IM 1 Flashcards
What is the lymphatic system?
network of small organs/tissues and vessels where lymph flows
what is lymph?
fluid derived from IF
what are the functions of the lymphatic system?
- drain excess IF and return to blood
- return filtered proteins to blood
- transport lipids (lacteals entry point for chylomicrons)
- immune role
what is lymph flow?
there’s filtration and absorption (20-17) that leaves around 3L per day of excess filtration (excluding kidneys)
this filtration enters lymphatic capillaries to become lymph where eventually re-enter blood
where does right lymphatic duct have capillaries flowing from?
upper right side of body?
lymphatic capillaries ___ ultimately flow into ___
in lower body and top left side, thoracic duct
what primarily maintains lymph flow?
smooth muscle contractions with distension
what assists with maintenance of lymph flow?
skeletal muscle and respiratory pump (both pressure gradient driven)
what happens when lymph flow is blocked?
IF builds up with no where to go and can cause edema (swelling)
what are primary lymphoid organs?
bone marrow and thymus, immune cell development and maturation
function of bone marrow?
immune cell development and maturation
function of thymus?
immune cell maturation
what are secondary lymphoid organs?
sites of immune cell residence, contact with pathogens leads to responses
includes spleen, lymph nodes, and lymphoid nodules
what is spleen?
where blood filters through
what are lymph nodes?
where lymph filters through?
what are the two types of lymphoid nodules?
- tonsils
- linings
where are tonsils positioned?
for inhaled and ingested pathogen around the pharynx
where are linings?
GI, RS, UR, reproductive tracts, basically external environment entry points
What’s immunity?
ability to resist or eliminate harmful substances (external and internal all working together to provide)
what is susceptibility
lack of resistance
what are pathogens
virus and microbes (bacteria, fungi, parasites)
what are immune responses?
- defend against invading pathogens
- remove worn out cells damaged by time, trauma, or disease (ex. RBC)
- faciliate wound healing and tissue repair
- immune surveillance
what are examples of external defenses?
physical and chemical
what are physical defenses
skin, hairs, mucus, reflexes
what are chemical defenses?
sebum, lysozyme, stomach acid
how does skin defend?
when intact, prevents external to internal crossing
how does hair defend?
in the nasal cavity, filter
how does mucus defend?
the upper respiratory and GI tracts are stick and bind
how do reflexes defend?
coughing and sneezing -> expelling
how does sebum defend?
oil on skin surface is slightly acidic which is a poor environment for pathogen growth
how do lysozymes defend?
in tears, perspiration, saliva, nasal secretions, tissue fluids. They have antimicrobial properties to break some pathogen cell membranes
how does stomach acid defend?
it’s highly acidic to kill some pathogens
where are white blood cells formed?
formed in red bone marrow by leuokpoiesis
what are the types of immune cells that are white blood cells
-neutrophils
-eosinophils
-basophils
-monocytes (form macrophages when we need them for immune response)
-dendritic cells
-mast cells
-lymphocytes (form B cells, T cells, NK cells)
