Physiology - Lymphatic System
What is the Lymphatic system and what is it responsible for?
Includes cells/tissues/organs responsible for defending body against pathogens / internal threats (Cancer)
Consists of two semi- independent parts
- A meandering network of lymphatic vessels
- Lymphoid tissues and organs scattered throughout the body
What are Lymphatic vessels?
- A one-way system in which lymph flows toward the heart
- Lymph vessels collect and transport lymph fluid from tissues to circulatory system
- Lymph vessels include: Microscopic, permeable, blind-ended capillaries
- Lymphatic collecting vessels: Trunks and ducts
What are Lymphatic capillaries?
Similar to blood capillaries, with modifications
-Loosely joined endothelial minivalves
- Withstand interstitial pressure and remain open
Explain the following:
Pathogens – responsible for human disease
Virus – abide in cells
Parasites – burrow through internal organs
Bacteria - release protein / damage cell organ
What are the primary cells of the Lymphoid system called?
- Known as immune response
- Vital to overcome infection / diseases
- Responds to: pathogens | body cells | proteins
- Eliminates threats = render them harmless
The Lymphoid System consists of:
- Lymphatic vessels (lymphatics)
- Lymphoid tissues / lymphoid organs
What is Lymph?
Lymph – a clear fluid which resembles plasma (lower concentration of suspended proteins)
- Interstitial fluid becomes lymph once it has entered lymphatic vessels
What are the main Lymphoid organs?
- Lymph nodes
What are the 2 main basic functions of the Lymphoid organs?
Their two basic functions are:
- Filtration – macrophages destroy microorganisms and debris
- Immune system activation – monitor for antigens and mount an attack against them
- Only lymph organ that filters lymph