8. heart and blood vessels

1.

Heart and blood vessels

2.

Lesson objectives
⚫ To describe structure of heart and blood
vessels.
⚫ To make a connection between structure
of blood vessels and their functions.

3.

What is the engine of your body
machine?

4.

Circulatory system
⚫Circulatory system
consists of three
parts:
1. Heart
2. Blood vessels
3. Blood

5.

Heart
⚫ Heart pumps blood
and makes blood
flow within the
vessels. Blood
reaches organs and
tissues via blood
vessels and
transports nutrients
and oxygen.
⚫ Heart is muscular
organ.
⚫ It is located in chest
cavity.

6.

Heart structure
⚫ There are four chambers
inside the heart:
⮚ Left ventricle
⮚ Right ventricle
⮚ Left atrium
⮚ Right atrium
• Between atria and
ventricles there are valves.
• Valves open in one
direction so they keep
blood flowing in one
direction.

7.

⚫Blood is pumped
from atria to
ventricles.
⚫Ventricles pump
blood to blood
vessels that
carry blood to
all other organs
and tissues.
⚫ That’s why
ventricle wall is
thicker than atria
wall.

8.

Blood vessels
⚫There are three types of blood vessels:
Arteries
2. Veins
3. Capillaries
1.

9.

Arteries
⚫Arteries are blood vessels that transport
blood from heart to tissues.
⚫Arteries have thick and elastic walls made
up of muscles.

10.

Veins
⚫Veins are blood vessels that carry blood
from tissues to heart
⚫They have thin muscular wall.
⚫Veins have valves that prevent back flow
of blood.

11.

Capillaries
⚫Capillaries connect arteries and veins.
⚫Material exchange take place between
tissues and blood in capillaries.
⚫Capillaries are made up of one layer of
epithelial cells.

12.

13.

Blood flow
⚫Heart-arteries-capillaries-veins-heart

14.

Blood speed
⚫Arteries>veins>capillaries

15.

Blood pressure
⚫Arteries>capillaries>veins

16.

Circulatory system of Annelida
⚫ It consists of:
Aortic arches (large
vessels that function like
heart)
2. Dorsal vessel
3. Ventral vessel
4. Small ring-like vessels that
connect dorsal and ventral
vessels in each segment.
⚫ They have closed
circulatory system
1.

17.

Circulatory system of Mollusks.
⚫It is consisted of :
Heart with one ventricle and one or
two atria.
2. Blood vessels
⚫They have open circulatory system.
1.

18.

Circulatory system of Arthropods
⚫It consists of:
Dorsal heart
2. Blood vessels
They have open
circulatory system.
1.

19.

New words