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Chapter 15: Animal Transport and exchange systems Unit 2: Multicellular Organisms Chapter 15: Animal Transport and exchange systems Lesson 1: Mammalian circulatory system: HEART 26/04/2017 Mrs Smith - National 5 Biology
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Chapter 15: Animal Transport and exchange systems
Unit 2: Multicellular Organisms Chapter 15: Animal Transport and
exchange systems 26/04/2017 Mrs Smith -National 5 Biology Chapter
15: Animal Transport and exchange systems
Unit 2: Multicellular Organisms Chapter 15: Animal Transport and
exchange systems Lesson 1: Mammalian circulatory system: HEART
26/04/2017 Mrs Smith -National 5 Biology Learning Intentions:
Animal Transport
By the end of this chapter you should: Be able to demonstrate the
pathway of oxygenated and deoxygenated blood through heart, lungs
and body. Describe the heart structure to include right and left
atria and ventricles and location and function of valves (you DO
NOT NEED valve names). Blood vessels to include: aorta, vena cava,
pulmonary arteries and veins. 26/04/2017 Mrs Smith -National 5
Biology Mrs Smith - National 5 Biology
Introduction A large multicellular organism has a small surface
area in relation to its volume. (See Torrance. ch14 pg111).
Therefore it needs additional absorbing areas to take in oxygen and
food. 26/04/2017 Mrs Smith -National 5 Biology The need for
additional absorbing areas in humans
Humans have for example Alveoli in the lungs Villi in the intestine
These greatly increase the surface area for the absorption of
oxygen and digested food respectively 26/04/2017 Mrs Smith
-National 5 Biology The need for a circulatory system
Once the essential substances have entered the animals body, they
must be carried to all of its living cells at a faster rate than is
possible by diffusion. In mammals, this rapid transport of
essential materials is achieved by an animals circulatory system.
26/04/2017 Mrs Smith -National 5 Biology Mammalian circulatory
system
The circulatory system consists of the Heart (a muscular pump)
Blood vessels (a system of tubes) These carry blood to all parts of
the body. Nutrients, oxygen, carbon dioxide and hormones are
transported in the body. 26/04/2017 Mrs Smith -National 5 Biology
Mrs Smith - National 5 Biology
The Heart The heart is a muscular pump located in the centre of our
chest. Its job is to pump blood all around the body. Group Task
Study this diagram of a section through a human heart. Try and work
out How many chambers (large spaces) there are in the heart? Why
one side is coloured blue and one side coloured red? Why one side
has a thicker wall than the other side? 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
The Heart - Chambers The heart is divided into two separate sides.
Each side has 2 hollow chambers - an atrium and a ventricle. The
upper chambers are the right and left atria these collect blood.
The lower chambers are the right and left ventricles, these pump
blood. The wall of the heart is made of cardiac muscle. The diagram
shows the 4 chambers viewed from the front of a person. The right
hand side of a person is therefore on the left of the diagram and
vice versa. 26/04/2017 Mrs Smith -National 5 Biology The function
of veins and arteries.
We will look at their structure later! Veins carry blood into the
heart while arteries carry blood away from the heart. The veins
carry blood into the atria while the arteries carry blood away from
the ventricles. vein Pulmonary vein artery Pulmonary Artery artery
vein Aorta Vena cava 26/04/2017 Mrs Smith -National 5 Biology Mrs
Smith - National 5 Biology
Blood flow This diagram shows the path taken by blood as it flows
through the heart and its associated vessels. Lets look at it in
more detail. 26/04/2017 Mrs Smith -National 5 Biology Blood flow
and associated vessels
Our blood flows through three different types of blood vessels is
shown below. VEIN HEART ARTERY CAPILLARIES 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
Flow of blood: Summary The flow of blood from the LV back to the
LV... As follows. LV> aorta> body> vena cava> RA>
RV> pulmonary artery> lungs> pulmonary vein> LA> LV.
Pulmonary Artery Pulmonary vein Aorta Vena cava 26/04/2017 Mrs
Smith -National 5 Biology Blood flow In more detail
Blood passes through the heart twice(each time it passes around the
body also called double circulation). The blood firstly is pumped
to the lungs where it picks up oxygen, becoming oxygenated. The
blood is then pumped around the body where respiring cells remove
the oxygen. This deoxygenates the blood. The blood vessels that
carry deoxygenated blood to the lungs are pulmonary arteries, while
pulmonary veins return oxygenated blood to the heart. The artery
that carries oxygenated blood away from the heart and around the
body is the aorta. The vena cava is the vein that returns
deoxygenated blood to the heart from the body. 26/04/2017 Mrs Smith
-National 5 Biology Rob the Red Blood Cells Journey!
