Ch 19

Transport in Human

1

You need to know……

Lymphatic system ABO blood groups

Composition of blood Rhesus Factor Blood pressure

Pulse

Coronary arteries & veins supplying the heart muscle

Role of muscle and valves in heart and blood vessels

Structure of the heart & path of blood path through it

Pulmonary & systemic circulation and portal systems

Arteries, arterioles, veins, venules and capillaries

The way a closed circulation system is organised

2

To survive what do cells need?Food and Oxygen

•A single celled animal like the amoeba, gets its food and oxygen by allowing materials to move across its cell membrane.•In large animals most cells are not close to the surface of the body so they would not get supplies quick enough.•So how does the food and oxygen get as far down as your Big toe?

Hence they need a transport System Circulatory System

1. Open Circulatory SystemHeart pumps blood into vessels that are open

ended eg in Insects

2. Closed Circulatory SystemBlood remains in a continuous system of blood

vessels, from which nutrients can diffuse eg in Humans.

Arteries carry blood away from the heart to the body organs, while veins carry blood from the organs to the heart.

Arteries and veins are linked by

a network of tiny blood vessels

called capillaries.

Advantages of a Closed Circulation System

1. Blood can be pumped faster

Therefore nutrients can be delivered faster to cells allowing the organism to be more active

2. Blood flow rate to different organs can be changed

E.g. blood flow can be increased

to the leg mucles when running

6

Circulatory System

7

Double Circulation System• Blood is first pumped by the

heart to the lungs, where it collects oxygen while simultaneously releasing carbon dioxide.

• Then the oxygenated blood is returns to the heart.

• The heart pumps this oxygenated blood all around the body.

8

Double Circulation System / Human Two-Circuit Circulation

1. Pulmonary Circuit:

heart – to lungs – back to heart

2. Systemic Circuit:

heart – to tissues of the body – back to heart

9

Double Circulation System

Pulmonary

Circuit

Systemic Circuit

Pumps to the head, trunk and limbs and back to the heart

Pumps to the lungs and back to the heart

10

Advantages of a Double Circulation System

1. Separation of oxygen rich and oxygen poor blood

2. Blood pressure can be kept high by the heart

11

Portal systems

The Hepatic Portal System carries blood from the intestine to the liver

A portal system is one that begins and ends in capillaries

12

13

Learning check1. How does food and oxygen get as far down as

your Big toe?

2. What is the Open Circulatory System?

3. What is the Closed Circulatory System?

4. What are 2 advantages of a Closed Circulation System?

5. What is the Double Circulation System?

6. What are 2 advantages of a Double Circulation System?

7. Explain what a portal system is? 14

Main parts of Human Circulation System

1. Heart

2 Blood Vessels

Arteries

3. Blood

Veins

Capillaries

Arterioles

Venules

15

Main Blood VesselsArteries

Veins

Carry blood away from the heart

Carry blood under high pressure

Thick elastic wall

Narrow lumen

Carry blood towards the heart

Carry blood under low pressure

Have valves to prevent backflow

Thin wall

Wide lumen 16

Blood vessels under the microscope

Thick Wall

Arteries Veins

Narrow lumen

Thin Wall

Wide lumen

Have valves to prevent backflow17

Smaller Blood vessels

Arterioles

Arterioles connect arteries and capillaries

Venules

Venules connect capillaries to the veins

Capillaries

Tiny blood vessels linking arterioles and venules

The thin wall allows easy exchange of materials with cells

18

19

20

Cross section of blood vessel

Collagen

Muscle andElastic fibres

Endothelium

Lumen

21

Learning check

1. What are the 3 main parts of Human Circulation System?

2. Name 5 Blood Vessels.

3. Give 4 features of Arteries.

4. Give 5 features of Veins.

5. Name 3 Smaller Blood vessels.

6. Give a features of each.

22

Pathway of blood Around Body

23

The Heart

• Is a strong double pump made of cardiac muscle, surrounded by a special membrane sac - pericardium to prevent friction.

• Found between the lungs, slightly to the left side in the thoracic cavity.

• The right & left halves are divided by the septum.• Each half consists of 2 chambers:

1.the atrium

2.the ventricle

24

• Each half is separated by a valve:

1.The Tricuspid valve on the right - Prevents backflow into right atrium when the right ventricle contracts.

