Chapter 21- Lymphatic and Immune Systems Flashcards
Components of Lymphatic and Immune Systems
Lymphatic Vessels
Lymphocytes- White Blood Cells
Lymphoid tissue and organs
Lymphoid vessels
Lymph capillaries
Lymphatic collecting vessels
Lymph nodes
Lymph Trunks
Lymph ducts
Lymphoid vessels functions
Collect lymph and deliver to brachiocephalic veins
Filter lymph
Lymph
Excess fluid and molecules surrounding capillary beds
Tissue fluid and blood proteins
Lymphoid Capillaries
First receive lymph from capillary bed
Contain 1-way valves to increase uptake
Receives bacteria, viruses, and some cancer cells
Lymphatic collecting vessels
Run alongside blood vessels with similar structure
Move lymph with force from skeletal muscles, arterial pressure, and tunica media
Lymph nodes
Lymphoid tissue scattered in clusters along collecting vessels
Filters lymph and cleanses of pathogens
Contain macrophages and lymphocytes in reticular fibers
Site of most antigenic challenges
Lymph trunks
Major vessels for lymph to travel
Lumbar (lower limbs)
Intestinal (digestive organs)
Bronchomediastinal (Thoracic viscera)
Subclavian (Upper limbs and trunk)
Jugular (head and neck)
Lymph ducts
Drainage point of lymph into blood circulation
Right lymphatic duct and Thoracic duct
Right lymphatic duct
Empties into right internal jugular and right subclavian veins
Serves superior right quarter of the body
Thoracic duct
Empties at the junction of the left internal jugular and subclavian veins
Serves 3/4 of body
Cisterna chyli
Joining of lumbar and intestinal trunks, start of thoracic duct
Lacteals
Specialized lymphatic capillaries in small intestine that uptake digested fats
Chyle
Fatty lymph absorbed by lacteals
Immune System
Recognize specific foreign molecules and destroys pathogens
Made of lymphocytes and lymphoid tissue/organs
Lymphocytes
Originate in bone marrow and undergo maturation to gain immunocompetence
Types of lymphocytes-
Cytotoxic T cells
B lymphocytes
Effector lymphocytes
Memory lymphocytes
Lymphocyte maturation
Gain ability to recognize unique antigen
T cells- Thymus gland
B cells- Bone marrow
Product- Naive cell that reside in lymph nodes
Effector Lymphocytes
Formed when naive cells are first presented with a pathogen
Short-lived immediately attack pathogens and are destroyed
Cytotoxic T lymphocytes
Attack foreign cells directly
Bind to cells, perforate membrane, and initiate apoptosis
Effective against viral and cancerous cells
B lymphocytes
Become plasma cells that secrete antibodies that mark cells for destruction by macrophages
Respond to 1 particular toxin- best against bacteria and bacterial toxins
Memory lymphocytes
Formed by cells after exposure to pathogen
Circulate in plasma until repeat encounter
Mucosa-Associated Lymphoid Tissue (MALT)
Makes up mucous membrane of digestive, urinary, respiratory, and reproductive tracts
Respond first to pathogens and trigger immune responses
Fight incoming bacteria and produce memory lymphocytes
Peyer’s patches
Intestinal lymph nodes
Lymphoid Organs
Thymus
Lymph nodes
Spleen
Tonsils
Appendix
Thymus gland
Most active in childhood
Site of T lymphocyte maturation
Secretes thymic hormones
Responsible for self-tolerance
Spleen
White pulp- Internal sleeves of spleen; Remove blood-borne pathogens and immune functions of spleen
Red pulp- Surrounds white pulp; Disposes of worn-out blood cells
Largest lymphoid organ
Produces RBC during fetal period
Tonsils
Swellings of mucosa around pharynx that gather and remove pathogens
Underlying tissue contains MALT
Groups of tonsils
Palatine- Oropharynx
Lingual- Base of tongue
Pharyngeal (Adenoids)- Nasopharynx
Tubal- Larynx
Appendix
Offshoot of cecum that contains lymphatic tissue