Rob is a new red blood cell and needs direction about where hes
going and what will happen to him on his journey around the body.
Can you help advise him? ? 26/04/2017 Mrs Smith -National 5 Biology
Mrs Smith - National 5 Biology
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
Review Questions Where did Rob pick up Oxygen? Where did Rob take
it to? Why did Rob change colour? What things would be floating
around Rob in the blood? What other cells are there in the blood
with 26/04/2017 Mrs Smith -National 5 Biology Thickness of
ventricle walls
The muscle wall of the left ventricle is THICKER than the right
ventricle. This is because the left ventricle has to pump blood
right round the body, whereas the right ventricle only has to pump
blood to the lungs. (which are right next to the heart). 26/04/2017
Mrs Smith -National 5 Biology Mrs Smith - National 5 Biology
The Heart - Valves The heart has four valves in it. The job of the
valves is to keep blood flowing in one direction through the heart.
The valves stop the blood flowing backwards within the heart. Valve
4 Valve 3 Valve 2 Valve 1 26/04/2017 Mrs Smith -National 5 Biology
Mrs Smith - National 5 Biology
The Heart Valves 1 and 2 Valves 1 and 2 are situated between the
atria and the ventricles. When they open, blood passes from the
atria into the ventricles. When the ventricles contract, the blood,
under pressure closes valves 1 and 2. This prevents blood flowing
back into the atria. 26/04/2017 Mrs Smith -National 5 Biology Mrs
Smith - National 5 Biology
The Heart Valves 3 and 4 Valves 3 and 4 are situated between the
ventricles and the two arteries that leave the heart. Once blood
has been pumped through valves 3 and 4 they close, preventing
backflow of blood from arteries into ventricles. Blood is therefore
only able to travel in one direction through the heart. 26/04/2017
Mrs Smith -National 5 Biology Our heart beat is caused by the valve
opening and closing
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
Heart valve disease If one or more valves arediseasedor damaged, it
can affect howblood flows through the heartin two ways: If your
valve does not open fully, it will obstruct the flow of blood. If
the valve does not close properly, it will allow blood to leak
backwards. People with heart valve disease may be advised to have
surgery on your valve, which can greatly improve the symptoms and
quality of life. 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith
- National 5 Biology
Heart valve surgery There aretwo options for valve surgery: valve
repair and valve replacement. Valve repairis often used for mitral
valves that become floppy and leak but are not seriously damaged.
Valve replacementis whenthe diseased valve is replaced with a new
valve. The most common types of replacement valves are mechanical
(artificial) valves or tissue (animal) valves. 26/04/2017 Mrs Smith
-National 5 Biology Consolidation exercise: The Heart
Individual task - collect the diagram which represents a section
through a human heart and stick it into the middle of a page in
your jotter. Now see if you can complete and label the diagram by -
naming the four chambers. drawing and shading in themuscular walls
of each ventricle. indicating the positions of the four valves.
naming the four blood vessels associated with the heart. drawing
arrows to show the flow of blood through the heart. colouring the
correct side of the heart blue and the other side red. indicating
what the red and blue colours represent. 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
The Heart: Watch this Watch the following video clip about the
human heart. Heart : Twig 26/04/2017 Mrs Smith -National 5 Biology
Chapter 15: Animal Transport and exchange systems
Unit 2: Multicellular Organisms Chapter 15: Animal Transport and
exchange systems Lesson 2: Mammalian circulatory system: BLOOD
VESSELS 26/04/2017 Mrs Smith -National 5 Biology Learning
Intentions: The vessels associated with the heart
By the end of this chapter you should: Be able to compare the
structure and function of arteries, veins and capillaries.
Specifically that Arteries have thick, muscular walls, a narrow
central channel and carry blood under high pressure away from the
heart. Veins carry blood under low pressure; have thinner walls and
a wide channel. Veins contain valves to prevent backflow of blood
and carry blood towards the heart. Capillaries form networks at
organs and tissues, are thin walled and have a large surface area,
allowing exchange of materials. Describe coronary arteries and
their function. 26/04/2017 Mrs Smith -National 5 Biology There are
three types of blood vessels
26/04/2017 Mrs Smith -National 5 Biology Task: Comparing Arteries
and Veins
Artery Vein Group Task Study these diagrams of an artery and a
vein. Stick copies into your notes. Describe three differences in
the structure of arteries and veins. Decide in which blood vessel
the pressure will be highest. Give a reason for your choice.
