Body fluids

1. Body Fluids & Lymphatic
System
Subject: Human anatomy and physiology-I
Unit-III
Prepared by: Kajale Fulchand V.
(M.Pharm Pharmacology)
Assistant Professor
Shivai Charitable trust’s College of Pharmacy.

2. Body fluids
• A body fluid is a substance, usually a liquid, that is produced by the body
and consists of water and dissolved solutes. In lean adults, body fluids
constitute between 55% and 60% of total body mass in females and males,
respectively. Body fluids are present in two main “compartments” inside
cells and outside cells.
• About two-thirds of body fluid is intracellular fluid (ICF) or cytosol, the
fluid within cells. The other third, called extracellular fluid (ECF), is
outside cells and includes all other body fluids. About 80% of the ECF is
interstitial fluid, which occupies the microscopic spaces between tissue cells,
and 20% of the ECF is blood plasma, the liquid portion of the blood.
• The branch of science concerned with the study of blood, blood-forming
tissues, and the disorders associated with them is known as Hematology.

3.  Blood
1. Transportation.
blood transports oxygen from the lungs to the cells of the body and carbon
dioxide from the body cells to the lungs for exhalation. It carries nutrients from
the gastrointestinal tract to body cells and hormones from endocrine glands to
other body cells. Blood also transports heat and waste products to various
organs for elimination from the body.
2. Regulation
Circulating blood helps maintain homeostasis of all body fluids. Blood helps
regulate pH through the use of buffers. It also helps adjust body temperature
through the heat-absorbing and coolant properties of the water in blood plasma
and its variable rate of flow through the skin, where excess heat can be lost
from the blood to the environment.

4. 3.Protection
• Blood can clot, which protects against its excessive loss from the
cardiovascular system after an injury.
• In addition, white blood cells protect against disease by carrying on
phagocytosis. Several types of blood proteins, including antibodies,
interferons, and complement, help protect against disease in a variety of
ways.
• The process by which the formed elements of blood develop is called
hemopoiesis
• Red bone marrow becomes the primary site of hemopoiesis in the last 3
months before birth.
• About 0.05–0.1% of red bone marrow cells are called pluripotent stem cells
or hemocytoblasts

5.  Components of Blood

7.  Formation of Haemoglobin
1. First step in heme synthesis takes place in the mitochondrion. Two
molecules of succinyl-CoA combine with two molecules of glycine and
condense to form δ-aminolevulinic acid (ALA) by ALA synthase.
2. ALA is transported to the cytoplasm. Two molecules of ALA combine to
form porphobilinogen in the presence of ALA dehydratase.
3. Porphobilinogen is converted into uroporphobilinogen I by
uroporphobilinogen I synthase.
4. Uroporphobilinogen I is converted into uroporphobilinogen III by
porphobilinogen III cosynthase.
5. From uroporphobilinogen III, a ring structure called coproporphyrinogen
III is formed by uroporphobilinogen decarboxylase.
6. Coproporphyrinogen III is transported back to the mitochondrion, where it
is oxidized to form protoporphyrinogen IX by coproporphyrinogen oxidase
7. Protoporphyrinogen IX is converted into protoporphyrin IX by
protoporphyrinogen oxidase.
8. Protoporphyrin IX combines with iron to form heme in the presence of
ferrochelatase.

9.  Anemia
• Anemia means deficiency of hemoglobin in the blood, which can be caused
by either too few red blood cells or too little hemoglobin in the cells.
1. Iron deficiency anaemia
• Dietary iron comes mainly from red meat and highly coloured vegetables.
Daily iron requirement in men is about 1–2 mg. Women need 3 mg daily
because of blood loss during menstruation and to meet the needs of the
growing fetus during pregnancy.
• In iron deficiency anemia, the red blood cell count is often normal, but the
cells are small, pale, of variable size and contain less hemoglobin than
normal.
2. Vitamin B12 Folic acid deficiency anaemia
• Deficiency of vitamin B12 impairs erythrocyte maturation and abnormally
large erythrocytes are found in the blood.
• When deficiency of vitamin B12 occurs, the rate of DNA and RNA
synthesis is reduced, delaying cell division.

10.  Vitamin B12 deficiency anaemia
• Pernicious anaemia
It is commonest in females over 50. It is an autoimmune disease in which
autoantibodies destroy intrinsic factor (IF) and parietal cells in the stomach
• Dietary deficiency of vitamin B12
• Other causes of vitamin B12 deficiency
• Gastrectomy (removal of all or part or the stomach) this leaves fewer cells
available to produce IF.
• Chronic gastritis, malignant disease and ionizing radiation these damage the
gastric mucosa including the parietal cells that produce IF.
• Malabsorption if the terminal ileum is removed or inflamed, e.g. in Crohn’s
disease, the vitamin cannot be absorbed.
 Folic acid deficiency anemia
• Deficiency of folic acid causes a form of megaloblastic anemia identical to
that seen in vitamin B12 deficiency.

