ICSE class 10 Biology
Circulatory system
All parts of the body that help in the transportation of various materials in the
body collectively constitute the circulatory system .
Function of circulatory system :
1) transporting materials between various parts of the body
2) exchanging materials with external environment
3) Elimination of metabolic wastes
In animals, the circulatory systems consists of the following part: 1) Fluid Transport medium (blood, lymph)
2) Controlling center (heart)
3) Pathway for transport (blood vessels, lymph vessesls)
Fluids in our body (40 litres total)
Intracellular fluid: present in side the cells (25 litres)
Extracellular fluid: present in various spaces in the body, outside the cells (15
litres)
ICSE class 10 Biology
Types of extra cellular fluid:
1) Blood
2) Tissue fluid
3) Lymph
Blood:
 Appearance: red colored fluid,
 Location: circulating within heart and blood vessels
Tissue fluid:
 Appearance: color-less fluid,
 Location: found in spaces between cells in the organs.
 Formed when plasma and WBC move out through the capillary walls into
the spaces between cells
Lymph fluid:
 Appearance: faint yellow colored,
ICSE class 10 Biology
 Location: found in lymph vessels and lymphatic organs(spleen, tonsils).
 Formation: Tissue fluid enters the lymphatic vessels, forming the lymph
fluid.
o Lymph vessels unite to form lymphatic trenks.
o They pour back into the heart via lymphatic trenks which empty
into the vein. The vein empties into the right auricle.
 Constitution: Consists of only WBC.
 FUnctions:
o They supply oxygen to parts where blood cannot reach,
o They contain WBC and monocytes which help remove bacteria
from tissue.
ICSE class 10 Biology
Blood
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It is bright red when oxygenated and dark red when deoxygenated.
Saltish in taste, slightly alkaline (pH 7.4)
Heavier than water
Viscous and sticky fluid
Composition of blood:
Consists of two major parts:
- Plasma : fluid part of the blood
- Cellular elements: RBC, WBC, Platelets
Plasma:
 Liquid portion of blood
 Appearance: slightly yellow and alkaline
o 50-60% of blood, heavier than water
 Composition: 90% water, 7-8% proteins, 1% inorganic salts and other
substances.
o Other substances include: blood proteins, glucose, amino acids,
fatty acid, urea, uric acid, ammonium salts, gases, hormones
o Types of blood proteins: Albumins, globulins, fibrinogen,
prothrombin
o Example of salts: sodium chloride, sodium bicarbonate
ICSE class 10 Biology
Formed cellular components of blood:
Formed cellular elements: structures visible under the microscope as cells
and cell-like structures in blood
- 40-45% of the blood
- Are of three types:
1. RBC
2. WBC
3. Platelets
RBC: Erythrocytes, Red Blood Corpuscels
- small, denucleated, disc like, biconcave cells in mammalian blood
- Most abundant type of blood cell
- 4-5 million/mm3 of blood
- When young, RBC COntains mitochondria, nucleus, ER and other organelles.
ICSE class 10 Biology
- When mature, looses all organelles to
1. accommodate haemoglobin for oxygen transport.
2. Small size and concave shape help in easy passage through capillaries.
Haemoglobin:
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Gives RBC the red color
Present in stroma of RBC
Consists of Haematin (iron containing pigment) and globin (protein part).
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Has great affinity for oxygen, and forms Oxyhaemoglobin with O2.
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HB can combine with Co2 to from carbamino haemoglobin.
Functions of RBC:
1) Transport of Oxygen: O2 binds to haemoglobin in the cytoplasm of RBC,
and is transported form respiratory organs to other tissues.
2) Transport of Co2 : 23% of Co2 carried from tissue to respiratory organs
for elimination
ICSE class 10 Biology
ICSE class 10 Biology
Answer the following:
1) Where is RBC produced in
a. Adults:
b. Children:
c. Embryo
2) Where is RBC destroyed?
3) What is polycythemia?
4) What is the life span of RBC?
5) What is the difference between carbamino hameoglobin and Carboxyhaemoglobin
ICSE class 10 Biology
Functions of blood:
1. Transport of
 digested food: nutrients from alimentary canal are transported to
other parts of the body via blood.
 Carbon-dioxide: carried partly dissolved in plasma and partly
bound to haemoglobin
 metabolic waste: nitrogenous waste products are transported to
kidney via blood.
 Hormones: secreted via endocrine glands directly into blood,
 Heat: distributes heat, keeping temperature of the body constant.
2. Homeostasis:
 Helps in homeostasis by maintaining different salts and organic
substances in constant amount
3. Protection:
 Helps in forming clots which prevents blood loss as well as
entry of germs into the body