26/04/2017 Mrs Smith -National 5 Biology Comparing Arteries and
Veins
ANSWER: Comparing Arteries and Veins Blood Vessels Arteries have
thick, muscular walls and a narrow central channel. Veins have
thinner walls and a wide channel. They also contain valves to
prevent the backflow of blood. Arteries carry blood at high
pressure AWAY from the heart. Veins carry blood under low pressure
back to the heart. Vein Artery Individual Task Study your wrists.
Are the blood vessels that you can see near the surface, arteries
or veins? Can you find your pulse in your wrist? What do you think
your pulse actually is? 26/04/2017 Mrs Smith -National 5 Biology
Mrs Smith - National 5 Biology
What is a pulse? Each time the heart beats, blood is forced along
the arteries at high pressure and this pressure wave can be felt as
a pulse beat. 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith -
National 5 Biology
Capillaries fun facts There are an estimated 10 billion
capillaries, measuring approximately 25,000 miles, in the average
human body. Each capillary has a length of about 1.1 millimeter.
Most capillaries are little more than a single cell layer thick.
Capillaries are the smallest and most numerous vessels in the body
through which blood flows. The thin capillary wall helps to
increase the exchange of materials between cells in the tissue and
the blood. While a person is resting, approximately 5% of the blood
circulating is in the capillaries, 26/04/2017 Mrs Smith -National 5
Biology Mrs Smith - National 5 Biology
Capillary networks 26/04/2017 Mrs Smith -National 5 Biology Mrs
Smith - National 5 Biology
Capillaries An artery divides into smaller vessels and finally into
a densenetwork of tiny, thin walled capillaries. Capillaries are
the most numerous type of blood vessel in the body. They present a
large surface area and are in close contact with all living cells
in tissues and organs. This diagram shows the network of
capillaries spreading through the skin in a fingertip. The larger
blood vessels are small arteries which carry the blood to the
capillaries. Individual Task Press on the tip of your fingernail
and watch what happens. Can you explain the change in colour that
occurs. 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith -
National 5 Biology
Capillaries cont Capillaries are often referred to as exchange
vessels since all exchanges of materials between blood and living
tissue takes place through their thin walls (only one cell thick).
Capillaries unite to form larger vessels that converge to form
veins. The diagram shows a simplified version of the human
circulatory system. 26/04/2017 Mrs Smith -National 5 Biology TASK
COPY: Capillaries
Blood flows from arteries into capillaries and then back to veins.
As the blood flows through capillaries substances are exchanged
with the nearby body cells This diagram shows a capillary network
in the inner lining of a cheek. Notice how all the cheek lining
cells are very close to a blood capillary. Group Task Decide
whether the following substances will be leaving or entering the
blood at this capillary network. Oxygen Carbon dioxide Glucose
26/04/2017 Mrs Smith -National 5 Biology Task: Stick your diagram +
complete the task below.
Individual Task Stick the diagram of a capillary network into your
notes. Colour the blood vessels red and the cytoplasm of the body
cells yellow. Individual Task - below your diagram draw one
enlarged body cell with a capillary beside it. Individual Task now
draw arrows to represent the movement direction (diffusion)of 1)
oxygen 2) carbon dioxide 3) glucose 26/04/2017 Mrs Smith -National
5 Biology Blood Vessels: Summary: Watch this
Watch the following video clip which contains information about
blood vessels and the blood that flows around in them. Blood : Twig
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
Coronary Artery This diagram shows the outside of the heart. Small
arteries can be seen branching off the aorta. These are called
coronary arteries and they are very important as they supply the
muscles in the wall of the heart with oxygen. 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
Coronary Heart Attack The coronary arteries can become narrower as
we get older. A fatty diet, smoking and lack of exercise all
contribute to this. Eventually, a clot can block the artery leading
to a heart attack. Muscle cells in the heart wall become starved of
oxygen and die. The heart may stop contracting and unless the heart
is quickly restarted the individual will die. 26/04/2017 Mrs Smith
-National 5 Biology Chapter 15: Animal Transport and exchange
systems
Unit 2: Multicellular Organisms Chapter 15: Animal Transport and
exchange systems Lesson 3: Mammalian circulatory system: BLOOD
26/04/2017 Mrs Smith -National 5 Biology Learning Intentions:
Blood
By the end of this chapter you should: Be able to describe that
mammals, nutrients, oxygen and carbon dioxide are transported in
the blood. Red blood cells are specialised by being biconcave in
shape, having no nucleus and containing haemoglobin. This allows
them to transport oxygen efficiently in the form of oxyhaemoglobin.