11. Dietary deficiency, e.g. In infants if there is delay in establishing a mixed diet,
in alcoholism, in anorexia and in pregnancy
Malabsorption from the jejunum caused by, e.g., Coeliac disease, tropical
sprue or anticonvulsant drugs
Interference with folate metabolism by, e.g., Cytotoxic and anticonvulsant
drugs.
3. Aplastic anaemia
Aplastic (hypoplastic) anemia results from bone marrow failure. Erythrocyte
numbers are reduced. the bone marrow also produces leukocytes and platelets.
leukopenia (low white cell count) and thrombocytopenia (low platelet count)
are also likely. When all three cell types are low, the condition is called
pancytopenia, and is accompanied by anemia, diminished immunity and a
tendency to bleed.
Drugs, e.g. Cytotoxic therapy and, rarely, as an adverse reaction to anti-
inflammatory and anticonvulsant drugs and some antibiotics .
Ionising radiation.
Some chemicals, e.g. Benzene and its derivatives.
Viral disease, including hepatitis.

12. 4. Haemolytic anaemias
• These occur when circulating red cells are destroyed or are removed
prematurely from the blood
• Congenital haemolytic anaemias
• In these diseases, genetic abnormality leads to the synthesis of abnormal
hemoglobin and increased red cell membrane fragility, reducing their
oxygen-carrying capacity and life span.
i. Sickle cell anaemia
The abnormal haemoglobin molecules become misshapen when
deoxygenated, making the erythrocytes sickle shaped.
ii. Thalassaemia
This inherited condition, commonest in Mediterranean countries, causes
abnormal hemoglobin production, which in turn reduces erythropoiesis and
stimulates haemolysis.
POLYCYTHAEMIA
This means an abnormally large number of erythrocytes in the blood. This
increases blood viscosity, slows blood flow and increases the risk of
intravascular clotting, ischaemia and infarction.

13. SIGNS AND SYMPTOMS OF ANEMIA
• Skin and mucous membrane color of the skin and mucous membrane
becomes pale.
• Cardiovascular system there is an increase in heart rate (tachycardia) and
cardiac output.
• Respiration there is an increase in rate and force of respiration.
• Digestion anorexia, nausea, vomiting, abdominal discomfort and
constipation
• Metabolism basal metabolic rate increases in severe anemia.
• Kidney renal function is disturbed
• Reproductive System in females, the menstrual cycle is disturbed
• Neuromuscular System common neuromuscular symptoms are increased
sensitivity to cold, headache, lack of concentration, restless ness,
irritability, drowsiness, dizziness or vertigo.

14.  Mechanisms of coagulation
• Two pathways, called the extrinsic pathway and the intrinsic pathway,
which lead to the formation of prothrombinase.
• Once prothrombinase is formed, the steps involved in the next two stages of
clotting are the same for both the extrinsic and intrinsic pathways, and
together these two stages are referred to as the common pathway.
• Prothrombinase converts prothrombin (a plasma protein formed by the
liver) into the enzyme thrombin.
• Thrombin converts soluble fibrinogen (another plasma protein formed by the
liver) into insoluble fibrin. Fibrin forms the threads of the clot.

17.  Blood grouping
ABO Blood Group
• The ABO blood group is based on two glycolipid antigens called A and B.
• A Person whose RBCs display only antigen A have type A blood.
• Those who have only antigen B are type B.
• Individuals who have both A and B antigens are type AB.
• those who have neither antigen A nor B are type O.

19.  Rh Blood Group
• The Rh blood group is so named because the Rh antigen, called Rh factor,
was first found in the blood of the Rhesus monkey.
• People whose RBCs have Rh antigens are designated Rh+ (Rh positive);
those who lack Rh antigens are designated Rh− (Rh negative).
• Normally, blood plasma does not contain anti-Rh antibodies. If an Rh−
person receives an Rh+ blood transfusion, however, the immune system
starts to make anti-Rh antibodies that will remain in the blood.
• If a second transfusion of Rh+ blood is given later, the previously formed
anti-Rh antibodies will cause agglutination and hemolysis of the RBCs in
the donated blood, and a severe reaction may occur.

20.  Transfusion
• A transfusion is the transfer of whole blood or blood components into the
bloodstream or directly into the red bone marrow. A transfusion is most often
given to alleviate anemia, to increase blood volume or to improve immunity.
• In an incompatible blood transfusion, antibodies in the recipient’s plasma
bind to the antigens on the donated RBCs, which causes agglutination, or
clumping, of the RBCs. Agglutination is an antigen antibody response in
which RBCs become cross-linked to one another.
• Consider what happens if a person with type A blood receives a transfusion
of type B blood. The recipient’s blood (type A) contains A antigens on the
red blood cells and anti-B antibodies in the plasma. In this situation, two
things can happen. First, the anti-B antibodies in the recipient’s plasma can
bind to the B antigens on the donor’s erythrocytes, causing agglutination
and hemolysis of the red blood cells.
• Second, the anti-A antibodies in the donor’s plasma can bind to the A
antigens on the recipient’s red blood cells, a less serious reaction because
the donor’s anti-A antibodies become so diluted in the recipient's plasma that
they do not cause significant agglutination and hemolysis of the recipient’s
RBCs.

