Blood Circulation

and Transport

What organ need to pumps blood to the whole body???

heart

2.1 Transport System in Humans

• The human circulatory system consists of:

1. The heart

2. Blood vessels

3. Blood

Structure of the heart

HEART

• Most powerful organ in the circulatory system.

• Cone-shaped organ.• Weight about 300g.• Location: in the thoracic cavity, between

the lungs.• A muscular organ made up of cardiac

muscles connective tissues and blood vessels.

• The heart pumps blood to the whole body.• The human heart consists of four chambers:

a) right atrium b) left atriumc) right ventricle d) left ventricle

• The heart is connected to four main blood vesselsi) vena cavaii) pulmonary veiniii) pulmonary artery

iv) aorta• The valves separate the atria/ atrium from the

ventricles. To ensure that the blood flows only in one direction.

• right side of the heart contains deoxygenated blood

• left side of the heart contains oxygenated blood (blood rich in oxygen).

• Function the parts in the heart:

Parts Function

Superior vena cava

Blood from the upper portion of the body flows into the heart.

Aorta Blood from the heart is pumped to the whole body.

Pulmonary vein

Blood from the lungs is pumped into the heart

Right atrium Cavity where blood flow from vena cava into the heart

Tricuspid valve

Prevents backflow of blood into the right atrium

Inferior vena cava

Blood from the lower portions of the body flows into the heart

Pulmonary artery

Blood is pumped into the lungs from the right ventricle.

Left atrium Cavity where blood flows from the pulmonary vein into the heart

Bicuspid valve

Prevent backflow of blood into the left atrium

Aortic valve Prevent backflow of blood into the left ventricle

Left ventricle Cavity where blood flow into from the left atrium through the bicuspid valve

Right ventricle

Cavity where blood flow into from the right atrium through the tricuspid valve

• Function of the heart:

1. pumps blood to the whole body.

2. The right side of the heart contains deoxygenated blood.

3. Left side of the heart contains oxygenated blood.

4. When the heart contracts, it forces the blood out of the heart into the arteries.

5. When it relaxes, it receives blood from the veins.

• Blood circulatory system

6. When the right atrium is filled with blood it contracts. This pushes the blood into the right ventricle through the tricuspid valve. This valve prevents blood from flowing back into the right atrium.

7. The right ventricle contracts and pushed the blood into the pulmonary artery.

8. The pulmonary artery then transports the blood to the lungs.

9. The blood receives oxygen in the lungs. Oxygenated blood is carried back to the left atrium by the pulmonary vein.

10. The left atrium contracts and pushes the blood into the left ventricle.

11. The left ventricle contracts and pushes the blood into the aorta.

12. The aorta branches into the arteries. These arteries transport oxygenated blood to all parts of the body except the lungs.

Blood vessels and their functions• When the heart pumps the blood flows around the

body in a system tubes called blood vessels.• There are three types of blood vessels1. Arteries / artery

-blood vessels which transport blood away from the heart.

2. Veins/ vein-blood vessels which transport blood towards the heart.

3. Capillaries/ capillary-consist of network of fine, microscopic blood vessels.

1. Characteristics and function of arteries

Artery

• In the arteries blood flows quickly and at the high pressure:

1. When the heart contracts,blood is forced at a high pressure into the arteries.

2. The thick,elastic walls prevent the arteries from bursting.

3. All arteries except the pulmonary artery transport oxygenated blood to body tissues.

2. Characteristics and function of the capillary

capillary

• Capillaries are found very close to the cells of the body.They join to form bigger tubes called veins.They connect the arteries to the veins.

• Blood flows slowly in the capillaries and at a higher pressure compared to the flows of blood in the veins.

• Capillaries transport oxygenated blood to the body cells.They transport deoxygenated blood from the cells.

• The thin walls of the capillaries allow the exchange of substances between the blood and body cells.

• Substances such as oxygen,carbon dioxide,nutrients and excretory products are exchange between the blood and body cells.

3. Characteristics and function of the veins

veins

Comparison between artery, vein and capillary

COMPARISON ARTERY VEIN CAPILLARY

Cross section

Lumen Narrow Wide Very narrow

Function Transport blood from the heart

Transport blood into the heart

Transport blood from artery to vein

Type of blood

carried

Oxygenated blood

(except pulmonary

artery)

Deoxygenated blood

(except pulmonary

vein)

Oxygenated and

deoxygenated blood

Blood pressure

high low Very low

Rate blood flow

fast slow Very slow

Structure of the wall

Thick, elastic, muscular

Thinner, less elastic and muscular

One-cell thick

Presence of valve

absent present absent

• The veins have thinner muscular walls compare to the arteries.

