Circulatory System PDF

3/21/2022 The circulatory system ❖ Is divided into 1. The cardio...

3/21/2022 The circulatory system ❖ Is divided into 1. The cardiovascular system The heart Blood & blood vessel 2. The lymphatic system, which Circulatory System consists of lymph vessels lymph nodes Lymphatic organs and lymph 2 Major Parts of the Cardiovascular Components of Blood ▪ Plasma - 55% system ▪ Formed elements(cells) - 45% Blood ✓ Erythrocytes -red blood cells (RBCs) ▪ It is a specialized fluid connective tissue ✓ Leukocytes -white blood cells (WBCs) ▪ It is denser & more viscous (thicker) than water and feels ✓ Thrombocytes-platelets slightly sticky Function of Blood 1. Transports oxygen, carbon dioxide, nutrients, hormones, heat, and wastes. 2. Regulates pH, body temperature and water content of cells. 3. Protects Against blood loss through clotting Against disease - phagocytic white blood cells & antibodies. 3 1  3/21/2022 Components of Blood… Components of Blood… Blood Cells (formed elements) Blood Plasma I. Red blood cells ▪A straw-colored (yellowish translucent) liquid II. White blood cells when the formed elements are removed from blood A. Granular leukocytes ▪ Composition 1. Neutrophils Water - 91.5% 2. Eosinophils Solutes - 8.5% includes plasma proteins like 3. Basophils Albumins, Globulins, Fibrinogen and other electrolytes B. Agranular leukocytes ▪ Serum - is the same as blood plasma except that 1. Lymphocytes clotting factors have been removed 2. Monocytes III. Platelets 5 6 Erythrocytes (RBC) Erythrocytes (RBC)… ▪ Lack nuclei and other organelles Life span ▪ Packed with hemoglobin- the O2-carrying protein Approximately 120 days, after which o Constitute ̴ 33% of the cell’s weight. ✓ ~90% of them are phagocytosed by macrophages in the ▪ Diameter - approximately 7.5µm spleen, bone marrow, and liver ▪ Shape - biconcave disks -This biconcave shape ✓ the remaining ~ 10% break down intravascularly, releasing o provides a large surface-to-volume ratio and insignificant amounts of hemoglobin into the blood o facilitates gas exchange. 8 7 2  3/21/2022 Leukocytes (white blood cells) Classification of WBC 1. Polymorphonuclear granulocytes ▪ have polymorphic nuclei with two or more lobe ▪ Includes neutrophils, eosinophils, and basophils ▪Possess two types of granules A. Specific granules that bind neutral, basic, or acidic stains have specific function B. Azurophilic granules, which are specialized lysosomes & stain darkly present at some level in all leukocytes ▪ Act collectively to kill and digest phagocytosed microorganisms 9 10 Classification of WBC… Neutrophils 2. Mononuclear agranulocytes ▪ Constitute 60–70% of circulating leukocytes. ▪ do not have specific granules but they do contain azurophilic ▪ They are dynamic granules (lysosomes) ▪ Nuclear shape - changes frequently ▪ Includes lymphocytes and monocytes ▪ Have 12µm–15µm diameter in blood smears ✓ Both types of WBCs are spherical while suspended in blood ▪ With nuclei having two to five lobes linked by plasma, but become amoeboid and motile after leaving the thin nuclear extensions blood vessels and invading the tissues ▪ Their cytoplasm contains specific and azurophilic granules ▪ Neutrophils are short-lived cells with a half-life of 6-7 hrs. in blood and 1–4 days in connective tissues before dying by apoptosis 11 12 3  3/21/2022 Neutrophils Eosinophils Function of neutrophils ▪ Constituting only 2–4% of leukocytes ▪ Have same size as a neutrophils ▪ Usually the first leukocytes to arrive at sites of infection ▪ Have bilobed nucleus ▪ Neutrophils are active phagocytes of bacteria ▪ Can kill bacteria and help clean up debris in poorly ▪ Have abundance of large, red specific granules also includes some azurophilic granules in their cytoplasm oxygenated regions, eg, inflamed or necrotic tissue by ▪ Have cytotoxic effects on parasites such as helminthic releasing chemicals such as Lysozyme, strong oxidants worms and protozoa. ▪ An increase in the number of eosinophils in blood (eosinophilia) is associated with allergic reactions and helminthic (parasitic) infections 13 14 Basophils Lymphocytes ▪ Constitute 20–25% of WBCs ▪ Make up less than 0.5–1% of blood leukocytes, ▪ have spherical nuclei ✓ difficult to find in smears of normal blood. ▪ They are agranulocytes and lack the specific granules ▪ Basophils are about 12µm–15µm