Download blood-vessels - Lesmahagow High School

Unit 2b:
The Cardiovascular System
What words do you associate
with …
Cardio
Cardiac
Heart
Activity
Exercise /
work out
Vascular
Veins
Vascularisation of
the endometrium
Vessels
B – The Cardiovascular System
Key areas:
1. The structure and function of arteries,
capillaries and veins
2. The structure and function of the heart
3. Pathology of cardio vascular disease
(CVD)
4. Blood glucose levels and obesity
KA 1: The structure and function
of arteries, capillaries and veins
Subtopics:
a) Structure and function of blood
vessels
b) Exchange of materials between tissue
fluid and cells
KA1: Learning Outcomes
• Describe the blood flow around the body (in general basic
terms)
• Describe the structure of arteries and veins using the following
terms:
–
–
–
–
–
–
Endothelium
Central lumen
Connective tissue
Elastic fibres
Smooth muscle
Valves
• State the role of arteries, veins and capillaries
• State the function of valves
• Describe what happens to blood pressure as blood moves away
from the heart
• State what is meant by vasoconstriction and describe how it is
caused
• State what is meant by vasodilation and describe how it is
caused
Blood flow around the body
(basic)
• You need to the order in which blood flows through
the vessels:
Capillaries
Artery
Veins
Artery
Veins
Capillaries
Blood flow around the body
(basic)
• Blood circulates from the heart through the
arteries to the capillaries to the veins and
back to the heart.
HEART
HEART
Re-cap: what do you already know
about the blood vessels
Arteries
Veins
Capillaries
FUNCTION
Description
of wall
Valves
present?
Pulse
present?
TASK: use your show me boards to complete the table
The ARTERY
Arteries carry blood away from the heart.
Outer layer:
Connective tissue
containing elastic
fibres
Middle layer:
Contains smooth
muscle with more
elastic fibres
The endothelium
lining of the
central lumen.
This lining is
then surrounded
by layers of
tissue.
Central lumen
The elastic walls of the arteries stretch and recoil to
accommodate the surge of blood after each contraction
of the heart.
The VEIN
Veins carry blood towards the heart.
Outer layer:
Connective
tissue containing
elastic fibres
The endothelium
lining of the
central lumen.
Middle layer:
Contains a much
thinner muscular wall
than arteries (also
has elastic fibres)
Central lumen
(much wider
than the
artery lumen)
Veins also contain VALVES. Valves prevent the
BACKFLOW of blood
A LOT more on valves in the next Key Area!!
Valves
VIDEO CLIP:
Valves in action
TASK: Demonstrating the emptying of part
of a vein in the arm
CAPPILARIES
RED BLOOD CELLS
THIN CELL
WALL
BODY CELLS
Arteries, Veins and Capillaries
Arteries carry high pressure
blood away from the heart.
Capillaries have a wall
which is ONE CELL THICK.
This allows for the
exchange of substances
such as glucose and oxygen
with the body tissues.
Veins carry low pressure blood back to the
heart.
Vasodilation
Vasoconstriction
VIDEO CLIP: vasodilation vasoconstriction
Vasodilation
Vasoconstriction
• This is the widening of
blood vessels
• Caused by smooth
muscle cells relaxing
• This results in the lumen
becoming wider and
blood flow increasing
• This is the narrowing of
blood vessels
• Caused by smooth
muscle cells contracting
• This results in the lumen
becoming narrower and
blood flow decreasing
– (To parts of the body
such as skeletal muscles
during exercise)
– (To parts of the body
such as the small
intestine during exercise)
KA1: Learning Outcomes
• Describe the blood flow around the body (in general basic
terms)
• Describe the structure of arteries and veins using the following
terms:
–
–
–
–
–
–
Endothelium
Central lumen
Connective tissue
Elastic fibres
Smooth muscle
Valves
• State the role of arteries, veins and capillaries
• State the function of valves
• Describe what happens to blood pressure as blood moves away
from the heart
• State what is meant by vasoconstriction and describe how it is
caused
• State what is meant by vasodilation and describe how it is
caused