• Veins have valves. These valves ensure that blood flows in only one direction, that is towards the heart.

• As the blood passes through the organ, it loses much of it pressure. By the time the blood enters the veins, the blood pressure is relatively low.

• This explain why veins have thinner walls compare to the arteries.

Compare oxygenated blood and deoxygenated blood

Characteristics Oxygenated blood

Deoxygenated blood

Content of oxygen

Colour

Gas

Rich Poor

Bright red Dark red

Oxygen Carbon dioxide

Path of blood flow in circulatory system.

• Humans have a double circulatory system.• This means blood passes through the heart

twice for one complete circulation in the body.

• The human circulatory system is divided into two sections:

1. The pulmonary circulation

2. The systemic circulation

Human circulatory system

The pulmonary circulation The systemic circulation

Arterial

• Oxygenated blood from the heart to other part of the body

venous

• deoxygenated blood from the heart to other part of the body

Role of blood in transport

• Transport oxygen-Oxygen is transported from the respiratory organ (lung) to the body tissues.

-The red blood cells transport oxygen to the body tissues where oxygen is used in cell respiration to release energy.

• Transport carbon dioxide-Carbon dioxide from respiring cells dissolves in the blood plasma. It is released into the alveoli and is excreted by the lungs.

• Transport digested food-Digested food such as glucose and amino acids diffuses into the capillaries and carried to the body cells.

• Remove excretory products and waste products-Excretory products such as carbon dioxide,urea,water are transported to specific organ for removal.

• Transport hormones

-Hormones which are secreted by the endocrine glands are transported to where they are needed.

• Distributes heat

-Heat produced locally is distributed to the whole body.

-This also helps maintain body temperature.

• 4) Distributes heat

Importance of a healthy heart

Why it is important to maintain a

healthy heart?????•An unhealthy heart may

causes various health problems which may lead to death.

Heart attack:

1.The heart will stop pumping blood.2.Blood will not reach critical organ like the brain

and the heart itself.3. If the heart muscles do not receives enough

blood within in a few minutes the cell in the area will die. This is fatal.

4. If the brain does not receive oxygenated blood, critical brain cells may die.This may cause coma or brain damage.

5.Toxic waste will quickly build up when blood stop flowing.

HEART ATTACKS

• Occur when the blood flow to a part of the heart is blocked, usually by a blood clot.

• If this clot cuts off the blood flow completely, the part of the heart muscle supplied by that artery begins to die.

b) STROKE and TIA (“mini-stroke”)

• happen when a blood vessel that feeds the brain gets clogged or bursts.

• Then that part of the brain can’t work and neither can the part of the body it controls.

1.List the importance to maintain a healthy heart.

2.List the risk factors that can trigger the heart attack.

3.List the ways to maintain a healthy heart.

• The importance to maintain a healthy heart.

Risk factors that can trigger the heart attack

• smoking

• high blood pressure

• too much fat in your diet/ obesity

• diabetes

• age,male

• hereditary

• poor blood cholesterol level.

The ways to maintain a healthy heart.

1. Avoid smoking

2. Reduce the intake of fatty foods.

3. Maintain a moderate body weight

4. Avoid drinking alcohol

5. Reduce mental and emotional stress.

Exercise 2.11. Name the four chambers of the human

heart and the blood vessel connected to each chamber.

2. State the difference in function between the vena cava and the pulmonary vein.

• the right atrium connected to the vena cava.

•The left atrium connected to the pulmonary vein

•The right ventricle connected to pulmonary artery

•The left ventricle connected to the aorta

The pulmonary vein transports oxygenated blood from the lungs to the right atrium whereas the vena cava transport deoxygenated blood from the body tissues to the right atrium.

3. List four substances which are transported by blood.

4. State four ways that can prevent heart disease.

1. Digested food

2. Excretory products

3. Respiratory gases

4. Hormones

1. Avoid smoking

2. Reducing the intake of fatty food.

3. Maintaining a moderate body weight

4. Avoid drinking alcohol

2.2 Human blood

• An adult human has about 5 litres of blood which is about 9% of his body weight.

• Blood is the main carrier of the body transport system.

• Carries nutrient and oxygen to the body cells.

• Transport carbon dioxide and waste products away from the cells.

