Lymphatic System Tutorial - Bioscience 2

Tutorial Module 7 **Student Guide** **Bioscience 2** **Lymphatic System** Reading: [Chapter 20](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=799), Marieb, E. N. & Hoehn, K. (2019). *Human anatomy & physiology* (10^th^ Global ed). Harlow, UK: Pearson Education **Pa...

Tutorial Module 7 **Student Guide** **Bioscience 2** **Lymphatic System** Reading: [Chapter 20](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=799), Marieb, E. N. & Hoehn, K. (2019). *Human anatomy & physiology* (10^th^ Global ed). Harlow, UK: Pearson Education **Part A: Anatomy and physiology of the Lymphatic system** Working closely with the cardiovascular system is another circulatory system called the lymphatic system. 1. What are the components of the lymphatic system? See [Page 799](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=800) (Marieb & Hoehn, 2019). As blood circulates through the body, nutrients and wastes exchange between the blood and the tissues. Fluid readily exits the bloodstream, into the extracellular space, and is reabsorbed back into the bloodstream. Fluid that is not returned immediately to the bloodstream remains in the extracellular spaces and contributes to the interstitial fluid. This fluid, that is not immediately reabsorbed must be returned to the bloodstream via the lymphatic system, to ensure sufficient blood volume is maintained. 2. What would the body look like if the fluid did not drain back into the bloodstream? **welling (Edema):** Fluid would accumulate in tissues, causing puffiness, especially in the legs, arms, or face.\ 🔴 **Tissue Damage:** Cells wouldn't get enough oxygen and nutrients, leading to **poor healing** and **pain**.\ 🔴 **Weakened Circulation:** Blood volume would decrease, making it harder for the heart to pump efficiently.\ 🔴 **Increased Risk of Infections:** The **lymphatic system removes waste and pathogens**---without drainage, toxins and bacteria would build up. Based on the figures below, how does the interstitial fluid drain into the lymphatic capillaries? See [Page 799](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=800) (Marieb & Hoehn, 2019) for assistance. **Step 1: Fluid Moves from Tissues to Interstitial Space** - Blood pressure forces fluid **out of capillaries** into the spaces between cells (interstitial fluid). 💧 **Step 2: Lymphatic Capillaries Absorb the Fluid** - Lymphatic capillaries have **flap-like valves** that open when fluid pressure outside is higher. - Fluid, proteins, and waste enter the **lymphatic system**. 💧 **Step 3: Lymph is Transported & Filtered** - Lymph travels through **lymph nodes**, which remove bacteria and debris. - It is eventually returned to the **bloodstream through the veins** near the hear 3.  4. What is the name of the fluid once it enters the lymphatic system? once interstitial fluid enters the lymphatic system, it is called **lymph** 5. Lymphatic vessels will pass through lymphatic nodes. What are the 3 main clusters of lymphatic nodes present in the body? This will be labelled in Q10. Lymph nodes filter lymph and help fight infections. The three main clusters are: 1️)Cervical lymph nodes -- Located in the neck, they filter lymph from the head and neck. 2️) Axillary lymph nodes -- Found in the armpits, they filter lymph from the arms, chest, and breasts. 3️) Inguinal lymph nodes -- Located in the groin, they filter lymph from the legs and lower abdomen. 6. The lymphatic vessels will continue to drain into larger and larger vessels until they drain into the two main lymphatic ducts. What are the names of these two ducts? See [page 801](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=802) for assistance. 1. Right Lymphatic Duct -- Drains lymph from the right side of the head, right arm, and right chest into the right subclavian vein. 2️)Thoracic Duct -- Drains lymph from the rest of the body into the left subclavian vein. 7. What part of the cardiovascular system will these lymphatic ducts eventually join? - The right lymphatic duct and thoracic duct both empty into the subclavian veins, which are part of the venous system. - These veins return the filtered lymph to the superior vena cava, which leads back to the heart. 8. Based on the figure below, outline the sequence of drainage from the interstitial tissue back to the heart. **Interstitial Fluid** -- Fluid leaks from blood capillaries into tissues.\ 2️) **Lymphatic Capillaries** -- Absorb excess fluid, turning it into **lymph**.\ 3️) **Lymphatic Vessels** -- Lymph moves through **larger vessels** and **passes through lymph nodes** for filtering.\ 4️) **Larger Lymphatic Trunks** -- Multiple vessels merge into **lymphatic trunks**.