Get a 10 % discount on an order above $ 100!
Peripheral Vascular And Lymphatic Systems Essay
Complete a 250-350-word reflection of what you have learned during this topic. Include the following in your reflection:
Think about an experience you’ve encountered when viewing or completing the particular assessment.
Discuss difficulties that could potentially arise or specific questions related to completing this type of assessment.
Include illustrative examples of potential strategies used to overcome the difficulties encountered when completing (the particular) assessment.
Describe how the Christian worldview and compassion for all plays a role in this type of assessment.
Solid academic writing is expected. Peripheral Vascular And Lymphatic Systems Essay
This assignment uses a rubric. Please review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.
The circulatory and lymphatic systems are networks of vessels and a pump that transport blood and lymph, respectively, throughout the body. When these systems are infected with a microorganism, the network of vessels can facilitate the rapid dissemination of the microorganism to other regions of the body, sometimes with serious results. In this section, we will examine some of the key anatomical features of the circulatory and lymphatic systems, as well as general signs and symptoms of infection.
The Circulatory System
The circulatory (or cardiovascular) system is a closed network of organs and vessels that moves blood around the body (Figure 1). The primary purposes of the circulatory system are to deliver nutrients, immune factors, and oxygen to tissues and to carry away waste products for elimination. The heart is a four-chambered pump that propels the blood throughout the body. Deoxygenated blood enters the right atrium through the superior vena cava and the inferior vena cava after returning from the body. The blood next passes through the tricuspid valve to enter the right ventricle. When the heart contracts, the blood from the right ventricle is pumped through the pulmonary arteries to the lungs. There, the blood is oxygenated at the alveoli and returns to the heart through the pulmonary veins. The oxygenated blood is received at the left atrium and proceeds through the mitral valve to the left ventricle. When the heart contracts, the oxygenated blood is pumped throughout the body via a series of thick-walled vessels called arteries. The first and largest artery is called the aorta. The arteries sequentially branch and decrease in size (and are called arterioles) until they end in a network of smaller vessels called capillaries. The capillary beds are located in the interstitial spaces within tissues and release nutrients, immune factors, and oxygen to those tissues. The capillaries connect to a series of vessels called venules, which increase in size to form the veins. The veins join together into larger vessels as they transfer blood back to the heart. The largest veins, the superior and inferior vena cava, return the blood to the right atrium. Peripheral Vascular And Lymphatic Systems Essay
a) Diagram of the circulatory system. Blood from the lower part of the body travels to the heart in the inferior vena cava. Blood from the upper part of the body travels to the heart in the superior vena cava. The pulmonary artery travels from the heart to the lungs and the pulmonary vein travels from the lungs to the heart. B) A diagram of the heart showing the flow of blood. Beginning in the superior and inferior vena cavas, blood travels to the right atrium, through the tricuspid valve, to the right ventricle and out the pulmonary artery. The image does not follow the pulmonary artery. From the pulmonary vein blood travels to the left atrium, through the mitral valve, to the left ventricle and out the aorta. C) The layers of the heart. The Pericardium is the outer layer. The myocardium is the thick middle layer. The endocardium is the inner layer.
Figure 1. Click for a larger image. The major components of the human circulatory system include the heart, arteries, veins, and capillaries. This network delivers blood to the body’s organs and tissues. (credit top left: modification of work by Mariana Ruiz Villareal; credit bottom right: modification of work by Bruce Blaus) Peripheral Vascular And Lymphatic Systems Essay
Other organs play important roles in the circulatory system as well. The kidneys filter the blood, removing waste products and eliminating them in the urine. The liver also filters the blood and removes damaged or defective red blood cells. The spleen filters and stores blood, removes damaged red blood cells, and is a reservoir for immune factors. All of these filtering structures serve as sites for entrapment of microorganisms and help maintain an environment free of microorganisms in the blood.
The Lymphatic System
The lymphatic system is also a network of vessels that run throughout the body (Figure 2). However, these vessels do not form a full circulating system and are not pressurized by the heart. Rather, the lymphatic system is an open system with the fluid moving in one direction from the extremities toward two drainage points into veins just above the heart. Lymphatic fluids move more slowly than blood because they are not pressurized. Small lymph capillaries interact with blood capillaries in the interstitial spaces in tissues. Fluids from the tissues enter the lymph capillaries and are drained away (Figure 3). These fluids, termed lymph, also contain large numbers of white blood cells.
Diagram of the lymphatic system. Lymph notes are swellings on tubes (called lymph vessels) that travel throughout the body. The right lymphatic duct and entering vein are in the neck. A tonsil is a swelling on the lymph vessel in the mouth. The thymus is a lumpy structure on the heart. A close-up of a lymph node shows a roundish structure with many tubes attached to it. The central area has a box labeled
Figure 2. The essential components of the human lymphatic system drain fluid away from tissues. Peripheral Vascular And Lymphatic Systems Essay
Blood enters the capillaries from an arteriole (red) and leaves through venules (blue). Interstitial fluids may drain into the lymph capillaries (green) and proceed to lymph nodes. A close-up of tissue cells in interstitial fluid. An arteriole and a venule are connected by a network of capillaries. Lymphatic vessels are also a network in this region and end in lymph capillarie.
Figure 3. Blood enters the capillaries from an arteriole (red) and leaves through venules (blue). Interstitial fluids may drain into the lymph capillaries (green) and proceed to lymph nodes. (credit: modification of work by National Cancer Institute, National Institutes of Health)
The lymphatic system contains two types of lymphoid tissues. The primary lymphoid tissue includes bone marrow and the thymus. Bone marrow contains the hematopoietic stem cells (HSC) that differentiate and mature into the various types of blood cells and lymphocytes (see Figure 1 in Cellular Defenses). The secondary lymphoid tissues include the spleen, lymph nodes, and several areas of diffuse lymphoid tissues underlying epithelial membranes. The spleen, an encapsulated structure, filters blood and captures pathogens and antigens that pass into it (Figure 4). The spleen contains specialized macrophages and dendritic cells that are crucial for antigen presentation, a mechanism critical for activation of T lymphocytes and B lymphocytes (see Major Histocompatibility Complexes and Antigen-Presenting Cells). Lymph nodes are bean-shaped organs situated throughout the body. These structures contain areas called germinal centers that are rich in B and T lymphocytes. The lymph nodes also contain macrophages and dendritic cells for antigen presentation. Lymph from nearby tissues enters the lymph node through afferent lymphatic vessels and encounters these lymphocytes as it passes through; the lymph exits the lymph node through the efferent lymphatic vessels Peripheral Vascular And Lymphatic Systems Essay