f3---notes-2.1

CHAPTER 2 : BLOOD CIRCULATION & TRANSPORT2.1 : Transport

System in Human

2.2 : Human blood2.3 : Transport

System in Plants

2.1 : Transport System in HumanGeneral Structure of the Human Heart

Human heart is located inside the thoracic cavity, behind the breastbone & between the left and right lung

Cone-shaped and tilts slightly towards the left side of our body

Has a mass of about 300g & is built of thick and strong cardiac muscles

Entire heart is covered with a long lasting membrane

The space between the heart and the membrane is filled with fluid to reduce friction between the heart and other organs next to it

2.1 : Transport System in HumanDetailed Structure of the Human Heart

There are four muscular chambers Left side : left

atrium, left ventricle

Right side : Right atrium, right ventricle

Septum separates the left and right chambers WHY ?

2.1 : Transport System in HumanDetailed Structure of the Human Heart

VENTRICLES Has a larger

volume of space than the atrium

Has a thicker wall than the atrium

Left ventricle is thicker and more muscular than the right ventricle WHY ?

2.1 : Transport System in HumanDetailed Structure of the Human Heart

Each ventricle & atrium is linked to one big blood vesselvLeft atrium

pulmonary veinvRight atrium

vena cavavLeft ventricle

aortavRight ventricle

pulmonary artery

Pulmonary artery

2.1 : Transport System in HumanDetailed Structure of the Human Heart

The one-way flow of blood in the heart is controlled by three types of valvesvBicuspid valve (mitra

valve) controls blood from left atrium to left ventricle

vTricuspid valve controls blood from right atrium to right ventricle

vSemilunar valve controls blood fromleft ventricle to

aortaright ventricle to

pulmonary artery

Bicuspid valve

Semilunar valve

Tricuspid valve

Semilunar valve

2.1 : Transport System in HumanFunctions of the Heart

Functions as a strong muscular pump to collect :- Deoxygenated

blood from the rest of the body is pumped to the lungs

Oxygenated blood from the lungs is pumped throughout the body

2.1 : Transport System in HumanFunctions of the Heart

Functions to circulate and transport :- Nutrients &

oxygen to the body cells

Excretory products (C02, urea & water) from the body cells to be removed from the body

Aorta

Pulmonary artery

Pulmonary veins

Left atrium

Bicuspid valve

Left ventricle

Semilunar valve

Septum

Aorta

Right ventricle

Tricuspid valve

Right atrium

Pulmonary veins

Semilunar valve

Vena cava

From le( lung

To le( lung

To body

From right lung

To right lung

From body

To body

1

1 2

3

4

5

6

67

8

9

10

11

12

2.1 : Transport System in HumanPathway of Blood Circulation

Vena cava

Right Atrium

Tricuspid valve

Right ventricle

Semilunar valve

Pulmonary artery Lungs

Pulmonary veins

Left atrium

Bicuspid valve

Left ventricle

Semilunar valve

Aorta (Whole body)

2.1 : Transport System in HumanTypes of Blood Vessels

Each blood vessel has lumen the tract that allows blood to flow in the blood vessel

Lumen is important because the size of lumen affects the blood flow in the blood vessels Narrow lumen will be

an obstacle to the blood flow blood flows faster & under high pressure

Wide lumen provides less resistance to the blood flow blood flows more slowly & under low pressure

2.1 : Transport System in HumanTypes of Blood Vessels

There are 3 types of blood vessels :ArteryVeinCapillary

As blood is pumped out of the heart, it travels through arteries, veins and capillaries

2.1 : Transport System in HumanTypes of Blood Vessels

ARTERY Carries blood out of

the heart Aorta : artery that

carries blood from left ventricle of the heart

Pulmonary artery : artery that carries blood from the right ventricle to the lung

Carries oxygenated blood except pulmonary artery

Has narrow lumen

2.1 : Transport System in HumanTypes of Blood Vessels

ARTERY The artery wall is

thick, elastic and muscular to withstand high blood pressure

Arteries dont have valves except pulmonary artery and aorta

Arteries which branch into smaller blood vessels are known as arterioles

2.1 : Transport System in HumanTypes of Blood Vessels

VEIN The blood vessel

that carries blood into the heart Vena cava :

transports blood to the right atrium of the heart

Pulmonary vein : transports blood from the lung to the left atrium

Transport deoxygenated blood except pulmonary vein

2.1 : Transport System in HumanTypes of Blood Vessels

VEIN Have wide lumen

blood flow is slow and under low pressure

The wall is thin & less muscular

Have semilunar valves to ensure one-way of blood flow

Branch into smaller vessels called venules

2.1 : Transport System in HumanTypes of Blood Vessels

CAPILLARY Joins the artery to

the vein The narrowest

blood vessel Carries a

combination of oxygenated & deoxygenated blood

Its wall is very fine : one-celled thick enables the exchange of gases & nutrients between blood & body cells

Vein

Artery Capillary

2.1 : Transport System in HumanTypes of Blood Vessels

CAPILLARY Blood flow is very slow and under low

pressure so that exchange of substance can take place more efficiently

Does not have any valves

2.1 : Transport System in HumanThe Human Blood Ciculatory System

Heart is at the centre of the human circulatory system

Blood circulation in the body happens due to the pumping action of our heart

Human blood circulation is completed through 2 stages :- Pulmonary

circulation Systemic

circulation

2.1 : Transport System in HumanThe Human Blood Ciculatory System

Both stages cause the blood to flow twice through the heart

Complete pulmonary circulation is the to-and-fro circulation from the heart to the lung

Pulmonary circulation alternates with the systemic circulation to complete the circulation around the body