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18 Cards in this Set

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COMPOSITION OF LYMPHATIC SYSTEM
A. LYMPHATIC VESSELS: transport tissue fluids tissue spaces (interstitial space) to the
blood

B. LYMPHATIC TISSUE: contains phagocytic cells and lymphocytes. Help body resist disease
II. LYMPH VESSELS
A. As plasma leaves blood and enters tissue spaces = interstitial fluid as mixes with tissue
secretions. As interstitial fluid enters lymphatic vessels = lymph

B. ONE WAY TRANSPORT OF LYMPH: from tissues to R & L subclavian vv

C. TYPES OF LYMPHATIC VESSELS AND ORGANIZATION
1. LYMPH CAPILLARIES:
blind-ended vessels that are found between tissues & blood capillaries in loose CNT

a. found where blood capillaries are found (not in bonemarrow, teeth, epithelia
or CNS)

b. ONE-WAY MINI-VALVES: loose, overlapping nature of endothelial cells of
lymph cap walls allows easy entrance of interstitial fluids, cellular debris,
bacteria, viruses, & cancer cells into lymph cap.

c. LACTEALS: specialized lymph cap in digestive tract (in villi of SI) receive
many large fats (called chylomicrons). Lymph in this area appears milky
white and is called, CHYLE
2. LYMPHATIC COLLECTING VESSELS
formed by the union of several lymph
capillaries. Are larger, thick-walled vessels

a. similar to veins (3 tunics): thinner walls, more valves, make more
anastomoses

b. travel along the same path as arteries or veins
LYMPHATIC TRUNKS
formed from collecting vessels, drain large body areas
LYMPHATIC DUCTS
largest lymph vessels in thoracic and abdominal regions,
formed by union of lymphatic trunks
RIGHT LYMPHATIC DUCT
: drains the R upper arm, the R side of the head
and thorax into R subclavian v.


b. THORACIC DUCT: largest duct, drains rest of the body into L subclavian v.
CISTERNA CHYLI: at beginning of thoracic duct in intestinal region:
is a large collecting sac
TRANSPORT OF LYMPH
1. no pump: allows return to the heart in a fashion similar to the circulatory system
veins
a. milking by skeletal muscle contractions
b. pressure changes within the thorax during breathing
c. valves to prevent back flow
d. regular contractions of smooth m within vessel walls
LYMPH CELLS: make up lymphatic tissue
A. LYMPHOCYTES
1. main warriors of the immune system (grown in bone marrow, matured by the thymus,
in thymus and in SKIN)

a. T-CELLS: manage the immune response and directly attack and destroy
foreign cells, antigens

b. B-CELLS: produce PLASMA CELLS which produce antibodies that help
destroy ANTIGENS (anything perceived as foreign: bacteria, toxins, viruses,
RBC's, cancer cells)

B. MACROPHAGES: phagocytize foreign items & help activate T cells

C. RETICULAR CELLS: produce reticular fibers -> STROMA of lymph tissue
IV. LYMPH TISSUE
A. main component of the immune system

B. RETICULAR CNT makes up parts of lymph organs except the thymus
C. TYPES OF LYMPHATIC TISSUE:
1. DIFFUSE: scattered reticular elements, found all over body

2. LYMPHATIC FOLLICLES (NODULES): no capsule. solid, round bodies of tightly
packed reticular elements and cells

a. central clusters of B-CELLS = GERMINAL CENTER

b. found in lg lymph organs & in other tissues small intestine: PYER'S
PATCHES
LYMPH ORGANS (4 types)
LYMPH NODES, SPLEEN, THYMUS, TONSILS
LYMPH NODES
along lymph vessels, filters lymph

1. remove & destroy antigens, help activate immune system

2. STRUCTURE OF THE LYMPH NODE: bean shaped, <1" long

3. LYMPH enters the lymph node on the convex side through AFFERENT
LYMPHATIC VESSELS-> SINUSES-> exits the node on concave side (HILUS)
through EFFERENT LYMPH VESSELS
OTHER LYMPH ORGANS
do not filter lymph
SPLEEN
largest lymphoid organ, located superior to the l kidney and adrenal gland

a. bean-shaped, with HILUS on its concave side

b. splenic arteries/veins enter/exit spleen at hilus, efferent lymphatics exit
spleen at hilus

c. FUNCTIONS
* filter blood: removes dead RBC's
* stores byproducts of RBC breakdown for later use
* produces RBC'S in fetus
* stores platelets
THYMUS
bilobed organ below sternum, on top of heart

a. large until puberty, then diminishes in size

b. involved in T-CELL maturation by secretion of thymosin
TONSILS
located in the pharynx: gather and remove pathogens entering the pharynx
in air or food

A. PALATINE TONSILS: r & l sides of post. oral cavity

B. LINGUAL TONSIL: at base of tongue

C. PHARYNGEAL TONSILS (ADENOIDS): posterior nasopharynx

D. TUBAL TONSILS: at auditory tube openings into pharynx
THE LYMPHATIC SYSTEM CH 20
THE LYMPHATIC SYSTEM CH 20