Month: January 2019

1. Rr. caroticotympanici penetrating the tympanic cavity.
2. A. ophthalmica, the ophthalmic artery, penetrates through the canalis opticus into the cavity of the orbit along with n. opticus, where it splits into its final branches. On the way to the eye socket gives a number of branches.

Branches a. ophthalmica:
1) to the dura mater of the brain, anastomosing with a. meningea media (branch a. maxilaris from system a. carotis externa);
2) to the lacrimal gland a. lacrimalis;
3) to the eyeball aa. ciliares, ending in the choroid; among them a. centralis retinae, penetrates into the optic nerve and, with it, forks into the retina;
4) to the muscles of the eyeball;
5) to the aa centuries. palpebralis laterales et mediales;
6) to the mucous membrane of the nasal cavity aa. ethmoidales anterior et posterior;
7) a. supraorbitalis emerges from the orbit through incisura supraorbitalis;
8) a. dorsalis nasi descends along the edge of the back of the nose.

3. A cerebri anterior, the smaller cerebral artery, moves forward and medially to the beginning of the longitudinal groove of the brain, bends around the corpus calorus and stretches back along the inner surface of the brain hemisphere to the beginning of the occipital lobe, giving it back to the cortex. At the beginning of the longitudinal groove of the brain connects with the same side artery of the other side with the help of the transverse stem, a. communicans anterior.

A. carotis interna, the internal carotid artery, starting from the common carotid artery, rises to the base of the skull and enters the canalis caroticus of the temporal bone. In the neck it does not give branches; at the very beginning lies outwards from a. carotis externa, respectively, the development of the lateral trunk of the dorsal aorta, but soon begins to go to the medial surface of the latter. According to the curvature of canalis caroticus, the internal carotid artery, passing first vertically in it, then bends in the anteromedial direction and, at the apex of the temporal bone, enters the cranial cavity through the foramen lacerum; curving upward, it rises along the sulcus caroticus of the sphenoid bone, turns back forward at the bottom of the Turkish saddle, passes through the thickness of the cavernous sinus, and in the canalis opticus makes the last bend upwards and backwards, giving its first branch, a. ophthalmica, after which it pierces the hard and spider shells and, finally, is divided into its final branches.

The branches of the first division of the maxillary artery go up to the external auditory canal, into the tympanum, where they penetrate through the fissura petrotympanica; to the hard shell of the brain – a. meningea media, the average meningeal artery (the largest branch), where it penetrates through the foramen spinosum, and down to the lower teeth, a. alveolaris inferior, inferior alveolar artery. The latter passes into the lower jaw through canalis mandibulae. Before joining the channel a. alveolaris inferior gives r. mylohyoideus to the muscle of the same name, and in the canal supplies the lower teeth with its branches and leaves it through the foramen mentale, receiving the name a. mentalis (submental artery), which branches in the skin and muscles of the chin.

The branches of the second section of the maxillary artery go to all the masticatory and cheek muscles, getting the names corresponding to the muscles, as well as to the sinus maxillaris mucosa and the upper molars – aa. alveolares superiores posteriores, posterior superior alveolar arteries.

The branches of the third division of the maxillary artery:

1) a. The infraorbital, the infraorbital artery, enters through the fissura orbitalis inferior into the eye socket, then through the canalis infraorbitalis enters the front surface of the upper jaw and sends branches to the lower eyelid, to the lacrimal sac and down to the upper lip and cheek. Here, she anastomoses with the branches of the facial artery, so that if there is difficulty in the blood flow in the trunk, a. maxillaris blood to its pool can flow through a. facialis. Still in the eye socket a. infraorbitalis gives branches to the muscles of the eyeball; passing in the infraorbital canal, it supplies canines and incisors {aa. alveolares superiores anteriores) and sinus maxillaris mucosa;

2) branches to the palate, pharynx and the auditory tube, some of which descend down to the canalis palatinus major, comes out through the foramina palatina majus et minores and forks in a hard and soft palate;

3) a. sphenopalatina, the sphenoid-palatine artery, penetrates through the eponymous opening into the nasal cavity, giving branches to its lateral wall and to the septum; the front of the nose gets blood through aa. ethmoidales anterior et posterior.