in diameter ▪ Classified as ▪ Have large cytoplasmic granules ✓T lymphocytes ✓ B lymphocytes and ▪ The nucleus is divided into two or more irregular ✓ Natural killer (NK) cells lobes, but the large specific granules overlying the nucleus usually obscure its shape ▪ They are the only type of leukocytes that, following ▪ Have granules containing heparin and histamine diapedesis, can return from the tissues back to the blood (mediators of inflammation) 15 16 4  3/21/2022 Monocytes Platelets (thrombocytes) ▪ Are bone marrow–derived agranulocytes ▪ Are nonnucleated, disk like cell fragments ▪ 3–8% of all WBCs ▪ 2µm–4µm in diameter. ▪ 2µm to 20µm in diameter (the largest of the WBCs) ▪ Platelets originate by fragmentation from megakaryocytes ▪ The nucleus is large, off-center, and may be oval, kidney- in the bone marrow. ▪ Normal platelet counts 200,000 - 400,000 per µL of blood. shaped, horseshoe shaped or U-shaped ▪ Life span - about 10 days. ▪ Cytoplasm of the monocyte contains very small Function azurophilic granules (lysosomes) ▪ Promote blood clotting and help repair minor tears or ▪ After crossing the walls of postcapillary venules, monocytes leaks in the walls of blood vessels, preventing loss of differentiate into macrophages in connective tissues, blood. microglia in the CNS, osteoclasts in bone, etc 17 18 ▪ Muscular, 4 chambered organ The Heart ▪ Wt 300 g [clenched fist) The mediastinum ▪ 2 cm long, 9cm wide & 6 cm thick ▪ Has apex, and base ▪ Located in the mediastinum ▪ 2/3rd on left side of the body, 19 20 5  3/21/2022 The Heart: location & protection Pericardium… Pericardium (peri = around) The serous pericardium ▪ A fibro-serous sac surrounding heart & roots of great vessels. is a thinner membrane which forms a double layer ▪ It consists of two principal portion: ❖ Parietal layer the fibrous pericardium ✓ is the outer serous pericardium the serous pericardium ❖ Visceral layer ▪ Fibrous pericardium The inner serous pericardium is tough inelastic, dense irregular connective tissue, which looks like a bag. adheres tightly to the surface of the heart. It rests & attaches to the diaphragm: ❖ Pericardial fluid ▪ Function of fibrous pericardium is a fluid in the cavity b/n two layers of pericardium prevents overstretching of the heart is important to reduce friction b/n the heart and the outer layers and also prevent the heart from external provides protection pressure. anchors the heart in the mediastinum 21 22 Pericardium… Layers of the heart wall… The heart contain 3 distinct layers: ❖Epicardium thin, external membrane around the heart allow protection against friction by rubbing organs ❖Myocardium thickest layer; consists of cardiac muscle. i.e. the bulk of the heart wall. It is involuntary muscle responsible for the ability of the heart to contract ❖ Endocardium a thin innermost layer; a unique type of epithelial tissue (endothelium) that lines the entire circulatory system 23 24 6  3/21/2022 Sulci of the heart Layers of the heart wall Sulci of the heart - are surface or external grooves 1. The coronary sulcus ✓ circles the heart, separating the atria from the ventricles. ✓ it contains the right coronary artery, the small cardiac vein, the coronary sinus, and the circumflex branch of the left coronary artery. 2. The interventricular sulci ✓ separate the two ventricles ▪ Anterior interventricular sulcus ✓ contains the anterior interventricular artery and the great cardiac vein ▪ Posterior interventricular sulcus ✓ is on the diaphragmatic surface of the heart ✓ contains posterior interventricular artery and middle cardiac vein. 25 26 Sulci of the heart Sulci of the heart 27 Diaphragmatic surface and base of the heart 28 7  3/21/2022 Blood supply of the Heart Blood supply of the Heart The Anterior Interventricular A. (AIVA) ▪ The heart is supplied by two major coronary arteries, ▪ lies in the anterior interventricular sulcus & is also known as ✓ Rt & Lt coronary aa. the Lt anterior descending a. ▪ Left coronary artery: divide into ▪ It supplies wall of right & left ventricles, interventricular ✓ Ant. interventricular & septum & apex of the heart. ✓ Circumflex branches. ▪ It is the most often involved in coronary occlusions & is often the that is bypassed in cardiac bypass surgery. The circumflex branch ▪ lies in the coronary sulcus ▪ Supplies walls of LA & LV & forms an anastomosis