Lymphatic system Flashcards
General (Lecture 8)
What structures make up the lymphatic system?
- Lymph
- Lymphatic Vessels
- Tissues
- Supporting Organs
- Spleen
- Thymus
What is the function of the lymphatic system?
- Manage Fluids
- Fat Transport
- Lacteals absorb fats
directly to lymphatic
system - Defense/ Protection
- phagocytic cells
- WBC
- antibodies
Lymphatic Vessel charcteristics
- One way
- Start as Blind Pouch
- Valves
- Highly (↑) Permeable
- Simple Squamous Endothelium
Lymphedema
= blockage of lymph flow
- lymphatic system isn’t doing it job
- Causes:
- tumors
- parasites
- surgery
- edema on both sides
→ Systemic condition
- edema on one side
→ Blockage
What flows into the lymphatic vessels?
Is it good or bad?
Good:
- Fluid
- Proteins
- Cells (WBC/ phagocytic but also cancer cells)
Bad:
- viruses
- bacteria
- cancer cells
(causes spread of cancer –> metastatic)
What allows lymph to flow (movement of fluid) ?
Skeletal Muscle Pump
Respiratory Pump
Pulse of the Artery
Valves
Organization of lymphatics
Lymph Capillaries
↓↓↓
Collecting Vessels
↓↓↓
Lymphatic Trunks
↓↓↓
Lymphatic Ducts
↓↓↓
Venous veins (Subclavian veins)
What are the 9 lymphatic trunks and what do they drain?
Jugular Trunks (R / L)
- head, neck, face
Subclavian Trunks (R / L)
- upper extremities
Bronchomediastinal Trunks (R / L)
- thoracic organs
Lumbar Trunks (R / L)
- lower extremities
Intestinal Trunks (Singular)
- abdominal organs
What are the lymphatic ducts and how much of the body do they drain?
Right Lymphatic Duct
( 1/3 ≈ 33 %)
Thoracic Duct
( 2/3 ≈ 67 %)
What trunks drain into the Right Lymphatic Dact and where does that drain?
R Jugular Trunk
R Suclavian Trunk
R Bronchomediastinal Trunk
—-> Right Subclavian Vein
What drains into the Thoracic duct
L Jugular Trunk
L Subclavian Trunk
L Bronchomediastinal Trunk
Cisterna Chyli
- R + L Lumbar Trunks
- Intestinal Trunk
—-> Left Subclavian Vein
Elephantiasis
tropical disease where lymphatics are clogged with parasitic round worms
- typically lower extremity and scrotum swell
- parasite enters foot → why affect lower extremity
What cells are found in the lymphatic system?
- Lymphocytes
- T- Lymphocytes (cellular immunity)
- B- Lymphocytes (humoral immunity)
- Macrophages
- phagocytosis
What tissue type is found with in the lymphatic system?
= Reticular (Loose) CT
Cells are found in the pockets left by the mesh network of reticular fibers
What are the levels of organization you will find lymphatic tissue?
- Diffuse Tissue
- found in most Organs
- non-encapsulated - Nodules / Follicles
- non-encapsulated
- ex: “Peyer’s Patches”
What are the primary lymphatic organs (tissue)?
Red Bone Marrow
Thymus Gland
What are the secondary lymphatic organs (tissue)?
Lymph Nodes
Spleen
Tonsils
Lymphatic nodules
What are lymphatic organs?
Encapsulated diffuse lymphoid tissue and follicles
Lymph Node structure
- 2.5 cm bean
- Capsule exterior = fibrous dense CT
- Trabeculae interior, capsule extension dividing the cortex into lobes
- Hilus (concave side of the node)
- 2 distinct regions
Cortex: superficial region with nodules that have proliferation center that produce B cells
Medulla: deeper region, that has T cells (& B cells) in tightly packed strands called medullary cords
What is the pathway of lymph through the lymph node?
Afferent lymphatic vessels
↓↓↓
Subcapsular sinus
↓↓↓
Trabecular sinus
↓↓↓
Medullary sinus
↓↓↓
Efferent lymphatic vessel
What is the Afferent to Efferent lymphatic vessel ratio and why?
There are many afferent lymphatic vessels entering a lymph node.
Only 1 efferent lymphatic vessel exiting a lymph node at the Hilus
Purpose:
To slow the flow of lymph to allow for the lymphocytes to inspect the lymph for pathogens
What are the 3 kinds of lymph nodes you are responsible for knowing and locating?
- Cervical
- moniter head, neck &
face - Axillary
- monitor flow from
arm
- taken out in breat
mastectomy - Inguinal
- moniter legs
Function of lymph nodes
To filter lymph as transported back to blood
- Phagocytes remove debris
- Lymphocytes monitor lymph as passes for antigens
What is the largest lymph organ?
Spleen
- site of lymphocyte proliferation
- stores breakdown products of RBC for recycling (Fe)
What are the 2 parts of the spleen?
White Pulp
Red Pulp
White pulp
What is it?
What is it made of?
Where is it found?
Function?
Islands of Lymphocytes and Reticular fibers that surround the branches off the splenic artery
Function:
Immune surveillance
Red Pulp
What will you find in it?
Function(s)?
RBCs and macrophages
contain Splenic Cords = regions of reticular fibers rich in macrophages
Function:
- breakdown of old RBC & pathogens
- stores platelets
- erythropoiesis during fetal life
Thymus
- functions first 10 yrs life
- degenerates w/ age & replaced w/ fat
- role development of T-cells (cell mediated immunity)
- Hormone Production:
- Thymosin
- thymopoietin
What are tonsils?
Types and locations
rings/ clusters of lymphoid tissue around the pharynx (throat)
1. Palatine Tonsils
- back of throat
2. Lingual Tonsils
- base of tongue
3. Pharyngeal Tonsils (adnoids)
- back of nose (nasopharynx)
4. Tubal Tonsils
- around opening of Eustachian tube
- goes to middle ear
