipital membrane – enters the skull through the foramen magnum – supplies the cervical spinal cord and meninges and deep cervical muscles – supplies meninges of the posterior cranial fossa – the posterior spinal artery descends to the posterolateral groove of the spinal cord – the anterior spinal artery descends to the anterior median fissureof the spinal cord – the posterior inferior cerebellar artery supplies the inferior surace of the cerebellum – the basilar artery arises by union of both vertebral arteries at the inferior border of the pons, supplies the inner ear and posterior part of the brain Internal thoracic artery (A. thoracica interna) – arises from the lower side of the first part of the subclavian artery – descends in a distance about 1 cm from the border of the sternum – at the level of the 6^th and 7^th costal cartilages divides into its terminal branches – the pericardiacophrenic artery arises below the superior thoracic aperture, gives off branches for the pericardium and diaphragm – perforating branches pierce the anterior thoracic wall and give off medial mammary branches – anterior intercostal branches supply 6 cranial intercostal spaces and anastomose with posterior intercostal arteries – the musculophrenic artery – a terminal branch which passes laterally at the circumference of the diaphragm and gives off anterior intercostal branches for 5 caudal intercostal spaces – the superior epigastric artery – the other terminal branch, penetrates the diaphragm in the sternocostal triangle, passes at the posterior surface of the rectus abdominis, supplies it, anastomoses with the inferior epigastric artery at the level of the umbilicus Thyrocervical trunk (Truncus thyrocervicalis) – arises from the first part of the subclavian artery – a short trunk directing cranially – the inferior thyroid artery runs first cranially, and then turns medially and caudally towards the thyroid gland (important relation to the recurrent laryngeal nerve). It gives off inferior laryngeal artery, pharyngeal, oesophageal, thymic, and tracheal branches for corresponding organs. – the ascending cervical artery ascends on the anterior tubercles of the cervical transverse processes, supplies the surrounding muscles – the suprascapular artery runs transversally towards the superior border of the scapula, enters the supraspinous fossa over the transverse ligament of the scapula, enters the infraspinous fossa where it anastomoses with the scapular circumflex artery, supplies the supraspinatus and infraspinatus – the transverse cervical artery passes through the scalenus anterior to the trapezius, gives off the superficial branch/superficial cervical artery for trapezius and levator scapulae (dividing into the ascending and descending branches) and deep branch/ dorsal scapular artery for trapezius and rhomboids Costocervical trunk (Truncus costocervicalis) – arises from the second part of the subclavian artery – directs dorsally towards the neck of the 1^st rib – the deep cervical artery passes between the C7 vertebra and neck of the 1^st rib, ascends between the semispinalis capitis and cervicis, supplies the adjacent muscles – the supreme intercostal artery gives off posterior intercostal arteries for two upper intercostal spaces Arteries of the upper limb (Table 7) Artery Primary branches Secondary branches A. axillaris Rr. subscapulares A. thoracica superior A. thoracoacromialis R. acromialis R. deltoideus Rr. pectorales A. thoracica lateralis Rr. mammarii lat. A. subscapularis A. circumflexa scapulae A. thoracodorsalis A. circumflexa humeri ant. A. circumflexa humeri post. A. brachialis A. profunda brachii R. deltoideus Aa. nutriciae humeri A. collateralis media A. collateralis radialis A. collateralis ulnaris sup. A. collateralis ulnaris inf. A. radialis A. ulnaris A. radialis A. recurrens radialis A. nutricia radii R. carpalis palmaris R. palmaris superficialis R. carpalis dorsalis Aa. metacarpales dorsales A. metacarpalis dorsalis prima A. princeps pollicis A. radialis indicis Arcus palmaris profundus Aa. metacarpales palmares Rr. perforantes A. ulnaris A. recurrens ulnaris A. interossea communis A. interossea anterior A. interossea posterior R. carpalis palmaris R. carpalis dorsalis R. palmaris profundus Arcus palmaris superficialis Arcus palmaris spf. 3 aa. digitales palmares communes 2 aa. digitales palmares propriae A. palmaris digiti quinti ulnaris Table 7. Arteries of the upper limb (some details explained in the following text) Axillary artery (A.axillaris) – a continuation of