Anatomy and Physiology of Circulatory system

1. CHAPTER NO:7
BLOOD
Prepared by,
RAMDAS BHAT
Asst. Professor
Karavali college of Pharmacy
Mangalore
7795772463
Ramdas21@gmail.com

2. BLOOD: “It is a liquid connective tissue” . Which consist WBCs, RBCS, Platelets and
other dissolved solutes and protein.
FUNCTIONS OF BLOOD:
1. Transports:
• Dissolved gases (e.g. oxygen from the lung to the cell of body and carbon dioxide from
the cell to the lung)
• Waste products o f metabolism (e.g. water, urea)
• Hormones from endocrine glands to other body cells.
• Enzymes
• Nutrients (such as glucose, amino acids, micro -nutrients (vitamins & minerals), fatty
a cids, glycerol from gastro intestinal tract to the cell of body)
• Plasma proteins (associated with defense , such as blood -clotting and anti -bodies);
• Blood cells (includes white blood cells 'leucocytes', and red blood cells
'erythrocytes').
2. Maintains Body Temperature :
• It has the heat absorbing and cooling properties because of its water contain.
• Blood flow s through out the body so heat can be lost from body to environment by
help of skin.
3. Controls pH :
• The pH of blood must remain in the range 7.3 to 7.4, othe rwise it b egins to damage
cells so it maintain the pH by help of buffer system.
4. Removes toxins from the body:
• The kidneys filter all of the blood in the body .
• Toxins removed from the blood to the kidneys and kidney leaves it in to urine.
5. Protection:
• The clotting mechanism protects us from blood loss.
• White blood cells of the blood protect us from harmful agents like bacteria,
virus, and toxin by forming antigen antibody reaction.

3. PHYSICAL CHARACTERISTICS OF BLOODS:
• Blood is heavier, thicker and more viscous than water so it flows more slowly than
water.
• Its sticky appearance fills during the touching.
• The temperature of blood is about 38o C which is slightly higher than normal body
temperature (37 ± 0.5 O C) .
• It has slightly alkaline pH of about 7.35 -7.40.
• Blood occupy 8% of the total body weight.
• According to average size, adult male contains 5 -6 liters of blood while adult
female contains 4 -5 liters of blood.

4. ERYTHROCYTES:
• Circular Biconcave disc like cells.
• Non-Nucleated, Simple in structure.
• Composed of network of protiens called as Strome
• They contain cytoplasm and Oxygen carrying pigment called as Haemoglobin.
• The average normal RBC count is - For men 5-6 million cells/mm3- For women 4.5-
5.5 million cells/ mm3.
• They are tiny (7.5u in diameter, 2 thick) biconcave and enucleated.
• They survive for about 120 days.
• About 5 X 10 11 RBCs are destroyed every day, in the liver and spleen.
• Hemoglobin is the most important component of red blood cells.
• It is composed of a protein called heme, which binds oxygen.
• In the lungs, oxygen is exchanged for carbon dioxide.
• Abnormalities of an individual’s hemoglobin value can indicate defects in red blood cell
balance. Both low and high values can indicate disease states.
Haemoglobin:
• Composed of Haem and Globin
• Haem is iron in ferric or ferrous form and Globin is a Polypeptide protein
• Haemoglobin is a Pigment that gives colour to the blood
• Each Haemoglobin contain 4 ferric or ferrous iron component
• Each Ferrous or ferrous atoms can carry one molecule of Oxygen.
• Hence each Hb molecule can carry 4 molecules of Oxygen or 8 atoms of oxygen.
• Haemoglobin that carries the oxygenated blood is red in color whereas haemoglobin not
carrying oxygen is dark red in color.
• Females shows less Hb than men as maximum blood gets transported into the foetus during
the pregnancy and bleeding during the menstrual cycle.
• Each erythrocyte contains about 28 million molecules of Hb.
Functions:
• Transport of Oxygen in the form of Oxyhaemoglobin
• Transport of Carbon dioxide in the form of Carbmino Hb.
• They act as buffer ie. they maintain Acid-Base balance

