Lymphatic System Flashcards
List the functions of the lymphatic system
- collects interstitial fluid
- transports dietary fats
- protects against microorganisms
Explain the process of interstitial fluid collection
collects interstitial fluid not absorbed by capillary beds and returns the fluid back to the blood
-about 15% of filtered fluid
Explain how transportation works in the lymph system
transports dietary lipids and lipid soluble vitamins from the gastrointestinal tract to the blood
Explain how the body protects against foreign invaders
-protects against invasion of micro-organisms through immune responses
List the components of the lymphatic system
- Lymph capillaries, vessels, and ducts
- associated with lymphatic organs containing leukocytes
how does lymph get around the body?
same as the return of blood in veins. Skeletal muscles pump, respiratory pump, and pressure differences
List the components of interstitial fluid
- dietary lipids
- lipid soluble vits
- lymphocytes
Where is lymph located
forms at capillary beds
How does lymph form at capillary beds?
The reabsorption rate of fluid does not quite equal the amount of fluid filtered from the blood. The excess remains as interstitial fluid and is drawn into lymphatic capillaries
What is significant about the lymphatic capillaries within small intestine
takes up large lipid molecules that can’t diffuse into blood capillaries
What can move into lymph capillaries
Pathogens, which is why leukocytes are present in lymph
What are the 2 components of the lymphatic system
Lymphatic Vessels
Lymphatic Tissues
List the different types of lymphatic vessels
- capillaries
- vessels
- ducts
List the different types of lymphatic tissue
- Thymus
- lymph nodes
- spleen
- tonsils
- other lymphatic tissue aggregations
List the names of the strucutres of the lymph system
A. Lymph Duct
B. Lymph Node
C. Lymph Capillary
D. Lymph Vessel
E. Valve
Describe Lymphatic capillaries
- smallest lymph vessel
- found within capillary beds of most tissue
- blind end vessel lymph can only travel in 1 direction
- thin walled - simple squamous epithelium
- flap like valves allow interstitial fluid to be pulled in but not able to backflow
What are lymphatic vessels
resemble veins in structure but have thinner walls and more valves
What are lymph ducts?
The 2 largest lymph vessels thoracic and right lymph duct
What is the role of the lymph ducts
- collect lymph from lymph vessels and return it to the blood
- joins up with the left and right subclavian veins
What is the role of the left lymph duct
receives lymph from the left side of the head, neck, chest, left upper limb, and the entire body below the ribs
what is the role of the right lymph duct
- drains the right side of the head, neck, chest, and arm
Name the lymphatic vessels and structures
a. right lymphatic duct
b. Lymphatic Vessel
c. thoracic duct
d. thoracic duct
e. left subclavian vein
f. right subclavian vein
g. Thymus
h. cervical node
i. intestinal node
j. inguinal node
k. axillary node
l. Spleen
where is the thymus located?
posterior to the sternum, medial to the lungs, and superior to the heart
what is the role of the thymus
site of T lymphocyte maturation
How do T cells get to the thymus?
immature T cells migrate from red bone marrow to the thymus
What occurs to the thymus as we age
it shrinks as T cells leave the organ
Describe lymph nodes
- kidney bean, shaped organ
- found in groups along lymph vessels scattered throughout the body
- enlarge when body has an infection
What is the role of lymph nodes
filters lymph
Why do lymph nodes enlage?
Due to an infection in the body. Occurs because lymph cells begin to multiply to counteract the pathogen.
Where are the structure of the body with the heaviest concentations of lymph nodes
- armpit
- mamory glands
- groin
- intestinal area
Where is the spleen located
lies between the stomach and diaphragm
What does spleen tissue consist of?
- White pulp
- Red pulp
Describe the role of white pulp spleen tissue
lymphatic tissue that carries out immune responses
Describe the role of red pulp spleen tissue
performs functions related to blood cells
What can happen if the spleen is damaged
- can cause intra-abdominal bleeding
- requires a splenectomy due to vessels being too numerous to repair
- can still live without spleen, other organs simply carry out the spleen’s function
Describe tonsils
multiple aggreations of lymphatic nodues embedded in muscous membranes of the pharynx
What is the role of the tonsils
- participates in immune response
- protects against invasion of foreign substances entering via the mouth or nose
List the 3 tonsil tissues in the mouth
- pharyngeal
- lingual
- palatine
What is another name for the immune system
resistance to disease
Define resistance
is the ability by the body to fight off disease
Define pathogens
disease producing organisms such as bacteria, viruses, and parasites
What are the 2 categories of the immune system
- nonspecific resistance or innate defense
- specific resistance or adaptive defense
Describe nonspecific resistance
- quick, general defence mechanisms against a wide range of pathogens
- invloves antibacterial proteins and some white blood cells
What are the white blood cells used in non-specific resistance
- macrophages
- neutrophils
what are some examples of non-specific defence mechanisms
- thick stratified epithelium of mucous membranes
- stomach juices with an acidic pH
- antibacterial substances lyosome in tears and vaginal secretions
- fever
- inflammation
Define fever
abnormally high body temp triggered by infection and inflammation
define inflammation
bought on by infection or tissue damage and characterized by redness, heat, swelling, and pain
How does inflammation work
- damage to tissue causes the release of chemicals that make blood vessels dilate and become leaky
- this permits more leukocytes to leave the blood and travel to the area where pathogens might enter
Describe specific resistance
- also called immunity
- slower initial response to a specific pathogen or antigen
- involves the activation of specific lymphocytes
- involves T lymphocytes, B lymphocytes, ad the production of antibodies
Define antigen
- large complex molecules recongnize as foreign by antigen receptors on immune cells
- parts of bacteria, viruses, toxins, foreign tissue, cancerous cells
Define antibodies
- are produced against antigens
- destroy the antigen by attracting phagocytic white blood cells
Describe specific resistance memory
- another feature of immunity
- when we recieve a vaccine it takes advantage of an immune response
- obtain a specific memory for a pathogen
- future quick and powerful response to the pathogen before it makes a person sick
- vaccines are key factors for increasing helathy lifespan of people
What are some examples of vaccines
- polio
- hepatitis
- influenza
- yellow fever
- measles/mumps, rubella
- tetanus
