Chapter 23: Lymphatic System Flashcards
Objectives
Describe the generalized functions of the lymphatic system and list the primary lymphatic structures.
Fyi
What are the Two most important functions of the lympathtic system?
(this is in red)
- maintain fluid balance in the internal environment
- immunity
What is the third function of the lymphatic system?
(this is in black)
it is to collect absorbed fat from the intestines and transport it to the systemic veins
- act as drains to collect excess interstitial fluid in tissues and return it to the venous blood just before it returns to the heart (Figure 23-1 pg 723)
- If this fluid was left in the tissue, even for a brief period, it could cause massive edema of the tissue, then tissue destruction and even death.
(in black)
Lymph vessels
The lymphatic system is a component of the circulatory system because it _______________
circulates lymph
The lymphatic system is composed of ……….
(in red)
- lymph
- lymphatic vessels
- isolated structures containing lymphoid tissue (lymphocytes & other defensive cells)
-lymph nodes, aggregated lymphoid nodules, tonsils, thymus, spleen, and bone marrow (Figure 23-2 pg 724)
(in red)
lymphocytes & other defensive cells
The lymphatic system
- transports tissue fluid, proteins, fats, and other substances to the general circulation-(in black)
- Lymphatic vessels begin blindly in the intercellular spaces of the soft tissues; do not form a _____________ (in red)
closed circuit
Plasma
- Fluid leaves through capillaries
- Moves into interstitial space
- Most absorbed by tissue cells or resorbed into blood by -the capillaries
- Some interstitial fluid accumulates: drains into lymph vessels and is returned to venous blood
Lymph system and fluid balance
Clear, watery fluid found in the lymphatic vessels
(in black)
Lymph (lymphatic fluid)
- Complex, organized fluid that fills the spaces between the cells and is part of the extracellular matrix
- Along with blood plasma, constitutes the extracellular fluid of the body
(in black)
Interstitial fluid
Both closely resemble blood plasma but have a lower protein concentration
- Lymph (lymphatic fluid)
- Interstitial fluid
microscopic blind-end vessels where lymphatic vessels originate (those originating in the small intestine villi are called lacteals) (in black)
Lymphatic capillaries
-Lymphatic capillaries: microscopic blind-end vessels where lymphatic vessels originate (those originating in the small intestine villi are called lacteals)
- Networks branch and anastomose (connect or join)freely(black)
- *-Lymphatic capillaries merge to form larger lymphatics and eventually form the main lymphatic trunks, the right lymphatic duct, and the thoracic duct**
- **-Lymph from upper right* quadrant empties into right lymphatic duct and then into right subclavian vein
- Lymph from rest of the body empties into the thoracic duct, which then drains into the left subclavian vein; thoracic duct originates as the cisterna chyli (chyle cistern)(red)**
DISTRIBUTION OF THE LYMPHATIC VESSELS
(Figures 23-2 and 23-3 pg 724-725
DRAW A PICTURE TO HELP VISUALIZE
This empties into the right lymphatic duct and then into right subclavian vein (red)
Lymph from upper right quadrant
This empties into the thoracic duct, which then drains into the left subclavian vein; thoracic duct originates as the cisterna chyli (chyle cistern) RED
Lymph from rest of the body (if not the upper right quadrent)
The thoracic duct originates as the- RED
cisterna chyli (chyle cistern)
Take a look at figure 23-3 on page 725
it is the drained by thoracic and drained by right lymphatic duct
KNOW THe FIGURE (red)
know it per ms. a
- Where the thoracic duct originates-red
- Dilated structure located in abdominal cavity in lumbar region (Fig 23-2 Pg 724) red
- Thoracic duct ascends and is about 40cm long-black
- -(fatty lymph) this, absorbs fats from intestinal tract and carries it up to the neck where it meets the L Subclavian Vein.red*
CISTERNA CHYLE
This is the structure of what?
- Similar to veins except these have thinner walls, have more valves, but contain lymph nodes
- their capillary wall is formed by a single layer of thin, flat endothelial cells making it very permeable (black)
_-One-way valves _ ( red)
lymphatic vessels (Figure 23-4 pg 725)
these are present every few millimeters in large lymphatics and even more frequently in smaller lymphatics. These allow the lymph to go in one direction, even against gravity.
One-way valves
THE ARE FUNCTIONS OF THE WHAT?
- Remove high-molecular-weight substances and particulate matter from interstitial spaces that are too large to be absorbed by blood BLACK
- Proteins that accumulate in tissue spaces can ONLY return to blood by way of the lymphatics (50% of blood proteins “leak”) BLACK
-Lacteals RED
LYMPHATIC VESSELS
these absorb fats and other nutrients from the small intestine RED
Lacteals
- Can be caused by injury to main lymphatic trunks
- Cannot maintain adequate plasma protein concentration
- Will have( decrease in total blood fat RED (lacteals of small intestine, no longer absorbing fat) and become emaciated
Blood osmotic pressure falls below normal resulting in a fluid imbalanceRED
Eventual DEATH RED
LOSS OR BLOCKAGE OF LYMPH FLUID
- From lymphatic capillaries, lymph flows through progressively larger lymphatic vessels to reenter blood at the junction of the internal jugular and subclavian veins (Figure 23-5 pg 726)
- In order to accomplish this, the lymph system must act as a pump.RED
- Lymphokinesis RED*
CIRCULATION OF LYMPH
the movement (flow) of lymph RED
Lymphokinesis
KNOW FIGURE 23-5 ON PAGE 726 RED
(ITS THE RED AND BLUE SAFETY PIN LOOKING PIC
KNOW THIS
- Lymph moves through the system, against gravity, because of the large number of valves RED
- Breathing movements and skeletal muscle contractions establish a fluid pressure gradient. RED
- Inspiration BLACK
- intraabdominal pressure to increase as intrathoracic pressure decreases. BLACK
THE LYMPHATIC PUMP -RED