Circulatory system (english), Appunti di Anatomia

Scarica Circulatory system (english) e più Appunti in PDF di Anatomia solo su Docsity! • APICE CARDIOVASCULAR SYSTEM organs that I find in cavities closed circuit system (inside the organs I find the blood, it does not come out of the organs that make up the system) the cardiovascular system includes: 1. blood. smooth connective tissue 2. blood vessels. system of vessels through which blood flows under the pressure of the heart 3. heart. organ responsible for the heart BLOOD VESSELS are classified according to the direction in which the blood flows (it is incorrect to classify them according to whether they carry oxygenated or deoxygenated blood): Ÿ ARTERIES. vessels originating from the heart carry blood away from the heart. Their wall consists of 3 layers: - tunica intima, more internally made up of endothelium - medium tunic - external tunic smooth muscle in the artery wall is able to contract (vasoconstriction) and relax (vasodilation) Ÿ VEINS. vessels to the heart carry blood to the heart. They differ from arteries for a less important muscular component and for the presence of dovetail valves that prevent the downward flow of blood. CAPILLARIES are very thin ducts whose wall is made up of a single layer of endothelial cells, at the level of the capillaries exchanges of material take place between the blood and the interstetial tissue HEART. defined as a pump because through its rhythmic contractions it is able to make the blood flow inside the hollow structures which are the blood vessels. location: lies within a ventral body cavity (chest cavity, cavity that lies above the diaphragm). located in the center and slightly shifted to the left between the two lungs, in a space called the mediastinum. tip or apex of the heart (left and anterior) base of the heart (widest part, where the great vessels originate) upper and posterior and central part The major axis of the heart is therefore oblique from the heart (which is a hollow organ), the great vessels originate and arrive: PULMONARY CIRCULATION right heart - lungs - gas exchange - left heart the right half contains venous blood. pumps its contents within a series of vessels that form the pulmonary circulation which has the function of oxygenating the blood from the right side (right ventricle) originate oxygen-poor pulmonary arteries (from the right heart to the lungs) the pulmonary veins instead carry blood from the lungs to the left heart, rich in oxygen SYSTEMIC CIRCULATION left heart - extremities - right heart the left half contains arterial blood, rich in oxygen Blood is pumped through a series of hollow structures towards the body's tissues and organs. the aorta originates from the left ventricle and runs at the thoracic and abdominal level branching out (the branches vascularize all the tissues). the deoxygenated blood is collected from the superior and inferior vena cava and drained towards the right heart the heart is made up of cells capable of inducing and maintaining involuntary contraction. despite being composed of striated musculature (which is generally voluntary), it is an involuntary organ. The walls of the heart chambers are made up of: - endocardium (innermost layer) - myocardium (striated cardiac muscle tissue) it is surrounded by the pericardium (membranous structure of connective tissue that surrounds the heart). composed of two components: - fibrous, fixes the heart to the diaphragm - serous, mesothelium (in the body they make up the pericardium, pleura, peritoneum). near the heart wall. sac that externally covers the myocardium and has two layers (visceral and parietal) between the two sheets I have a space containing the pericardial fluid whose function is to lubricate the cardiac contraction (pericardial cavity). the pericardium also covers where the great vessels emerge from the heart. between the atria and ventricles, in a groove (called coronary) externally I find adipose tissue. in this sulcus the coronary arteries run which deal with the vascularization and nourishment of the heart wall. There is another sulcus between the ventricles and it is the anterior interventricular sulcus (coronaries flow here too) posteriorly I recognize the posterior interventricular sulcus. I see vessels that have direction towards the heart (veins). on the right I see superior and inferior vena cava (point of arrival of the systemic circulation in the right atrium). on the left there are 4 vessels that transport oxygenated blood (pulmonary veins) the heart comprises four cavities. The two upper ones are called the right atrium and the left atrium respectively and are separated by a thin wall called the interatrial septum. the lower two are cavities the right ventricle and the left ventricle separated by the interventricular septum. The right atrium is in communication with the right ventricle through a valve (formed by connective tissue), called the tricuspid valve (because it is made up of three flaps), which allows blood to pass from the atrium to the ventricle, but not in the opposite direction. The left atrium