anatomy of blood

1. ANATOMY OF BLOOD

2. INTRODUCTION
•Blood is red coloured, opaque, viscid fluid.
• In the body of an adult male of 70 kg weight, there will
be about 5600 ml of blood.
• Haematology is the branch of science that deals with
the study of blood and blood forming tissues.

3. DEFINITION
Blood is defined as a type of
connective tissue that flows through the blood vessels
and carries oxygen, nutrients and carbon dioxide to
cells throughout your body.

4. FUNCTIONS OF BLOOD
Blood has three general functions:
1. Transportation.
2. Regulation.
3. Protection.

5. 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

6.  Blood also transports heat and waste products
to various organs for elimination from the
body.

7. 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.

8. 3. Protection
 Blood can clot (become gel-like), which protects
against its excessive loss from the cardiovascular
system after an injury.
 White blood cells protect against disease by
carrying on phagocytosis.
 Several types of blood proteins, including
antibodies, interferon, help protect against
disease.

9. PHYSICAL CHARACTERISTICS OF
BLOOD
 Temperature:- 38o C (100.4F)
 pH:- 7.35 to 7.45 (alkaline pH)
 Colour:- When saturated with oxygen, it is
bright red. When unsaturated with oxygen, it
is dark red.

10.  Volume:- The blood volume is 5 to 6 litres (1.5
gal) in an average sized adult male and
4 to 5 litres (1.2 gal) in an average-sized
adult female.
 Hormone:- aldosterone, antidiuretic hormone,
and atrial natriuretic peptide.
It is regulated by negative feedback
mechanism.

11. COMPONENTS OF BLOOD:-
Whole blood has two components:
 Blood plasma:- a watery liquid extracellular matrix
that contains dissolved substances.
 Formed elements:- These are cells and cell
fragments.

15. Blood Plasma
 When the formed elements are removed
from blood, a straw-colored liquid called
blood plasma is left..
 Blood plasma is about 91.5% water and 8.5%
solutes, most of which are proteins. These
proteins are known as plasma proteins.

16. Plasma proteins.
Hepatocytes (liver cells) synthesize
most of the plasma proteins, which include the
 albumins
 globulins
 fibrinogen

17. Formed Elements

18. Red blood cell
 Red blood cells or erythrocytes transport
oxygen from the lungs to body cells and
deliver carbon dioxide from body cells to the
lungs.

19. White blood cells :-
 White blood cells or leukocytes protect
the body from invading pathogens
and other foreign substances.

20. Platelets:-
 Besides the immature cell types that develop
into erythrocytes and leukocytes, hemopoietic
stem cells also differentiate into cells that
produce platelets.
 Between 150,000 and 400,000 platelets are
present in each microliter of blood.

22. FORMATION OF
BLOOD CELLS

23.  The process by which the formed elements
of blood develop is called hemopoiesis or
hematopoiesis.
 Before birth, hemopoiesis first occurs in the
yolk sac of an embryo and later in the liver,
spleen, thymus, and lymph nodes of a fetus.

24.  Red bone marrow becomes the primary site of
hemopoiesis in the last 3 months before birth
and continues as the source of blood cells
after birth and throughout life.
 It is present chiefly in bones of the axial
skeleton, pectoral and pelvic girdles, and the
proximal epiphyses of the humerus and femur.

25.  About 0.05–0.1% of red bone marrow cells are
called pluripotent stem cells.
 These cells have the capacity to develop into
many different types of cells.

27. Red Blood Cells
 Anatomy of RBCs:-
 RBCs are biconcave discs with a diameter
of 7– 8µm.
 plasma membrane is both strong and
flexible.
 RBCs lack a nucleus.

29.  Physiology of RBC:-
 Red blood cells are highly specialized for their oxygen
transport function.
 RBCs lack mitochondria and generate ATP
anaerobically (without oxygen), they do not use up any
of the oxygen they transport.
 Each RBC contains about 280 million haemoglobin
molecules.

30.  A haemoglobin molecule consists of a protein called
globin, composed of four polypeptide chains (two alpha
and two beta chains); a ring like non-protein pigment
called a heme is bound to each of four chains.
 At the centre of each heme ring is an iron ion that
can combine reversibly with one oxygen molecule

31. allowing each haemoglobin molecule to bind four oxygen
molecules.
 Haemoglobin releases oxygen, which diffuses first into the
interstitial fluid and then into cells.
 Haemoglobin also transports about 23% of the total carbon
dioxide, a waste product of metabolism.

32.  RBC Life Cycle:-
 Red blood cells live only about 120 days.
 Ruptured red blood cells are removed from
circulation and destroyed by fixed phagocytic
macrophages in the spleen and liver, the breakdown
products are recycled and used in numerous metabolic
processes, including the formation of new red blood
cells.

