PPT about AS Biology chapter 1B

1. Chapter 1B
CIRCULATION IN THE BLOOD
VESSELS

2. Understand how the structure of blood vessels relate to
their functions.
LEARNING OBJECTIVES

3. • There are 3 types of blood
vessels:
• 1. Arteries
• 2. Veins
• 3. Capillaries
BLOOD VESSELS

4.  Carry blood away from the heart
 Carry mostly oxygenated blood
 Exceptions are pulmonary and umbilical arteries
 By diving change into many arterioles
 Contain 3 layers:
 1. Outer layer- tough collagen fibers
 2. Middle layer- elastic fibers and smooth
muscle
 3. Inner layer- endothelium(epithelial tissue)
ARTERIES

6. DIFFERENCES BETWEEN ARTERIES

7.  Links arterioles and venules
 Smallest blood vessels
 Walls contain only endothelium(one cell
thick)
 Blood flow rate is slowest
CAPILLARIES

8.  Carry blood towards the heart
 Carry mostly deoxygenated blood
 Exceptions are pulmonary and umbilical veins
 Smaller branches are venules
 Layers are the same with arteries, but thicknesses
are different
 Contain valves
VEINS

10.  Skeletal muscle contraction in legs
 Having valves
ADAPTATIONS FOR BLOOD
MOVEMENT IN VEINS

11.  Reason: Weak or damaged valves can lead to varicose
veins
 Factors: Age, sex, pregnancy, family history, obesity,
standing r sitting longer periods of time
VARICOSE VEINS

12. DIFFERENCES BETWEEN ARTERY
AND VEIN

13. ORDER OF BLOOD VESSELS ACCORDING TO
PRESSURE, VELOCITY, TOTAL AREA