2.The Bicuspid Valve on the left - Prevents backflow into left atrium when the left ventricle contracts.

25

Blood supply to the heart wall

• The heart has its own blood supply from the coronary arteries (oxygen & nutrients) which come from the aorta &

• the coronary veins (carbon dioxide & wastes)which empty into the vena cava.

26

Vena Cava

Right Atrium

Tricuspid Valve

Right ventricle

Left Ventricle

Left Atrium

Pulmonary Vein

Aorta

Pulmonary Artery

Bicuspid Valve

Septum

Cardiac muscle

Semi Lunar Valves 27

Blood pathway through heart

Right Atrium

Tricuspid valve

Right ventricle

Left atrium

Bicuspid valve

Left ventricle

Vena Cava

Pulmonary arteryAorta

Pulmonary vein

28

Valves

Semi Lunar valves

Tricuspid valve

Bicuspid Valve

Prevent backflow into heart

Prevents backflow into left atrium

Prevents backflow into right atrium

29

Learning check1. The heart is a pump made of what muscle?2. The heart is surrounded by a special

membrane?3. The heart is found in what cavity?4. The heart is divided by the?5. Each half consists of 2 chambers called?6. Each half is separated by valves called?7. The heart has its own Blood supply, explain?

30

Heartbeat and its control

The heart beat consists of alternate contraction and relaxation of the cardiac muscle

The heart beat is controlled by the pacemaker

The pacemaker / SA node is a specialised knot of muscle embedded in the top wall of the right atrium

31

The pacemaker / SA nodeThe pacemaker / SA node:

1.sends out waves of impulses (electrical signals)

2.which causes the artium to contract (atrial systole)

3.the impulse wave reaches the AV node (specialised knot of muscle embedded in the bottom wall of the right atrium)

4.which coducts the waves of impulses from the artium to the ventricles,

5.Causing them to contract (ventricular systole). 32

33

34

135

• Heart Song

36

Pulse

A pulse is a wave of vibration that passes down the walls of arteries when the aorta expands following the contraction of the left ventricle.

The alternate expansion and contraction of arteries can be felt in the wrist / neck.

Average pulse rate is

72 beats per minute

37

Blood PressureBlood Pressure is the force of blood pushing against the wall of a blood vessel

Blood is forced into arteries under pressure from the left ventricle, the region of highest pressure

And eventually comes back to the heart in the right atrium, the region of lowest pressure

38

Blood PressureHuman blood pressure is taken from the artery in the upper arm.

It is measured with an instrument that records the pressure it takes to stop the blood flow through this artery.

39

Effect of smoking on the circulation system

1. Nicotine increases the heart rate, blood pressure & the amount of cholestrol in the blood. These puts a bigger workload on the heart.

2. Carbon monoxide reduces the amount of O2 carried by the blood. This reduces energy levels.

3. Other chemicals in tobacco, increase the chance of clots.

40

Effect of Diet on the circulation system

High salt intake

High intake of fat causes a build up of cholesterol

Cholesterol may block arterioles and lead to stroke or heart attack

Raises blood pressure which can cause heart attack

41Clotting of artery

Effect of Exercise on the circulation system

Exercise increases our ability to transport oxygen

Exercise strengthens the heart

This improves circulation

This gives increased energy levels

42

Learning check

1 What causes the blood to be under pressure in the arteries ?

2 Explain the term Pulse

3 What controls the rate of heartbeat

4 Give two harmful effects of cigarette smoke on the circulation system

5 Explain why salt can have a negative effect on the circulation system 43

Lymphatic System

A secondary transport system consisting of one way system of vessels that collects and returns excess tissue fluid to blood system

1. Lymph vessels

2. Lymph Nodes

3. Lymph

Structure

44

Lymph vessels & blood vessels

45

Lympha t I c

System

46

Lymphatic System Functions

1.Collect tissue fluid and return it to the blood system

2. Fight Infection by

3. Transport digested fat away from intestine

(a) Filtering out microorganisms in the lymph nodes

(b) Destroying microorganisms by antibody production

(c) Mature and store lymphocytes

47

Learning check

1 Name the three main parts of the Lymphatic System

2 Name three substances dissolved in plasma

3 Name a blood grouping system other than the ABO System

4 What is the function of white blood cells

5 Give two functions of the Lymphatic System48

END

49