Chapter 7 Flashcards
Lymphatic and immune system
Has the lymphatic vessels and organs
- the lymphatic system and the immune system are so strongly associated with one another that the two are virtually indistinguishable.
Lymphatic system
A system of vessels, cells, and organs that carry excess fluids to the blood stream and filters pathogen fro the blood.
Lacteals
Lymphatic capillaries that transport dietary lipids and fat-soluble vitamins to the blood stream.
Provide two examples of connections between the lymphatic and immune systems
- swelling of the lymph nodes via the lymphatic vessels
- transport of lymphocytes via the lymphatic vessels
Functions of the lymphatic and immune systems
Homeostasis mechanism
Absorption and transportation: fats, proteins, fat-soluble nutrients (A, D, E, and K), other nutrients
Fluid balance - drains excessive interstitial fluid
Hematopoiesis - formation of new blood cells
Immune function
Interstitial fluid (IF)
Fills the spaces between the cells, is not the simple fluid that it seems to be
- interstitial fluid and blood plasma together constitute the extracellular fluid compartment of the body (internal environment of the body)
Passages
Lymph
Pump
Lymph vessels
Fluid
Skeletal muscles
Lymphatic vessels
“Lymphatics” - originate as microscopic blind-end vessels called lymphatic capillaries
Lymphatic capillaries
- consist of a single layer of flattened endothelial cells
- slightly larger than blood capillaries
- allow interstitial fluid to flow in but NOT out
Lymphatic anatomy
Lymph vessel resemble veins in structure with these exceptions:
- lymphatics have thinner walls
- lymphatics contain more valves
- lymphatics contain lymph nodes located at certain intervals along their course
Lymph and interstitial fluid together
- lymphatic networks are in the intercellular (interstitial) spaces and are widely distributed throughout the entire body. - however they are not located throughout the whole body
- As a rule: lymphatic and blood capillary networks lie side by side but are always independent of each other.
The two lymphatic collecting ducts
Thoracic duct- the main collecting duct of the lymphatics, received lymph from the whole body, EXCEPT THE UPPER RIGHT QUADRANT
Right lymphatic duct - drains lymph from the upper right quadrant of the body
Lymphatic pump
- there is no muscular pumping organ connected with the lymph system.
-However, the movement of blood, keeps lymph moving slowly throughout the day - lymph flows though the thoracic duct and renters the general circulation (3 liters per day)
Lymphokinesis:
Movement, or flow of lymph
- the two primary mechanisms are?
Skeletal
Thorax (inspiration)
Lymph nodes
Lymph nodes are reticular “lymph glands”
- oval/bean shaped structures (1-2.5mm), that act like filters
- located in intervals along the lymphatic vessels
- remove microorganisms, debris, and abnormal cells.
- nodes are composed of connective tissue, macrophages, and lymphocytes. They act as filters, to cleanse the lymph as it passes through them
Lymph enter and exits nodes how
Lymph moves into a node by way of afferent lymphatic vessels and emerges by one or more efferent vessels
Sinus channels
Sinus channels slow the lymph flow
Reticuloendothelial cells
- mechanical filtration
- biological filtration (phagocytosis)
Tonsils are?
Masses of lymphoid tissue
Located in the pharyngeal lymphoid ring
First line of defense: filter food and air entering the throat
Types of tonsils
Palatine tonsils
Pharyngeal tonsils
Lingual tonsils