Blood and Lymph — Part 1: Blood, its cells and clotting: visual lesson, ICSE Class 10 Biology (Science Paper 3)

Lesson

Circulatory System: Blood and Lymph

Part 1 — what blood is made of, and how it seals a wound.

In this lesson you will

State the functions of plasma, red blood cells, white blood cells and platelets
Identify blood cells from diagrams and explain why mammalian red cells are efficient
Outline the steps from injury to clot formation

Concept

Blood is a fluid connective tissue: liquid plasma carrying red cells, white cells and platelets.

Table of the parts of blood, what each contains and its main job
Part	Contains	Main job
Plasma (about 55%)	Water (about 90%), proteins (albumin, globulins, fibrinogen, prothrombin), glucose, amino acids, salts, urea, hormones, carbon dioxide	Transport; clotting proteins; antibodies
Red blood cells	Haemoglobin	Carry oxygen
White blood cells	Nucleus; some have granules	Defence
Platelets	Cell fragments	Start clotting

Worked example

An adult has about 5 litres of blood; about 55% of it is plasma.