Transcript Interstitial fluid

Interstitial fluid
Interstitial fluid; also known as intercellular fluid and tissue fluid is fluid between the cells
of multicellular organisms bathes and surrounds the cells of the body, and provides a
means of delivering materials to the cells, intercellular communication, and removal of
metabolic waste.
-it represents the largest portion of the ECF compartment . The plasma and the interstitial
fluid intermingle through pores in the blood capillaries which allow water and most
dissolved substances except protein to diffuse .
- The exchange of material across the capillaries occurs at high rate by diffussion in both
directions .
- Formation of the IF ;The high content of proteins in the plasma accounts for its higher
osmotic pressure compared to that of the IF which will attract fluid and dissolved
substances into the circulation from the tissue spaces . Opposing this force is the
hydrostatic pressure of the blood which tends to force fluids out of the circulation and
into the tissue spaces, thus equilibrium is always maintained.
- Edema; Is the term used to describe an unusual accumulation of interstitial fluid which
occurs when an alteration in the balance mentioned earlier occurs . It could happen due
to decrease in plasma albumin concentration leading to a decrease in blood osmolarity
thus allowing fluid to escape from the circulation to the interstitial space.
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Interstitial fluid
Lymph fluid composition
The lymphatic system is made up of vessels which collect excess fluid from around the
cells by diffusion into lymph capillaries, and returns it to the circulatory system.
It consists of;
composition of the Lymphatic System ;
-Lymph fluid.
-Lymph vessels.
-Lymph duct.
- lymph node.
Function
1) lymphatic vessels
transport fluids and protein that have escaped from blood vascular system back to the
blood
- 30 liters of plasma pass out of capillaries each day into the IF.
-27 liters get resorbed at capillary
-3 liter left in tissue spaces get resorbed into lymph vessels
2) Fat transport from gastrointestinal tract to the blood.
3) Body defense system
-lymph nodes filter lymph
contains lymphocytes
Lymph fluid
It is that colorless, watery fluid originating from the interstitial
fluid that is present in the lymphatic system .
Composition of lymph.;
• It has the same composition as interstitial fluid.
• It has a higher content of protein and contains white blood
cells, (its protein content will vary according to which tissue it
penetrates).(thus containing proteins , fat absorbed from
intestine , waste products , antibodies and lymphocytes .)
• Formation of lymph: filtration forces water and dissolved
substances from the capillaries into thetissue space forming
the interstitial fluid. Not all of this water is returned to the
blood by osmosis, thus excess fluid is picked up by lymph
capillaries thus forming the lymph fluid.
Lymph vessels
Lymph vessels; The lymphatic vessels are a network of thin tubes that
branch, like blood vessels, into tissues throughout the body.
-They are one cell thick.
-They are slightly larger and more permeable than blood capilleries.-They remove excess fluid from around the cells thus preventing
edema.
- Thus Lymphatic vessels carry lymph, a colorless, watery fluid
originating from interstitial fluid (fluid in the tissues to drain it into
larger vessels called the ducts.
-Unlike the circulatory system, the lymphatic system is not closed and
has no central pump; the lymph moves slowly and under low
pressure. Like veins, lymph vessels have one-way valves thus
allowing the interstitial fluid to enter the lymph capillaries and flow
in one direction to the lymph ducts passing through the lymph
nodes to empty eventually into the blood circulation.
Lymph composition
Lymphatic system
Lymph nodes
Along the network of lymph vessels are small organs called lymph nodes. They are
small oval like structures that are 1-25mm long.
Clusters of lymph nodes are found scattered around the body especially in the
underarms, groin, neck, chest, and abdomen.
Function of Lymph nodes ;
-They contain cavities called sinuses ,In to which the lymph flows. The walls of the
sinuses are lined with Phagocytic cells, which engulf and destroy any foreign
particles,e.g., bacteria, viruses that might be present in the lymph thus filtering
the lymph as it passes by.
-It also play a vital role in the production of immuno competent lymphocytes and
macrophages in the specific immune response.
When the body is fighting an infection, these lymphocytes multiply rapidly and
produce a characteristic swelling of the lymph nodes. Approximately 25 billion
different lymphocytes migrate through each lymph node every day.
Thus it cleans the lymph before it returns it back to the blood ,produces lymphocytes
and antibodies.
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Disorders of the lymphatic system
Whenever the lymphatic system cannot drain interstitial fluid from tissues faster
than they accumulate, the resulting swelling is known as lymphedema.
Accumulation of lymph fluid in the pleural cavities leads to chylothorax. Cancers
that develop from lymphocytes are known as lymphomas.