RAT 9 Flashcards
what two systems are covered in this chapter? why are they covered together?
- lymphatic and immune system
- they function together in immunity
what system is technically not a system? why?
immune system because it doesn’t contain organs or tissues of its own instead it consist of cells and proteins
what are the main components of the lymphatic system?
- lymphatic vessels
- lymphatic tissue and lymphatic organs
what are the functions of the lymphatic system?
- regulation of interstitial fluid volume
- absorption of dietary fats
- immune functions
what is lymph?
interstitial fluid that has exited the extracellular space and extended and entered the lymphatic vessels
what is a lymph collecting vessel?
vessels that collects lymph
what is a lymphatic trunk?
large vessel made up of lymph collecting vessels
what do the intestinal and lumbar trunks drain into?
cisterna chyli
what is drained by the thoracic duct?
all of the lower body and the left side of the upper body
what is drained by the right lymphatic duct?
the right side of the upper body
what does the thoracic duct drain into?
junction of the left internal jugular and left subclavian veins
what does the right lymphatic duct drain into?
junction of the right internal jugular and right subclavian veins
what structure/mechanisms aid in the flow of lymph?
- lymphatic valves: prevent backward flow of lymph
- found between contracting muscles, where contracting muscles massage lymph up toward the heart
- flows through the vessel driven in part by contractions of smooth muscle found in the walls of lymph-collecting vessels
describe the structure of lymphatic capillaries
weblike networks that surround blood capillary beds
what is a lacteal?
specialized lymphatic capillary that collects fat in the small intestine
name the predominant type of tissue in the lymphatic system.
reticular tissue
what is another name for reticular tissue?
lymphoid tissue
what cells are found in lymphoid tissue?
- lymphocytes (B & T)
- phagocytes (macrophages and dendritic cells)
- reticular cells
what is MALT?
- mucosa-associated lymphatic tissue
- loosely organized clusters of lymphoid tissue
where is MALT found?
scattered throughout the gastrointestinal tract, the respiratory passage, and the genitourinary tract
what are lymphoid follicles/lymphoid nodules?
roughly spherical clusters that consist primarily of B cells
name the three locations where lymphoid follicles are found.
- tonsils
- peyer’s patches
- appendix
where are tonsils located?
around the oral and nasal cavities
what are the deep indentions in the tonsils called?
tonsillar crypts
what is the function of tonsillar crypts?
trap bacteria and debris
where are peyer’s patches located?
in the last portion of the small intestine (the ileum)
what is the function of peyer’s patches?
defend against any bacteria that have escaped from the large intestine
where is the appendix located?
located off the large intestine