Blood circulation is probably both open blood empties into tissue of pulp that is percolates through and is later collected into sinusoids that connect to venules and closed blood from arterioles empties into sinusoids that are directly connected to venules. Functions of the spleen. Production of blood cells. This stops about the time of birth. Destruction of erythrocytes. Recycling of ferritin from worn out erythrocytes for synthesis of hemoglobin. Immune response. Storage of erythrocytes that can be released into circulatory system when needed.
What is the lymphoid system? The lymphoid system consists of 2 major components, A. The lymph vascular network that permeates all tissues of the body and has two functions, 1.
This group of organs and non-organ lymphatic tissue serves at least two roles: a. Tissues of lymphoid organs consist of two major cell types, A. There are 2 major types of lymphoid tissue, A. Unencapsulated, sub-epithelial, aggregations of lymphocytes that can occur anywhere in the body 2. Non-nodular parenchyma of lymphoid organs such as the thymus, lymph nodes and spleen B. Nonencapsulated lymph nodules 2.
Encapsulated lymph nodes 3. Spleenic white pulp 4. Immune system functions of the lymphoid system A. Immune response : 1. Involves the recognition of foreign antigens by certain lymphatic cells a. An immune response results in changes in the metabolism and chemical programming of lymphocytes that allows them to act in destroying the foreign substance or organism C.
Structure and function of lymphoid organs A. No connective tissue capsule surrounds free lymphatic nodules 3. Lymphoid tissue consists of: a. Lymph nodes 1. Oval or bean shaped bodies surrounded by a dense connective tissue capsule 3. Node consists of: a. Palatine tonsils a. Pharyngeal tonsils a. Lingual tonsils a. Thymus 1. Cortical layer of thymus a.
Thus, there is considerable mitotic activity of lymphoblasts c. This barrier consists of: a. Non-fenestrated, continuous endothelium of blood capillaries b. Thick basal lamina of epithelial reticular cells e. Desmosome connections forming tight junctions between adjacent endothelial cells of capillaries, as well as similar connections between surrounding epithelial-reticular cells 7.
Medullary zone a. Blood supply a. Branches from the internal thoracic and inferior thyroid arteries that penetrate the capsule surrounding the thymus b.
Spleen 1. General characteristics a. Structure a. Melanoma is the third most common type of skin cancer. Due to its ability to grow and spread quickly - with the potential to become life-threatening in as little as six weeks - it is considered the most serious type of skin cancer.
If untreated, it can spread rapidly to other areas of the body. Awareness of the differences can assist with timely referral and treatment, thereby reducing morbidity associated with aggressive tumours. Strep throat, otherwise known as group A strep, is a bacterial infection of the throat and tonsils. The bacteria that causes strep throat is called group A streptococcus. It is most common among school-aged children and teenagers between 5 and The tonsils, which form part of the immune system, consist of two pads of lymphatic tissue at the back of the throat.
They help to prevent infection by trapping pathogens that enter the nose and mouth and producing antibodies to kill them. The tonsils are prone to infection and inflammation. Healthdirect Australia is not responsible for the content and advertising on the external website you are now entering.
Examination of lymph nodes. There is a total of 5 error s on this form, details are below. Please enter your name Please enter your email Your email is invalid. Please check and try again Please enter recipient's email Recipient's email is invalid. Please check and try again Agree to Terms required. Thank you for sharing our content. A message has been sent to your recipient's email address with a link to the content webpage.
Your name: is required Error: This is required. Your email: is required Error: This is required Error: Not a valid value. Red pulp consists of venous sinuses filled with blood.
Splenic cords consisting of reticular connective tissue, macrophages, and lymphocytes form a mesh between the venous sinuses and act as a filter as blood passes between arterial vessels and the sinuses. The spleen filters the blood. Macrophages in the spleen remove bacteria and other pathogens, cellular debris, and aged blood cells. There are no afferent lymphatic vessels, and unlike lymph nodes, the spleen does not filter lymph.
The spleen destroys old red blood cells and recycles their parts. It removes the iron from heme groups and binds the iron to the storage protein. The spleen provides a reservoir of blood. The diffuse nature of the red pulp retains large quantities of blood, which can be directed to the circulation when necessary. One third of the blood platelets are stored in the spleen. The spleen is active in immune responses. T cells proliferate in the white pulp before returning to the blood to attack nonself cells when necessary.
B cells proliferate in the white pulp, producing plasma cells and antibodies that return to the blood to inactivate antigens. The spleen produces blood cells.
Red and white blood cells are produced in the spleen during fetal development. Previous Quiz Lymphoid Cells. Next Lymphatic System Components. Removing book from your Reading List will also remove any bookmarked pages associated with this title.
Lymph , containing micro-organisms, soluble antigens, antigen presenting cells, and a few B-cells, enters the lymph node via afferent lymphatic vessels which enter the subcapsular sinus. It then runs through cortical sinuses into medullary sinuses and leaves through the efferent lymphatic vessels , at the Hilium as efferent lymph.
This contains lots of T-lymphocytes, B-lymphocytes, plasma cells and antibody. All the blood sinuses are lined by a discontinuous layer of simple squamous endothelium, and they also contain lymphocytes and macrophages. The cortex is divided into an outer and an inner cortex. The outer cortex has lymphatic nodules that mostly contain B-cells.
Small lymphocytes sit in the spaces between the reticular fibre meshwork in the cortex.
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