with the right coronary a. 29 30 Blood supply of the Heart Blood supply of the Heart Right coronary a. Right Coronary Artery ▪ Lies in the coronary sulcus ▪ supplies Rt atrium & Rt ventricle, sinoatrial & atrioventricular ▪ Immediately after leaving ascending aorta gives rise to nodes, interatrial- septum, a portion of Lt atrium, ➔anterior right atrial: which gives rise to the important nodal posteroinferior one-third of interventricular septum, & a artery. portion of posterior part of Lt ventricle. ▪ ➔ nodal artery supplies the sinoatrial node (SA node) or pacemaker of the heart. ▪ When the nodal artery fails to supply the node, an artificial pace maker, is required. 31 32 8  3/21/2022 Venous drainage of the heart Venous drainage of the heart o About 2/3rds drain into the coronary sinus in the coronary sulcus, located posteriorly. ➔ The coronary sinus opens into the right atrium. ▪ Veins that drain into the coronary sinus include: ✓ Great cardiac vein – accompanies anterior interventicular a. ✓ Middle cardiac vein – accompanies posterior interventricular a. ✓ Small cardiac vein – accompanies right marginal artery, ✓ Posterior left ventricular vein ✓ Oblique vein of left atrium. o About 1/3 of the blood drains by small veins directly into the cardiac cavity: ✓ Anterior cardiac vein → drain into right atrium, ✓ Venae cordis minimae → drain into all chambers, mainly atria. 33 34 Chambers of the heart Valves of the Heart 1. Atrioventricular valves(AV) ▪ The heart has four chambers ✓ b/n atria and ventricles ✓ two upper chambers- atria ✓ have chorda tendenae ✓ two lower chambers- ▪ Right- atrioventricular valve (tricuspid valve) ventricles ✓It has an anterior, posterior & septal cusps ▪ Interatrial septum ▪ Left atrioventricular valve (Mitral /bicuspid valve) separates the atria ✓ Has the anterior and posterior cusps ▪ Interventricular septum 2. Semilunar valves separates the ventricles o do not have chorda tendenae ▪ Pulmonary valve ▪ Atrioventricular septum ✓Consists the left, right and anterior semilunar cusps separates the atria & the ▪ Aortic valve ventricles ✓ Consists the left, right and posterior semilunar cusps 35 36 9  3/21/2022 Valves of the Heart… Valves of the Heart… Right ventricle Left ventricle 37 38 Valves of the Heart… Conducting System of the Heart ▪ The heart has a specialized system to generate a rhythmic stimulus for contraction that is spread to the entire myocardium. ▪ This system consists of o Two nodes located in the right atrium ✓ Sinoatrial (SA) node (pacemaker) ✓ Atrioventricular (AV) node o Atrioventricular bundle (of His)- splits into ✓ Left & right bundle branches ✓ Conducting myofibers or Purkinje fibers 39 40 10  3/21/2022 Conducting System of the Heart… Conducting System of the Heart… 41 42 Blood vessels (bvs) The SA node sends out a stimulus, which cause the ▪The three types of blood vessels atria to contract. ✓ Arteries When this stimulus reaches ✓ Capillaries the AV node, it signals the ✓ Veins ventricles to contract. Impulses pass down the two branches of the atrioventricular bundle to the Purkinje fibers, and thereafter the ventricles contract. 43 44 11  3/21/2022 Arteries Blood vessels (bv)… ▪ Tunics/histological layers of blood vessels ▪ A series of efferent vessels that carry the blood away from the Wall of arteries and veins, composed of 3 distinct layers (tunics): heart to the tissues 1. Tunica adventitia or tunica ▪ An artery has a thicker tunica media and relatively narrow externa; outer layer lumen than a corresponding vein ✓ Consists principally of type I collagen and elastic fibers. ▪ Most tissues of the body receive blood from more than one 2. Tunica media; middle layer artery. ✓ most variable of the tunics ▪ Anastomosis = The union of the branches of two or more ✓ consists chiefly of concentric arteries supplying the same body region layers of helically arranged ➔Provide alternate routes – collateral circulation smooth muscle cells ➔ Veins anastomose much more freely than arteries ✓ In arteries, the media has a thinner external elastic lamina, which separates it from the tunica adventitia 45 46 Blood vessels (bv) … Compare A VS V 3. The tunica intima (tunica interna); Inner layer ▪ Has ▪ Endothelium - innermost layer of simple squamous epithelium ▪ Basement membrane - deep to the endothelium. ✓ The basal lamina anchors the endothelium