26/04/2017 Mrs Smith -National 5 Biology Remember blood is made of
different cells
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
Blood Blood is a liquid tissue consisting of: plasma red blood
cells white blood cells platelets One of the functions of blood is
to transport materials around the body. White blood cells and
platelets are part of the body's immune system, but plasma and red
blood cells are involved in transport. 26/04/2017 Mrs Smith
-National 5 Biology Task: Can you name three nutrients that are
carried in the blood?
Group Task Look at this diagram which represents the parts of
blood. Decide which part carries oxygen carbon dioxide nutrients.
How many did you get correct? 26/04/2017 Mrs Smith -National 5
Biology Mrs Smith - National 5 Biology
The Blood Nutrients such as glucose and amino acids dissolve in the
fluid part of the blood the plasma. Carbon dioxide gas is also
carried around the body in blood plasma. Oxygen is transported
around the body in red blood cells. Group Task can you find out
what white blood cells and platelets do? 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
Plasma Plasma is a straw-coloured liquid. It transports dissolved
substances around the body, including: Hormones, (Remember hormones
are chemical substances that help to regulate processes in the
body) such as insulin which regulates the level of glucose in the
blood. Oestrogen and progesterone are two hormones involved in the
female menstrual cycle. Nutrients, such as water, glucose, amino
acids, minerals and vitamins Waste substances, such as carbon
dioxide and urea 26/04/2017 Mrs Smith -National 5 Biology
Microscopy - Seeing the composition of Blood
This diagram shows a drop of blood asviewed under a microscope. The
nuclei of the white blood cells have been stained purple to make
them visible. Notice how few white cells there are compared to red
cells. 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith -
National 5 Biology
Why is blood is red? This diagram represents an image of blood
magnified thousands of times using an electron microscope. The
bright red colour of the red blood cells comes from the presence of
a pigment called haemoglobin. Haem = Containing iron 26/04/2017 Mrs
Smith -National 5 Biology Red blood cells have no nucleus
The absence of a nucleus is an adaptation of the red blood cell for
its role. It allows the red blood cell to contain
morehaemoglobinand, therefore, carry more oxygen molecules. It also
allows the cell to have its distinctive bi-concave shape which aids
diffusion 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith -
National 5 Biology
Red Blood Cells FUN FACT: The average healthy adult has 35 trillion
red blood cells in their body. Red blood cells have a biconcave
shape which allows them to absorb lots of oxygen as blood passes
through the lungs. Red blood cells are very small so they can
easily pass through narrow blood vessels. 26/04/2017 Mrs Smith
-National 5 Biology Haemoglobin & Oxyhaemoglobin
As blood passes through the lung capillaries, haemoglobin (a dark
red colour) combines with oxygen to form oxyhaemoglobin (bright
read colour). When blood reaches the capillaries beside respiring
cells. Oxyhaemoglobin quickly releases the oxygen which then
diffuses into cells. 26/04/2017 Mrs Smith -National 5 Biology
Consolidation exercise: The Blood
Individual Task Stick this diagram into your notes. Then underneath
your diagram. 1.List all the substances that are carried dissolved
in the plasma. 2. Describe three ways that red blood cells are
designed to carry oxygen around the body. 26/04/2017 Mrs Smith
-National 5 Biology TYK Torrance pgs 123/4 Qus 1-3
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
TYK How did you do? 26/04/2017 Mrs Smith -National 5 Biology Mrs
Smith - National 5 Biology
TYK How did you do? 26/04/2017 Mrs Smith -National 5 Biology
Chapter 15: Animal Transport and exchange systems
National 5 Biology Unit 2: Multicellular Organisms Chapter 15:
Animal Transport and exchange systems Lesson 4: Organs of gaseous
exchange 26/04/2017 Mrs Smith -National 5 Biology Learning
Intentions: Structure of the lungs
By the end of this chapter you should: Be able to describe the
structure of the lungs This should include... The trachea and its
rings of cartilage which keep main airways open. Comparisons can be
made between cartilage in airways and lignin in xylem. The cilia
and mucus. Specifically that mucus traps dirt and microorganisms
and cilia moves this up and away from the lungs. 26/04/2017 Mrs
Smith -National 5 Biology Mrs Smith - National 5 Biology
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
The Lungs The lungs are a mammals gaseous exchange (where gases
enter and leave the bloodstream). Can you name the gas that enters
the blood and the gas that leaves the blood in the lungs? Inhaled
air enters the body through the mouth or nose. It then travels down
through a system of tubes decreasing in diameter -the windpipe
(trachea) which divides into bronchi (singular bronchus) which
enter each lung. Each bronchus then branches into lots of smaller
tubes called bronchioles which carry air throughout each lung.
