30-06-2012, 03:20 PM
Seminar on Thalassaemia
Thalassaemia.pdf (Size: 4.13 MB / Downloads: 38)
Blood and Thalassaemia
The thalassaemias are a group of disorders that prevent
the body from producing a sufficient quantity of high
quality blood. As we will see, the human body relies on
the blood to survive, so it is important to understand any
problem that affects the blood and how the body
copes with it.
The role of blood
Blood performs many important functions:
(i) Transports oxygen: The body relies on blood to bring
it the essential nutrients it needs to function, and to
carry away the poisonous waste products it needs
to get rid of. For example, all cells and living organ
isms need oxygen - a gas found in the air we breathe
- to survive and function. The blood picks up oxygen
from the lungs carrying it to different parts of the
body.
(ii) Picks up carbon dioxide, another gas that is a waste
product formed by cells, carrying it back to the lungs
to be released into the outside air. The blood also
collects other waste products, such as urea and uric
acid, carrying them to the kidneys and liver. Eventually.
Composition of blood
Blood is produced in the bone marrow (see 1f),
a tissue found in the middle (central cavity) of
bones. In infants, blood cells are made in several
body tissues. In adults, blood cells are only
produced in the marrow of the skull, spine,
ribs and pelvis.
Whole blood
Whole blood is made up of two parts:
(i) non-cellular -- the part that contains no cells -- and
(ii)cellular -- the part that contains cells.
Our bodies are made up of trillions of microscopic
units - tiny building blocks called cells. Cells are
far too small to be seen by the naked eye. In
most tissues, they are stuck together. But in blood,
cells float around. Each cell has three major parts
or compartments: the centre or nucleus, the
substance around the nucleus known as the cytoplasm,
and the structure surrounding the cell --
the cell membrane (see 1g). Numerous other smaller
structures are found within each of these major
cell compartments, each with a specific function.
However, a large part of every cell is water, along
with proteins, fats, carbohydrates, nucleic acids,
dissolved molecules and inorganic ions. Proteins
are the 'workhorses' of our cells, and there
are 100,000 different types of proteins
in our body. Some of the functions
of proteins in cells include:
ñ Providing the building blocks for
most cellular structures
ñ Acting as enzymes - catalysts for the
chemical reactions that make life possible
ñ Controlling communications between
cell surfaces
ñ Controlling the expression of genes
ñ Replicating genetic material