the subclavian artery in the axilla – extends from the lateral margin of the 1^st rib to the lower border of the pectoralis major – the superior thoracic artery supplies pectoral muscles – the thoracoacromial artery enters the deltoideopectoral triangle and gives off branches for the acromial anastomosis, the deltoid and pectoral muscles – the lateral thoracic artery descends at the lateral side of the serratus anterior, supplies it and gives off branches for the mammary gland – the subscapular artery divides into the scapular circumflex artery, which traverses the triangular space (Foramen omotricipitale) and anastomoses with the suprascapular artery in the infraspinous fossa, and the thoracodorsal artery, which supplies the latissimus dorsi – the anterior humeral circumflex artery is a thin branch that runs horizontally anterior to the surgical neck of the humerus, supplies the shoulder joint and anastomoses with the posterior circumflex humeral artery, which runs through the quadrangular space (Foramen humerotricipitale) and supplies the shoulder joint, deltoid, teres major and minor, long and lateral heads of triceps Brachial artery (A. brachialis) – a continuation of the axillary artery – from the lower margin of the pectoralis major to the cubital fossa – runs in the medial bicipitalis groove – in the cubital fossa divides into terminal branches – the radial and ulnar arteries – the profunda brachii artery accompanies the radial nerve in the groove for radial nerve and reaches the cubital region, supplies the deltoid, humerus, and ends in the rete articulare cubiti – the superior ulnar collateral artery arises from the brachial artery in the halfway of the arm, accompanies the ulnar nerve, descends first on the anterior side of the medial intermuscular septum, then pierces the septum to its dorsal side, and ends in the rete articulare cubiti – the inferior ulnar collateral artery arises from the brachial artery proximal to the cubital fossa, gives off branches for surrounding muscles, ends in the rete articulare cubiti Radial artery (A. radialis) – arises behind the bicipital aponeurosis – descends between the pronator teres and brachioradialis – distally between the brachioradialis and flexor carpi radialis – at the level of the wrist passes beneath the tendon of extensor pollicis brevis – enters the anatomical snuff box (Foveola radialis) – beneath the tendon of extensor pollicis longus enters the dorsum of the hand – penetrates through the first dorsal interoseus muscle to the palm – gives off muscular branches for the surrounding muscles – the superficial palmar branch arises at the distal end of the forearm, runs through the thenar muscles which it supplies, beneath the palmar aponeurosis anastomoses with the superficial palmar arch of the ulnar artery – the first dorsal metacarpal artery arises from the radial artery on the dorsum of the hand and supplies the dorsal side of the thumb and radial side of the index – the princeps pollicis artery arises in the palm, supplies the palmar side of the thumb – the radialis indicis artery for the radial part of the index from the palmar side – the deep palmar arch (Fig. 44) the terminal branch, which anastomoses with the deep palmar branch of the ulnar, lies in the palm at the bases of the 2^nd to 4^th metacarpal bones between the interosseous muscles and tendons of flexors and gives off three palmar metacarpal arteries that join the common digital branches of the superficial arch – the perforating branches pass through interosseous muscles to dorsal metacarpal arteries Ulnar artery (A. ulnaris) – runs underneath the common origin of flexors – descends at the ulnar margin of the forearm to the hand – is located between the flexor digitorum profundus and superficialis – distally between tendons of the flexor carpi ulnaris and flexor digitorum superficialis – accompanies the ulnar nerve – enters the palm over the flexor retinaculum – the anterior interosseous artery descends on the anterior side of the interosseous membrane between the flexor pollicis longus and flexor digitorum profundus, proximal to the pronator quadratus pierces the interosseous membrane and ends in the dorsal carpal arch, it gives off the median artery – the posterior interosseous artery pierces the interosseous membrane in its proximal part, descends between the deep and superficial groups of extensors, gives off the recurrent interosseous for the cubital anastomosis – the deep palmar branch penetrates muscles of the hypothenar, anastomoses with the deep