Lecture 5 Lymphatic System Flashcards
What type of system is the lymphatic system?
Circulatory system
How is the lymphatic system different than the blood circulation?
- Its only HALf a circulatory system
- no pump that’s part of it
The heart is not running the lymphatic system T/F
True
What are the major functions of the lymphatic system?
- To maintain fluid balance in the internal environment
- Produce, maintain, and distribute lymphocytes
- It carry lipids that you absorb from what you’ve ingested
What don’t we see in lymph but see in blood?
Clotting proteins
If a person has an issue with their lymphatic system and one of their large lymphatic vessels are damaged, what happens?
They need surgery to repair it because lymph can’t clot, you can’t stop the loss
- if you have a hole in a big lymphatic vessel, you’re not getting fluid back into the blood that’s supposed to be there.
What does the lymphatic system start with?
Capillaries
Lymphatic capillaries are _______ than blood capillaries
Bigger
Lymphatic capillaries are blind ended whereas blood capillaries_____
One end starts where arterial starts and it ends where Venules are
- Lymph capillary starts with blind ended thing and the lymph capillaries will pick up fluid which will move it into small lymphatic vessels and into large lymphatic vessels.
Lymphatic capillaries are more permeable than?
Sinusoids
Why do we need the lymphatic capillaries to be the most permeable?
It makes it the easiest for fluid to move into the lymphatic capillaries
- big holes in the walls of lymphatic capillaries makes it easier for the lymphocytes to go in from tissues and into lymph capillaries or from lymph capillaries and into the tissues
Where can we find lymphatic capillaries? And why?
Around blood capillaries
- to absorb (fluid that needs to be picked up by lymphatic capillaries is coming out of the blood capillaries)
- location that makes it the easiest to pick up so we can get it back to the lymphatic system
As we move away from the lymphatic capillaries and toward larger lymphatic vessels, what do they have?
Tunica interna, tunica media, and tunica external like arteries and veins do and they tend to travel together
Just like blood capillaries, the walls of the lymphatic capillaries are?
Single cell layer thick
Lymphatic vessels look and act a lot like?
Veins
How are lymphatic vessels different than veins?
- lymphatic vessels have more valves (bc we don’t have a pump directly attached to lymphatic system. Completely dependent on skeletal muscle pump and respiratory pump)
- lymphatic vessels seem to have the ability to repair themselves faster than blood vessels do
We get a solid cord of cells that hollows out an connect back to lymphatic vessels that are working
What helps us a make lymph move?
The same things that’s gonna help us increase venous return
- skeletal muscle pump and respiratory pump
The heart being connected to the arterial side of the blood circulation, it’s pumping power helps what
Helps blood move through capillaries
- Lymphatic system doesn’t have that
Valves in lymphatic vessels work exactly the same way that valves work in a _____
Peripheral vein
When you look at a lymphatic vessel, larger than a capillary, it has the three layers but what are the distinctiveness between the three layers are NOT as?
clear as it is in an artery.
What are the two large lymphatic vessels ?
Right lymphatic duct
Thoracic duct
The right lymphatic duct drains what?
The right side of head, right side of thoracic cavity, and right arm
The right lymphatic duct empties into?
Right subclavian vein
- that’s how we’re gonna get it back into the blood
The thoracic duct is gonna receive lymph from?
Left side of head, left side of thoracic cavity, left arm, and everything below diaphragm
Where does the thoracic duct empty into?
Left subclavian vein
What is the structure in the beginning of the thoracic duct called?
Cisterna chyle
- in abdominal cavity
The fluid in the cisterna chyle and most of thoracic duct looks like what and why?
Milk
- all the lipids that were absorbed from what you digested go into thoracic duct
How long is the thoracic duct itselF
16 inch long
1.5 diameter
We sort lymphocyte into two major catergories:
T cells/T lymphocyte (T stands flfthymus dependent)
B cells/B lymphocyte (bone dependent)
When B cells are activated, what does it become?.
Plasma cells that’s secrete antibodies
When different types of T cells are activated ___
Directly attack invading cells or help another T cell attack
T cells give what and B cells give us what
T cells give cell mediated immunity
B cells give antibody or humoral mediated immunity
What is diapedesis?
WBC can migrate out of blood vessels
What is chemotaxis
Interested in a specific chemical or repels
What is the circulation of lymphocytes spend time in blood, tissue, and then lymph , and then go back to repeat?
Lymphocyte are in the blood and they exit blood and capillary. They hang in the tissue for a while and might go back into the blood capillary or lymphatic capillary. They go into lymphatic capillary and gets exposed to what’s in the lymph and returns to the blood through Thoracic duct or right lymphatic duct
For the repeated circulation of the lymphocytes spending time in blood, tissue and lymph, it increases the likelihood that the lymphocytes run into things that’s supposed to what
Save us from
Places where we have accumulations of lymphocytes and why?
Urinary tract, digestive tract, and respiratory tract
- it’s where we introduce things into our body that need extra protections
The first lymphoid tissue?
Tonsils
What are the ring of tonsils?
Pharyngeal tonsils (back of nasal cavity)
Palatine tonsil
Lingual tonsil
Tubal tonsil (sit at Eustachian tube at either side)
Those four tonsils forms what?
A ring that protects the entrance to the respiratory and digestive tract
Even when tonsils are not infected or ugly, they are built to catch stuff using?
Cracks so things gets stuck
- Regions of lymphocytes that are waiting to get exposed to the thing that stimulates them so that it becomes activated and attacks this thing.
What is an adenoid?
Only properly applied to infected pharyngeal tonsils
- If it’s healthy we don’t call it an adenoid
Less organized lymphatic tissue
MALT (mucosa associated lymphoid tisues)
Why do we need MALT?