communicates with the left ventricle through the bicuspid valve or mitral valve (because it is formed by two flaps whose shape resembles that of the mitre, the bishop's headgear). the two flaps of these two valves are held by thin strands of connective tissue, called tendinous cords that insert into the myocardium of the ventricles a difference between arteries and veins is the presence of dovetail valves: they allow the correct flow of venous blood avoiding reflux. skeletal muscles contribute to blood flow SYSTEMIC CIRCULATION. it originates from the left heart and more precisely from the aorta. from this originate collateral branches at the abdominal level, at the pelvic level it bifurcates (terminal branches because the artery ends here: illiac arteries) ARTERIES (description starts from the heart to the periphery) Ÿ AORTA. large arterial vessel originating from the left ventricle - ascending aorta : first section upwards (from these originate coronary arteries) - aortic arch gives rise to three collateral branches: innominate or branchiocephalic artery left carotid artery left subclavian artery. go to vascularize the brain and upper limb - descending aorta : the aorta moves to the left of the vertebral column (thoracic part above the diaphragm and abdominal part below the diaphragm) it crosses the diaphragm until it reaches the terminal branches. - abdominal aorta (above the diaphragm) even branches (originating laterally) or uneven branches (originating anteriorly) branch from the aorta. 1. celiac trunk, uneven, branches into 3 arteries: left gastric artery (stomach), splenic or splenic artery (spleen) and common hepatic artery (liver but not only that). 2. uneven branch that supplies the diaphragm: inferior fremic artery 3. unequal branch superior mesenchemic artery supplying intestine. 4. two branches equal renal arteries 5. paired genital arteries 6. unequal branch of inferior mesenchemic artery (intestine). - two terminal branches are common iliac arteries: internal (genitals) and external (lower limb) - thoracic aorta . the lungs are supplied by bronchial arteries, a branch supplies the diaphragm (superior phremic artery) A RCO AORTICO AORTA ASCENDENTECAROTIDE DI SX CORONARIE ILIACA INTERNA ILIACA ESTERNA Ÿ subclavian artery supplies blood to the upper limb and part of the chest wall. From the subclavian artery originates vertebral artery and axillary artery which continues at the level of the arm (brachial artery). The brachial artery branches into two branches: the lateral radial artery and the ulnar artery. In the hand these anaxomize (the two vessels exchange blood) Ÿ carotid and vertebral arteries (it is one of the vessels which, together with the internal carotid artery, supplies blood to the brain through the foramen magnum). The vertebral artery passes through the transverse holes of the cerebral vertebrae. it is important that the blood supply is constant in pressure and volume. From the carotid canal enters a branch of the common carotid artery (internal carotid artery). The external carotid artery supplies blood to the face. the right and left part of the brain communicate with each other through the vessels between the carotids and the vertebral polygon of Willis or circle of Willis. ensures proper vascularization of the brain Ÿ lower limb. common illiac arteries branch into internal iliac (supplies the pelvis) and external iliac (supplies - ARCATA ANASTOMOSI CA lower limb, thigh) this continues in the femoral artery which at the level of the knee branches into the tibial artery and the peroneal artery. At foot level, it is formed in the anastomotic arch. * where I have joints that allow me to make large movements there are anastomosing mechanisms between the vessels PULMONARY CIRCULATION. originally made up of arteries (pulmonary artery) that carry deoxygenated blood to the lungs. at the level of the lung parenchyma the blood is oxygenated from orifine to the pulmonary veins which lead to the right side of the heart (4 pulmonary veins) VEINS OF THE SYSTEMIC CIRCULATION. Cetripeta direction. Venas cavae carry blood to right atria veins are satellites of arteries, except for blood vessels that carry waste blood from the head: external and internal jugular. one on the right and one on the left flow into the brachiocephalic vessel. the two brachiocephalic trunks join together giving rise to a large caliber vein (superior vena cava). in the upper limb the two main vessels of the forearm and arm are: - cephalic vein, flows into the axilla at the point where it joins the subclavian - basilic vein, runs medially, this also goes into the axillary. at elbow level I have anastomosis. median cubital vein (from which samples are taken). - inferior vena cava carries waste blood from the abdomen, pelvis and lower limb. lower limb veins. as regards surface crcolazione we have: - the saphenous (large, near the medial malleolus and continues up the thigh until it flows into the femoral vein in the groin and small near the lateral malleolus and flows into the deep circulation at the posterior level of the knee in the popliteal vein)