palmar arch of the radial – the superficial palmar arch (Fig. 44) enters the palm anterior to the flexor retinaculum, between tendons of flexors and the palmar aponeurosis, anastomoses with the superficial palmar branch of the radial, lies approximately anterior to the halfway of the metacarpal bones, its three common palmar digital arteries give off proper palmar digital arteries that supply adjacent sides of 2^nd to 5^th fingers Arterial plexuses of the upper limb Cubital anastomosis (Rete articulare cubiti) is located around the elbow joint. Tributaries: – the middle and radial collateral of the deep brachial artery – the superior and inferior ulnar collateral of the brachial artery – the radial recurrent of the radial artery – the ulnar recurrent of the ulnar artery – the recurrent interosseous of the posterior interosseous artery Palmar carpal arch (Rete carpale palmare) lies on the palmar side of the wrist behind the tendons of flexor digitorum profundus and supplies the carpal articulations and joints. Tributaries: – palmar carpal branches of the radial and ulnar arteries – branches of the anterior interosseous artery – branches of the deep palmar arch Dorsal carpal arch (Rete carpale dorsale) lies on the dorsal side of the carpal dorsum under the extensor tendons Tributaries: – dorsal carpal branches of the radial and ulnar arteries – terminal branches from the anterior and posterior interosseous artery This plexus sends three dorsal metacarpal arteries, each divides into two dorsal digital arteries to supply dorsal sides of the 2^nd to 5^th fingers. Thoracic aorta (Aorta thoracica; Table 8) – in the dorsal mediastinum – descends from the left side of T3 to the level of T11-12 – leaves the thoracic cavity through the aortic hiatus of the diaphragm to continue as the abdominal aorta – first descends at the left side of the thoracic vertebral column and oesophagus, more caudally descends between the oesophagus and the vertebral column – gives off paired parietal branches for the thoracic wall and visceral branches for mediastinal organs Artery Primary branches Secondary branches Aorta thoracica Parietal branches: Aa. intercostales post. R. dorsalis R. collateralis R. cutaneus lat. Aa. subcostales R. dorsalis Aa. phrenicae sup. Visceral branches: Rr. bronchiales Rr. oesophageales Rr. pericardiaci Rr. mediastinales Table 8. Thoracic aorta – branches (some details explained in the following text) – the posterior intercostal arteries (9 pairs) for the 3^rd to 11^th intercostal spaces run in the costal groove, first at the inner side of external intercostal muscles, then between internal and innermost intercostals, anastomose with anterior intercostal branches from the internal thoracic and musculophrenic arteries – the dorsal branch of the posterior intercostal artery supplies the skin and muscles of the back, vertebrae, spinal cord and meninges – the collateral branch of the posterior intercostal arises near the costal angle, runs at the upper margin of the subjacent rib – the lateral cutaneus of the posterior intercostal artery supplies the skin of the thorax, it gives off also lateral mammary branches for the breast – the subcostal arteries are below the twelfth ribs, enter the abdomen behind the lateral arcuate ligaments, anastomose with the superior epigastric, posterior intercostal and lumbar arteries – the superior phrenic arteries supply the cranial surface of the diaphragm Abdominal aorta (Aorta abdominalis; Table 9) – from the aortic hiatus to the level of L4 where it divides into the right and left common iliac arteries (Bifurcatio aortae) – its continuation is the median sacral artery, which descends to the apex of the coccyx and terminates there by a ball of the arteriovenous anastomosis (Glomus coccygeum); it gives off arteriae lumbales imae and sacral branches that anastomose with the lateral sacral arteries – located retroperitoneally – on the left side of the inferior vena cava – anteriorly related to the left renal vein, pancreas, duodenum and root of mesentery – parietal branches of the abdominal aorta are paired – visceral branches are either paired or unpaired Artery Primary branches Secondary branches Aorta abdominalis Parietal branches: Aa. phrenicae inf. A. suprarenalis sup. Aa. lumbales R. dorsalis Paired visceral branches: Aa. suprarenales mediae Aa. renales A. suprarenalis inf. R. uretericus R. anterior R. posterior A. testiculares (male) Rr. ureterici A. ovarica (female) Rr. ureterici Rr. tubarii Unpaired visceral branches: Truncus coeliacus