Download Lymphatic System

Lymphatic System
Instructions: Read chapter 13 (pp. 254-271). While you are
reading, please complete the graphic organizer. This will serve
to help you summarize the key points of this system.
Functions:
1. Fluid Balance: pulls fluid from tissues into lymph capillaries to
avoid edema.
2.Fat Absorption – taken care of by the lymph capillaries
embedded in the intestines (fats and fat soluble vitamins)
3.Defense – WBC’s (Lymphocytes and Macrophages)
Primary Organs and their Roles:
Red Bone Marrow- in the epiphysis of long bones; area where
hemopoesis occurs and where B cells differentiate.
Thymus Gland- within the thoracic cavity; superior to the heart;
bi-lobed gland responsible for the differentiation of T cells –
also produces thymus hormones that help T cells mature. This
gland shrinks as you get older which may be why you are more
prone to disease as you age.
Secondary Organs and their Roles:
Lymphatic Vessels- contain lymph (fluid) to combat edema –
vessels and capillaries – capillaries have simple squamous -these
vessels can assist tumors in metastasis
Lymph Nodes-swollen areas of vessels contain T, B cells and
macrophages.
Spleen-located near stomach – two areas red and white pulp –
full of macrophages and lymphocytes which react to pathogens
in the blood and help to clean out old red blood cells.
Lymphatic Nodules-tonsils, peyers patches, and appendix –
concentrated area of lymph tissue.
Defense:
Nonspecific
Briefly describe the Barriers to Entry and their link to this
system.
Mechanical barriers like mucous membranes in the respiratory
system, digestive system etc block pathogens. Oil glands in the
integument block bacteria colonization and the acid pH of the
stomach kills pathogens that may enter on consumed food.
Describe the Inflammatory Reaction.
Symptoms are redness, heat, swelling, and pain. White blood
cells release histamine causing blood vessels to dilate becoming
permeable to fluids. Increased blood flow results in red, warm
skin. Dilated capillaries cause proteins and fluid to enter
tissues causing swelling. Swollen tissues push on nerves
resulting in pain.
Neutrophils and Monocytes (Macrophages) are stimulated to
come to the inflamed area and phagocytose the bacteria and
dead tissue due to the trauma.
Natural Killer Cells
Lymphocytes that kill virus-infected cells and tumor cells by cell
to cell contact. May also be cells involved in the aging process –
may be involved in apoptosis (programmed cell death).
Specific Response to Antigens (Lock and Key systems)
B-cells and Antibody Immunity
B lymphocytes give rise to plasma cells that create antibodies
for specific antigens. The body has the ability to recognize its
own cells and distinguish it from trespassers. Antibodies are
proteins shaped like the antigen receptor and capable of
combining with and neutralizing specific antigens on the surfaces
of cells.
T-cells and Cell Immunity
Lymphocytes are capable of recognizing an antigen because
they have antigen receptors which are plasma membrane
proteins that combine with a specific antigen. In this way they
can target and connect to invader cells.
Induced Immunity
Define: occurs naturally through infection or is brought about
artificially through medical intervention.
Active Immunity Body creates its own antibodies in response to
antigens of invading cells. Vaccines induce this process.
Passive Immunity Individual given prepared antibodies. It is a
temporary immunity. (Breastfeeding)
Aging and the Lymphatic System
Disappearing Thymus Gland
B cells don’t form clones
Response to vaccines not as good
Questions:
1. Describe how the lymphatic system helps maintain
homeostasis in the respiratory and cardiovascular systems.
2. Discuss how allergies, tissue rejection and auto immune
diseases result.
3. Describe what happens to a person who has an
autoimmune disease.
Inflammatory Response:
1. Histamine (protein complex) causes tissue capillaries to
become more permeable.
2. Increased blood flow to enlarged capillaries causes skin to
become red and warm.
3. Capillaries cause proteins and fluids to escape into
nearby tissues- puts pressure on exposed nerves. (causes
pain!)
4. WBC’s engulf pathogens contained within the fluids
(pus)
Symptoms  Redness, swelling, pain, heat at the site,
itchiness
3 Effects of inflammation temporary repair, barrier against
pathogens; retard the spread of pathogens into surrounding
tissues; mobilization of local and systemic defenses of the
body.