Lecture 11 - Lymphatics Flashcards
State the 2 parts of the lymphatic system
- lymphatic vessels
- lymphatic tissues/organs
Where are the lymphatic vessels in the body? Where are they not found?
-everywhere
EXCEPT = bone, teeth, bone marrow
What do the lymphatic vessels do?
drains up to 3L of lymph fluid from tissues back into the bloodstream
If the fluid pressure in the tissues increases what is likely to occur in the lymph capillaries?
-the valves open and fluid flows in
If the fluid pressure in the capillary increase what is likely to occur?
-the valves close and no movement of fluid
How does the capillary stop collapsing?
collagen anchors
Where does the right lymphatic duct drain from?
-right upper arm
-head
-thorax
Where does the thoracic duct drain from?
-everywhere else in the body
What is the function of lymphoid cells?
to fight infectious microorganisms
What are the 2 types of lymphoid cells and what are their jobs?
- T-cells (soldiers, fight, like but not macrophages)
- B-cells (plasma cells; immunoglobulin)
What are the 2 main functions of lymph nodes?
I) filter lymph
II) activate the immune system
There are 3 specific types of lymph nodes based on their position in the body, name them and where they are.
I) cervical node (neck)
II) axillary (armpit)
III) inguinal nodes (pelvis)
Lymphoid tissue is what kind of tissue? Where is it found? Where not found?
-reticular CT
-all lymphoid organs
-EXCEPT thymus
Why is the reticular CT of lymphoid tissue so good? Why is it used?
-houses and provides proliferation sites (rapid increase) lymphocytes
-ideal surveillance
Review lymph node anatomy in notes
have fun
Why are there more afferent vessels compared to efferent vessels?
-slow, thorough cleaning/filtering
What occurs at the cortex?
-follicles with germinating centres (alert/check)
-dividing B-cells
-T-cells passing through
-dendritic cells
What occurs at the medulla?
-houses medullary cords
-houses medullary large lymph sinuses (macrophages)
What are the 5 functions of the spleen?
I) lymphocyte proliferation (fast make lymph cells)
II) blood cleansing
III) store iron
IV) RBC products in the fetus
V) store blood platelets
What occurs in the red pulp of the spleen?
RBC graveyard
What occurs in the white pulp of the spleen?
immunity
What are the consequences of the spleen having such a thin capsule?
-easily rupture
-regrow and recover well
What are the 2 functions of the thymus?
I) lymphoid maturation
II) thymocyte secretion of thymosin + thymopoietin
What are the 4 tonsils’ names and where are they?
I) pharyngeal tonsil (wall nasopharynx)
II) palatine tonsil (end of the oral cavity)
III) lingual tonsil (base of tongue)
IV) tubal tonsils (ears)
State the aggregates of lymphoid nodules
I) Peyer’s patches (lymph nodule clusters in the wall small intestine)
II) appendix (lymph nodules at cecum)
What does MALT stand for?
mucosa-associated lymphoid tissues
What are the MALT structures? (6)
-Peyer’s patches
-appendix
-tonsils
-nodules in bronchi
-GI tract
-genitourinary system (urinary + genital)
How is lymph transported? (4)
I) lymphatic capillaries
II) lacteals in intestinal villi
III) lymph nodes
IV) lymphatic trunks
Lymphatic vessels vs veins
-wall layers
-wall thickness
-valves
-pumps
-anastomoses
-tunica intima, “—” media, “—” adventitia (SAME)
-L < V
-L > V
-L = V
-L > V
Go over diagram on 3rd page notes
have fun
What induces lymph transport? (5)
I) pressure changes
II) muscles
III) respiratory
IV) valves
V) SM in walls of lymphatic trunks/ducts
How is the speed of the lymphatic system increased?
local movement
What happens when there is a blockage or removal of lymphatics?
-severe local edema
-drainage restored by regrowth of remaining vessel
