Lymphatic System Flashcards
It is a vast collection of cells and biochemicals that travel in lymphatic vessels. It is closely associated with the cardiovascular system. A network of vessels that assist in circulating fluids.
Lymphatic System
Organs of Lymphatic System
Lymph
Lymphatic Capillaries and Vessels
Lymphatic Tissues and Organs
Sites where stem cells divide; Provide a location for B and T lymphocytes to mature. Thymus and bone marrow.
Primary
Sites where most immune responses occur; lymph nodes, tonsils, peyer’s patches and spleen.
Secondary
Removes excess tissue fluid and returns it to the bloodstream.
Fluid balance
Approximately ____ of fluid pass from the blood capillaries into the interstitial fluid each day, whereas only ____ pass from the interstitial fluid back into the capillaries.
30 L
27 L
Instead, the 3 L of fluid enters the lymphatic capillaries, where it is called ______ and passes through the lymphatic vessels back to the blood.
lymph
If the extra 3 L of fluid were to remain in the interstitial fluid, _______ would result, causing tissue damage and eventual death.
edema
The lymphatic system absorbs lipids and other substances from the digestive tract through lymphatic vessels called lacteals.
Liquid absorption
Absorb digested fat and fat-soluble vitamin.
Lacteals
Lacteals: specialized lymph capillaries located in the villi of the small intestine that absorb? (and carry them to the general circulation)
digested fat and fat-soluble vitamins
Lipids enter the lacteals and pass through the lymphatic vessels to the?
venous circulation
The lymph passing through these lymphatic vessels, called ______, appears white because of its lipid content.
chyle
Pathogens are filtered from lymph by lymph nodes and from blood by the spleen.
Defense
In addition, ___________ and other cells are capable of destroying microorganisms and other foreign substances.
lymphocytes
Microorganisms and other foreign substances are filtered from lymph by ___________ and from blood by the _______.
lymph nodes
spleen
Because the lymphatic system fights infections, and filters blood and lymph to remove microorganisms, many infectious diseases produce symptoms associated with the?
lymphatic system and organs
That’s why usually if we have an infection the lymph nodes?
swell
- also known as intercellular fluid
- Acts as the intermediary between the blood in capillaries and the tissue.
- It diffuses from the capillaries into the tissue spaces.
Interstitial fluid
Because the fluid fills the surrounding spaces between tissue cells, it is also referred to as?
intercellular fluid
Most of this fluid is reabsorbed into the?
capillaries
When an excess fluid enters the lymphatic capillaries, it is called the?
lymph
If some of this fluid may not get reabsorbed, it can result in swelling of the tissue which is also known as EDEMA which is?
fluid accumulation in tissues
Give at least 3 Composition of Interstitial fluid.
Water
lymphocytes
some granulocytes
digestive nutrients
hormones
salts
carbon dioxide
urea
Composition of Interstitial fluid is similar in composition to?
blood plasma
Interstitial fluid carries metabolic waste products such as _______________ and ____________ away from the cells back into the capillaries for excretion.
carbon dioxide
urea wastes
It is a clear, colorless fluid that flows in only one direction toward the heart through the lymphatic vessels.
Lymph
Composition of Lymph
Water and solutes derived from 2 sources: substances in plasma and substances derived from cells.
Substances in plasma.
ions, nutrients, gasses and proteins
Substances derived from cells.
hormones, enzymes and waste products
- Run parallel to blood capillaries in all body tissues.
- Also made of simple squamous epithelium
- Allows diffusion of tissue fluid from interstitial spaces into the lymphatic pathway.
Lymphatic Capillaries
Lymphatic Capillaries is responsible for absorbing small chain fatty acids in the small intestine, using?
specialized lymphatic capillaries called lacteals
- Have thin walls and valves to prevent backflow.
- Filled with lymph.
- Larger vessels lead to lymph nodes and then to larger lymphatic trunks
Lymphatic Vessels
3 layers of Lymphatic Vessels
Endothelial lining
Smooth muscle
Connective tissue
Like veins, lymphatic vessels have thin walls and valves to prevent the?
fluid from flowing backwards
Lymphatic vessels are located in almost all of the tissues and organs that have?
blood vessels
As the lymphatic vessels progress on their path toward the heart, they?
converge to form larger and larger vessels
Periodically, these vessels lead to lymph nodes, where immune cells?
phagocytize bacteria
Then these lymphatic vessels continue to merge, eventually forming still larger lymphatic trunks, which?
drain major regions of the body
- Site of T lymphocytes maturation and production.
- Located in the superior mediastinum and is divided into a cortex and a medulla.
Thymus Gland
T and B lymphocytes develop from stem cells in red bone marrow.
Bone Marrow
Commonly called T cells.
T Lymphocytes
Before the T cells have fully matured, they leave the bone marrow and travel to the thymus gland, where they remain until?
fully functional
Once these T cells are immunocompetent or they are capable of recognizing antigens, they leave the thymus and migrate to lymphatic organs and tissues such as?
lymph nodes
spleen
tonsils
T cells that bind with specific antigens presented by macrophages.
Helper T cells