Physiology Lecture 27 - Immune Organs

what pushes fluid out?

capillary hydrostatic pressure

what is hydrostatic pressure?

force exerted by fluid against a wall

how much fluid is pushed out each day?

20L

how do you retain fluid in blood?

colloid osmotic pressure

what is colloid osmotic pressure created by?

non-diffusible molecules that draw some fluid back

besides colloid osmotic pressure, what else returns fluid to blood?

lymphatic system

via colloid osmotic pressure how much fluid per day is reabsorbed into the capillaries at the venous end?

17L

for all capillary beds, how much fluid is filtered out per day via hydrostatic pressure?

20L

fluid moves through the _______ ________

interstitial space

about how many liters of fluid per day are removed by the lymphatic system?

3L

what is the lymphatic system?

network of vessels that take up fluid from the interstitial space and return it to the blood

lymphatic capillary ends have ______ anchored to ______ ______

minivalves anchored to connective tissue

_______ fluid levels pull minivalves apart

increased fluid levels

once fluid enters lymphatic capillaries, it is called ______

lymph

lymphatic vessels are all over the body except ______ and ______

bone, teeth

where does lymph go?

all roads lead to the heart

what is going on here?

extreme lymphatic disruptions

_______ is cleansed of debris and surveyed for pathogens

lymph

lymph travels through ______ _____

lymph nodes

what do immune cells do to pathogens?

detect and eliminate pathogens

what are lymph nodes?

solid spherical bodies that cluster along lymphatic vessels

what do lymph nodes provide for immune cells?

a meeting, surveillance, proliferation site for immune cells

what are the two cells of lymphoid organs?

lymphocytes and antigen presenting cells

what are lymphocytes?

the soldiers, T cells, B cells

what are T cells?

T lymphocytes, manage response, attack infected cells

what are B cells?

B lymphocytes, produce antibodies

what are macrophages?

antigen presenting cells, phagocytose foreign substances and present antigens

what are dendritic cells?

antigen presenting cells, capture antigens in tissues and bring them back to the lymph node

what bring in lymph to the lymph nodes?

afferents bring in lymph

what returns lymph to the body from the lymph nodes?

efferents return lymph

what is the cortex in lymph nodes?

dividing B cells (germinal centers), T cells in transit

what is the medulla in lymph nodes?

drains sinuses that allow lymph efflux

other lymphoid organs protect the body, but ONLY _____ ____ filter lymph

lymph nodes

what are some other lymphoid organs besides the lymph nodes?

tonsils, thymus, spleen, peyer’s patches, appendix

what does the spleen do?

immune surveillance of blood (white pulp), removal of old RBCs (red pulp)