Pulmonary circulation What is the cardiovascular system The

Pulmonary circulation What is the cardiovascular system? The heart is a double pump heart arteries arterioles veins venules capillaries Page 1 of 67

Heart’s position in thorax In mediastinum – behind sternum and pointing left, lying on the diaphragm It weighs 250 -350 gm (about 1 pound) Feel your heart beat at apex Page 2 of 67 2

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Starting from the outside… Pericardium (see next slide) Page 4 of 67 Without most of pericardial layers 4

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Circulation Patterns Page 6 of 67 Figure 21 -18

Superior vena cava Pulmonary artery Capillaries of right lung 7 Capillaries of Head and arms Aorta 9 6 2 3 Pulmonary vein RIGHT ATRIUM RIGHT VENTRICLE 3 4 11 5 1 Pulmonary vein LEFT ATRIUM LEFT VENTRICLE 10 Aorta Inferior vena cava 8 Page 7 of 67 Pulmonary artery Capillaries of left lung Capillaries of abdominal organs and legs

The double pump Page 8 of 67

Chambers of the heart; valves Page 9 of 67

Circulatory System Functions Carry O 2 to cells and CO 2 away from cells Deliver nutrients through body (after absorption in small intestine) Carry liquid wastes away from cells (H 2 O, salt, urea) Help in fighting infections Temperature regulation Page 10 of 67

The Pulmonary Circuit Page 11 of 67 Figure 21 -19

The Pulmonary Circuit (1 of 3) 1. Deoxygenated blood arrives at heart from systemic circuit: Page 12 of 67 passes through right atrium and ventricle enters pulmonary trunk

The Pulmonary Circuit (2 of 3) 2. At the lungs: Page 13 of 67 CO 2 is removed O 2 is added

The Pulmonary Circuit (3 of 3) 3. Oxygenated blood: Page 14 of 67 returns to the heart is distributed to systemic circuit

Three circuits Pulmonary Blood goes from heart to lungs to pick up oxygen and release carbon dioxide Systemic Blood pumped out of heart to the rest of the body Sound of heart (lub/dub) made by valves closing Coronary Heart muscle itself supplied with oxygen, nutrients, etc. Page 15 of 67

Requirements of gas exchange Moist environment O 2 and CO 2 must be dissolved to diffuse Lungs, gills, moist surface (slime) help Surface area--large area allows for more diffusion Cleaned and filtered Warmed Page 16 of 67

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Components of Alveolus Page 18 of 67

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Movement of air into body Nose--external opening to allow entry Air is filtered, cleaned, warmed, moistened Enters a series of tubes Protected by cartilage to keep tubes firm/open Mucus--traps foreign particles Cilia-- “sweep” foreign material away from lungs to be swallowed (or spit/coughed) Page 21 of 67

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Diffusion of gases O 2 concentration is higher in alveoli than blood: oxygen diffuses into blood Remember High Conc. -> Low Conc. At body cells O 2 concentration is higher in blood: oxygen diffuses out of blood Page 23 of 67

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Oxygen Transport O 2 diffuses from alveoli to the pulmonary capillaries. O 2 -rich blood travels to heart and pumped to the body O 2 diffuses into cells. In tissues O 2 levels are lower triggers Hb to release O 2 In tissues, CO 2 makes blood more acidic and causes Hb to change shape. CO 2 diffuses from cells to blood. Travels to heart in form of Bicarbonate ions (HCO 3 -) Heart pumps blood to lungs where CO 2 is released in in gaseous form and then expelled. Page 26 of 67

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LYMPHATIC SYSTEM Page 28 of 67

LYMPH What is lymph ? Tissue fluid (interstitial fluid) that enters the lymphatic vessels Page 29 of 67

FORMATION AND TRANSPORT OF TISSUE FLUID Page 30 of 67

LYMPHATIC SYSTEM Essentially a drainage system accessory to venous system larger particles that escape into tissue fluid can only be removed via lymphatic system Page 31 of 67

Functions of the Lymphatic System Reabsorbs excess interstitial fluid: returns it to the venous circulation maintain blood volume levels prevent interstitial fluid levels from rising out of control. Transport dietary lipids: transported through lacteals drain into larger lymphatic vessels eventually into the bloodstream. lymphocyte development, and the immune Page 32 of 67

Components of the Lymphatic System 24 Lymph Lymphatic Vessels 33 Lymphatic Capillaries Lymphatic Vessels Lymphatic Trunks Lymphatic Ducts Lymphatic Organs Thymus Lymph Nodes Spleen Tonsils Lymphatic cells 33 of 67 Page

Lymph Vessels Lymphatic capillaries – Lymphatic collecting vessels Lymphatic trunks – Lymphatic ducts – Page 34 of 67

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Lymphatic Capillaries 2436 Features of structure: Blind end Single layer of overlapping endothelial cells More permeable than that of blood capillary Absent from avascular structures, brain, spinal cord splenic pulp and bone marrow Page 36 of 67

Lymphatic Capillaries – Lacteals 2437 The small intestine contains special types of lymphatic capillaries called lacteals. Lacteals pick up not only interstitial fluid, but also dietary lipids and lipidsoluble vitamins. The lymph of this area has a milky Page 37 of 67 color due to the lipid and is also called

Lymphatic Vessels 23 8 Features of structure q Three layered wall but thinner than vein, q More numerous valves than in vein q Interposed by lymph nodes at intervals q. Page Arranged in 38 of 67

