BLOOD CIRCULATION AND TRANSPORT

CHAPTER 2

2.1Transport System In Humans

1. Human transport system called the blood circulatory system, to transport substances around the body.

2. The blood circulatory system is made up of the heart, blood vessels and blood.

Structure of the Human Heart

1. A thick wall of tissue divides the human heart into right and left halves.

2. Each half of the heart divided into two chambers.

3. The upper chambers is called the atrium and lower chamber called ventricle.

4. The atrium and ventricles are separated by valves which prevent the backflow of blood from the ventricles to the atrium.

5. The chambers of the heart are connected to the vena cava, pulmonary artery, pulmonary vein and aorta

Function of the Heart

1. Pump the blood to all the parts the body.

2. The right side of the heart pumps blood which has less oxygen to the lungs.

3. The left side of the heart pumps oxygenated blood to all parts of body.

4. The human heart pumps by contracting and relaxing its muscles at the same time.

a) When the heart relaxes, blood flows into the two atrium of the heart through the pulmonary veins.

b) When the atrium contract, they push the blood through the valves into the ventricles

c) When the ventricles contract , they push the blood out of the heart to other parts of the body through the pulmonary artery and aorta.

c) One complete contraction and relaxation of the heart is called a heartbeat.

Blood Vessels

Arteries

1. Carry oxygenated blood away from the heart to all part of body. (except pulmonary artery)

2. The walls thick and elastic.3. High pressure pump from heart.4. Very small Lumen.

Veins

1. Carry deoxygenated blood back to the heart. (except pulmonary vein)

2. Have thinner and less muscular walls

3. Bigger Lumen than arteries.

4. Have valves to ensure the one way flow of blood back to the heart.

Capillaries

1. Tiny blood vessels found inside organs and tissue.

2. Have very small Lumen

3. Very thin walls.

4. Carries both type of blood.

5. Capillaries join up to form larger blood vessels called veins.

6. Cells absorb oxygen and digested food from the blood and release carbon dioxide and waste product into the blood.

Blood

Blood transport a oxygen, carbon dioxide, digested food, urea and hormones.

Carbon dioxide is carried in plasma from all part of body to lungs.

Digested food is carried in plasma from the small intestine to the liver and all part of body.

Urea is carried in plasma from the liver to the kidneys for excretion.

Hormones are carried in plasma from the glands to target organs.

Path of Blood Flow in the Blood Circulatory System

2.2 HUMAN BLOOD

1. Plasma2. Red Blood Cells3. White Blood Cells4. Platelets

1. Plasma a. Consist 90% water and 10%

dissolved substances.b. Function of plasma is to carry

dissolved substances and heat around the body.

2. Red Blood Cells

a. RBC contain a red pigment called haemoglobin.

b. Have biconcave disc shape.c. Do not have nuclei.d. To transport oxygen to all parts of

the body.

3. White Blood Cells

a. Larger than red blood cellsb. Irregular in shape and have nucleic. Less than the number of red blood

cellsd. The function is to fight infections by

killing microorganism.

4. Platelets

a. Not a cells b. Do not have nucleic. Very small pieces d. Irregular smaller than rbc and wbce. The function is help in blood clotting

to stop bleeding.

Human Blood Group

A universal donor can donate blood to everyone.

A universal recipient can receive blood from anyone.

Donar’s blood group

Recipient’s Blood group

A B AB O

A / X / X

B X / / X

AB X X / X

O / / / /

Blood Donation1. Weight 50 kg and age between 17

to 60 can donate2. Up to 0.5 litres of blood at one time

How donated blood is stored and handled?

1. Blood is taken from a vein in the arm.

2. Blood is collected in a sterilised bag containing Sodium Citrate to prevents clotting of the blood.

3. Donator blood is stored in a refrigerator at 5ºC for 10 days or longer if glucose is added.

4. Before blood is transfused it tested against the recipient’s blood.

5. The blood is transfused through a vein at the arm at the correct rate and temperature.

2.3 TRANSPORT SYSTEM IN PLANTS

Soil lack of water. Rate of water loss faster than rate of

absorption.

Transpiration

1. Water is lost in the form of water vapour from the surface of a plant into the air by evaporation.

2. Leaf consist of a single layer of epidermal cells that cover both the upper and lower surfaces of the leaf.

3. Epidermal cell secrete a waxy cuticle covering the outer surface of the leaf that will reduce water loss during transpiration.

4. Water loss takes place through the stomata.

5. The cells that control the opening and closing

of a stomata are called guard cells.

6. Water vapour is lost through stomata.

7. Oxygen and Carbon dioxide diffuse in and

out through the stomata during

Photosynthesis and Respiration.

Rate of Transpirati

on

Number of

stomata

Light Intensit

y

Temperature

Humidity

Wind

Rate of Transpiration

1. The number of stomata in plant affect the rate of

transpiration.

2. A plant can transpire faster if it has a larger number of

stomata.

3. Also affected by light intensity, temperature,

humidity and wind.

4. To estimate the transpiration rate of a plant is to

measure its loss in weight using a weight

potometer.

Important Roles of Transpiration

1. When water evaporate from leaves a large amount of heat energy is lost.

2. Produce a cooling effect on the leaves help plant to withstand high temperatures.

3. Transpiration helps in the transportation of water and minerals salts in plant.

4. During transpiration absorbed water and dissolved mineral salts sucked up from the roots, up the stem and then to its leaves.

Flowering plants

1. Transport system consist of two conducting tissue, the Xylem and the Phloem.

2. The Xylem transport water and mineral salts from the roots to the leaves for Photosynthesis and to replace water lost during transpiration.

3. The Phloem transport food produced in the leaves by photosynthesis to other parts of the plants.

4. The xylem and phloem are often found together in flowering plants as a group of tubes called Vascular Bundle.