windpipe bronchus bronchioles 26/04/2017 Mrs Smith -National 5
Biology Mrs Smith - National 5 Biology
Task Collect a diagram of the lungs and label the various tubes.
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
The Trachea - Windpipe The windpipe and bronchus (larger airways)
are surrounded by rings of cartilage. rings of cartilage These
rings are not complete. They are c-shaped held together by ligament
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
Is there something in common with rings of cartilage in the trachea
and lignin in xylem vessels (plants) ?? Rings or spirals of Lignin
reinforces cell walls, keeping them from collapsing. This is
particularly important in the xylem, because the column of water in
the hollow xylem cells is under tension and without the lignin
reinforcement the cells would collapse. 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
The Trachea - Windpipe Individual Task see if you can feel the
rough rings of cartilage in your own throat. You can also feel this
rubbery material in your ears and at the tip of your nose. Paired
Task decide what you think the function of this cartilage is. Clue
ligament? rings of cartilage The rings of cartilage protect the
windpipe by preventing it from collapsing if it is struck. They
spring back keeping the windpipe open and air moving into and out
of the lungs. 26/04/2017 Mrs Smith -National 5 Biology The Trachea
Cilia & mucus
The trachea and bronchi are lined with tiny hair-like cilia and
cells that secrete sticky mucus Dirt particles and microorganisms
that we inhale stick to the mucus lining the windpipe. This traps
them and prevents them entering the lungs. The cilia then beat
rhythmically back and forward sweeping the dirty mucus away from
our lungs, up to our mouth. This mucus is then swallowed and the
acid in our stomach kills the microorganisms. 26/04/2017 Mrs Smith
-National 5 Biology Microscopy of the Windpipe
Section through lining layer (epithelium) of windpipe showing cilia
and mucus-producing goblet cells Scanning electron micrograph image
of cilia in the windpipe. 26/04/2017 Mrs Smith -National 5 Biology
The internal structure of the lung -Alveoli
This diagram shows that the bronchioles in each lung end in groups
of tiny air sacs deep in the lungs called alveoli (singular
alveolus). These air sacs are the place where oxygen and carbon
dioxide are exchanged with the bloodstream. 26/04/2017 Mrs Smith
-National 5 Biology Why are alveoli so numerous?
Alveoli are so numerous that they provide a very large surface area
for gas exchange with the blood. There are around 300 million
alveoli in each lung (600 million in total). The total internal
surface area of the two lungs is about 90m2 If they were flattened
and stitched together they would cover an area equal to a tennis
court. 26/04/2017 Mrs Smith -National 5 Biology Chapter 15: Animal
Transport and exchange systems
National 5 Biology Unit 2: Multicellular Organisms Chapter 15:
Animal Transport and exchange systems Lesson 5: Gas Exchange
26/04/2017 Mrs Smith -National 5 Biology Learning Intentions: Gas
Exchange
By the end of this chapter you should: Be able to describe the gas
exchange in the lungs This should include... Oxygen and carbon
dioxide are exchanged through the alveolar walls. Alveoli have a
large surface area, thin walls and a good blood supply for more
efficient diffusion of gases. 26/04/2017 Mrs Smith -National 5
Biology Internal structure of the lung - Alveoli and capillary
network
Alveoli are well designed for gaseous exchange. They are surrounded
by a dense network of capillaries which give a rich blood supply.