• Fight diseases

• Helps to maintain a constant body temperature.

Blood constituents

Red blood cells

White blood cells

Plasma Platelets

Forms about 55% of the volume of bloodForms about 45% of

the volume of blood

Functions of blood constituents

1. Plasma

plasma

• a) It is light yellow in colour.

• b) 90% water and 10% dissolved substances.

c) Dissolved substances in plasma include

• mineral salts

• excretory products

• oxygen

• carbon dioxide.

• nutrients

d) Function

i) Medium for transport nutrient and oxygen

ii) Transport excretory products

iii) Transport other substances such as enzymes, hormones and antibodies.

iv) Helps to maintain the body temperature.

v) Fibrinogen is the plasma protein responsible for the clotting blood.

2. Red blood cells (erythrocytes)

• a) Colour: red

• b) Shape: biconcave

• c) No nucleus

• d) Contains haemoglobin (red pigment)

Red blood cells

• e) Function: Transport oxygen from the lung to the body cells.

• f) Produced in the bone marrow.

• g) Have a lifespan of about 4 months.

• h) Old red blood cells not function normally. These are destroyed in the liver and spleen.

3. White blood cells (leucocytes) • a) Larger than a red blood cells.• b) There are about 600 to 700 red blood

cells to one white blood cells.• c) Has no definite shape.• d) Has a nucleus,colourless,not contain

haemoglobin.

White blood cell

• e) Produced in the bone marrow, lymph nodes and spleen.

• f) These cells have lifespan of about few days.

• g) Old white blood cells are destroyed in the liver and spleen.

h) Function:

1.Protect the body against diseases.

2.Digest bacteria

3.Produce antibodies

4.Produce antitoxins to neutralise poisonous substances.

4. Platelets • a) Fragment of cell produced in

the bone marrow.• b) A platelets does not have any

nucleus.• c) Does not have a definite

shape.

• d) Platelets play an important role in the clotting of blood.

• e) They prevent excessive bleeding and initiate healing or repairing of the injury.

Blood group and compatibility

• Human blood can be classified into four main groups which are O,A,B and AB.

• Every individual belongs to a particular blood group.

• Blood transfusion is the transfer of blood from a donor to a recipient.

• In blood transfusions, the recipient’s blood must be compatible with the donor’s.

• If they are incompatible, blood cells will agglutinate. This may lead to death.

• A person with blood type O is known as a universal donor.

• This blood group is compatible with all other blood groups.

• It does not cause agglutination of the blood cells inside the blood vessels.

• A person with AB blood group is known as a universal recipient.

• He can receive blood from all the blood group, however he can only donate blood to people of blood group AB.

Compatibility blood transfusions between the four blood groups:

Blood group Can donate to Can receive from

A A, AB O, A

B B, AB O, B

AB AB O, A, B, AB

O O, A, B, AB O

The importance of blood donation• Blood donation does not bring us

any ill effects nor does it endanger our health.

• Our body produces and replaces blood very quickly.

• Therefore we should adopt a positive attitude towards blood donation.

Blood is needed in the following situation:

1.For major and minor surgeries

2.To replace blood lost due to accidents.

3.To make blood constituents like red blood cells, plasma and platelets.

4.For children suffering from thalassaemia (bleeding disorders).

5. For mother who encounter complications during childbirth.

6. For patient suffering from anaemia and leukaemia.

7. For victims who suffer burns on their body.

8. To help controls blood clots.

Storage and handling ofdonated blood

a) The donor is interviewed and

given medical counseling.

b) The donated blood is tested for

Hepatitis B, C and HIV.

• c) The blood sent to the hospitals where they are

stored in blood bank at 4°C.

• 4. Before the blood is used for transfusion, the bags are taken out and left at room temperature for two hours

5. There are two types of blood in the blood banks:

a) Fresh blood which can last for 24 hours.

b) Stored blood at 4°C which can last for about 40 days

Exercise 2.2

1. What is meant by blood?

2. State three functions of blood.

Blood is a tissue which consist of cells suspended in a liquid medium called plasma.

1. Transported digested food

2. Transported excretory product

3. Protects the body against diseases

3. How do white blood cells react to an attack by bacteria?

4. Complete the following table to show compatible blood transfusions.

The white blood cells will digest the bacteria and produce antitoxin to neutralise the toxins produced by bacteria.

Blood group Can donate blood to blood group

Can receive blood from blood group

O

A

O, A, B, AB O

A, AB O, A

How the leaves at the top of a tall tree obtain water necessary for photosynthesis???