to the underlying connective tissue ▪ Internal elastic lamina - thin outermost part , sheet of elastic fibers ✓In arteries, the intima is separated from the media by an internal elastic lamina 47 48 12  3/21/2022 Blood vessels (bv) … Capillaries ▪ Large vessels usually have vasa vasorum ("vessels of the ▪ They have no tunica media & externa vessel") in the tunica adventitia and the outer part of the media ▪ Have endothelium and basement membrane in the tunica intima → Endothelium; simple squamous epithelium ▪ Because of their thin walls and slow blood flow, capillaries are a favorable place for the exchange of ✓ water, solutes, and macromolecules b/n blood and tissues 49 50 Types of Capillaries Types of Capillaries Three types of capillary ▪ Depending on the continuity I. The continuous (tight) capillary of the endothelial cells & the ✓ Characterized by the distinct continuity of the endothelial basement membrane cells in its wall 1. Continuous – most common ✓ Allows regulated exchange of materials 2. Fenestrated – have pores 3. Sinusoids(discontinuous) ✓ Found in all kinds of muscle tissue, connective tissue, exocrine glands, and nervous tissue (a) Continuous 51 52 13  3/21/2022 Types of Capillaries Types of Capillaries II. Fenestrated capillary III. The sinusoid or discontinuous capillary ✓ Characterized by the presence of small circular fenestrae ✓ Endothelial cells have large fenestrae without diaphragms ✓ Each fenestra is usually covered by a very thin diaphragm ✓ The cells form a discontinuous layer and are separated from ✓ The fenestrae allows more extensive molecular exchange one another by wide spaces across the endothelium ✓ The basal lamina is also discontinuous. ▪ Found in tissues where rapid interchange of substances ✓ Sinusoids are irregularly shaped occurs b/n the tissues and the blood. ✓ Have diameters as large as 30–40µm ✓ Blood flows slowly at this site eg. Like in the kidney, ✓ Permits maximal exchange of the intestine, macromolecules b/n tissues and blood the choroid plexus & the endocrine glands ▪ Found in the liver, spleen, bone marrow & some endocrine organs (ant. pitutary, parathyroid gld), 53 54 Veins Veins Valve ▪ Blood vessels that return blood back to the heart closed ▪ Blood entering veins is under very low pressure and moves toward the heart by contraction of the tunica media and Valve opens above external compressions from surrounding muscles and other contracting muscle organs Valve closed ▪ Vein has a larger lumen and its tunica externa is the thickest layer ▪ Valves project from the tunica intima (folded) to prevent back-flow of blood. Valve closes below ✓ Numerous in veins of the legs contracting muscle 55 56 14  3/21/2022 Principal Arteries of the body Aorta: has three parts ❖ Ascending aorta ascends from the heart (left ventricle) The coronary arteries are the only branch of the ascending Principal Arteries of the body aorta that supplies the heart ❖ Aortic arch Three vessels arise from the aortic arch: ✓ the brachiocephalic artery–further bifuricates into Right subclavian and common carotid aa that supply the right upper limbs and head regions ✓ left common carotid artery ✓ left subclavian artery ❖ Descending aorta (thoracic & abdominal) 57 58 Arteries of the neck and head  Common carotid artery Ascends upwards in the neck lateral to trachea Divides at the superior border of the larynx, into  the internal carotid artery and  the external carotid artery  The brain is supplied by four arteries: Paired vertebral arteries (i.e., right and left) which forms basilar artery and Paired internal carotid arteries. 59 60 15  3/21/2022 Arteries of the neck and head 1.The vertebral artery arises from the subclavian artery ascends in the neck through the transverse foramen enters the cranial cavity through the foramen magnum. The right and left vertebral arteries unite to form the basilar artery. 61 62 Arteries of the neck and head… The internal carotid arteries ▪ is divided into ▪ the ophthalmic artery supplies the eye, and ▪ the anterior and middle cerebral arteries supply the cerebrum. The external carotid branches are named according to the area or structures they supply Superior thyroid artery supply hyoid, larynx, vocal cords, thyroid gland. 