immune system- lymphatic system section 1 Flashcards
what do leukocytes do?
protect the body against invading microorganisms, cancer cells, clean up extracellular debris and enhance healing process
leukocytes are divided into two groups based on what?
according to whether their cytoplasm contained highly visible granules
what are the two types of groups of leukocytes?
granular, agranular
what are granular L?
contain abundant granules within cytoplasm, include MAST CELLS, NEUTROPHILS, EOSINOPHILS, BASOPHILS
what are agranular L?
lack abundance L include monocytes (macrophages), lymphocytes (T cells, B cells, natural killer cells)
what is a neutrophil
- most common granulocyte in blood
- rapid responders to site of infection, efficient phagocytes, prefer bacteria
- their granules include lysozyme (enzyme capable of breaking down bacteria walls) and defensins (proteins that bind to and puncture bacterial and fungal plasma membranes
What is an eosinophil?
some granules of eosinophil include antihistamine molecules- anti-inflammatory molecules. capable of phagocytosis
what is a basophil?
lease common granulocyte in blood. releases histamine- contributes to inflammation and heparin- which opposes blood clotting
mast cells
similar to basophil, mostly present in tissues > blood
B cells
part of adaptive immune system, responsible to humeral immune response via antibodies
T cells
part of adaptive immune system. 2 types:
1. helper T cells: secrete signalling molecules that help to activate other parts of immune system
2. cytotoxic T cells: kill infected or abnormal cells- responsible for cellular immune system
natural killer cells?
part of innate immune system- kill infected or abnormal cells
monocytes include:
-macrophages (found in most tissues)
-dendritic cells (found in skin and mucus membranes)
what are macrophages
phagocytize debris, foreign pathogens, many dead cells including RBC. also release defensins and chemoattractant molecules that recruit other L to infection cite
what are dendritic cells?
- found in skin and mucus membrane
- similar in functions to macrophages, specialized to reside in skin and mucus membrane which are portals of entry for pathogens, initial site of most infections
what’s a differential count
measurement of % of different kinds of WBC in patient sample.
- high than normal- indicative of infections of autoimmune disorders
- lower than normal amount of L in blood can be due to stress or hormonal imbalance
major function of lymphatic system
drain body fluids and returns them to bloodstream.
BP can cause leakage of fluid from Capp. resulting in accumulation of fluid in interstitial space
lymph:
term used to describe interstitial fluid once entered lymphatic system. lymphatic vessels is also for transporting cells of immune system and dietary lipids and fat soluble vitamins absorbed in gut.
what does lymphatic system consist of
lymphatic vessels, primary lymphatic organs, secondary lymphatic organs
major distinctions between lymphatic system and cardio vascular
- lymph not actively pumped by the heart, forced through vessels by movement of body- contraction of skeletal muscles during movements and breathing
- one way valves In lymph. system keep lymph moving towards heart
how does lymph enter circulatory system
lymph flows from lymphatic Capp. through lymphatic vessels and then re enters circulatory system via lymphatic ducts located at junction of jugular and subclavian veins in neck
lymphatic capp
where interstitial fluid enters lymphatic system to become lymphatic fluid.
- located at almost every tissue in body
- vessels are interlaced among arterioles and venues of circulatory system in soft connective body tissues
lymphatic Capp empty into:
larger lymphatic vessels (similar to veins)
how is lymphatic trunk formed?
superficial and deep lymphatics merge to form larger lymphatic vessels- lymphatic trunks