A. mesenterica sup. A. mesenterica inf. Terminal branches: Aa. iliacae communes A. sacralis mediana Tr. coeliacus A. gastrica sin. Rr. oesophageales Rr. gastrici A. splenica Rr. pancreatici A. gastroomentalis sin. Aa. gastricae breves Rr. splenici A. gastrica post. A. hepatica communis A. hepatica propria A. gastroduodenalis A. gastroduodenalis A. gastroomentalis dx. A. pancreaticoduodenalis sup. ant. A. pancreaticoduodenalis sup. post. Aa. retroduodenales A. mesenterica sup. A. pancreaticoduodenalis inf. R. anterior R. posterior 10 – 18 aa. jejunales et ileales A. ileocolica R. ilealis R. colicus R. appendicularis A. colica dx. A. colica media A. mesenterica inf. A. colica sin. Aa. sigmoideae A. rectalis sup. Table 9. Abdominal aorta – branches (some details explained in the following text) Abdominal aorta – the inferior phrenic arteries supply the caudal surface of the diaphragm and upper part of the adrenal glands – the lumbar arteries are four paired segmental branches that run at the bodies of lumbar vertebrae and behind the psoas major to the lateral abdominal wall; each gives off the dorsal branch that supplies the dorsal muscles, skin and spinal cord – the renal arteries arise at the level of L1 or L2; each runs laterally over the psoas major and enters the hilum of the kidney; the right is longer than the left one; the anterior branch runs between the renal vein and pelvis and divides into four segmental branches; the posterior branch passes behind the renal pelvis and continues as the posterior segmental artery – the accessory renal arteries often arise from the aorta or some other neighboring artery (25%), they may enter the kidney at any site of the renal surface and may be the cause of complications during surgery of kidneys – the male testicularis arteries arise at the level of L2; each descends on the psoas major, enters the pelvis anterior to the common or external iliac vessels, then passes through the inguinal canal as the component of the spermatic cord and supplies the testis and epididymis – the female ovarian arteries descend to the pelvis; each reaches the ovary through the suspensory ligament of ovary and anastomoses with the ovarian branch of uterine artery Coeliac trunk (Truncus coeliacus; Fig. 45) – arises from the anterior side of the aorta at the level of T12-L1 – is short (1-2 cm) and thick – the left gastric artery runs at the dorsal wall of the omental bursa along the upper border of the pancreas to the gastric cardia and lower part of the esophagus and continues along the lesser curvature of the stomach where anastomoses with the right gastric artery – the splenic/lienal artery runs to the left along the upper margin of the pancreas – the left gastroomental artery arises from the splenic near the hilum of spleen, and gives off branches through the gastrosplenic ligament to the proximal part of the greater curvature and to the greater omentum – the posterior gastric artery ascends behind the omental bursa to the gastric fundus to supply the posterior wall of stomach – the hepatic artery proper runs to the porta hepatis in the hepatoduodenal ligament; it gives off the right gastric artery, which descends in the lesser omentum to the pyloric end of the stomach, and the right and left branches for hepatic lobes – the cystic artery for the gallbladder is commonly a branch of the right hepatic branch – accessory hepatic arteries are usually from the superior mesenteric or left gastric artery – the gastroduodenal artery descends behind the pylorus – superior pancreaticoduodenal arteries descend between the head of the pancreas and the descending part of the duodenum and anastomose with branches of the inferior pancreaticoduodenal artery Superior mesenteric artery (A. mesenterica superior) – arises from the aorta at the level of L1 – enters the mesentery at the lower border of the pancreas – forms the arch convex to the left – ends in the right iliac fossa – jejunal and ileal arteries arise from the convex side of the superior mesenteric, jejunal are longer and form 1-2 arcades, ileal are shorter and form 3-4 arcades – the right colic artery for the ascending colon – the middle colic artery enters the transverse mesocolon, supplies the transverse colon Inferior mesenteric artery (A. mesenterica inferior) – arises from the aorta at the level of L2-3 – descends retroperitoneally to the left side – the left colic artery for the descending colon – the superior rectal artery anastomoses with the sigmoidal arteries and middle rectal artery Branches for the