lymphatic system

list three things the lymphatic system is responsible for

fluid balance

absorption of fat

immunological defense

what is the function of the lymphatic capillaries

pick up excess ISF (10%) and returns it to blood vessels

.  What is a major difference between lymphatic capillaries and blood capillaries?

lymphatic capillaries- one way opening which allows fluid to enter but not leave

blood capillaries- allow fluid to move in and out.

Large lymphatic vessels return lymph to blood via what blood vessels?

 

right and left subclavian veins

Define edema.

excess interstitial fluid

What anatomical structures found in lymph capillaries help reduce edema?

high permeability of lymph to blood valves in larger lymphatics

What physiological aids help return lymph to the blood?

skeletal muscles contraction

contraction of smooth muscles in lymphatic vessels

lower pressure in thoracic region

What is the function of the tonsils?

to protect against pathogens

What is the function of the lymph nodes?

produce and store lymphocytes

filter lymph

.  List four functions of the spleen.

production of lymphocytes

destruction of old red blood cells

filters blood

releases blood into circulation with the help of sympathetic stimulation

Can one live without a spleen?  Explain.

yes, because it’s not a major organ in the immune system it only helps to fight infections.

During what period of one’s life is the thymus gland most important?  Why?

the youth because it helps the body develop and train T cells that are need in the immune system.

What is the function of the thymus gland?

it secretes the hormone thymosin

it’s the site of maturation of T lymphocytes (T cells).

Define innate immunity. 

natural Nonspecific defense

.  Give examples of physical barriers used in innate immunity.

keratin of skin

mucus membrane, cilia

tears saliva, urine

coughing, sneezing