chapter 2 : blood circulation & transport2.1 !: !transport system in human! detailed structure...
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CHAPTER 2 : BLOOD CIRCULATION & TRANSPORT 2.1 : Transport
System in� Human �
2.2 : Human blood�2.3 : Transport
System in Plants �
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human General 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 Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Detailed 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 ?
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Detailed 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 ?
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Detailed Structure of the Human Heart
• Each ventricle & atrium is linked to one big blood vessel v Left atrium –
pulmonary vein v Right atrium –
vena cava v Left ventricle –
aorta v Right ventricle –
pulmonary artery
Pulmonary artery
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Detailed Structure of the Human Heart
• The one-way flow of blood in the heart is controlled by three types of valves v Bicuspid valve (mitra
valve) – controls blood from left atrium to left ventricle
v Tricuspid valve – controls blood from right atrium to right ventricle
v Semilunar valve – controls blood from ² left ventricle to
aorta ² right ventricle to
pulmonary artery
Bicuspid valve
Semilunar valve
Tricuspid valve
Semilunar valve
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Functions 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
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Functions 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
Prepared by Ms Sue Soh Ya Lee
Aorta
Pulmonary artery
Pulmonary veins
Left atrium
Bicuspid valve
Left ventricle
Semilunar valve
Septum Inferior vena cava Right ventricle
Tricuspid valve
Right atrium
Pulmonary veins
Semilunar valve
Superior Vena cava
From le( lung
To le( lung
From body
From right lung
To right lung
From body
To body
1 �
1 �2
3
4
5
6
67
8
9
10 �
11 �
12 �
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Pathway 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)
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types 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 Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types of Blood Vessels
• There are 3 types of blood vessels : – Artery – Vein – Capillary
• As blood is pumped out of the heart, it travels through arteries, veins and capillaries
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types 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 Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types of Blood Vessels
ARTERY • The artery wall is
thick, elastic and muscular to withstand high blood pressure
• Arteries don’t have valves except pulmonary artery and aorta
• Arteries which branch into smaller blood vessels are known as arterioles
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types 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
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types 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
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types 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
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human Types 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
Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human The 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 Prepared by Ms Sue Soh Ya Lee
2.1 : Transport System in Human The 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 Prepared by Ms Sue Soh Ya Lee
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