LYMPH TRUNKS q right and left jugular trunks q right and left subclavian trunks q right and left bronchomediastinal trunks q. Page right and left lumbar trunks 39 of 67

LYMPHATIC DUCTS 2440 Right lymphatic duct Formed by union of right jugular, subclavian, and bronchomediastinal trunks Ends by entering the right venous angle Page 40 of 67

LYMPHATIC DUCTS p. Thoracic duct Begins in front of L 1 as a dilated sac, the cisterna chyli, formed by left and right lumbar trunks and intestinal trunk Enter thoracic cavity & ascends Travels upward, veering Page 41 of 67

THORACIC DUCT…. . At the root of the neck, it turns laterally arches forwards and descends to enter the left venous angle before termination, it receives the left jugular, Subclavian and bronchomediastinal trunk Page 42 of 67

DRAINAGE PATTERN RIGHT LYMPHATIC DUCT Receives lymph from right half of head, neck, thorax and right upper limb, right lung, right side of heart, right surface of liver THORACIC DUCT - Drains lymph from lower limbs, pelvic cavity, abdominal cavity, left side of thorax, and left side of the head, neck and left upper limb Page 43 of 67

Lymphatic Cells 2444 Also called lymphoid cells. Located in both the lymphatic system and the cardiovascular system. Work together to elicit an immune response. Types of lymphatic cells are: macrophages epithelial cells dendritic cells lymphocytes Page 44 of 67

LYMPHATIC ORGANS Primary organs Red bone marrow Thymus gland Secondary organs Lymph nodes Lymph nodules Spleen Page 45 of 67

2446 Lymph Nodes Small, round or oval located along the pathways of lymph vessels. length from 1 - 25 millimeters Typically found in clusters receive lymph from many body regions. Lymph nodes are also found individually throughout the body tissues. Page 46 of 67

Lymph node Features q Bean-shaped bodies q With afferent vessels (entering at the periphery) and efferent lymph vessels(emerging at the hilus) q Arranged in groups, along the blood vessels or the flexural side of the joint q Divided into superficial and Page 47 of 67

Regional Lymph drainage Regional Lymph Node is the lymph node where the lymph of the organ or part of the body drainge to firstly Sentinel Lymph Node Page 48 of 67

Spleen q. Location Ø Left epigastric region Ø between 9 th-11 th rib Ø in line of 10 th rib Largest lymphatic organ in the body. Can vary considerably in size and weight q. Function Page 49 of 67

THYMUS Features q Consists of two elongated lobes q Is a large organ in the fetus q Occupies the thoracic cavity behind the sternum q Secrete Page 50 of 67 lymphopoietin

Lymphatic Nodules Oval clusters of lymphatic cells with some extracellular matrix that are not surrounded by a connective tissue capsule. Filter and attack antigens. In some areas of the body, many lymphatic nodules group together to form larger structures. mucosa-associated lymphatic tissue (MALT) or tonsils very prominent in the mucosa of the small intestine, primarily in the ileum Peyer patches also present in the appendix Page 51 of 67

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Tonsils clusters of lymphatic cells and extracellular matrix not completely surrounded by a connective tissue capsule. Consist of multiple germinal centers and crypts Several groups of tonsils form a protective ring around the pharynx. pharyngeal tonsils (or adenoids) in nasopharynx palatine tonsils in oral cavity lingual tonsils along posterior one-third of the tongue Page 53 of 67

MALT (Mucosa Associated Lymphoid Tissue) Page 54 of 67

APPLIED ANATOMY Page 55 of 67

LYMPHANGITIS Inflammation of the lymph vessels Page 56 of 67 Commonest cause bacteria called streptococcus pyogenes(most common). Lymph vessels appear as red streaks through the skin

FILARIASIS Page 57 of 67

LYMPHEDEMA Occurs due to accumulation of lymphatic fluid in the interstitial tissue Sometimes can be appreciated after wearing tight clothing or jewellary on 58 ofaffected limb Page 67

LYMPHADENOPATH Y Means a disease of the lymph nodes Lymph nodes become swollen/ enlarged and may be painful to touch Page 59 of 67

LYMPHOMAS Cancers originating either from the lymphocytes in the lymph nodes or the lymphatic tissue in organs Risk factors -- HIV, HEPATITIS, EBV Page 60 of 67 infections

TONSILLITIS Infection of the pharyngeal tonsils Tonsils are swollen, Fever and pain during swallowing usually present Treatment – surgical removal of tonsils Page 61 of 67 (TONSILLECTOMY)

SPLENOMEGALY Enlarged Spleen Various causes Page 62 of 67

QUESTION. 1 Name the structures labelled AE. Page 63 of 67

QUESTION. 2 I am a part of lymphatic system and protect the body by clearing worn out red cells and foreign bodies from the blood stream. Who am I? A. Thymus B. Palatine Tonsil C. Spleen Page 64 of 67

QUESTION. 3 Which is the correct statement about the Lymphatic system? A. It Reabsorbs excess interstitial fluid and returns it to the venous circulation. B. Transports dietary lipids through lacteals. C. Helps in lymphocyte development, and the immune response. Page 65 of 67 D. All of the above

QUESTION. 4 Which disease caused by mosquito bite blocks the lymphatic drainage causing huge swelling of body parts (commonly lower limb) A. Malaria B. Filaria C. Dengue D. Yellow fever Page 66 of 67

QUESTION. 5 Which of these is a primary lymphoid organ ? A. Lymph Node B. Spleen C. Tonsil D. Bone Marrow Page 67 of 67