63 64 16  3/21/2022 Arteries of the neck and head… Arteries of the neck and head… The external carotid … Ascending pharyngeal artery - supply pharyngeal area Lingual artery -supply tongue and sublingual gland Facial artery- supply pharyngeal, palate, chin, lips, nasal region Occipital artery supply scalp (posteriorly), meninges, mastoid region, some of the posterior neck muscles Maxillary artery supply teeth, gums, muscles of mastication, nasal cavities, eyelids Superficial temporal artery supply parotid gland, side of the head. 65 66 Arteries of the upper limbs Arteries of the upper limbs… Right subclavian- from brachiocephalic. The brachial artery bifurcates at and the cubital fossa into: left subclavian- from aortic arch. Radial artery- supplies muscles It has the several branches in the thorax on the radial side of the forearm. but becomes the axillary artery as it It is the site of measuring pulse. passes in the axilla. Ulnar artery – supplies muscles At the inferior border of the teres major muscle on the ulnar side of the forearm. Both arteries form →It becomes the brachial artery in the arm. ✓ palmar arch in the palm and Site for BP(blood pressure) digital arteries supplying the measurement. digit 68 17  3/21/2022 Arteries of the upper limbs… Arteries of the upper limbs… 69 70 Branches of thoracic aorta It is a continuation of the aortic arch descends though the thoracic cavity to diaphragm gives branches to the muscles (post. Intercostal aa.) and organs of thoracic region; Pericardial artery supply the pericardium of heart, Bronchial artery supply the lungs. (systemic/pulmonary circulation?) 71 72 18  3/21/2022 Branches of abdominal aorta Branches of abdominal aorta Has three unpaired midline branches Three unpaired Other paired branches 1. Celiac trunk short, thick, branch, which divides into three vessels: ✓ Splenic artery (to spleen) ✓ Left gastric artery ( to stomach) ✓ Common hepatic (to liver) 73 74 Branches of abdominal aorta… Branches of abdominal aorta… 3. Superior mesenteric a. to the small intestine, cecum, appendix, ascending colon, and Transverse(2/3) ➔ Midgut Six branches 1. Inferior Pancreaticoduodenal a. 2. Middle Colic a. 3. Right Colic a. 4. Ileocolic a. 5. Jejunial a. 75 6. Ileal a 76 19  3/21/2022 Branches of abdominal aorta 3. Inferior mesenteric a. last major, anterior, unpaired branch just before ▪ Divisions of the GIT into bifurcation into the foregut, midgut & hindgut; common iliac a. Supplies half part of the ➔ summarizing the primary transverse colon, the arterial supply to descending, and sigmoid each segment colons, rectum Three Branches 1. Lt colic a. 2. Sigmoidal a. & 3. Superior rectal a. 77 78 Branches of abdominal aorta… Arteries of the pelvis and lower limbs ▪ The abdominal aorta terminates by bifurcating into ✓ right common iliac artery ✓ left common iliac artery ▪ The common iliac aa. divides into ✓ internal iliac and ✓ external iliac. (Anterior & posterior branches) Paired branches Renal artery– to kidney; Testicular a. (M) - to testes Ovarian a. (F) - to ovaries; Suprarenal a. - to adrenal glands 79 80 20  3/21/2022 ❖ The internal iliac artery Arteries of the pelvis and lower limbs.. supply gluteal muscles and organs of the pelvic region Urinary bladder, rectum, anal canal The external iliac artery Passes out of pelvis beneath the inguinal ligament to become the femoral artery Femoral artery Passes through the femoral triangle on the upper medial portion of the thigh. At this point it is close to the surface, hence for palpation and pressure. It becomes the popliteal artery as it passes across the 81 posterior aspect of the knee. 82 Arteries of the pelvis and lower limbs.. The popliteal artery Divides into the ✓ anterior tibial and ✓ posterior tibial arteries ▪ The anterior tibial artery at the ankle, becomes ✓ the dorsal pedal artery ✓ forms the plantar arch with the lateral plantar artery of the posterior tibial artery. ✓ The dorsal pedal artery is the site from which the most distal pulse is recorded to get information about circulation. 