33. Macrophages in the spleen, liver or red bone marrow
phagocytise ruptured and worn-out red blood cells.
The globin and heme portions of haemoglobin
are split apart.
Globin is broken down into amino acids, which can be
reused to synthesize other proteins.

34. Iron is removed from the heme portion in the form of
Fe.
In muscle fibers, liver cells, and macrophages of the spleen
and liver, Fe3 detaches from transferrin
On release from a storage site or absorption from the
gastrointestinal tract, Fe3 reattaches to transferrin.

35. The Fe–transferrin complex is then carried to red bone
marrow, where RBC precursor cells take it up through
receptor mediated endocytosis for use in haemoglobin
synthesis.
Production of red blood cells, which enter the circulation.

36. Bilirubin enters the blood and is transported to the
liver
When iron is removed from heme, the non-iron
portion of heme is converted to biliverdin, a green
pigment, and then into bilirubin, a yellow orange
pigment.
Bilirubin enters the blood and is transported to the liver
Bilirubin is released by liver cells into bile, which passes
into the small intestine and then to large intestine.

37. In the large intestine, bacteria convert bilirubin into
urobilinogen
Some urobilinogen is absorbed back into the blood,
converted to a yellow pigment called urobilin, and
excreted in urine
Most urobilinogen is eliminated in feces in the form of a
brown pigment called stercobilin .

39. Production of RBC
 Erythropoiesis, the production of RBCs, starts
in the red bone marrow with a precursor cell
called a proerythroblast.
 The proerythroblast divides several times,
producing cells that begin to synthesize
haemoglobin.

40.  Ultimately, a cell near the end of the development
sequence ejects its nucleus and becomes a
reticulocyte.
 Reticulocyte retains some mitochondria, ribosome,
and endoplasmic reticulum.
 They pass from red bone marrow into the

41. bloodstream by squeezing between the endothelial
cells of blood capillaries.
 Reticulocyte develops into mature red blood cells
within 1 to 2 days after their release from red bone
marrow.
 Normally, Erythropoiesis and red blood cell destruction
proceed at roughly the same pace.

43. WHITE BLOOD CELLS
 Types of White Blood Cells:-
 White blood cells or leukocytes which have
nuclei and a full complement of other
organelles but they do not contain
haemoglobin.

44.  WBCs are classified as either granular or
agranular.
 Granular leukocytes include neutrophils
eosinophils, and basophils;
 Agranular leukocytes include lymphocytes
and monocytes.

45. i. Neutrophils:-
Neutrophils (also known as
neutrocytes or heterophils) are the most
abundant type of granulocytes and make up
40% to 70% of all white blood cells in
humans.
 Neutrophils are a type of white blood cell that
helps heal damaged tissues and resolve
infections.

46. ii. Basophils:-
Basophils account for only around
0.1-1% of the body’s white blood cells.
 They are responsible for inflammatory
reactions during immune response, as well as
in the formation of acute and chronic allergic
diseases.

47. iii. Eosinophil:-
 They form about 2 to 3% of WBC's.
 They also control mechanisms associated with
allergy and asthma.
 It has a nucleus with two lobes (bilobed) and
cytoplasm filled with approximately 200
large granules.

48. iv. Monocytes:-
• They are the largest type of WBC.
• They are important cells involved in first-line
defense against pathogenic organisms or
foreign cells ( phagocytosis).
• Monocytes are amoeboid in appearance,
and have non granulated cytoplasm
(agranulocytes)

49. v. Lymphocytes:-
• It is a form of small white blood cell with a
single round nucleus.
• There are two types of lymphocytes known as
B lymphocytes and T lymphocytes.
• They are the main type of cell found in lymph,
which prompted the name "lymphocyte"

50. PLATELETS
 Anatomy of platelet:-
 Each is irregularly disc-shaped, 2–4 m in diameter, and
has many vesicles but no nucleus.
 Their granules contain chemicals that, once released,
promote blood clotting.
 Platelets help stop blood loss from damaged blood
vessels by forming a platelet plug.

51.  Platelets have a short life span, normally just
5 to 9 days.
 Aged and dead platelets are removed by
fixed macrophages in the spleen and live

52. BLOOD GROUPS:-
 A blood group also called a blood type.
 There are mainly two blood group systems:
 ABO blood group system.
 Rh blood group system.

54. • The blood used in a transfusion must be compatible
with the patient’s blood type.
Type ‘O’ blood is called Universal donor.
Type ‘AB’ blood are called Universal
recipients.

55. • Rh FACTOR:- There are six common types of Rh
antigen (C, D, E, c, d, e).Each of them is called Rh
factor. The type ‘D’ antigen is most common than
others.
• Therefore,
any person who has d antigen is Rh positive and
any person who do not have D antigen is Rh
negative.

56. • People with Rh positive blood can get Rh positive or
Rh negative blood.
• People with Rh-negative blood should get only Rh-
negative blood.

57. THANK YOU