7. Types of Blood
Components.
1) Red blood cells (RBCs)
2) White Blood Cells (WBCs)
3) Platelets (thrombocytes)
4) Plasma
8. Red blood cells (RBCs /
erythrocytes)
• Contains haemogoblin.
• Shaped like slightly indented, fattened disks.
• Blood gets its bright red colour when haemogoblin
picks up oxygen in the lungs.
• As the blood travels through the body, the
haemogoblin releases oxygen to tissues.
• It has no nucleus.
9. White Blood Cells
(WBCs / leukocytes)
• Key part of the body’s system for defending itself
against infection
• Much bigger in size than Red blood Cells
• Fewer in number than Red blood cells
• Colourless
• Contains a nucleus
10. Platelets
(thrombocytes)
- -> Are tiny oval-shaped cells made in the
bone marrow.
->They help in the clotting process. When a
blood vessel breaks, platelets gather in the
area and help seal off the leak.
- -> Platelets survive only about 9 days in the
bloodstream and are constantly being
replaced by new cells.
11. Plasma
• Yellow straw coloured liquid.
• Contains 90% water, but it also
contains other components such as
salts, proteins, lipids and glucose.
• makes up around 55% of the total
volume of blood in the human body.
12. Blood Vessels
Content
- The main blood vessels connected
to the heart.
- The structures of Arteries, Veins
and Capillaries.
- The function of the Arteries, Veins
and Capillaries.
13. Main Blood Vessels connected to the
heart.
• Aorta
• Vena Cava
• Pulmonary Vein
• Pulmonary Artery
14. Structures of Arteries
• The innermost layer, the tunica intima (also called tunica
interna), is simple squamous epithelium surrounded by a
connective tissue basement membrane with elastic fibers.
The middle layer, the tunica media, is primarily smooth
muscle and is usually the thickest layer. It not only provides
support for the vessel but also changes vessel diameter to
regulate blood flow and blood pressure. The outermost
layer, which attaches the vessel to the surrounding tissue, is
the tunica adventitia.
15. Structures of Veins(:
• The walls of veins have the same three layers
as the arteries. Although all the layers are
present, there is less smooth muscle and
connective tissue. This makes the walls of
veins thinner than those of arteries, which is
related to the fact that blood in the veins has
less pressure than in the arteries. Because
the walls of the veins are thinner and less
rigid than arteries, veins can hold more blood.
16. Structures of Capillaries :P
• Smooth muscle cells in the arterioles where they branch to
form capillaries regulate blood flow from the arterioles into
the capillaries.
17. Functions of Blood Vessels
• #1 Arteries
- Carry blood away from the heart
- All arteries carry oxygenated blood except for the pulmonary artery
#2 Veins
- Carry blood back to the blood.
- All veins carry deoxygenated blood except for the pulmonary vein.
#3 Blood Capillaries
- Carry blood from an arteriole(small artery) to a venule(small vein).
- In capillaries, the blood is slowed down, giving more time for the exchange
of substances.
- They branch repeatedly and provide a large surface area for the exchange
of substances between the blood and arteries.
