The circulatory system consists of the blood circulatory system and lymphatic system. The blood circulatory system contains blood, heart, and blood vessels. Blood is a connective tissue composed of plasma, red blood cells, white blood cells, and platelets. Plasma is 90-92% water and contains proteins like albumins, globulins, and fibrinogen. Red blood cells are biconcave and transport oxygen and carbon dioxide. White blood cells help fight infection. The heart has four chambers and uses double circulation to oxygenate blood in the lungs and transport it to the body before repeating the cycle. Lymph flows unidirectionally through lymph vessels and drains excess fluid from tissues.

2. Body fluids & circulation
• Circulatory system is of two types
• 1. Blood circulatory system
• 2. Lymphatic system

3. Components of the blood
circulatory system
• 1. Blood
• 2 Heart
• 3. Blood vessels

4. Blood
• BLOOD IS A
FLUID
CONNECTIVE
TISSUE
• It has
• 1) Plasma
• 2) RBC
• 3) WBC
• 4) Blod platelets

5. Plasma
• The liquid part of
the blood is said to
be plasma
• It is a straw
coloured ,viscous
fluid
• 90 to 92 % of
plasma is water &
proteins contribute
to 6-8 percent

6. Plasma proteins
• They are of three types
• 1. Albumins
• 2. Globulins
• 3. fibrinogen

7. FUNCTIONS OF PLASMA
PROTEINS
• Albumins maintain osmotic
balance
• Globulins are involved in the
defense mechanism
• Fibrinogen is needed for the
coagulaton of the blood

8. Types of the blood cells
• 1. RBC
• 2. WBC
• 3. Thrombocytes

10. Erythrocytes
They are
biconcave , flat
structures
They are red in
colour due to the
presence of the
haemoglobin

11. RBC transport oxygen from
lungs to various tissues
CO2 from tissues to lungs

12. Types of WBC
• They are of two
types
• 1. Granulocytes
• 2. Agranulocytes

13. GRANULOCYTES
• They have granules in the cytoplasm
• They have lobed nucleus
• They are of three types
• 1. Eosinophils
• 2. Basophils
• 3. Neutrophils

14. Agranulocytes
• They lack granules in the cytoplasm
• Nucleus is not lobed

17. EXTERNAL STRUCTURE OF
HEART

19. Double circulation
• In human beings, the blood goes through the heart twice during each
cycle i.e. the blood passes through the human heart two times to
supply once to the whole body. So, it is called Double Circulation of
blood.
• The double circulation of blood includes:
• (i) Systematic Circulation
• (ii) Pulmonary Circulation
• Systematic Circulation: It supplies oxygenated blood from left auricle
to left ventricle, thereby pumped to various body parts. The
deoxygenated blood is collected from the various body organs by the
veins to pour into vena cava and finally into the right atrium (auricle).
Right atrium transfers the blood into the right ventricle.
• Pulmonary Circulation: The deoxygenated blood is pumped by the
right ventricle into the lungs for oxygenation. The oxygenated blood is
brought back to left atrium (auricle) of the human heart. From left
atrium, the oxygenated blood is pushed into the left ventricle. The left
ventricle pumps oxygenated blood into aorta for systematic
circulation.

20. Necessity (Importance) of
Double Circulation:
• There is a partition between the right side
and the left side of human heart which is
particularly useful to prevent mixing of
deoxygenated with oxygenated blood.
• This type of separation of deoxygenated and
oxygenated blood ensures highly efficient
supply of oxygen to the body. This is
important in case of humans because it
constantly gives energy to maintain their
body temperature

23. SINGLE CIRCULATION IN FISH
Ex- Fish
Blood flows
once in the
heart before it
is supplied to
body parts

24. Blood vessels
• 1. Arteries
• 2. Veins
• 3. Blood
capillaries

25. Arteries & Veins
• Arteries
• Arteries carry pure blood from heart to
different body parts except pulmonary artery
• They have thick walls
• Veins
• They carry impure blood from different body
parts to heart
• They have thin walls

27. Lymph
• Lymph (like blood) is a
circulatory fluid. It flows in
the lymph vessels.
• Lymph (also called tissue
fluid) is colourless.
• It consists of lymphocytes
which kills germs and
protect the human body
from infections.
• Lymph carries digested and
absorbed fat from intestine.
• It drains excess fluid from
extra cellular space back
into the blood.
• Its flow is unidirectional i.e.
from tissues → lymph
capillaries → veins → heart.