\ 5️) **Lymphatic Ducts** -- - Right lymphatic duct → **Right subclavian vein** - Thoracic duct → **Left subclavian vein**\ 6️) **Subclavian Veins → Superior Vena Cava → Heart** -- Lymph is returned to the **bloodstream** and circulates again. 9. The lymphatic system does not have an organ that acts as a pump to circulate the lymph. Describe the five ways by which movement of fluid is achieved in the lymphatic system? [See page 801](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=802) - **Skeletal Muscle Contractions** 💪 - Muscles squeeze lymphatic vessels during movement (e.g., walking, stretching). - This **pushes lymph forward** toward larger vessels and ducts. 2️) **Breathing Movements (Respiratory Pump)** 🌬️ - Inhaling and exhaling **creates pressure changes** in the chest. - This **draws lymph** from smaller vessels into larger ones. 3️) **Valves in Lymphatic Vessels** 🚪 - Lymphatic vessels have **one-way valves** that prevent **backflow**. - This ensures **lymph moves in the right direction**---toward the heart. 4️) s**mooth Muscle Contractions in Lymphatic Vessel Walls** 🏋️ - Larger lymphatic vessels have **smooth muscle** in their walls. - These muscles **contract rhythmically** to keep lymph flowing. 5️) **Gravity and Body Position** 🛌 - Lying down or elevating the legs can help **lymph drain from lower limbs**. - Changing positions **encourages lymph movement** throughout the body. 10. In the diagram below, label the axillary, inguinal and cervical nodes and explain why a quarter of the body is coloured green and the remaining three-quarter is pink? [See page 801](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=802) (Marieb & Hoehn, 2019)  This color-coding represents **lymph drainage regions**: ✅ **Green Area (Right Upper Quadrant)** - Drains into the **Right Lymphatic Duct** - Includes the **right side of the head, right arm, and right chest** - Lymph from this area enters the **right subclavian vein** ✅ **Pink Area (Remaining Three-Quarters of the Body)** - Drains into the **Thoracic Duct** - Includes the **left side of the head, left arm, entire lower body, and abdomen** - Lymph from this larger area enters the **left subclavian vein** **Part B: [Case study]** Mrs Jean Page, aged 56 years, was diagnosed with cancer in the right upper quadrant of her right breast. The lumpectomy & axillary resection of lymph nodes from the armpit was performed 8 weeks ago. Besides the numbness & pulling feeling in her right hand, Jean noticed that her right arm was oedematous, reddened, and painful, indicating a possible cellulitis. She also noticed that her arm was slowly getting bigger and more swollen. She was instructed to seek medical advice that she would very likely be put on antibiotic therapy. She was also instructed to monitor the swelling of her arm. 1. Trace the flow of lymph in the affected side of Jean's body. **Lymph Capillaries** -- Absorb excess fluid from tissues in the right arm.\ 2️) **Lymphatic Vessels** -- Transport lymph through the arm toward the lymph nodes.\ 3️)**Axillary Lymph Nodes (Right Armpit)** -- Filter lymph, removing waste and pathogens.\ 4️) **Right Lymphatic Duct** -- Collects lymph from the right arm, right chest, and right side of the head.\ 5️) **Right Subclavian Vein** -- Lymph re-enters the bloodstream, maintaining fluid balance. 2. Explain why the removal of her lymph nodes caused the swelling in her right arm. **Lymph nodes act as filters and drainage points for lymph fluid.**\ 🔹 **When removed, the lymphatic system cannot drain properly**, leading to fluid retention in the arm.\ 🔹 **Without proper drainage, excess fluid accumulates in tissues**, causing persistent swelling. 3. What is this swelling called? Lymphedema is swelling due to blocked or damaged lymphatic drainage, often caused by surgery, cancer treatment, or infection. 4. One of the major complications of lymphoedema is cellulitis. Explain what cellulitis is, why patients with lymphoedema develop cellulitis, and what is the reason for antibiotic therapy. Lymphedema causes fluid buildup in tissues, making it harder for the immune system to fight infections. 📌 Poor lymph drainage means bacteria are not cleared properly, increasing infection risk. 📌 Small cuts, scratches, or insect bites can allow bacteria to enter the skin, triggering cellulitis **Antibiotics are essential to treat cellulitis and prevent serious complications, including:** **✅ Preventing infection spread -- Cellulitis can spread to deeper tissues and the bloodstream (sepsis).** **✅ Reducing swelling and inflammation -- Treating the infection helps control lymphedema symptoms.