The Lymphatic System. Kufre Roberts Ignacio Rodriguez Brandon Smith. The Lymphatic System. The Lymphatic System consists of lymphatic vessels and the lymphatic organs, and it has three main functions that contribute to homeostasis:
The Lymphatic System
Lymphatic Vesselsform a one-way system that begins with lymphatic capillaries.
Capillaries join to form Vessels that merge before entering the thoracic duct or right lymphatic duct.
The structure of larger lymphatic vessels is similar to cardiovascular veins.
Secondary Lymphatic Organs are places where lymphocytes encounter and bind antigens. These places are:
Sec. 3 Nonspecific & specific Defenses.
Barriers to Entry: Built in barriers, both physical and chemical that help to prevent infection by microbes.
Inflammatory Reaction: Happens whenever tissue is either damaged chemically or physically or by pathogens.
Natural Cell (NK) killers: Kill virus infected cells and tumor cells by cell-to-cell contact.
Protective Proteins (The complement system): These proteins “complement” certain immune responses, which accounts for their name.
-It is said that the immune system is able to distinguish “self” from “non self”.
-The clonal selection theory states that the antigen “selects” one particular lymphocyte to reproduce multiple copies of itself.
-It is important that this happens otherwise, the body could mistakenly destroy body cells in an autoimmune response.
- Each arm has a “heavy” (long) and “light” (short) polypeptide chain (shown below.)
(look in the book, when I tried to copy the chart from the book it only showed the outline, not the text) Pg. 285 Table 13.1 Antibodies.
-This response to the antigens called allergensusually includes some degree of tissue damage.
- An example of this would be when pollen gets into your nose and your eyes start to get watery also causing a runny nose called a hey fever.
-Anaphylactic shock: Occurs when the antigen enters the bloodstream. This response is characterized by a sudden life-threatening drop in blood pressure due to blood vessel dilation.
-Example: Skin being tested for tuberculosis (TB). When the test result is positive, the tissue where the injected antigen becomes red and hardens.
- Some autoimmune diseases are:
2.Multiple sclerosis (MS)
3.Systemic lupus erythematosus
4. Rheumatoid arthritis
- Without treatment, one could die from the common cold.
Effects Of Aging
With advancing age, people become more vulnerable to all types of infections and disorders because the Immune System exhibits lower levels of function.
The thymus gland degenerates. When it reaches its maximum size in early childhood, it begins to shrink after puberty and has virtually disappeared by old age.
As the gland decreases so does the number of T cells. The remaining T cells do not respond to foreign antigens, this process increases the chance of having cancer increased with age.
The B cells sometimes fail to form clones amongst the elderly, or when they do form the clones the antibodies released may not function well. Which causes infections to be more common in the elderly.
The antibodies are more likely to attack the body’s own tissues which increases the incidence of autoimmune diseases.
Due to the overall low level of the immune response, it is beneficial that the elderly get vaccination each year.
The lymphatic system helps the digestive system by absorbing fats. In the process of absorbing dietary fats ,lacteals also absorb fat soluble vitamins.
The lymphatic system also assist the cardiovascular system by absorbing excess tissue fluid, it returns the excess tissue fluid as lymph to cardiovascular veins in the thorax, without this process it would be difficult for the body to maintain the blood volume and pressure needed for the capillary exchange.