The Lymphatic System Flashcards
What are the PRIMARY FUNCTIONS of the lymphatic system?
- helps DRAIN any interstitial fluid aka LYMPH
- return of LEAKED PLASMA PROTEINS into the blood
- TRANSPORTATION of dietary fats
- aids in IMMUNE RESPONSE
what PARTS make up the lymphatic system?
- a network of LYMPHATIC VESSELS aka lymphatics
- fluid known as LYMPH; interstitial fluid entering lymphatics
- system of LYMPH NODES; cleans the LYMPH
describe the distribution and structure of our LYMPHATIC VESSELS.
- typically these BV begin as “LYMPHATIC CAPILLARIES”
- often located in between cells of many tissues
- known as a ONE-WAY SYSTEM: lymph will flow back towards the heart
describe the DISTRIBUTION + SPECIAL FEATURES of our LYMPHATIC CAPILLARIES.
- our lymphatic capillaries are actually BLIND-ENDED VESSELS (often going in and out between tissue cells and blood capillaries)
- found throughout the body (EXCEPT avascular tissue, CNS, spleen portions, & red bone marrow)
- have a slightly LARGER DIAMETER vs. blood capillaries **MORE PERMEABLE
(due to this can take in larger particles)
what are LACTEALS + CHYLE? How are they related to our lymphatic capillaries?
LACTEALS:
- specialized lymph capillaries present in intestinal mucosa
*helps transport digested fats from the small intestine into blood
CHYLE:
- milky-white fatty lymph that drains through the lacteals
describe the DISTRIBUTION + SPECIAL FEATURES of our LARGER LYMPHATIC VESSELS.
after our lymphatic capillaries, they drain into our COLLECTING LYMPHATIC VESSELS:
- similar structure to VEINS;
- have thinner walls + more internal valves
- anastomose more frequently
- VASA VASORUM - supplies nutrients
describe the DISTRIBUTION + SPECIAL FEATURES of our LYMPHATIC TRUNKS.
LYMPHATIC TRUNKS:
formation of union of largest collecting vessels and help DRAIN LARGE AREAS of the body
- formed from the lumbar, intestinal, bronchomediastinal, subclavian, and jugular trunks
describe our two most LARGEST LYMPHATIC TRUNKS.
our largest lymphatic trunks are our RIGHT LYMPHATIC DUCT + THORACIC DUCT:
RIGHT LYMPHATIC DUCT:
- drains our right upper arm and right side of head and thorax
- drains lymph into venous blood via the RIGHT SUBCLAVIAN VEIN
THORACIC DUCT:
- drains the rest of our body
- begins at a dilation called the CISTERNA CHYLI
- main collecting duct
- drains lymph into venous blood via the LEFT SUBCLAVIAN VEIN
describe clinical condition; LYMPHANGITIS
LYMPHANGITIS:
- a condition in which lymphatic vessels appear as painful red lines under the skin
- also often known as the “Gardener’s Disease”
describe clinical condition; LYMPHEDEMA
LYMPHEDEMA:
- severe localized edema
what is the FLOW PASSAGEWAY of LYMPH within our lymphatic system?
- Begins within the ARTERIES + BLOOD CAPILLARIES (form of BLOOD)
- enters into our INTERSTITIAL SPACES (form of INTERSTITIAL FLUID)
- drains into our LYMPH CAPILLARIES (form of I.F.)
- drains into our LYMPHATIC VESSELS (form of I.F.)
- drains into our main LYMPHATIC TRUNKS (form of I.F.) (DUCTS)
- leaves into the SUBCLAVIAN VEINS (form of BLOOD)
*this flow is regulated by our SKELETAL MUSCLE CONTRACTIONS + RESPIRATORY MOVEMENTS + MINI VALVES (prevention of backflow)
*low-pressure system similar to the VENOUS SYS.
what type of LYMPHOID CELLS do we have in our lymphatic system?
we have TWO SPECIFIC TYPES;
- IMMUNE SYSTEM CELLS (lymphoid tissue)
- SUPPORTING CELLS (lymphoid tissue structures)
what are the IMMUNE SYSTEM CELLS + their FUNCTIONS?
T CELLS + B CELLS
- important for PROTECTION vs. ANTIGENS
- B cells more specifically aid in antibody production
MACROPHAGES
- help activate ur T cells + phagocytize foreign substances
DENDRITIC CELLS
- help capture antigens + activation of T cells
what are the SUPPORT CELLS + FUNCTIONS?
RETICULAR CELLS
- help with the creation of LYMPHOID TISSUE STRUCTURES/synthesizes COLLAGEN
- creation of STROMA; a scaffolding network structure for lymphoid organs
describe LYMPHOID TISSUE.
LYMPHOID TISSUE:
the basic home and proliferation sites for lymphocytes (immune sys. cells - t cells and b cells)
- mostly made of RETICULAR CONNECTIVE TISSUE
what are the MAIN TYPES OF LYMPHOID TISSUE?
we have TWO MAIN TYPES;
- DIFFUSE LYMPHOID TISSUE
a basic loose arrangement of lymphoid cells and reticular fibers
- seen typically within the respiratory tract + GI tract - LYMPHOID FOLLICLES (NODULES)
-tissue of tightly packed lymphoid cells and reticular fibers; spherical-shaped
- seen in small intestine, appendix, etc…
what are the PRIMARY + SECONDARY LYMPHOID ORGANS? (describe their functions as well)
PRIMARY LYMPHOID ORGANS
- thymus + red bone marrow
SECONDARY LYMPHOID ORGANS
- lymph nodes, tonsils, spleen, peyer’s patches, and the appendix
PLO FUNCTIONS;
- this is where our T CELLS AND B CELLS mature
SLO FUNCTIONS;
- this is where lymphocytes have their FIRST ENCOUNTER with antigens and become ACTIVATED
what are the TWO MAIN FUNCTIONS of LYMPH NODES?
