Lymphatic System Flashcards
What are the three functions of the Lymphatic System?
- Fluid Balance
- Fat Absorption
- Defense
How does the lymphatic system regulate fluid balance?
Excess interstitial fluid enters lymphatic capillaries and becomes lymph. Small lymphatic vessels are embedded in our tissues and drains fluid to prevent swelling.
How does the lymphatic system regulate fat absorption?
Fat is absorbed from small intestines via a special lymph vessel called lacteals.
How does the lymphatic system help with the bodies defense system?
Microorganisms and other foreign substances are filtered from lymph by lymph nodes and from blood by the spleen. Lymphocytes are the major players.
What is the composition of lymph?
Water plus solutes from nutrients, gases, cells and proteins.
How does lymph get its milky appearance?
It gets this appearance due to its lipid content.
Where does lymph end up once it drains fluid?
It drains into the circulatory system.
What is the similarity between lymphatic vessels and veins?
Lymphatic vessels start from capillaries and they carry fluid away from tissues and they also contain valves.
In what direction does lymphatic vessels carry lymph?
Carries lymph away from tissues.
What are the names of the 5 lymphatic trunks?
Jugular, Subclavian, Bronchomediastinal, Intestinal, Lumbar
Lymph trunks drain into lymph ducts.
What are the two lymph ducts and there function?
They drain tissues and move lymph into major veins.
Right Lymphatic Duct: Drains right side of head, right upper limbs and right thorax.
Thoracic Duct: Drains remainder of body.
Which Lymphatic Duct is the largest?
Thoracic Duct because it drains the lower body tissues and the left side body tissues.
What is the path of lymph?
Lymphatic capillaries leave tissues draining fluid –> They pass through lymph nodes –> Lymphatic Vessels –> Form Lymphatic Trunks –> Form Lymphatic Ducts
What is the function of lymphocytes?
White blood cells derived from bone marrow, and attack pathogens that may be entering the lymph.
What is the function of Fine Collagen Reticular Fibers in the lymphatic tissue?
Act as a filter to trap pathogens so lymphocytes can deal with them.
What are the two types of lymphatic tissue?
Encapsulated (surrounded by a capsule) and Unencapsulated.
What are tonsils?
Large groups of lymphatic nodules in the naso-pharynx and oral cavity
What is the function of tonsils?
They provide protection against bacteria and other harmful material.
What are the three groups of tonsils?
Palatine
Pharyngeal
Lingual
What is the role of lymph nodes?
To filter lymph and eliminate pathogens
What are the two parts of the vessels that pass through the lymph nodes?
Afferent: Carry lymph to the lymph node to be filtered
Efferent: Carry lymph away from lymph node after it’s been filtered.
What is the while pulp of the spleen?
Associated with arteries
What is the red pulp of the spleen?
Associated with veins
What is the function of the spleen?
Destroys defective RBC’s
Detects and responds to foreign substances
Contains limited reservoir for blood and has ability to contract during extreme blood loss to keep organism alive.
What are the major parts of the thymus?
Cortex: Outer, contains numerous lymphocytes
Medulla: Inner, contains few lymphocytes
What is the role of the thymus?
It is the site of maturation of T cells.
What is the definition of immunity?
Ability to resist damage from foreign substances such as microorganisms and harmful chemicals.
What are the two categories of immunity?
Innate Immunity
Adaptive Immunity
Describe innate immunity
Mechanical Mechanisms prevent entry of microbes.
Chemical Mediators promote phagocytosis
Inflammatory Response: local and systemic.
Describe adaptive immunity
B and T cells are involved in the response.
Specificity: Ability to recognize a particular substance.
Memory: Ability to remember previous encounters with a particular substance and respond rapidly.
Where are Pre-B and Pre-T cells formed?
They originate from red bone marrow
Where do Pre-B cells mature?
In the red bone marrow before they are released into the blood.
Where do Pre-T cells mature?
In the thymus then move into the blood.
What do B and T cells do after they migrate into the blood?
They populate all lymphtic tissues and respond to infections.
What are the mechanical mechanisms of the immune system?
Skin, mucous membranes block foreign bodies.
Tears, saliva, and urine flush out bacteria.
Cilia in the respiratory tract.