large intestine form also arcades but not so branched as at the small intestine. Right and left common iliac artery (A. iliaca communis dextra et sinistra) – arise at the level of L4 – each descends at the medial surface of the psoas major – the right artery is longer than the left one and crosses the left common iliac vein anteriorly – each divides into the internal and external iliac arteries anterior to the sacroiliac joint Arteries of the pelvis (Table 10) Artery Primary branches Secondary branches A. iliaca int. A. iliolumbalis R. iliacus R. lumbalis R. sacralis 2 aa. sacrales laterales Rr. spinales A. obturatoria R. pubicus R. anterior R. posterior A. glutea superior R. superficialis R. profundus A. glutea inferior A. commitans n. ischiadici A. umbilicalis Aa. vesicales superiores A. ductus deferentis(male) Rr. ureterici A. vesicalis inferior A. vaginalis (female) A. rectalis media Rr. vaginales (female) Rr. prostatici (male) A. uterina (female) Rr. helicini Rr. vaginales R. tubarius R. ovaricus A. pudenda interna A. rectalis inf. A. perinealis A. urethralis (male) Rr. scrotales posteriores (male) Rr. labiales posteriores (female) A. bulbi penis (male) A. bulbi vestibuli (female) A. dorsalis penis (male) A. dorsalis clitoridis (female) A. profunda penis(male) A. profunda clitoridis (female) Aa. perforantes penis (male) A. iliaca ext. A. epigastrica inferior R. pubicus A. cremasterica (male) A. ligamenti teretis (female) A. circumflexa ilium profunda Table 10. Arteries of the pelvis (some details explained in the following text) Internal iliac artery (A. iliaca interna) – supplies the wall and organs of the lesser pelvis – the iliolumbar artery supplies the iliacus, psoas major, quadratus lumborum and sacral canal – lateral sacral arteries run medial to the pelvic sacral foramina and anastomose with the middle sacral artery – the obturator artery gives off the pubic branch, which anastomoses with the pubic branch of the inferior epigastric artery (Corona mortis), then passes through the obturator canal to supply adductors (the anterior branch) and muscles attached to the ischial tuberosity (the posterior branch). The posterior branch gives off the acetabular branch that enters the hip joint and if small in infants it may result in constrained supply of the developing femoral head. – the superior gluteal artery supplies the gluteus maximus and medius (the superficial branch) and gluteus medius and minimus (the deep branch) – the inferior gluteal artery supplies the gluteus maximus and gives off the artery for the sciatic nerve – the umbilical artery carries blood from the fetus to the placenta. After birth it obliterates nearly completely to form the cord of the umbilical artery (Pars occlusa) but the beginning segment of the artery remains patent (Pars patens). It supplies the fundus of the urinary bladder, lower portion of the ureter and ductus deferens (in male). – the inferior vesical artery supplies the lower part of the urinary bladder, in male also the seminal vesicle and prostate – the vaginal artery (in female) – branches to the vagina, vestibular bulb, fundus of bladder and adjacent part of the rectum – the middle rectal artery supplies the middle part of the rectum, vagina (in female) and prostate (in male), and anastomoses with the superior and inferior rectal arteries – the uterine artery (in female) runs in the broad ligament of the uterus to the cervix of uterus, crosses the ureter from above (2 cm lateral to the cervix and 1.5 cm above the vaginal fornix), its helicine branches enter the uterine muscle and have tortuous course – the internal pudendal artery passes through the foramen infrapiriforme and then through the greater sciatic foramen, enters the ischioanal fossa where passes through the pudendal canal (Canalis pudendalis, Alcock), then it proceeds below or above the perineal membrane to end behind the inferior pubic ligament dividing into the deep and dorsal arteries of the penis/clitoris. External iliac artery (A. iliaca ext.) – thicker than the internal iliac artery – directs ventrally along the medial border of the psoas major – passes through lacuna vasorum (lateral to the vein) – the inferior epigastric artery ascends in the interfoveolar ligament to the dorsal side of the rectus abdominis, raises the peritoneal lateral umbilical fold, and anastomoses with the superior epigastric artery – the deep iliac circumflex artery directs along the inguinal ligament towards the anterior superior iliac spine Arteries of the lower limb (Table 11) Artery