What are the 4 parts of the lymphatic system?
- Lymph
- Vessels that transport lymph
- Lymphatic tissue
- Red bone marrow, where stem cells develop in to red blood cells, including lymphocytes
What is the structure of lymphatic tissue?
LYMPHOCYTES
- B cells
Mature in the bone marrow
- T cells
Mature in the thymus
What are the 3 types of lymphatic vessels?
- capillaries
- vessels
- nodes
What are the lymphatic trunks?
Union of vessels exiting most proximal chain of lymph nodes
How does lymph flow around the body?
- skeletal muscle pump
- respiratory pump
What are the 2 functional classifications of lymphatic organs?
PRIMARY ORGANS
- immunocompetent
- red bone marrow
- thymus
SECONDARY ORGANS & TISSUES
- immune response
- lymph nodes
- spleen
- lymph nodules (lack capsule)
What is the function of the thymus?
2 LOBES
- populates secondary lymph organs with T cells
CORTEX
- produces thymus hormones
- T cells, dendritic & macrophages
MEDULLA
- T cells more mature
- thymic (hassal’s corpuscle)
Where are the lymph nodes?
- along vessels & scattered throughout the body
groups near surface regions of:
- cervical area
- axillary
- inguinal
- capsule with traneculae
- inner network of reticular fibres & fibroblasts
What 2 tissue types are found in the spleen?
HILUS
- passage for splenic artery, vein & efferent vessels
WHITS PULP
- around branches of splenic artery
RED PULP
- blood filled venous sinuses
- strands of splenic tissue
What are the lymph nodules?
- mucosa- associated lymph tissue (MALT)
- peyers patches (GIT)
- tonsils
PATHOGEN
Disease producing microbe
RESISTANCE
Ability to defend against damage or disease
SUSCEPTIBILITY
Lack of resistance
NON-SPECIFIC RESISTANCE / INNATE DEFENCES
Provide immediate & general protection
SPECIFIC-RESISTANCE / ADAPTIVE IMMUNITY
Develops in response to a particular invader
What are the 1st line of defences?
Primary goal is to prevent organism from entering the body
- Skin
- Mucous membranes
- Secretions
What are the 2nd line of defences?
Recognise, neutralise, destroy invaders.
- Phagocyte cells
- engulf foreign particles - Antimicrobial proteins
- complement, interferon - Inflammatory response
What are the cells of the 2nd line of defence?
- natural killer (lymphocyte)
- phagocytes
- neutrophils
- macrophages
What are the 5 phases of phagocytosis?
- Chemotaxis
- Adherence
- Ingestion
- Digestion
- Killing
What are the 5 signs of inflammation?
- redness
- swelling
- heat
- pain
- loss of function
What are the stages of inflammatory response?
- vasodilation & increased permeability of blood vessels
- emigration of phagocytes
- chemotaxis & microbial attack
- tissue repair
What inflammatory mediators contribute to the inflammatory response?
- histamine
- prostaglandins
- leukotrines
- compliment (group of plasma proteins)
What cells are involved in immunocompetent & where do they mature?
B CELLS
- develop in red bone marrow throughout life
- produces antibodies that are specific for antigens
T CELLS
- mature in the thymus
- antigen receptors
- recognise specific antigens
What a the 3 main functions of the lymphatic system?
- Drains excess interstitial fluid
- Transports dietary lipids
- Carries out immune responses