- the CLEANSING of the lymph
- IMMUNE SYSTEM activation
*lymph nodes are the principal SECONDARY LYMPHOID ORGANS of the body
describe the STRUCTURE of a LYMPH NODE.
- looks like a BEAN + small in shape
- has an EXTERNAL FIBROUS CAPSULE
- capsule fibers go INWARD
- TRABECULAE divides the nodes into more parts
SPECIFIC REGIONS:
CORTEX;
(SUPERFICIAL AREA)
- has germinal centers; division of B CELLS
- has dendritic cells
(DEEP AREA)
- helps with the transport of T CELLS
- has dendritic cells
MEDULLA;
- extends more inward from the cortex
- contains B/T CELLS + PLASMA CELLS + MACROPHAGES
describe LYMPH CIRCULATION within the LYMPH NODES+ what cell is within lymph nodes to help with filtration?
- Enters AFFERENT lymphatic vessels (Convex side)
- travels through SUBSCAPULAR SINUS
- Enters the MEDULLARY SINUSES
- Exits at the HILUM via EFFERENT lymphatic vessels (Concave side)
*within the lymph nodes, macrophages destroy foreign substances through phagocytosis
describe clinical condition; BUBONIC PLAGUE
BUBONIC PLAGUE:
- presence of BUBOES; inflamed, swollen, tender lymph nodes that result when nodes are overwhelmed by what they are trying to destroy
describe clinical condition; CANCER
CANCER:
lymph nodes can become secondary cancer sites if metastasizing cancer cells become trapped in lymph node
describe lymphatic organ; SPLEEN
DESCRIPTION;
- the LARGEST lymphoid organ
- aided by the splenic artery/vein (enters/exits the HILUM)
- BLOOD-RICH ORGAN found on the left side of abdominal cavity
FUNCTIONS;
- stores breakdown products of RBC’s (recycling)
- stores BLOOD PLATELETS + MONOCYTES (helps with necessary blood release)
- sites of FETAL ERYTHROCYTE PRODUCTION
HISTOLOGY;
- WHITE PULP:
where immune function happens, has mostly lymphocytes
- RED PULP:
this is where old blood cells/bloodborne pathogens die + splenic cords help separate splenic sinusoids
describe lymphatic organ(s); MALT
DESCRIPTION;
stands for MUCOSA-ASSOCIATED LYMPHOID TISSUE
- seen within MUCOUS MEMBRANES thrghout. the body
- found in the respiratory tract, digestive tract, genitourinary organs
FUNCTION:
aids for pathogen protection
MALT ORGANS:
- tonsils
- peyer’s patches
- appendix
describe lymphatic organ; TONSILS (MALT)
TYPES OF TONSILS;
- palatine tonsils (largest + most infected)
- lingual tonsils
- pharyngeal tonsils
- tubal tonsils (auditory tubes into pharynx)
FUNCTIONS:
- helps with the creation of TONSILLAR CRYPTS
bacteria/various matter can be trapped and destroyed
describe clinical condition; INFLAMED TONSILS
TONSILITIS: INFLAMMATION OF TONSILS
- commonly caused by viral or bacterial infection
- common symptoms include sore throat and fever
describe lymphatic organ; PEYER’S PATCHES (MALT)
FUNCTIONS:
- destroys bacteria
- protection of intestinal wall
- creation of memory lymphocytes
describe lymphatic organ; APPENDIX
“same functions as Peyer’s Patches”
describe clinical condition; APPENDICITIS
inflammation of the appendix
describe lymphatic organ; THYMUS
FUNCTION:
T cell maturing site
LOCATION:
seen witin the outer cortex and inner medulla;
- CORTEX:
- lots of dividing lymphocytes + scattered macrophages
- MEDULLA:
- has thymic corpuscles; regulates the development of T cells
DIFFERENCES:
- has NO FOLLICLES; lack of B cells
- no DIRECT FIGHT to antigens; helps only for T LYMPHOCYTE MATURATION through the bLOOD THYMUS BARRIER (prevents premature activation)
- has STROMA; creation of immunocompetent biome for T lymphocytes
describe the DEVELOPMENT of LYMPHATIC TISSUES.
LYMPHOID ORGANS:
developed from MESODERMAL mesenchymal cells
THYMUS:
from ENDODERMAL ORIGIN + OUTGROWTH of PHARYNX
FIFTH WEEK:
start of lymphatic vessel/lymph node growth
what are PLASMA CELLS?
differentiated B LYMPHOCYTE WHITE BLOOD CELLS capable of secreting immunoglobulin or antibodies.
- helps STOP INFECTION and DISEASE
describe our IMMUNE RESPONSES–HUMORAL vs CELL MEDIATED
IMMUNE RESPONSE:
response of the body that enables proper defense against HARMFUL AGENTS –such as BACTERIA, VIRUSES, and TOXINS
HUMORAL IMMUNITY:
use of an ANTIBODY-MEDIATED RESPONSE against foreign material
- seeing ANTIGENS in the body
- often controlled by our B CELL LYMPHOCYTES
CELL-MEDIATED IMMUNITY:
does NOT DEPEND on ANTIBODIES
- driven by MATURE T CELLS + MACROPHAGES + CYTOKINES–responding to an antigen