Primary branches Secondary branches A. femoralis A. epigastrica superficialis A. circumflexa ilium superficialis A. pudenda externa superficialis A. pudenda externa profunda Rr. scrotales anteriores (male) Rr. labiales anteriores (female) Rr. inguinales A. profunda femoris A. descendens genus R. saphenus Rr. articulares A. profunda femoris A. circumflexa femoris medialis R. superficialis R. profundus R. acetabularis A. circumflexa femoris lateralis R. ascendens R. descendens R. transversus A. perforans prima A. nutricia femoris sup. A. perforans secunda A. perforans tertia A. nutricia femoris inf. A. poplitea Aa. surales A. superior lateralis genus A. superior medialis genus A. media genus A. inferior lateralis genus A. inferior medialis genus A. tibialis anterior A. tibialis posterior A. tibialis anterior A. recurrens tibialis posterior A. recurrens tibialis anterior A. malleolaris anterior medialis A. malleolaris anterior lateralis A. dorsalis pedis Aa. tarsales mediales A. tarsalis lateralis A. arcuata 3 aa. metatarsales dorsales A. digitalis dorsalis V. A. metatarsalis dorsalis prima Aa. digitales dorsales A. plantaris profunda A. tibialis posterior R. circumflexus fibularis A. fibularis A. nutricia fibulae R. communicans R. perforans Rr. malleolares laterales Rr. calcanei A. nutricia tibiae Rr. malleolares mediales Rr. calcanei A. plantaris medialis R. profundus R. superficialis A. plantaris lateralis A. plantaris lateralis Arcus plantaris profundus 4 aa. metatarsales plantares A. metatarsea plantaris R. perforans A. digitalis plantaris communis 2 aa. digitales plantares propriae Table 11. Arteries of the lower limb (some details explained in the following text) Femoral artery (A. femoralis) – a continuation of the external iliac artery – starts behind the middle part of the inguinal ligament – descends medially in the femoral triangle – covered by the sartorius – then through the adductor canal – ends at the adductor hiatus (Hunter’s canal) – the superficial epigastric artery traverses the cribriform fascia and ascends in the subcutaneous tissue of the anterior abdominal wall – the superficial iliac circumflex artery enters the subcutaneous tissue below the inguinal ligament and directs to the anterior superior iliac spine – the external pudendal arteries supply the lower abdominal, perineal, penile, scrotal or labial skin, anastomosing with branches of the internal pudendal – the deep femoral artery arises 3-5 cm below the inguinal ligament, descends behind the femoral artery, enters the dorsal side of the thigh between the adductor longus and magnus; its medial femoral circumflex artery supplies adductors and flexors of the thigh and the hip joint, its lateral circumflex femoral artery forms the anastomotic ring around the femoral neck with the gluteal arteries and the medial circumflex artery (supplies head and neck of the femur), and the cruciate anastomosis with the medial circumflex, inferior gluteal, and first perforating artery – all perforating arteries supply posterior compartment of the thigh. They have ascending and descending branches, which interconnect to form a longitudinal channel on the posterior side of the femur. Superiorly it anastomoses with the circumflex arteries and inferiorly with the popliteal artery. – the descending genicular artery arises in the adductor canal, descends on the medial side of the knee joint, supplies the adductor magnus, vastus medialis, knee joint, and proximomedial area of the leg Popliteal artery (A. poplitea) – the continuation of the femoral – from the adductor hiatus to the distal border of the popliteus – inclines laterally – the deepest structure in the popliteal fossa (deep to the vein and nerve) – at the proximal end of the crural interosseous space divides into terminal branches – the anterior and posterior tibial arteries – the sural arteries supply the gastrocnemius, soleus and plantaris – the superior and inferior genicular arteries end in the rete articulare genus – the middle genicular artery supplies the cruciate ligaments and synovial membrane of the knee joint Anterior tibial artery (A. tibialis anterior) – pierces the crural interosseous membrane to the ventral side of the crus – descends between the tibialis anterior and extensor digitorum longus – distally between the tibialis anterior and extensor hallucis longus – at the ankle it is midway between the malleoli – the posterior tibial recurrent artery arises before the anterior tibial artery penetrates through the interosseous membrane, ends in the rete