Chapter 21 Flashcards
Lymphatic system
helps maintain blood volume by returning fluid to the blood & lymphoid organs & tissues are critical for the body’s defense system
3 functions of lymphatic system
- Drains excess interstitial fluidand small plasma proteins back into venous circulation to assist cardiovascular system
- Maintains blood volume
- Transports lipids na dlipid soluble from GI tract to the blood
- defends against infection
How does the Lymphatic system defend against infection
-Produce, maintain, and distribute lymphocytes and macrophages
-Detect potentail threates
-Activates immune response
Where is most fluid reabsorbed
85% at the venous end of the capillary
Hydrostatic pressure of blood
forces fluid & dissolved substances out of blood capillaries and into the interstitial space
(3L per day (15%) )
lymph
fluid outs the lymph vessels
-Water dissolve solutes, protein, foreign material, pathogens, metastasized cancer cells
Difference between lymph and Plasma
Plasma is a blonde-colored, clear, protein-rich, aqueous fluid that comprises up to 50% of blood. Lymph is a colorless, sometimes milky, protein-poor fluid originating as interstitial fluid from between and engulfing cells in tissues.
Lymphatic cappilaries
microscopic, closed end vessels that absorb interstitial fluid where lymph enters through
Where are lymphatic capillaries found
Everywhere except avascular tissues, CNS, red marrow & spleen
What are lymphatic capillaries in the GI tract called
Lacteals Lipid rich lymph = chyle
Hydrostatic pressure
The pressure exerted by a fluid at equilibrium at any point of time due to the force of gravity
AS fluid acculates from blood filtration what happens to hydrostatic pressure
increases
When does fluid push into lymphatic capillary
when Hydrostatic pressure is greater out then in
Lymphatic vessel size
smaller then arteries and veins
Where are Lymphatic being connected
Connect to lymph nodes where lymph is filtered
Lymphatic vessel pumps
Skeletal m. & respiratory
Vascular pulsation
Smooth m. in walls of trunks & ducts
what are lymphatic trunks
Lymphatic vessels drain into lymphatic trunks on both the right and left sides of the body
Jugular trunks
darin lymph node from both the head and the neck
Subclavian Trunk
Remove lymph from the upper limbs (breast, and superficial wall)
Bronchomediastinal trunk
drains lymph from deep thoracic structures
intestinal trunk
(only 1)
Drains the abdomen
Lumbar trunks
Darin lymph from lower limbs, abdominopelvic wall, and pelvic organs
Lymphatic ducts
What the trunks Darin into, there are only 2. Right lymphatic duct and thoracic duct
Right Lymphatic duct
Located near right clavicle and drains the right side. Drains from upper right quadrant of body
Thoracic duct
This is the larger of the 2 ducts 37.5-45 cm in length. Extends from the diaphragm to the junction of the left subclavian and left jugular vein
Cisterna Chyli
Found at the bottom of the thoracic duct. Both ducts drain into here
Primary lymphoid structure
involved in the formation and maturation of lymphocytes. Both the red bone marrow and thymus are considered primary lymphoid structures
Secondary lymphoid structure
not involved in lymphocyte formation but structures the site where an immune response is initiated. Includes the lymph nodes, spleen, tonsils, lymphoid nodules, and MALT
Thymus
Is a Bi-lobed structure in mediastinum, posterior to sternum, anterior to major heart vessels.
-Primary
Located: superior medistaum
Function: Sit of T Lymphocytes maturation and differentiation
Organs and Nodule
-store lymphocytes and other immune cells (spleen, lymph nodes)
Lymphoid nodules have incomplete or absent capsule grouped together
Lymphnodes
Filter lymph, remove unwanted substances
Located along deep and superficial pathways of lymph vessels
Clusters receiving lymph from body regions
Where are the lymph nodes found
-Cervical (head and neckO
Axillary (arm pit)
Inguinal groin
Cortex
Contains multiple lymphoid nodules (the outer part)
Medulla
Inner part of lymph node (B and T cells)
Germinal Center
Proliferating (rapidly dividing) B cells and some macro
Mantle zone
T cells from thymus that will circulate macro dendrite cells
Cortical sinus
tiny channels lymph flows lined by macro
Spleen
Largest lymphoid organ
-located left upper abdominal quadrant, inferior to diaphragm between 9th and 11th ribs
White pulp in spleen
-an immune function T cells, B cells, and macro clustered around central artery
Red pulp in spleen
-Cleaning function of the blood
-RBC, platelets, acrophaged and B cells
-Splenic cords
-splenic sinusoids (very permeable) filled with blood
Function of the spleen
-filter and monitor blood
-Phagocytosis of foreign materials, old defective erythrocytes and platelets, cellular debris
-Storage of RBD and platelets 30%
What is MALT -Tonils
A secondary lymphoid structure
-Phagoctosis of inhaled ingested substances
-Tonissar crypts Invations that are trapped material
MALT Peyers patches
Large collections of lymphoid nodules within the wall of the small intestine, especially ileum (distal)
