Cardiovascular System

Noadswood Science, 2012

Cardiovascular System

To know the pathway of oxygen through the circulatory system

Wednesday, April 19, 2023

Pathway

Have a look at the following anagrams - merit for the first to get them all (written down)!

– Threa– Reeisart– Pillaarisce– Sinev– Nxyoge– Boncar Ddiioxe– Bicroeana– Tionaripser– Bicroea– Threabngi

HeartArteriesCapillariesVeinsOxygenCarbon DioxideAnaerobicRespirationAerobicBreathing

Circulation

What is the function of the circulatory system? What does it transport?

The circulatory system is the body's main transport system, carrying food and oxygen to the cells and taking waste products (carbon dioxide) away

It consists of the heart; arteries; veins; and capillaries

Circulatory System

Oxygen

Oxygen is initially absorbed into the blood within the lungs (via diffusion)

It will now travel through a variety of systems in order to get to the cell, where it is needed for respiration

Traveling

Blood travels through three types of vessel - arteries, veins and capillaries with have specific properties: -

– Arteries are thick-walled muscular tubes which carry blood away from the heart - fast flowing!

– Veins are thin walled tubes which carry blood back to the heart – they have a large diameter and valves as the blood flows slower

– Capillaries are extremely narrow tubes which carry blood through our tissues: their walls are just one cell thick - so thin that oxygen, food and waste products can easily pass through them

Blood Vessels – Artery

thick outer wall

thick inner layer of muscle and elastic fibres

narrow central tube (lumen)

Arteries are thick-walled muscular tubes which carry blood away from the heart - fast flowing!

Blood Vessels – Veins

Veins are thin walled tubes which carry blood back to the heart – they have a large diameter and valves as the blood flows slower

thin outer wall

thin inner layer of muscle and elastic fibres

wide central tube (lumen)

Blood Vessels – Capillaries

Capillaries are extremely narrow tubes which carry blood through our tissues: their walls are just one cell thick - so thin that oxygen, food and waste products can easily pass through them

wall only one cell thick

Blood Vessels

blood from the heart

blood to the heart

carries blood to and from the body’s cells

Artery

Carries blood away

from the heart

Vein

Carries blood back

into the heart

Blood

Blood is a liquid tissue whose function is to fight disease and to transport materials around the body

Blood plasma (liquid) containing glucose, amino acids, nutrients, hormones, as well as waste materials like urea Red blood cells contain haemoglobin, a protein which picks up oxygen molecules in the lungs White blood cells fight disease by making antibodies and fighting germs Platelets are cell fragments. Together with fibrinogen they form clots to repair cuts or tears in nearby tissue

Blood Plasma

Blood plasma is the liquid which carries everything in the blood (a pale straw-coloured liquid)

Red and white blood cells; nutrients such as amino acids and glucose; carbon dioxide; urea; hormones; antibodies and antitoxins are all carried in the blood plasma

Red Blood Cells

Red blood cells carry oxygen from the lungs to all the cells in the body – they have a doughnut shape to maximise their surface area and they contain no nucleus at maturity

They contain the red pigment haemoglobin which combines with oxygen at the lungs (becoming oxyhaemoglobin)

In body tissues the oxygen and haemoglobin split (which releases the oxygen to the cells)

White Blood Cells

White blood cells defend against disease – they can change shape to consume unwelcome microorganisms (they do contain a nucleus)

White blood cells also produce antibodies to fight microorganisms and antitoxins to neutralise any toxins produced by harmful microorganisms

Platelets

Platelets are small fragments of cell and have no nucleus

They help the blood to clot at a wound stopping blood loss (and microorganisms entering)

A lack of platelets can cause excessive bleeding and bruising

Heart

What do you know about our heart? How does it work? How is it specialised?

The heart pumps blood around the body – in humans this is a four chambered pump

The right side of the heart pumps deoxygenated blood to the lungs to pick up oxygen

The left side of the heart pumps the oxygenated blood from the lungs around the rest of the body (which is why it is more muscular)

Heart

The right side of the heart pumps deoxygenated blood to the lungs to pick up oxygen

The left side of the heart pumps the oxygenated blood from the lungs around the rest of the body (which is why it is more muscular)

Heart

body’scells

lungsOxygenated blood

returns to the heart through the pulmonary vein

Oxygenated blood is pumped at high pressure from the heart to the body through the aorta

Deoxygenated blood returns to the heart through the

vena cava

Deoxygenated blood is pumped from the heart to the lungs

through the pulmonary artery

Double Circulation

The pulmonary circulation carries: -– Deoxygenated blood from the heart to

the lungs– Oxygenated blood back from the lungs

to the heart, ready to be pumped out to the body

lungs

The systemic circulation carries: -– Oxygenated blood to the rest of the

body through the arteries– Deoxygenated blood back to the heart

through the veins body’scells

Cells

Oxygen and glucose leak out of the capillaries and the cells close by absorb the required oxygen and glucose

The waste products (including carbon dioxide) pass out of the cells and into this fluid, that is then re-absorbed by the blood

Capillaries do not join up to every cell - instead fluid is passed out of them, with cells close by absorbing what they need

Summary

Oxygen enters the body in the lungs, via breathing

It is absorbed into the blood, where it passes through the heart and then throughout the body (via the circulatory system)

It travels through arteries, veins and capillaries

Cells and blood exchange materials in the fluid, which is released adjacent to the capillaries

The cells then use this oxygen for respiration

Stents

Stents keep arteries open (tubes inserted inside arteries keeping them opening allowing blood to pass)

Stents lower the risk of a heart attack, especially for individuals who suffer coronary heart disease (fatty deposits blocking the blood supply to the heart)

Worksheet

Match the circulatory key words with their function

Worksheet

Complete the circulatory system worksheet

Arteries

Heart

Veins

Capillaries

One cell thick

Donation

Donation