83 84 21  3/21/2022 Arteries of the pelvis and lower limbs.. ▪ The posterior tibial artery ✓ forms the large fibular a. which supplies peroneal muscles of the Venous drainage of leg. ✓ At the ankle it bifurcates into the body the lateral and medial plantar arteries. ✓ The lateral plantar artery forms the plantar arch and gives off digital arteries to the digits of the foot. 85 Veins Draining the neck and head Veins Draining the neck and head ▪ External jugular vein from scalp, portions of face, superficial neck region drain into right and left subclavian vein. ▪ Internal jugular vein from brain, meniges, deep regions of face and neck larger and deeper than the external jugular vein passes in carotid sheath with the common carotid and vagus nerve beneath sternocleidomastoid muscle ▪ Subclavian vein and internal jugular unite to form the brachiocephalic vein ▪ the two brachiocephalic veins merge to form the superior vena cava, which empties into the right atrium 87 88 22  3/21/2022 Veins of the upper extremity Veins of the upper extremity… Consists of superficial and deep venous drainage Superficial veins of UL 1. Basilic vein ▪ Deep veins drains blood from ulnar side of forearm, medial side of arm Accompany the arteries and bear their names / region merges with brachial vein near to head of humerus to form radial vein & ulnar vein axillary v. ✓ both drain from deep and superficial palmar arches 2. Cephalic vein ✓ radial and ulnar veins join in cubital fossa to form brachial drains superficial region of hand and forearm on radial side vein, which continues up on the medial side of arm. joins axillary vein in the shoulder region Brachial vein -axiliary → subclavian + internal jugular → median cubital vein ascends from the cephalic vein to join basilic vein. brachiocephalic ✓ It is a site of venipuncture 89 90 Veins of the thorax ▪ Superior vena cava receives blood from the right and left brachiocephalic veins, which drain head, neck, and upper limb as well as from azygous veins. lacks valves which are characteristics of most veins ▪ The azygous vein extends superiorly along the dorsal abdominal and thoracic walls on the right side of the vertebral column joins the superior vena cava at T4. 91 92 23  3/21/2022 Veins of the thorax… Veins of the thorax… ▪ The azygous vein… From left of the vertebral column Its tributaries are: Hemiazygous vein Ascending lumbar veins - drain from lumbar and sacral region ▪ It receives from 9-11 left posterior intercostal veins and the All of the right posterior intercostal veins (except the first), subcostal vein. Intercostals veins- from intercostals regions Accessory hemiazygous ▪ It is superior part of hemiazygus vein ▪ Receiving 4/5 -8 left posterior intercostal veins ➔Both hemi and accessory azygus courses to the right to join the azygos. 93 94 Veins of the lower extremity Veins of the lower extremity Have a deep and a superficial group The deep veins The deep veins ❖ These include: … accompany the corresponding arteries ▪ The femoral vein ❖ These include: ✓ receives blood from the deep femoral vein and above this, ▪ Posterior and anterior tibial veins originate in the foot and descend upwards in front of the tibia to the receives from the great saphenous vein, then becomes back of the knee where they merge to form the popliteal vein. the external iliac vein. ▪ Popliteal vein ▪ The external iliac vein drains blood from the knee region and above the knee, it becomes the ✓ merges with the internal iliac vein to form the common femoral vein iliac vein 95 96 24  3/21/2022 Veins of the lower extremity… The superficial vein include ▪ Small saphenous vein arises from the lateral side of the foot, courses posteriorly along the surface of the calf of the leg and enters deep into the popliteal vein behind the knee. ▪ Great saphenous vein longest vessel in the body, originates at the arch of the foot and ascends superiorly along the medial aspect of the leg and thigh before draining into the femoral vein. 97 98 Veins of the Abdominal Region Veins of the Abdominal Region… ❖ The inferior vena cava Paired lumbar veins parallels the abdominal aorta on the right as it ascends Right and left Renal veins through the abdominal cavity. Right and left testicular veins (M) It penetrates the diaphragm and empties into the right atrium Right and left ovarian veins(F) largest in diameter of all vessels in the body Right and left suprarenal veins in the abdomen has tributaries corresponding to the Right and left Inferior phrenic vein branches of the abdominal aorta. Right and left hepatic veins (Exceptions: the left testicular vein, left ovarian vein and the left suprarenal vein drain into the left renal vein) 99 100 25  3/21/2022 Veins of the Abdominal Region… Hepatic portal system Portal vein  is a vein which drains the abdominal part of alimentary canal except the lowest part of rectum and anal canal.  