1. A. pharyngea ascendens, the ascending pharyngeal artery, is directed upwards along the pharyngeal wall, supplying it with a soft palate, palatine tonsil, auditory tube, tympanic cavity, and a hard shell of the brain.

2. A. temporalis superficialis, the superficial temporal artery, one of the two terminal branches of the external carotid artery, proceeds as a continuation of the trunk a. carotis externa in front of the external auditory canal to the temple, located under the skin on the fascia of the temporal muscle. Here the artery can be pressed against the temporal bone. Its terminal branches, ramus frontalis and ramus parietalis, branch in the region of the vertex and temple. On the way, it gives branches to the parotid gland, to the lateral surface of the auricle and to the external auditory canal; part of the branches goes to the back of the face, to the outer corner of the eye, to m. orbicularis oculi and zygomatic bone. A. temporalis superficialis also supplies m. temporalis.

3. A. maxillaris, the maxillary artery, is another terminal branch of the external carotid artery. Its short trunk is divided into three sections to facilitate the study of branches: the first goes around the neck of the jaw, the second passes into the fossa infratemporalis on the surface m. pterygofdeus lateralis, third penetrates fossa pterygopalatina.

External carotid artery, a. carotis externa, supplies blood to the outer parts of the head and neck, which is why it received the name of the external part, unlike the internal carotid artery, which penetrates the cavity of the skull. From the place of its origin, the external carotid artery rises upward, passes inwards from the posterior abdomen m. digastrici and m. stylohyoideus, pierces the parotid gland and behind the neck of the condylar process of the mandible, splits into its final branches.

The branches of the external carotid artery for the most part are remnants of arterial arcs and nourish organs arising from the gill arches. They go (number 9) as if along the radii of a circle corresponding to the head, and can be divided into three groups of three arteries in each — anterior, middle, and posterior groups, or triples.

The anterior group is caused by the development and location of the organs supplied by the arteries of this group and derived from the gill arches, namely: the thyroid gland and the larynx – a. thyroidea superior, tongue – a. lingualis and face – a. facialis.

1. A. thyroidea superior, the upper artery of the thyroid gland, which leaves the external carotid artery immediately above its beginning, goes down and forward to the thyroid gland, where it anastomoses with other thyroid arteries. Along the way gives a. laryngea superior, which together with n. laryngeus superior pierces lig. thyrohyoideum and supplies the branches of the muscles, ligaments and mucous membrane of the larynx.

2. A. lingualis, the lingual artery, departs at the level of the large horns of the hyoid bone, goes up through the Pirogov triangle, covered with m. hyoglossus, and goes to the tongue. Before joining, it gives branches to the hyoid bone, the palatine tonsils and the hyoid gland. Entering the tongue, the lingual artery trunk extends to the tip of the tongue called a. profunda linguae, which along the way gives multiple branches to the back of the tongue, rr. dorsales linguae.

3. A. facialis, the facial artery, departs somewhat higher than the previous one at the level of the angle of the mandible, runs medially from the posterior abdomen m. digastricus and reaches the leading edge m. masseter, where she bends over the edge of the jaw on the face. Here, ahead of m. masseter, it can be pressed to the lower jaw. Then it goes to the medial corner of the eye, where the end branch (a. Angularis) anastomoses with a. dorsalis nasi (a. ophthalmica branch from the system of the internal carotid artery). To bend through the lower jaw, it gives branches to nearby formations: to the pharynx and soft palate, to the tonsils, to the submandibular gland and the diaphragm of the mouth, to the salivary glands; after the bend – to the upper and lower lips.