As a backup to protect epithelial barrier
What is included as a MALT?
Pairs and patches in intestinal tract
Appendix
Tonsils but more organized than others
First lymphoid organ is?
Lymph node
Why do we use lymph node clinically
To check all sorts of things
- if swollen, they’re fighting something
Most lymph nodes appear in?
Clusters
A lymph node is a?
Filter
The first group of nodes are called?
Preauricular nodes (in front of ears)
What do Preauricular nodes do?
Filter lymph coming from superficial surfaces of lateral part of head
What’s the second group of nodes?
Submental group & submandibular group (submaxillary)
- floor of mouth
What does the Submental group & submandibular group (submaxillary) do?
Filters lymph coming from nose, lips, and teeth
What are the third group of lymph nodes?
Superficial cervical nodes
- sit in the neck right at the border of
- big enough to feel
Why are the Superficial cervical nodes important?
- if you have it swell, you have a serious infection because all lymph going through has already been filtered by other lymph nodes
What are the fourth group of lymph nodes?
Superficial cubital nodes (supratrochlear lymph nodes)
- just above anticubital area
What does the Superficial cubital nodes (supratrochlear lymph nodes) do?
Filtering lymph coming from forearm
What is the fifth group of nodes?
Axillary nodes
-large accumulation of nodes in axillary area
- 20-30 nodes on each side
What do axillary nodes do?
Filter lymph coming from upper regions of body including breasts
- different about lymphatic drainage of breast is that there’s a lymphatic connection from one breast to another
If a person gets breast cancer, it moves out to?
the axillary nodes very easily and to the other breast very easily
What is the sixth group of node?
Iliac nodes and inguinal nodes
- groin
Why are Iliac nodes and inguinal nodes important?
Has been filtered by other lymph nodes. If swollen or inflamed, you have a big infection
What are the lymphoid organs surrounded by?
A fibrous capsule
A lymph node has multiple ?
Afferent vessels
- they’re bringing lymph INTO lymph node
What do the efferent vessels do?
Carry lymph away from lymph node
Do lymph nodes vary in size? Yes or no
yes
What is the cortical nodule made up of?
B lymphocytes that are tightly packed together
- and if lymph has something in it that activates this lymphocyte, it will get reactive and some cells it produces will wind up in lymph and travel with it to hunt it down.
What is a germinal center?
where you make lymphocyte to contribute to the other part of cortical nodule.
- Less tightly packed area
What is the central section of the lymph node called?
Medulla
Area where we have nodules is called?
Cortex
Medulla does not have?
Germinal centers
What are Reticuloendothelial cells (aka dendritic cells)?
Final cleanup for the lymph
- Final thing that takes smtn out of lymph
Two types of filtration?
Mechanical filtration and biological filtration
What is mechanical filtration?
Things that are too big to pass through sinuses
- They get stuck and Reticuloendothelial cells (aka dendritic cells) eat them
Why does it not matter if cells are yours or not?
It matters if clump of wave gets stuck in sinus
- If too big, will get eaten
What is biological filtration?
- Is it yours and normal (nothing happens)
- Is it yours and abnormal (might run into natural killer cell or get labeled by a T cell and Reticuloendothelial cells will eat it
- Is it not yours (Reticuloendothelial cells should eat it)
(possibility that all three are small enough to fit through sinuses)
(nothing to do with size)
Other function beside filtration is?
Early warning
- if you have a small invasion of bacteria, lymph nodes can get antigens out of the and wake up B cells which will go out into the circulation and get put into blood to defend against bacteria before infection gets bigger
Where is the thymus located?
Organ before thyroid, above heart
By early adulthood, the thymus is starting to?
Decrease in size and active thymus tissue is being replaced by fat
What is that process of active thymus tissue is being replaced by fat called?
Involution
What is the job of a thymus?
Quality control
- all T cells have to go through thymus and get through obstacles. If they pass, they’re released into blood. If they don’t, they get killed off
95% of T cells that go into thymus never come out again T/F
True
The 5% of T cells that pass the immunological obstacle course
Where we get memory T cells, helper T cells, and
Are absolutely amazing
Where is the spleen located?
Oval shaped under diaphragm on left
Spleen changes size throughout life not just bc of involution T/F
True
Why does the spleen change size?
It hypertrophies when you have an infection and shrinks in size when you don’t
Spleen has a huge blood supply for an organ of its size T/F
True
White pulp
Where the lymphocytes are
What surrounds white pulp?
Red pulp
What is red pulp?
Maddie up of sinusoids and there’s blood in there
What do we have Inside sinusoids in spleen?
Reticuloendothelial cells
Functions of spleen
- Defense
- Reticuloendothelial cells that eat things that are labeled by lymphocytes - Hematopoiesis
- monocytes and lymphocytes (except T cells) have last stage of maturation happen in spleen before going off to other tissues
- spleen is first organ in body in utero that makes RBC - Spleen is spongy organ
- fibrous capsule around it (bc lymphatic organ),there’s smooth muscle in that fibrous capsule and after hemorrhage, while sympathetic nervous system does it’s thing, it cause smooth muscle to contract squishing blood out of spleen and it’s called auto transfusion (200 ml of blood getting stronger out
Spleen along with liver help recycle RBC and platelets, they get stuck in sinusoids. In spleen, phagocytic cells that are doing recycling are Reticuloendothelial cells
Spleen is useful and essential T/F
FALSE
- useful but NOT essential
All lymphoid organs are going to?
Involute
- different time frames
- Last one to show major involution is the spleen
Our allergies get worse as we grow older due to?
Our immune system react more strongly to what you’re allergic to
