Chapter 22 The Lymphoid system and immunity Flashcards
What is nonspecific resistance (innate Immunity)
Present at birth and includes defense mechanisms that provide general protection invasion by a wide range of pathogens
What is immunity (adaptive immunity)
Involves activation of specific lymphocytes that combat a particular pathogen or other foreign substances
What is the lymphatic system?
Consists of several structures and organs that contain
1. lymphatic tissue
2. bone marrow
3. Lymph fluid that flows within lymphatic vessels
What is the functions of the lymphatic systems?
- Drain excess interstitial fluid
- transport dietary fats
- Carries out immune response
Lymphatic vessels begin as what?
Lymphatic capillaries, which are closed on one end
Lymphatic capillaries are located where?
Between cells of many tissues
Lymphatic capillaries merge to form what?
Lymphatic vessels, which have thin wall and many valves
From Lymphatic vessels, lymph passes through what?
Lymph nodes and then into lymph trunks
What does lymph trunk include?
- lumbar
- intestinal
- bronchomediastinal
- subclavian
- jugular trunks
Lymph trunks then merge to form what?
Either Thoracic ducts or the right lymphatic duct
What is the formation and flow of lymph?
- interstitial fluid
- lymph capillaries
- lymph vessels
- lymph trunks
- lymph ducts
- Subclavian veins
What happens at primary lymphatic organs
Immune cells become immunocompetent
What are some sites of primary lymphatic organs/ sites?
Red bone marrow and thymus
Secondary lymphatic organs and tissues include what?
- Lymph nodes
- Spleen
- lymphatic nodules
Lymphatic nodules are masses of lymphatic tissues that are what?
Surrounded by a capsule
Where are lymphatic nodules scattered?
Throughout the lamina propria of mucous membranes lining the
1. gastrointestinal
2. Urinary
3. Reproductive tracts
4. Respiratory airways
What are Mucosa- associated lymphatic tissue (MALT)
Lymphatic nodules found throughout the lamina propria of mucous membranes
What is innate immunity?
Wide variety of body responses that serve to protect us against invasion by a wide variety of pathogens and their toxins
What are the two lines of defense in innate immunity?
- Skin and mucous membranes
- Internal defenses
What are mechanical defenses?
- skin
- mucous membranes
- Tears
- Saliva
- Mucus
- Cilia
- epiglottis
- Urine flow
- Defecating
- Vomiting
What are chemical defenses?
- sebum
- lysozyme
- gastric juice
What are internal defenses?
- Antimicrobial proteins
- phagocytes
- Natural killer cells
- Inflammation
- Fever