Lecture 12: Lymphatics Flashcards
Functions of the lymphatic system
- Protect body against infection by activating immune response
- Collect tissue fluids, solutes, hormones and plasma proteins and return them to the circulatory system.
- Absorb fat from small intestine
Lymph surrounds blood vessels and the absorb the stuff that leaks out of vessels
Lymphoid system. What is in it?
Lymph Lymphatic plexuses Lymphatic vessels Lymph nodes Lymphocytes Lymphoid organs
What is in lymph
Interstitial fluid Immune cells Antigens Lipids Macromolecules Particulate matter
Lymphatic drainage.
How much fluid does lymph return to blood stream each day?
Lymph vessels transport lymph everywhere in body except we’re?
3.5-4L of fluid per day back into bloodstream
Lymphatic vessels transport lymph from everywhere in your body EXCEPT your CNS and bones
Lymphatic transport, how does it move around?
No pump! Uni directional flow towards heart Flow propelled by -respiration (pressure changes) -skeletal muscle contraction -pulsation of nearby arteries -intrinsic smooth muscle contraction of large lymph vessels MOVING
Lymphatic capillaries. Tell me about them, ie what there called, were the run, what they do
As said before are absent from bones, teeth, marrow and CNS
Lacteals: specialised lymph capillaries present in intestinal mucosa
-absorb digested fat and deliver fatty lymph (chyle) to the blood
Lymph is delivered into one of 2 large ducts. What are they, we’re are they?
Right lymphatic duct: drains right upper arm and right side of head and thorax. It empties into venus angle, between jugular vein and subclavian.
Thoracic duct arises as cisterna chyli; drains the rest of the body
Slide 11
How does lymph get back into circulatory system?
Venus angle, between internal jugular vein and our subclavian veins. All of that fluid moves into the brachiocephalic vein, into superior vena cava into heart etc. slide 12
Why are there more afferent than efferent lymphatic vessels in a lymph node?
So that there is more filtration occurring in the lymph nodes.
Ie more time for the macrophages to eat debri, and more time for lymphocytes to make antigens.
Function of lymph nodes
- Filter lymph - macrophages destroy microorganisms and debris
- Immune system activation- lymphocytes activates and mount attacks against antigens
What are the superficial lymph nodes. Need to know these for next unit!
Submental Submandibular Occipital, parotid, mastoid Cervical Supra & infra-clavicular Axillary Superficial inguinal Cubital = epitrochlear Popliteal Slide 16
What are the supraclavicula lymph nodes. Know them, be able to label them
Cervical Sub mental Submandibular Prelaryngeal Paralaryngeal Pretracheal Mastoid Parotid Occipital Slide 17
Discuss the axillary lymph nodes.
We’re they drain
75% drains laterally and superiorly into the axillary nodes
Small amount may drain to the posterior intercostal nodes
Lumphatics are involved in the Metastis of breast cancer: and can spread to other cancers liver, lung, bones, brain
Axillary and cubital lymph nodes
Slide 19- be able to label
Cubital nodes surround the median cubital vein in the cubital fossa of the arm.
There are lots or lymph capillaries in the hand coz we cut them often. Ie get more damage to drain away debri etc.
They dump into the axillary nodes
Superficial inguinal and popliteal nodes
Lymphatics surrounding great saphenous vein drain to?
Lymphatics surrounding the small saphenous vein drain to?
Slide21: label it
All of the lymph from the legs drain up there (on underwear line)
Superficial inguinal lymph nodes
Popliteal lymph nodes
If you get cancer of the uterus or cervix it is going to enlarge what lymph nodes?
Internal iliac lymph nodes. Deep lymph nodes
Deep: intestinal nodes
Absorb fat
Deep pulmonary nodes
Remove debris
What is a disease called when the lymphatics aren’t working?
Lymphoedema
What is it called when there is inflammation of lymphatic vessels
Lymphangitis
-red streaks along course of lymph vessels
-red colour come from the congestion of the vasa vasorum (tiny blood vessels supplying blood vessels)
If you see a patient with red streaks, it means the lymphatic vessels are becoming inflamed. GET THEM TO A DOCTOR IMMEDIATLY.
What is it when there is inflammation in the lymph nodes?
Lymphadenitis
Lymph nodes become large and tender
Note: bacterial infected nodes are swollen and usually painful
Cancer-infiltrates lymph nodes are swollen but usually not painful
Lymphogenous spread of cancer. How does it happen?
Cells break- off epithelial tumour and enter lymphatic vessels ➡ tumour cells get trapped in lymph nodes ➡ tumour cell multiply in lymph nodes forming secondary (metastatic) cancer site. Which can spread to numerous nodes in the body
Lymphoid organs and tissues
Provide structural basis of immune system
House phagocytic cells and lymphocytes
Structures include spleen, thymus, tonsils, lymph nodes, oth lymphoid tissue
Label diagram on slide 29
Yee
Thymus
Superior to the heart
- important function early in life
- increases in size in child hood then stops growing then decreases in size as we get older
- produces immunocompetent cells
- produces most lymphocytes
Spleen
Location
Function
Label it slide 29
Spleen located in the left hypochondriac region of the abdomen.
Most vulnerable abdominal organ. Not vital to sustain life
Protected by inferior thoracic cage
-largest lymphoid organ
-served by splenic artery and vein
-located at the tail end of the pancreas
Functions:
-site of lymphocyte proliferation and immune response
-cleans blood of aged cells and platelets, macrophages remove debris
-fetal spleen (but no adult) produces erythrocytes (RBCs)
-stores breakdown products of RBC eg iron for later use
-stores blood platelets and monocytes
-may be site of fetal erythrocyte production (cease before birth)
-encased by fibrous capsule
-contains lymphocytes, macrophages, and huge number of erythrocytes
What could be the consequence of the spleens topographical relationship with the ribs? Slide 36
If you get broken ribs it pops
Label slide 37
Yer yer
What’s in the white pulp?
What’s in the red pulp? Of the spleen?
Lymphocytes
Erythrocytes
Tonsils
Name them
Function
Form rings of lymphatic tissue around pharynx
-palatine tonsils: at posterior end of oral cavity
-lingual tonsils: grouped at base of tongue
-pharyngeal tonsils: in posterior wall of nasopharynx
-tubal tonsils: surroundings openings of auditory tubes into pharynx
Gather and remove pathogens in food or air
Aggregates of lymphoid follicles?
Peyers patches and appendix
Peyer’s patches
- clusters of lymphoid follicles
- in wall of ileum only
- similar structures are also found in the appendix
Peyers patches and appendix
-destroys bacteria, preventing them from breaching intestinal wall
Appendix slide 44
Comes of the cecum