articulare genus – the anterior tibial recurrent artery arises after the anterior tibial artery pierces the membrane, ends in the genicular anastomosis Dorsal artery of foot (A. dorsalis pedis) – the continuation of the anterior tibial artery distal to the ankle – runs medially along the dorsum to the proximal end of the first intermetatarsal space – enters the sole between the heads of the first dorsal interosseous muscle – the medial tarsal arteries (2-3) supply the medial margin of the foot – the lateral tarsal artery runs under the extensor hallucis brevis and extensor digitorum brevis to the lateral margin of the foot, anastomoses with the arcuate artery – the arcuate artery arises above the base of the 2^nd metatarsal bone, directs laterally over the metatarsal bases deep to the tendons of digital extensors to form the arch convex distally, each of its dorsal metatarsal arteries divides into 2 dorsal digital arteries for adjacent sides of the 2^nd to 5^th toes – the first dorsal metatarsal artery divides into dorsal digital for both sides of the big toe and the medial margin of the 2^nd toe – the deep plantar artery runs through the first interosseous fissure to the sole and anastomoses with the the lateral plantar artery Posterior tibial artery (A. tibialis posterior) – the continuation of the popliteal artery – supplies the posterior and lateral compartments of the leg – runs under the arcus tendineus m. solei – descends on the deep flexors covered by the deep layer of the crural fascia – runs behind the medial maleolus deep to the flexor retinaculum – enters the sole where it divides into its terminal branches – medial and lateral plantar arteries – the fibular circumflex branch directs laterally round the fibular neck to the rete articulare genus – the fibular artery runs laterally paralel to the posterior tibial artery, enters the musculofibular canal (between the fibula and flexor hallucis longus), ends at the level of the lateral maleolus; its communicating branch anastomoses with the posterior tibial artery at the level of ankles, its perforating branch passes between the distal ends of the tibia and fibula to the arteries of dorsum of the foot Lateral plantar artery (A. plantaris lateralis) – runs distally and laterally between the flexor digitorum brevis and quadratus plantae – below the base of the 5^th metatarsal bone it continues to the deep plantar arch, which is convex distally and runs between the metatarsals and oblique head of the adductor hallucis to the 1^st interosseous space where it anastomoses with the deep plantar artery of the dorsalis pedis and with the deep branch of the medial plantar artery – each plantar metatarsal artery gives off the perforating branch, which connects to the dorsal metatarsal artery, and common plantar digital artery that divides into two plantar digital proper arteries for adjoining sides of the 1^st to the 5^th toes (the medial side of the big toe and the lateral side of the little toe are supplied by the direct branches from the arch) Medial plantar artery (A. plantaris medialis) – thinner than the lateral plantar artery – runs between the abductor hallucis and flexor digitorum brevis – supplies the medial side of the foot Arterial plexuses of the lower limb Genicular anastomosis (Rete articulare genus) Tributaries: – the descending genicular artery of the femoral artery – the medial and lateral superior genicular arteries of the popliteal artery – the medial and lateral inferior genicular arteries of the popliteal artery – the fibular circumflex artery of the posterior tibial artery – the posterior and anterior tibial recurrent arteries of the anterior tibial artery Medial malleolar network (Rete malleolare mediale) Tributaries: – the medial anterior malleolar artery of the anterior tibial artery – medial malleolar branches of the posterior tibial artery – calcaneal branches of the posterior tibial artery – medial tarsal arteries of the dorsal artery of foot – branches of the medial plantar artery Lateral malleolar network (Rete malleolare laterale) Tributaries: – the lateral anterior malleolar artery of the anterior tibial artery – lateral malleolar branches of the fibular artery – the perorating branch of the fibular artery – branches of the lateral tarsal artery of the dorsal artery of foot – branches of the lateral plantar artery Calcaneal anastomosis (Rete calcaneum) Tributaries: – calcaneal branches of the posterior tibial artery – calcaneal branches of the fibular artery – branches of the lateral plantar artery