Chapter 22 Flashcards
Immunity
Ability to ward off damage or disease through defences
Susceptibility
Vulnerability or lack of resistance
What are the two general types of immunity?
- Innate
- Adaptive
Innate immunity
Defences that are present at birth
Nonspecific
First line: physical and chemical barriers of skin
Second line: Antimicrobial substances, natural killer cells, phagocytes, inflammation and fever
Adaptive immunity
Specific recognition of microbes once it has breached the innate immunity defences
What does the lymphatic system consist of?
Lymph
Lymphatic vessels
Lymphocytes
Red bone marrow
Lymph
Interstitial fluid that passes into lymphatic vessels
Clear, pale yellow fluid
Lymphatic tissue
Specialized form of reticular connective tissue that contains large number of lymphocytes
Immune responses: B cells and T cells
Three primary functions of the lymphatic system?
- Drains excess interstitial fluid
- Transports dietary lipids
- Carries out immune responses
Lymphatic capillaries
Start of lymphatic vessels
Spaces between cells
Closed at one end
Unite to form larger lymphatic vessels
Greater permeability than blood capillaries
Can absorb proteins and lipids
One way permeability
Lacteals
Specialized lymphatic capillaries in the small intestine carry dietary lipids into the lymphatic vessels and ultimately into the blood
Chyle
Creamy white lymph that drains from the small intestine
What are the lymph trunks following the lymph nodes
- Lumbar
- Intestinal
- Bronchomediastinal
- Subclavian
- Jugular
Lumbar trunks drain lymph from where?
Lower limbs
Wall and viscera of the pelvis
Kidneys
Adrenal glands
Abdominal wall
Intestinal trunk drains lymph from where?
Stomach
Intestine
Pancreas
Spleen
Part of liver
Bronchomediastinal drains lymph from where?
Thoracic wall
Lung
Heart
Subclavian trunks drain lymph from where?
Upper limbs
Jugular trunks drain lymph from where?
Head and neck
Flow of lymph
Blood capillaries
Interstitial spaces
Lymphatic capillaries
Lymphatic vessels
Lymphatic trunk or ducts
Junction of internal
What are the two main pumps that support flow of lymph?
Respiratory pump
skeletal muscle pump
What are the primary lymphatic organs?
where stem cells divide and become immunocompetent including red bone marrow and thymus
What are the secondary lymphatic organs?
Where most immune responses occur including lymph nodes, spleen, lymphatic nodules
Thymus
Pre-T cells migrate from the red bone marrow to the cortex of the thymus where they become T cells consist of enclosed capsules and extensions call trabeculae
Lymph nodes
Contain lymphatic nodules which are egg shaped aggregates of B cells
lymphatic nodules containing mostly B cells are primary lymphatic nodules
lymphatic nodules in the outer cortex are secondary lymphatic nodules