If the capillaries from a mans lungs were unwound and laid end to
end they would stretch for 600 miles. 26/04/2017 Mrs Smith
-National 5 Biology Alveoli and capillary network Structure related
to function
As discussed the alveolus is surrounded by a dense network of blood
capillaries. The lining of an alveolus is very thin and in close
proximity to the walls of the blood capillaries, which are
themselves only one cell thick. This combination of Large surface
area Short distance Thin walls Good blood supply Presents ideal
conditions for gas exchange to occur between alveolar air and
blood. 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith -
National 5 Biology
Task: Alveoli Paired task Study the diagram Decide which part of
the blood oxygen enters and which part carbon dioxide leaves.
Suggest why the red blood cells are shown in different colours in
the diagram. - SEE ANIMATION 26/04/2017 Mrs Smith -National 5
Biology Gas Exchange - Getting oxygen from the air into the
blood,
Blood arriving at the lungs is described as deoxygenated because it
contains a low concentration of oxygen. Since air breathed into an
alveolus contains a higher concentration of oxygen, diffusion
occurs. Oxygen first dissolves in the moisture on the inner surface
of the thin lining of the alveolus and then diffuses into the blood
and surrounding capillaries. The blood therefore becomes oxygenated
(rich in oxygen) before leaving the lungs and passing to all parts
of the body. 26/04/2017 Mrs Smith -National 5 Biology Mrs Smith -
National 5 Biology
Gas Exchange - Removing waste carbon dioxide from the blood into
the air Deoxygenated blood contains a higher concentration of
carbon dioxide than the air entering the alveoli. Therefore carbon
dioxide diffuses from the blood into the alveoli from where it is
exhaled. 26/04/2017 Mrs Smith -National 5 Biology Individual
consolidation task:
Collect the alveoli diagrams and stick them into your jotter. 2) On
the first diagram label the alveoli, blood capillaries and the
bronchiole. 3) On the second diagram do the following Draw in some
red blood cells. Label the capillary, alveolus wall and bronchiole.
Draw arrows in different colours to show the flow of oxygen and
carbon dioxide between the alveolus and the blood. Underneath your
diagrams list three ways that alveoli are designed to allow
efficient diffusion of gases. 26/04/2017 Mrs Smith -National 5
Biology Mrs Smith - National 5 Biology
The Lungs in Action Individual Task Study the animation which
illustrates the flow of gases into and out of the lungs(Multimedia
Science School). List all the parts of the body that oxygen passes
through from entering the body until it reaches the muscles. Now
list all the parts of the body that carbon dioxide passes through
from the muscles until it is breathed out. Can you now explain why
there is less oxygen and more carbon dioxide in the air we breathe
out. Finally, describe what happens to our breathing when we start
to run having been resting. Can you now explain why this change in
our breathing happens? 26/04/2017 Mrs Smith -National 5 Biology Mrs
Smith - National 5 Biology
The Lungs Watch this Watch the following video clips about the
lungs. Lungs : Twig FactPack: Lungs : Twig 26/04/2017 Mrs Smith
-National 5 Biology Chapter 15: Animal Transport and exchange
systems
National 5 Biology Unit 2: Multicellular Organisms Chapter 15:
Animal Transport and exchange systems Lesson 6: Food Transport
System 26/04/2017 Mrs Smith -National 5 Biology Learning
Intentions: Food Transport System
By the end of this chapter you should: Be able to demonstrate that
Food is moved through the digestive system by peristalsis.
Understand the structure of villi in the small intestine
Specificallythey have a large surface area, thin walls and a good
blood supply to aid absorption of glucose and amino acids.
Understand the structure of villi in relation to the lacteals which
absorb fatty acids and glycerol (the products of fat digestion).
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
Food transport system The alimentary canal is our bodys digestive
system. As insoluble molecules of food pass along this muscular
tube they are broken down to a soluble state by digestive enzymes.
The salivary glands, liver and pancreas, which are connected by
ducts to the alimentary canal (gut) are described as associated
organs. 26/04/2017 Mrs Smith -National 5 Biology Revision:
Digestive System Structure
The digestive system is essentially a continuous tube which runs
from the mouth to the anus. The human gut is over 5 meters long!