21.  Disorders of blood
• Sickle Cell Disease
• The RBCs of a person with sickle cell disease (SCD) contain Hb-S, an
abnormal kind of hemoglobin. When Hb-S gives up oxygen to the interstitial
fluid, it forms long, stiff , rodlike structures that bend the erythrocyte into a
sickle shape. The sickled cells rupture easily.
• Anaemia
• Haemophilia
• Hemophilia is an inherited deficiency of clotting in which bleeding may
occur spontaneously or after only minor trauma.
• Leukemia
• The term leukemia refers to a group of red bone marrow cancers in which
abnormal white blood cells multiply uncontrollably.

22.  Reticuloendothelial system
• The Monocyte Macrophage System. This is sometimes called the
reticuloendothelial system, and consists of the body’s complement of
monocytes and macrophages. Some macrophages are mobile, whereas
others are fixed, providing effective defense at key body locations.
• Function of RES
• The system forms first line defence of body against microorganism
• Immune response
• Imp site for hemopoiesis
• They play role in inflammation

23.  Lymphatic system
• The lymphatic or lymphoid system consists of a fluid called lymph, vessels
called lymphatic vessels that transport the lymph, a number of structures and
organs containing lymphatic tissue, and red bone marrow. The lymphatic
system assists in circulating body fluids and helps defend the body against
disease-causing agents.
• It is a one-way system and allows the lymph flow from tissue spaces toward
the blood.
• Functions of the Lymphatic System
1. Drains excess interstitial fluid. Lymphatic vessels drain excess interstitial
fluid from tissue spaces and return it to the blood. This function closely links it
with the cardiovascular system. In fact, without this function, the maintenance
of circulating blood volume would not be possible.
2. Transports dietary lipids. Lymphatic vessels transport lipids and lipid-
soluble vitamins (A, D, E, and K) absorbed by the gastrointestinal tract.
3. immune responses. Lymphatic tissue initiates highly specific responses
directed against particular microbes or abnormal cells.

25. Lymph
• Lymph is a clear watery fluid, similar in composition to plasma, with the
important exception of plasma proteins, and identical in composition to
interstitial fluid.
• Lymph transports the plasma proteins that seep out of the capillary beds back
to the bloodstream. It also carries away larger particles, e.g. bacteria and
cell debris from damaged tissues, which can then be filtered out and
destroyed by the lymph nodes. Lymph contains lymphocytes, which
circulate in the lymphatic system allowing them to patrol the different
regions of the body.
• Formation and Flow of Lymph
• Most components of blood plasma, such as nutrients, gases, and hormones,
filter freely through the capillary walls to form interstitial fluid, but more
fluid filters out of blood capillaries than returns to them by reabsorption. The
excess filtered fluid about 3 liters per day drains into lymphatic vessels and
becomes lymph.

26. • Respiratory pump. Lymph flow is also maintained by pressure changes that
occur during inhalation
• Skeletal muscle pump. The “milking action” of skeletal muscle
contractions compresses lymphatic vessels and forces lymph toward the
junction of the internal jugular and subclavian veins.

27.  Lymphatic Organs and Tissues
1. Thymus
• The thymus is a bilobed organ located in the mediastinum between the
sternum and the aorta. It extends from the top of the sternum or the inferior
cervical region to the level of the fourth costal cartilages, anterior to the top
of the heart and its great vessels
2. Lymph Nodes
• Located along lymphatic vessels are about bean-shaped lymph nodes.
• Lymph nodes are 1–25 mm long and, like the thymus, are covered by a
capsule of dense connective tissue that extends into the node.
• The capsular extensions, called trabeculae, divide the node into
compartments, provide support, and provide a route for blood vessels into the
interior of a node.
3. Spleen
• The oval spleen is the largest single mass of lymphatic tissue in the body. It is
a soft , encapsulated organ of variable size, but on average it fits in a person’s
open hand and measures about 12 cm (5 in.) in length.

30. Reference
1. Anatomy and Physiology in Health and Illness by Kathleen J.W.
Wilson, Churchill Livingstone, New York
2. Principles of Anatomy and Physiology by Tortora Grabowski.
Palmetto, GA, U.S.A.
3. Essentials of Medical Physiology by K. Sembulingam and P.
Sembulingam. Jaypee brothers medical publishers, New Delhi.
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