5. ERYTHROPOESIS:
DISORDERS OF RBC:
POLYCYTHEMIA:
• Abnormal Increase of RBC above the normal range of 7 million cells/mm3.
• Blood viscosity and the BP will be elevated.
• That may result in the internal injury to blood vessels, Haemorrhage, Blood clotting and
thrombosis etc.
• Causes include Over transfusion of Abnormally large number of erythrocytes.
• It can be also due to the Hypoxia or due to tumor releasing erythropoietin.
• Polycythaemia can be also seen in the person living in the higher altitude areas and also due
to the exercise.
ANAEMIA:
• Characterised by decrease on the oxygen carrying capacity of blood.
• It can be caused due to decreased number of erythrocytes, decrease in Hb or abnormality in
Hb.
• Anaemia leads to the lack of oxygen supply to the tissue thereby causing Hypoxia and
Ischemia followed by Acidosis and cellular damage.
• Types:
Colony Forming Unit- Erythrocytes (CFU-E) & Burst
forming unit -Erythrocytes (BFU-E)

6. 1. Aplastic anaemia: Damage to the bone marrow causes decrease in the production of RBC.
2. Iron deficiency anaemia: Decrease in Haem.
3. Sickle cell anaemia: It is an AUTOSOMAL RECESSIVE DISSORDER. The shape of the cell is
Sickle.
4. Thalassemia: Thalassemia is an inherited (i.e., passed from parents to children through
genes) blood disorder caused when the body doesn’t make enough of a protein called
hemoglobin, an important part of red blood cells.
5. Vitamin B deficiency anaemia (Megaloblastic anaemia): Megaloblastic anaemia is a form
of anemia characterized by very large red blood cells and a decrease in the number of those
cells. Megaloblastic anaemia is due to acquired deficiency in vitamin B12 or folic acid. The
deficiency can be related to inadequate dietary intake of these B vitamins or poor intestinal
absorption
6. Haemolytic anaemia: Hemolytic anemia is a disorder in which red blood cells are destroyed
faster than they can be made. The destruction of red blood cells is called Hemolysis.
JAUNDICE:
• Jaundice is a condition in which the skin, sclera (whites of the eyes) and mucous membranes
turn yellow.
• This yellow color is caused by a high level of bilirubin, a yellow-orange bile pigment.
• Bile is fluid secreted by the liver.
• Bilirubin is formed from the breakdown of red blood cells ie end product of Haemoglobin
breakdown.
• More the Haemolysis in liver more the breakdown of Haemoglobin in liver leading to
increased Bilirubin.
• Hemoglobin is the molecules which are present in to the RBC.
• In Hemoglobin protein part is known as globin and non-protein heme.
• Globin molecules: Transport carbon dioxide and nitric oxide
• Heme molecules: Transport oxygen.
• Globin composed by four polypeptide chain 2 and 2.
• Each heme is associated with one polypeptide chain and iron ion (Fe+2) that can combine
reversibly with oxygen.
• Each hemoglobin has the capacity to carry four molecules of O2 which release in to
interstitial fluid from there in to cells
• Each (RBC) one contains about 280 million hemoglobin molecules.

7. • It has no nucleolus because all space is available for oxygen transport
• As well as RBC has no mitochondria so it generates ATP by anaerobically so they do not use
O2 which they transport.
WHITE BLOOD CORPUSCLE:
➢ WBC anatomy and types:
• Leukocyte is also known as White blood cells it contains the nucleus.
• It is divided in to two groups:
1)Granular leukocyte:
• It develops from myeloblast.
• It contains protein which is known as Major Histocompatbility (MHC) Antigen.
• It contains the clear granules in cytoplasm that can be seen under light microscope.
• Its further divided in to three types:

8. a) Eosinophils:
▪ It is 10-14 μm in diameter.
▪ Its granules produce red or orange stain with acidic dyes.
▪ The nucleus of eosinophils has two lobes connected by thin or thick fiber.
▪ The granules are large and uniform in size that are present in group in cytoplasm
but do not cover the nucleus.
▪ They contain granules of histamine that help in allergic response, Vasodilation and
Bronchoconstriction.
▪
b) Basophils:
▪ It is 8-10 μm in diameter.
▪ Its granules give Blue-purple stain with basic dyes.
▪ Its nucleus is in irregular shape often in form of letter S.
▪ The cytoplasmic granules are round and variable in size.
▪ Their granules contain histamine as well as Heparin (Anticoagulant).
c) Neutrophils:
▪ It is 10-12 μm in diameter.
▪ Its granules known as neutral because it produces pale lilac stain with mixture of acidic
and basic dye.
▪ Their nucleuses contain two to five lobes connected by very thin fibers of chromatin.
▪ They are also called as Polymorphonuclear leukocytes as they are having nucleus of
multiple lobes.
▪ Younger neutrophils are known as bands because their nucleus is rod shaped.
▪ Their granules contain Pyrogenic substances that produce heat.
▪ Neutrophils also helps in Phagocytosis, Emigration and Antibiotic action.
2)Agranular leukocyte:
▪ It has the granules but do not see under the light microscope because of their small size
so it is known as agranular.
▪ It is further classified in to two types:
a) Lymphocytes:
▪ Small lymphocytes are 6-9 μm in diameter and large lymphocytes are 10-14 μm in
diameter.
▪ It is formed from lymphoblast.
▪ Their nucleus is in round shaped and produce dark stain.
▪ The cytoplasm produce border around the nucleus and it produce sky blue stain.
Functions of lymphocytes:
▪ There are mainly three types of lymphocytes
– B-lymphocytes (B cell)
– T-lymphocytes (T cell)
– Natural killer cells
▪ B cells are partially effective in destroying bacteria and inactivating their toxin.
▪ Activation of B cells and kill the bacteria are known as humeral immunity.
▪ T cells attack on viruses, fungi, transplanted cells, cancer cells and some bacteria.
▪ T cell mediated activity is known as cell mediated immunity.
▪ Natural killer cells attack a wide verity of infectious microbes and certain
spontaneously arising tumors.

9. b) Monocytes:
▪ It is 12-20 μm in diameter.
▪ It is developed from monoblast.
▪ Their nucleus is in kidney shaped.
▪ Its cytoplasm has foamy appearance and produce blue grey stain.
▪ Monocytes migrate from blood to tissue where they enlarge their size and
differentiated in to macrophages.
▪ Some are known as fixed macrophages because they are fixed on particular tissue
such as alveolar macrophages, spleen macrophages etc.
▪ Other are known as free or wandering macrophages which travel tissue to tissue at
inflammation or infection site for to repair it.
PLATELETS
▪ They are disc shaped.
▪ They have two types of granules in their cytoplasm
– Alpha granules
– Dense granules
▪ Their granules release several chemical mediators which promote blood clots.
▪ In each cubic millimeter blood contains 2,50,000 to 4,00,000 platelets.
▪ Platelets stop blood loss from damaged blood vessels by forming platelet plug.

10. The formation process of platelets is:
Hemopoietic stem cells (Derived from Red bone marrow) Differentiate in to
megakaryoblasts
It forms metamegakaryocetes by help of hormone thrombopoietin Metamegakaryocetes
breaks in to 2000-3000 fragments
Each fragment covered by cell membrane and enter in to blood circulation in the
blood circulation membrane covered fragments known as platelets

11. Mechanism of Blood Coagulation:
The physiology of coagulation of the blood is termed as Haemostasis.
The contains following stages:
1. Vasoconstriction
2. Platelet plug formation.
3. Blood clotting.
4. Clot retraction and repair.
5. Fibrinolysis.
1. Vasoconstriction:
• This is the first process that happens during the damage to the tissue.