2.3 Transport system in Plants

Transport tissues in plant

• 1. The transport system in plant helps transport substances to all part of the plant.

• 2. The transport system in plant consists of thin tubes called vascular bundles.

• 3. Vascular bundles found in the roots, stems and leaves.

• 4. Vascular bundles are made up of the phloem, xylem andcambium.

• 5) Xylem and phloem are two types of tissues that involve in the transport system of plant.

a) Xylem

• i) transport water and dissolved minerals from the roots to the stems and

leaves.

• ii) Long tubes.

• iii) Have a thick and strong walls which support the plant.

b) Phloem

• transport food from the leaves to the stems and roots

• 5. There are two types of tissues that are involved in the

transport system of plant.• 6. These are xylem and phloem. • 7. Both of xylem and phloem

tissues present in roots, stems and leaves.

Tissues involved in the transport system of plant:

Xylem

• transport water and dissolved minerals from the roots to the steams and leaves.

•Long tubes.

•Have a thick and strong walls which support the plant.

•Xylem walls contain lignin. Water cannot go through lignin because it is not permeable to water. This allow the xylem vessels to transport water efficiently.

Phloem

• transport food from the leaves to the steams and roots

STEM

ROOT

In the morning In the afternoon

What differences do you notice??

• The plant wilts.

• When a plant wilts there is not enough water inside the plant because it is losing more water than it is absorbing.

What are the process which a plant loses water???

Transpiration

Transpiration • 1. Transpiration is the process by

which a plant loses water in the form of water vapour from leaves to

the environment.

• 2. The water vapour passes out of the leaf through tiny pores called stomata in the epidermis.

• 3. A stoma is a tiny pore surrounded by a pair of cells known as a guard cells.

• 4. The opening and closing of the stomata are controlled by the guard cells.

• 5. More stomata are found on the lower side of the leaf compared to the upper side.

An open stoma:

• the stomata of plants are normally open during the day to allow the exchange of carbon dioxide and oxygen.

•Takes place during photosynthesis.

•Loss of water by transpiration.

A closed stoma:

• occurs at night.

•Photosynthesis does not take place.

•Slows down water loss.

Guard cells

Factors that affect the rate of transpiration• A potometer is used to measure the rate of

transpiration.• The rate of transpiration depends on the:Factors ` Rate of transpiration Reason

Humidity Increases with lower humidity

On dry days,there is less water vapour in the air.

Temperature Increase with an increase in temperature.

Rate of evaporation increases.

Light intensity Increases with greater light intensity

Evaporation of water through the open stomata increases.

Air movement Increases on windy days Moving air removes water vapour from the surface of the leaves.

The role of transpiration

1. Absorption and transport of water

2. Absorption and transport of mineral salts from the soil.

3. Removal of excess water.

4. Cooling of plant

5. Exchange of gases

1. Absorption and transport of water

• Enable water to be transported from the root and steam to the leaves.

• This enables all cells in the plant to be active and to remain in a state of turgidity.

• This flow of water is continuous and is called the transpirational stream.

2. Absorption and transport of mineral salts from the soil.

• Water in the soil contains dissolved minerals salts.

• During transpiration,the minerals salts present in the soil are absorbed by the roots and transported up the stems and to the leaves.

3. Removal of excess water.• Transpiration thus helps to get rid of the

excess water from the plant. 4. Cooling of plant• Transpiration has a cooling effect on

plants.• As the water from the transpiration

evaporates, heat from the plant is used up.This cools the plant.

5. Exchange of gases• Carbon dioxide is needed for

photosynthesis.During transpiration,the opening of stomata allows carbon dioxide from athmosphere to diffuse inside the leaf.

• Oxygen which is produced during photosynthesis diffuses out into the athmosphere through the stomata.

Exercise 2.3

1. Name the structure P and Q.State one function of P and Q.

PQ

P is guard cells which controls the size of the stoma.

Q is stoma which allow water vapour from the leaf to escape to the athmosphere during transpiration.

2. What is the meaning of transpiration.

3. Give two reason why transpiration is important to plant.

4. State four factors which affect the rate of transpiration.

Transpiration is the process by which plant lose water in the form of water vapour from its leaves to the environment

• helps the plant to absorb water containing dissolved

minerals.

• get rid of excess water from the plant.

1. Humidity

2. Temperature

3. Light intensity

4. Movement of air