CHAPTER 2BLOOD CIRCULATION AND TRANSPORT

• VIDEO 1

1. The transport system in humans is called circulatory system.

2. Circulatory system is made up of heart, blood and blood vessels.

Structure of the human heart1. A muscular, cone-shaped organ.2. Located in the chest cavity between the lungs.3. The size of fist.4. Made up of cardiac muscles5. Has 4 chambers: upper chambers (right atrium, left

atrium), lower chambers (right ventricle, left ventricle)

2.1 The Transport System in Humans

Function of The Heart

The function of the heart is to pump blood to all parts of the body.

Function of the Heart1. The right side of the heart

pumps blood to the lungs.2. The left side heart-pumps

blood to the other parts of the body.

3. The heart pumps blood by contracting and relaxing its muscles.

4. The contractions can be heard as heartbeat.

a) Blood flows into the two atria through the veins.

b) The atria contract and push blood through the valves into the ventricles.

c) The ventricles contract and force the blood through the arteries.

d) The valves are closed to prevent blood flowing back into the atria.

Function of the Heart

Blood Vessels and Their Functions• There are 3 types of blood vessels.• Arteries• Veins• Capillaries

Differences in characteristics of blood vessels

Characteristics Arteries Veins Capillaries

Carry blood Away from the heart

Towards the heart

From arteries to veins

Blood pressure High Low Very low

Type of blood carried (function)

Oxygenated

(except pulmonary artery)

Deoxygenated

(except pulmonary vein)

Exchanging

nutrients and gases with cells

Structure of wall Thick and muscular with elastic fibres

Thin, less muscular and less elastic

One cell thick

Path of blood flow in circulatory system

1. Human have a double circulatory system.

2. Blood passes through the heart

twice as it circulates in the body.

Path of blood flow Path 1: from the heart to the lungs and back again to the heart

•The right atrium receives deoxygenated blood from different parts of the body •and pushes it into the right ventricle•The right side of the heart then pumps blood to the lungs to collect oxygen and remove carbon dioxide.

Path 2: From the heart to the rest of the body and back again to the heart

•The oxygenated blood returns to the left atrium and flows into the left ventricle.

•Then the left side of the heart pumps blood to the rest of the body to supply oxygen to the cells and to collect carbon dioxide.

Path of blood flow

Importance of a healthy heart • Heart is a very

important organ.• An unhealthy heart

leads to problems.• Coronary heart disease• Heart attack• High blood pressure• Stroke

2.2 Human Blood• Adult human has ± 5 litres of blood (9% of

body weight).• Blood carries nutrients and oxygen to the

body cells and transports carbon dioxide and waste products away from the cells.

• Fight diseases.• Helps to maintain a constant body

temperature.

Blood constituents and their functions

Blood constituents and their functionsCharacteristics Red blood cell White

blood cellPlatelets

Nucleus content No Yes No

Shape Biconcave Irregular Small fragments(ser-pihan) of cells made in the bone narrow

Function Carry oxygen (oxyhaemoglobin)

Protect body against diseases & fight infections

Help in blood clottting

Blood performs the following functions

1. A transport medium that carries gases and dissolved substances from one part of the body to another.

2. Red blood cells carry oxygen3. Blood plasma carries dissolved substances4. White blood cells protect against diseases5. Blood maintains the body temperature at

37ºC.

Blood GroupBlood group

Can donate blood to

Can receive blood from

A A and AB

A and O

B B and AB

B and O

AB AB A, B, AB and O

O A, B, AB and O

O

• Blood group O is known as universal donor.

• Blood group AB is known as universal recipient.

• A healthy person can donate blood every 56 days or about 4 to 6 times per year.

• Blood is needed during• Surgery• Childbirth• Cancer treatment

2.3 Transport System in PlantsLEARNING OUTCOMES

describe how wilting occurs,describe what transpiration is,describe the functions of stomata,identify the factors affecting the rate of transpiration,describe how the factors affect the rate of transpiration,describe the roles of transpiration,investigate the pathway of water in a cut stem using a suitable stains,identify the locations of xylem and phloem,describe the functions of xylem and phloem.

Lesson 11

2.3 Transport System in Plants1. Why a plant wilt? Because it losing more water than it is absorbing from the soil, hence there is not enough water inside the plant.

Lesson 11

2. What is transpiration? The process by which a plant loses water in the form of water vapour, from its leaves to the environment.

Lesson 12

3. Flow path of transpiration process ground Root Stem Leaves environment

2.3 Transport System in Plants4. How the water vapour passes out of the leaf? Through tiny pores called stomata. 5. What is stoma (singular for stomata)? A tiny pore between a pair of cells known as guard cells.6. What is the function of the cells (guard cell)? Control the opening and closing of the stoma. Water vapour is lost through the stoma. Gases like Carbon Dioxide and Oxygen diffuse in and out of the leaf through the stoma during photosynthesis and transpiration.

• An open stoma• normally open during the day

to allow the exchange the carbon dioxide and oxygen (during photosynthesis)

• Also results in the loss of water by transpiration

• A closed stoma• May be closed on a hot day to

reduce the loss of water by transpiration

2.3 Transport System in Plants

Lesson 12 : Function

2.3 Transport System in Plants

2.3 Transport System in PlantsFunction of Transpiration1.Helps roots to absorb water and minerals from soil.2.Helps plants to keep cool especially during hot days through the evaporation of water.3.Allows the exchange of gases during photosynthesis and respiration.

Lesson 13: Factors

2.3 Transport System in Plants

Lesson 14: Transport Tissues in Plants

2.3 Transport System in Plants

1. TWO types of tissue that are involved in the transport system in plants.i. Xylemii. Phloem

2. Functions 1. Xylem- carry water and dissolved minerals absorbed in

the roots stems leaves2. Phloem-carry glucose (produced during photosynthesis)

from leaves to all parts of plants

Transport Tissue in Plants

Vascular bundle