12. • When tissue undergoes damage even the blood vessels lying underneath the tissues also
undergo the damage.
• In order to prevent the extra loss of blood there is a reflex action shown by the blood vessels.
• Damaged endothelium cells release endothelin that comes in contact with the proprioceptor
of the smooth muscles causing the increased contraction of the smooth muscles.
• The myogenic mechanism of the smooth muscles of the blood vessels can also lead to the
vasoconstriction during the time of injury to blood vessels.
2. Platelet plug formation:
• The endothelium of the damaged blood vessels starts secreting over them called as Von-
Willebrand factor (VWF)
• Platelets now binds to VWF with the help of the glycoprotein present on the surface of the
platelets called as GP-Ib. This process is termed as Platelet adhesion.
• The adhered platelets now get activated this is termed as Platelet activation.
• The activated platelet now starts releasing chemicals from their granules called as ADP,
Serotonin and Thromboxane A-2 (TXA-2)
• Released TXA-2 and ADP helps in the chemotaxis of platelets towards the site of injury.
• Platelets now come to the site of the injury and attach to each-other with the help of another
glycoprotein called as the GP-IIb,IIIa.
• Aggregated platelets now form the plug called as the platelet plug and the process is termed
as Platelet plug formation.
Blood coagulation:
Definition: “A set of reactions in which blood is transformed from a liquid to a gel is known
as clotting or coagulation.”
▪ Clotting process is well described by three main pathways which are:
a) Extrinsic pathway b) Intrinsic pathway and c) Common pathways
a) Extrinsic pathways:
▪ It has fewer steps than the intrinsic pathway.
▪ It’s a fast process than the intrinsic pathway usually takes few seconds.
During the injury
Endothelial cells which line the blood capillary get damaged
So, Factor VII leaves the circulation and comes into contact with tissue
factor (TF) It activate the clotting factor VII
Which combine with the factor X and activate
factor X It combines with factor V in the presence
of Ca++, Platelet Phospholipid Which form the
active enzyme PROTHROMBINASE

13. ▪ Tissue factor (TF) is a complex mixture of lipoprotein and phospholipids, It release from the
surface of damaged cells.
b) Intrinsic pathways:
▪ It is a more complex process than the extrinsic pathway.
▪ It is a slow process than the extrinsic pathway usually required several minutes
During the injury
Endothelial cells which lines the blood capillary get damaged
Blood come with contact of collagen in the surrounding basal lamina (Junction between
Endothelial tissue and Connective tissue)
Activate the clotting factor XII, Clotting factor XII activates
factor XI
Factor XI activates the factor IX which is also activate by extrinsic pathway factor VII
Factor IX by the help of factor VIII and platelet phospholipids activate factor X
Activated factor X combine with factor V and Ca++ (same as extrinsic pathway processes)
Which form the active enzyme PROTHROMBINASE
c) Common pathway:
▪ Once prothrombinase is form it start the common pathway.
▪ It this pathway:
Prothrombinase convert in to thrombin by the help of Ca++
Thrombin activates factor XIII as well as convert in to Fibrinogen in the presence of Ca++
Fibrinogen converts into soluble fibrin
Soluble fibrin converts in to insoluble fibrin by the help of activated factor XIII

14. 3. Clot Retraction and repair
• Process takes place after the formation of insoluble fibrin.
• Platelet from the platelet plug starts retracting the endothelium back to its normal position.
• Retraction of endothelium is done by actin and myosin present over the platelets that pull
the endothelium present on both the sides of the injured site towards each-other.
• Process of repair happens when the platelet from the plug releases Platelet derived growth
factor that repairs damaged smooth muscles and collagen fibres of basement membrane
and Vascular derived growth factor released by platelet of plug that repairs the damaged
endothelium.
• Thus, this process causes both retraction of endothelium and repair of endothelium, smooth
muscles and collagen fibres thereby causing the sealing of the blood vessels.
4. Fibrinolysis:
▪ Once repair is over, the fibrinolysis system is activated. This process inhibits the clot
formation in blood because in clot formation soluble fibrin is converted into
insoluble while in fibrinolysis insoluble fibrin will be converted in to soluble fibrin.
▪ Due to the formation of insoluble fibrin, there may be chances of formation of
bigger clot that may occlude the blood vessels thereby may causes decreased blood
flow through that blood vessel or no blood flow. It may lead to ischemia.
▪ Thus, endothelium of the blood vessel possesses a protein over them called as
Tissue plasminogen activator (tPA) that activates the Plasminogen in the blood to
its active form Plasmin.
▪ Plasmin thus formed causes dissolving of the fibers and platelets will be released
back into the blood.