It carries products of digestion of carbohydrates and proteins to the liver and contains one–third of the total volume of blood in the body.  It is formed behind the neck of the pancreas by union of splenic and superior mesenteric veins. 101 102 103 104 26  3/21/2022 Fetal Circulation: Fetal Circulation… Two major differences between fetal and postnatal circulation: I. The fetus must supply blood to the placenta Pair of umbilical arteries carry deoxygenated blood II. Because the fetal respiratory organ is the placenta and the & wastes to placenta. Umbilical vein carries fetus does not breathe, its lungs do not need much blood. oxygenated blood and nutrients from the Umbilical Vessels placenta. The fetal vessels that carry blood to and from the placenta The placenta -facilitates gas and nutrient exchange → Paired umbilical aa. & unpaired v between maternal and fetal blood. 105 106 Fetal Circulation: Shunts Away from the Pulmonary Circuit Foramen ovale: → some of the blood is shunted from right to left atrium Ductus arteriousus The blood pumped from the right ventricle to pulmonary trunk. Most of this blood is shunted into the aortic arch through the ductus arteriousus. 107 108 27  3/21/2022 Adult derivatives of fetal circulation Adult derivatives of fetal circulation Fetus Adult Foramen ovale Fossa ovale Ductus arteriosus Ligamentum arteriosum Umbilical aa. Medial umbilical ligaments Umbilical v. Round ligament (ligamentum teres) Ductus venosus Ligamentum venosum (within liver) 109 110 The lymphatic system Lymph ❖ Its components includes : Lymph means Fluid (clear water) of the lymphatic system Lymph Lymphatic Organs is similar in composition to blood plasma& interstitial fluid Lymph Vessels ▪ The only difference is Protein concentration of lymph is lower Lymphatic Tissues Function: than in plasma and rate of formation -Transport of fluid back to the body against gravity The fluid is in the blood stream- plasma - Immunological function - Absorption of vitamins & minerals The fluid is b/n the cell –interstitial fluids - Draining fluid into the bloodstream A fluid when it pass in the lymphatic system is Lymph - Filtering lymph - Filtering the blood 111 112 28  3/21/2022 Types of Lymphatic organs Lymph Nodes ▪ a number of small swellings(bean shaped) found at intervals Primary lymphatic organs, site where Lymphocytes are along the lymphatic system. formed They are widely distributed throughout the body along the ▪ it includes lymphatic pathways. Thymus gland ▪ Composed of lymphoid tissue Bone marrow Secondary lymphatic organs The reticular tissues contain phagocytic cells which filter or sites where lymphocyte activation and proliferation Occur purify the fluid(lymph). most immune response also occur Afferent lymphatic vessels carry lymph to the lymph nodes Encapsulated, include the spleen , lymph nodes, and lymphatic nodules. Efferent lymphatic vessels carry away from the lymph nodes. Unencapsulated diffuse lymphoid tissue includes gut- Lymphatic nodules within the lymph nodes are the sites of associated lymphoid tissues and tonsils. lymphocyte proliferation 113 114 Lymph Nodes Function of Lymph nodes Filter the lymph before it is returned to the blood Lymph nodes usually occur in clusters in specific regions of the Preventing foreign particles from entering the bloodstream body They also produce lymphocyte Some of the principal Lymphatic (Lymph) vessels groups are: o Tubular vessels transport back lymph to the blood ultimately replacing the volume lost from the blood during the formation of ✓ Popliteal the interstitial fluid. ✓ Inguinal ✓ Lumbar Lymph capillaries ✓ Cubital lymph nodes Lymph vessels Circulation(path) of lymph ✓ Axillary Lymph node ✓ Cervical Lymphatic trunks payer’s patches occur in the ileum. Lymphatic ducts 115 116 29  3/21/2022 ❖ The two main lymph ducts are: 1. Right lymphatic duct 2. Thoracic duct 1. Right lymphatic duct (shorter) -drains in to Rt subclavian V. from Rt upper limb, Rt thoracic region, Rt side of head and neck ✓ The rest of the body is drained by the thoracic duct. 2. Thoracic duct (larger) - drains from lower limbs, abdomen, Lt thoracic and Lt upper limb, Lt side of the head and neck and empties into Lt subclavian V. 117 118 119 30