Common carotid artery, a. carotis communis (cara – plunge into sleep), develops from the ventral aorta over the 3rd to 4th aortic arches; on the right, it departs from truncus brachiocephalicus, on the left, independently from the aortic arch. The common carotid arteries are directed up the sides of the trachea and esophagus. The right common carotid artery is shorter than the left, since the latter consists of two sections: the thoracic (from the aortic arch to the left sternoclavicular joint) and the cervical, the right only from the cervical. A carotis communis passes into the trigonum caroticum and at the level of the upper edge of the thyroid cartilage or the body of the hyoid bone is divided into its final a. carotis externa et a. carotis interna (bifurcation). The common carotid artery is pressed to stop bleeding to the tuberculum caroticum VI of the cervical vertebra at the level of the lower edge of the cricoid cartilage. Sometimes, the external and internal carotid arteries do not depart from the common trunk, but independently from the aorta, which reflects the nature of their development. From the trunk a. carotis communis all over the small branches for the surrounding vessels and nerves – vasa vasorum and vasa nervorum, which can play a role in the development of collateral circulation around the neck.

The branches of the aortic arch. Shoulderhead. The branches of the ascending part of the aorta. Since, according to the law of the shortest distance, the heart from which it comes out lies closest to the aorta, the first vessels extending from the aorta are its branches to the heart – aa. coronariae dextra et sinistra, described above.

The branches of the aortic arch. From the concave side of the aortic arch, the arteries move to the bronchi and to the thymus, and from the convex side of the arch, three trunks go from right to left: truncus brachiocephalicus, a. carotis communis sinistra and a. subclavia sinistra.

The brachiocephalic trunk, truncus brachiocephalicus, about 3–4 cm long, represents the remnant of the right ventral aorta of the embryo; it goes obliquely up, back and to the right, being located in front of the trachea, where it gives a branch to the thyroid gland – a. thyroidea ima, and is divided behind its right branches: right common carotid and right subclavian arteries behind the right sternoclavicular joint.

Pulmonary veins. Venae pulmonales, pulmonary veins, carry arterial blood from the lungs to the left atrium. Starting from the capillaries of the lungs, they merge into larger veins, reaching the bronchi, segments and lobes, respectively, and in the gates of the lungs they form large trunks, two trunks from each lung (one is the top, the other is the bottom) to the left atrium and fall into its upper wall, each trunk flows into a separate hole: the right – at the right, left – at the left edge of the left atrium. The right pulmonary veins on the way to the left atrium cross transversely the back wall of the right atrium. The symmetry of the pulmonary veins (two on each side) is obtained because the trunks extending from the upper and middle lobes of the right lung merge into one trunk. The pulmonary veins are not completely separated from the veins of the pulmonary circulation, as they anastomose with the bronchial veins flowing into the v. azygos. Valves pulmonary veins do not have.

Arteries of the small (pulmonary) circulation. Pulmonary trunk. The pulmonary trunk, truncus pulmonalis, carries venous blood from the right ventricle to the lungs. It is a continuation of the truncus arteriosus and is directed obliquely to the left, crossing the aorta lying behind it. The location of the pulmonary trunk in front of the aorta is explained by the fact that the truncus pulmonalis develops from the ventral part of the truncus arteriosus, and the aorta from the dorsal. Having passed 5 – 6 cm, the pulmonary trunk is divided under the aortic arch at the level of the IV – V thoracic vertebra into two terminal branches – a. pulmonalis dextra and a. pulmonalis sinistra, each going to the corresponding lung. The right and left pulmonary arteries develop from 6 arterial arcs laid in the embryonic life. The right one, longer, passes to the right lung behind aorta ascendens and the superior vena cava, the left one in front of aorta descendens. Passing to the lungs, a. pulmonalis dextra and a. pulmonnalis sinistra are again divided into branches to the corresponding lobes of the lungs and to the pulmonary segments and, accompanying the bronchi, branch into the smallest arteries, arterioles, precapillaries and capillaries. To the site of division, truncus pulmonalis is covered with a leaf of pericardium. From the site of division to the concave side of the aorta, the connective tissue cord stretches – lig. arteriosum, which is obliterated ductus arteriosus.