** **✅ Avoiding recurrent infections -- Repeated cellulitis episodes can further damage the lymphatic system.** **Part C: Lymph nodes** 1. What is the role of lymph nodes? [Page 803](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=804) **Lymph nodes** act as **filters** for lymph fluid, trapping **bacteria, viruses, and other harmful substances** before they reach the bloodstream.\ 🔹 They **contain immune cells (like lymphocytes and macrophages)** that detect and destroy pathogens.\ 🔹 Lymph nodes **help activate the immune response** when an infection is detected. 2. Which white blood cell is most abundant within the lymph nodes? Lymphocytes (B cells and T cells) are the most abundant white blood cells in lymph nodes. B cells produce antibodies to fight infections. T cells help attack infected or abnormal cells. 3. When exposed to foreign cells, why do lymph nodes swell? **Lymph node swelling (lymphadenopathy)** happens when the immune system is actively fighting an infection.\ 📌 **Reasons for swelling:** - **Increased lymphocyte production** -- More immune cells are made to fight the invaders. - **Accumulation of trapped pathogens** -- Lymph nodes collect and contain bacteria or viruses. - **Inflammation** -- The immune response triggers swelling as part of the body\'s defense. 4. In your own words explain why there is such a marked difference between the number of afferent and efferent lymphatic vessels in a lymph node? [See p. 804](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=805). **Afferent lymphatic vessels bring lymph into the lymph node, while efferent lymphatic vessels carry it out.** **🔹 There are more afferent (incoming) vessels than efferent (outgoing) vessels, which causes lymph to slow down inside the node.** **Part D: Lymphatic organs and tissues** 1. Label the main lymphatic organs in the diagram below. [See p 803](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=804) (Marieb & Hoehn, 2019) 2. **Lymph nodes** -- Found in clusters (neck, armpits, groin) and filter lymph.\ 2️)**Spleen** -- Removes old red blood cells and helps fight infections.\ 3️)**Thymus** -- Where T cells mature.\ 4️)**Tonsils** -- Trap and destroy pathogens from food and air.\ 5️) **Bone marrow** -- Produces white blood cells, including lymphocyte C:\\Users\\H8237400\\AppData\\Local\\Microsoft\\Windows\\Temporary Internet Files\\Content.Word\\figure\_20\_04\_labeled.jpg 3. Identify the primary lymphoid organs. What is their role? Primary lymphoid organs are where lymphocytes (B and T cells) develop and mature before they enter circulation. 🔹 Bone Marrow -- Produces B cells and T cells; B cells mature here. 🔹 Thymus -- T cells travel here from the bone marrow to mature and become functional. 4. Identify the secondary lymphoid organs. What is their role? **Secondary lymphoid organs are where mature immune cells gather, interact, and respond to infections.** **🔹 Lymph Nodes -- Filter lymph and activate immune responses.** **🔹 Spleen -- Filters blood, removes old red blood cells, and helps fight infections.** **🔹 Tonsils -- Trap and destroy pathogens from food and air.** **🔹 Mucosa-Associated Lymphoid Tissue (MALT) -- Includes Peyer's patches in the intestines, which monitor and fight gut infections.** **Part E: Additional activity:** 1\. A specialised set of lymphatic capillaries are present within the villi of the small intestines. Label the picture below. What is the name of the specialised lymphatic capillaries (coloured green) and what is their role? See [page 934](https://ebookcentral.proquest.com/lib/uwsau/reader.action?docID=5573766&ppg=935)  Please watch this short Khan academy video that describes lymph. 2\. Based on the video, will lymph contain higher or lower percentages of proteins and fats compared to blood plasma? 3\. What cells can enter the lymphatic system? (Hint: these cells are not normally part of the body). 5. Complete the following sentences relating to the [functions of the Lymphatic System] using the following terms: - To control tissue fluid......... - To produce the......... response to specific........ - To provide a long-term defense against......... - To absorb digested fat and........... in the intestine through......... which are specialized......... present in the mucosa - To return excess interstitial fluid and protein back to the......... To control tissue fluid composition. To produce the immune response to specific antigens. To provide a long-term defense against pathogens. To absorb digested fat and fat-soluble vitamins in the intestine through lacteals, which are specialized lymph capillaries present in the mucosa. To return excess interstitial fluid and protein back to the blood.