Individual Task Study this diagram of the digestive system and see
how many parts (A-E) that you can identify. A A = Oesophagus
(gullet) B = Stomach C = Small Intestine D = Large Intestine E =
Rectum B C D E 26/04/2017 Mrs Smith -National 5 Biology Oesophagus
and Peristalsis
The oesophagus (gullet) is a muscular tube that connects the mouth
to stomach. Once food had been swallowed, it is moved down the
oesophagus by muscular action called peristalsis. 26/04/2017 Mrs
Smith -National 5 Biology Mechanism of Peristalsis
Contraction behind food Relaxation in front of food Part of the gut
wall is composed of circular muscles. When this contracts behind a
portion of food, the central hole of the tube becomes narrower and
the food is pushed along. At the same time the circular muscle in
front of the food becomes relaxed allowing the central hole to
enlarge and let the food slip along easily 26/04/2017 Mrs Smith
-National 5 Biology Functions of Peristalsis
Peristalsis also squeezes semi-solid food through the stomach and
along the intestines. 1. PERISTALSIS OF THE STOMACH This movement
helps to mix the food with digestive juices. 26/04/2017 Mrs Smith
-National 5 Biology Functions of Peristalsis
Peristalsis also squeezes semi-solid food through the stomach and
along the intestines. 2.PERISTALSIS OF THE INTESTINE This movement
helps Following absorption of the end products of digestion in the
small intestine peristalsis keeps unwanted wastes on the move
through the large intestine on their way to be eliminated.
26/04/2017 Mrs Smith -National 5 Biology End products of
digestion
Imagine the small intestine of a person that has just eaten an egg
sandwich. As a result of complete digestion the starch in the bread
has been broken down into glucose. The protein in the eggto amino
acids The fat in the butter to the products of fat digestion (Fatty
acids and glyserol) 26/04/2017 Mrs Smith -National 5 Biology What
happens to the end products of digestion?
So after complete digestion Carbohydrates are broken down into
glucose. Proteins are broken down int amino acids Fats are broken
down into fatty acid and glycerol All of these different substances
must now be absorbed and transported around the body 26/04/2017 Mrs
Smith -National 5 Biology Absorption in the small intestine
Mans small intestine is around 7 metres in length and 25cms in
diameter. The main function of the small intestine is to absorb the
end products of digestion through its wall and then pass them into
the circulatory system. 26/04/2017 Mrs Smith -National 5 Biology
Absorption in the small intestine Structure related to
function
The small intestine is very efficient at its job because of its
structure. In biology structure is always related to function! It
is long and its internal structure is folded. The inner lining of
the small intestine is not smooth. Instead, it has thousands
microscopic, finger-like, projections called villi (singular
villus) protruding from it. 26/04/2017 Mrs Smith -National 5
Biology Mrs Smith - National 5 Biology
Task: Villi Paired task Study this diagram which shows villi on the
inner lining of the small intestine. Decide what their function
might be. Clue they contain a rich blood supply. b) Suggest how
their shape helps them to function? 26/04/2017 Mrs Smith -National
5 Biology Mrs Smith - National 5 Biology
The role of Villi Villi increase the surface area of the small
intestine for the absorption of digested food into the bloodstream.
In addition to providing a large surface area villi are ideally
suited to the jobs of absorption and transport of digested food
because each villus has a special structure 26/04/2017 Mrs Smith
-National 5 Biology Mrs Smith - National 5 Biology
Villus Structure This diagram represents a section through one
villus. There are three structural features which aid absorption.
The surface walls are thin (one cell thick)to allow digested food
to easily diffuse (pass) through rapidly. It contains a good blood
supply. A dense network of blood capillaries absorb glucose and
amino acids. Tubes in the centre called lacteals absorb and
transport the products of fat digestion. 26/04/2017 Mrs Smith
-National 5 Biology TASK: Villus Structure
Individual Task Collect the villus diagram and stick it into the
centre of your jotter. Draw an arrow onto your diagram to represent
the absorption of glucose and amino acids. Now draw another arrow
on the diagram to represent the absorption of the products of fat
digestion. Note you will have to distinguish these arrows in some
way. glucose and amino acids products of fat digestion 26/04/2017
Mrs Smith -National 5 Biology Mrs Smith - National 5 Biology
The Digestive System Watch the following video clips about
digestion and the small intestine. Introduction to Digestion : Twig
Small Intestine : Twig 26/04/2017 Mrs Smith -National 5 Biology TYK
Torrance pgs 128 Qus 1-4
26/04/2017 Mrs Smith -National 5 Biology Mrs Smith - National 5
Biology
TYK How did you do? 26/04/2017 Mrs Smith -National 5 Biology