15. BLOOD GROUPS AND BLOOD TYPES
▪ The surface of the erythrocyte contains some glycoprotein and glycolipids that can act
as antigen
▪ These antigens are known as isoantigens or agglutinogens.
▪ Based on the presence or absence of various isoantigens blood is categorized in to
different blood groups.
▪ More than 100 isoantigens that can be detected on the surface of red blood cells and
according to that total of 35 human blood group systems are now recognized by
the International Society of Blood Transfusion (ISBT).
▪ The two most important ones are:
ABO and the RhD antigen; they determine someone's blood type (A, B, AB and O, with +,
− or Null denoting RhD status).
➢ ABO blood groups:
• The ABO blood groups is based on two glycolipids isoantigens called A and B.
• The person’s RBCs contain only antigen A have type A blood group.
• The person’s RBCs contain only antigen B have type B blood group.
• The person’s RBCs contain both antigen A and antigen B have type AB blood group.
• The person’s RBCs contain neither antigen A nor antigen B have type O blood group.
• The above four ABO bloods types result from the inheritance of various combination of
three different genes known as I gene:
a) IA codes for the A antigen
b) IB codes for the B antigen.
c) i codes for neither A nor B antigen.
• Each inherits two I-genes alleles, one from mother side and one from father side.
• The six possible combinations genes of mother and father produce four blood types:
i) IA IA or IAi produces type A blood.
ii) IB IB or IBi produces type B blood.
iii) IA IB Produce type AB blood.
iv) ii produce type O blood.
CHILD BLOOD TYPE ESTIMATE TABLE
Father's Blood Type
A B AB O
Mother's
Blood Type
A A/O A/B/AB/O A/B/AB A/O
B A/B/AB/O B/O A/B/AB B/O
AB A/B/AB A/B/AB A/B/AB A/B
O A/O B/O A/B O

16. PARENT BLOOD TYPE ESTIMATE TABLE:
Child's Blood Type
A B AB O
One
Parent's
Blood
Type
A A/B/AB/O B/AB B/AB A/B/O
B A/AB/O A/B/AB/O A/AB A/B/O
AB A/B/AB/O A/B/AB/O A/B/AB Impossible
O A/AB B/AB Impossible A/B/O
• In addition to isoantigens of RBCs our blood plasma usually contains naturally
occurring isoantibodies or agglutinins.
– The persons RBCs contain antigen A that blood plasma contain anti-B antibodies.
– The persons RBCs contain antigen B that blood plasma contain anti-A antibodies.
– The persons RBCs contain both antigen A and antigen B that blood plasma contains
neither anti-A antibodies nor anti-B antibodies.
• When we transfuse the blood have same blood groups antigen and antibody it does not
produce antigen-antibody reaction.
• But when we transfuse the different kind of blood it produces antigen-antibody
reaction.
➢ Rh Blood groups:
• Rh antigen first finds out in to Rhesus monkey so it is known as Rh blood groups.
• The alleles of three genes C, D and E may code for Rh antigen.
• People whose blood have Rh antigen is known as Rh positive (+).
• People whose blood have not Rh antigen is known as Rh negative (-).
• According to Rh positive and Rh-n egative ABO blood group further divided in to
eight types:

17. HUMAN ANATOMY AND PHYSIOLOGY NOTES
RAMDAS BHAT
KARAVALI COLLEGE OF PHARMACY 17
a) A+ve blood group
b) A-ve blood group
c) B+ve blood group
d) B-ve blood group
e) AB+ve blood group
f) AB-ve blood group
g) O+ve blood group
h) O-ve blood group.
• If the Rh-ve person receives the blood from Rh+ve the Rh-ve person starts producing
antibodies that will remains in the blood and during the second transfusion the previous
formed anti-Rh antibodies will cause hemolysis of donated blood and cause severe
reaction.