Lymphatic Lecture

Question 1

Lymph Organs -

Answer 1

Spleen
Thymus

Question 2

What is the largest lymph organ?

Answer 2

the spleen

It does some immune stuff
Distinctly cardiovascular stuff

Question 3

Thymus – is

Answer 3

1. a gland
2. produces hormones
   (thymopeitin & thymosin)
3. aids the lymphatic system
   (trains the T cells)
   (B cells form and mature in the bone marrow)
   (T cells form in the bone marrow and mature in the thymus)

Question 4

Spleen is connected to

Answer 4

vascular system but not the lymphatic system

Question 5

Children born without a thymus…

Answer 5

DO NOT develop a functional immune system

Question 5

Functions of the spleen

Answer 5

1. has white blood cells - macrophages
2. very generalist WBCs
3. going to look out for infectious agents (bacteria)
4. will do phagocytosis
5. helps remove worn-out red blood cells
6. helps deal with excess platelets (blood clotting platelets)
7. helps deal with bacteria
8. Fetal spleen produces RBCs
9. Sever anemia can initiate RBC formation
10. Spleen can CONTRACT to RELEASE 200-300 ml of BLOOD back to circulation (as in hemorrhaging - severe blood loss_

Question 6

Lymphatic system connects

Answer 6

lymphatic system and immune system

Question 7

Basic Lymph function

Answer 7

1. Excess NFP (net filtration pressure)
2. Disease surveillance - aids in immunity
3. Lipid transport to GI to circulation –

(Does NOT transport through the blood). - Lipid absorption from the digestion system:
1. goes into the lymphatic system
2. then to circulation
3. where it plays a normal role in metabolic processes - can take food and use it for energy

Question 8

Lymphatic system consists of three parts

Answer 8

1. A network of lymphatic vessels
2. Lymph nodes - filter fluid (around the jaw line)
3. Lymphoid organs - disease prevention

Question 9

The goal of the lymphatic vessels

Answer 9

1. ensure one-directional flow
2. Lymph vessels are DEAD-END –unlike cardiovascular system which is a circuit
3. They hang out in the extremities
4. as they soak up fluid they have to push fluid back

There is no force in the lymphatic system - it relies on other factors.

Question 10

Lymphatic capillaries are made of

Answer 10

single layer of endothelium

The cells overlap instead of being physically connected

Has pseudo valves for one way flow - do not open and shut

Question 11

Lymphatics - capillaries merge & empty into two ducts:

Answer 11

1. R lymphatic duct
2. Thoracic duct

Question 12

The lymphatic ducts empty into the

Answer 12

subclavian veins

Question 13

Which lymphatic duct does the most work?

Answer 13

Thoracic Duct

Question 14

What areas of the body do the lymphs drain to (2 areas)

Answer 14

1. R lymphatic duct - drains R half of head, R arm, & R upper chest
2. Thoracic duct - drains the rest of the body lymph (does the most work)

Question 15

Similarities of lymphatics relative to veins

Answer 15

1. Lymph moves via skeletal muscle, valves, thoracic pump (assists) & fluid pressure gradient

Not a high-pressure system - relies on you to keep moving

Question 16

Differences of lymphatics relative to veins

Answer 16

1. Thinner walls, more valves & modify to form lymph nodes

DISTINCTIVE FEATURE - many more valves than veins.

Also modified to form other tissues.

Because they have overlapping cells - there are a lot more valves in the lymphatic vessels than what you see in the veins

Even though they are thin, they are not structurally organized the way veins are - with more muscle and more CT.

Question 17

Common blockage that produces edema in this drainage area

Answer 17

Thoracic duct

Question 18

Edema =

Answer 18

Fluid build up in interstitial space

Lack of albumin

Concentration of albumin - osmotic pressure regulator - in capillary

Blockage of lymph vessels - elephantiasis

Inflammation - change in permeability of blood and lymph vessel walls

Question 19

Lymphatic Tissues

MALT =

Answer 19

Monitoring system in 4 open pathways

1. Respiratory, digestive, urinary, reproductive
2. Protects against foreign matter

Monitoring of disease causing pathogens

Question 20

Example of a MALT that monitors one of the routes into the body - for pathogens

Answer 20

Tonsils

Function similar to lymph nodes, filtering germs entering the nose or mouth and reduce infection

Question 21

MALT that is all about the intestines

A type of MALT

Answer 21

Peyer’s Patches

1. At junction of small & large intestine & in appendix
2. Destroy bacteria & generate lymphocytes

Peyer’s Patches are going to seek out any harmful bacterial infections or agents in the nutrients and other substances we might consume.

Will create WBCs called lymphocytes

Question 22

General Locations of the Lymph Nodes

Answer 22

1. Cervical - neck
2. Axillary - armpit
3. Abdominal Region - inguinal region - AKA groin region

Question 23

What do the Lymph nodes do?

Answer 23

1. Fluids are moving around
2. Fluids out of cardiovascular system
3. goes into intestinal
4. soaked up by the lymphatic system
5. WBCs hang out around the Lymph nodes (Hall Monitor)
6. Another method to add more protection

Question 24

Where do WBCs hang out?

Answer 24

Lymph nodes (Hall Monitor)