The document summarizes key components and functions of the circulatory and excretory systems. It describes the components of blood and the double circulatory system, which transports blood to and from the heart and lungs. The document also outlines urine formation through the kidneys and excretory system. Major illnesses like arteriosclerosis, thrombosis, heart attacks and cystitis are also summarized.

1. Unit 4:
Circulatory
and Excretory
Systems
Learning objectives:
• Recognise the components of the circulatory and excretory systems and
understand how they work.
• Explain blood circuits and urine formation.
• Recognise healthy livestyle habits.
• Identify the main illnesses related to the circulatory and excretory systems.

2. 1. 2 Blood composition
Blood has two components:
•Blood plasma, which is made up of water, minerals, nutrients,
waste products, etc.
•Blood cells. There are three types of blood cells, which are:
Leukocytes or white blood cells: they are involved in immunity,
this means that they defend the body against infection.
Erythrocytes or red blood cells: they contain hemoglobin,
a red pigment which carries oxygen.
Thrombocytes or platelets: they are fragments of cells
containing substances that allow blood to coagulate (blood clotting).
1. The Blood

6. FUNCTIONS OF THE BLOOD
 Transport of:
 Nutrients
 Waste products
 Hormones
 Oxygen and carbon dioxide
 Keeping the normal temperature
of the body
 Defence against disease

7. The different types of blood groups are determined by the presence or
absence of certain proteins in the red blood cells.
Blood groups
ABO blood
group
Rh factor

9. 2. Blood Circulation
Components
Blood
vessels
Arteries
Capillaries
VeinsThe heart

10. Arteries
 thick walls,
 no valves and
 they carry blood away
from the heart
Capillaries
 link arteries to veins.
 formed by walls that only have one
layer of cells. This allows substances
to pass into and out of the blood.
Veins
• thin walls
• valves to stop blood from going
backwards
• they carry blood to the heart
http://www.youtube.com/watch?v=CjNKbL_-cwA  Types of blood vessels
2.1 Blood vessels

11.  It is a pump that pushes the blood into the arteries.
 It is made of cardiac muscle, a special kind of muscle that
never tires.
 It is divided into two sides by a wall called the septum.
RIGHT PART
LEFT PART
2.2 The Heart

12.  Atria: the two upper
chambers (singular:
atrium). They have thin
walls. They pump blood to
the ventricles.
 Ventricles: the two lower
chambers. They pump
blood out of the heart.
right ventricle, with
thin wall, pumps the
blood to the lungs .
left ventricle, with
thicker and stronger
wall, pumps the blood
to the body.
The heart has got four chambers:
lungs
body

13. Valves
Valves
prevent the
backflow of
blood.
Tricuspid valve and bicuspid or mitral valve,
between atria and ventricles.
Aortic valve and pulmonary valve between
ventricles and arteries.
HCLStructure of the Human Heart  https://www.youtube.com/watch?v=qmpd82mpVO4 OR
HowHeartWorks3D

14. The Heartbeat (latido)
 Systole: heart chambers contract.
 Diastole: heart chambers relax.

15. Heart rate: number of times the heart beats per unit of time.
Blood pressure: pressure applied by blood on the artery walls.

16. 2.3 Blood circuits
Blood circulation in human being is double, complete and
closed.
It has two circuits (systemic and pulmonary), this means that
the blood has to travel twice through the heart in order to complete the whole circuit
Oxygenated blood from the lungs never mixes with
deoxygenated blood from the body.
The blood never leaves the blood vessels.

18. 2 veins
Vena cava (From the body
to R.A)
Pulmonary
vein
(from lungs to
L.A.)
2
arteries
Aorta (from L.V to
body)
Pulmonary
artery
(from R.V. to
lungs)

20. The movement of blood through the heart
1. Blood from the body enters the right atrium through the vena cava.
The atria contract, the blood is pushed through the tricuspid valve, into the right
ventricle.
2. When the right ventricle contracts, the blood is pumped through the pulmonary valve into
the pulmonary arteries.
3. Blood goes to the lungs.
In the lungs, the blood collects up oxygen and gets rid of its carbon dioxide.
Right
atrium
Left
atrium
Right
ventricle
Left
ventricle
To the lungs
From the body

21. 4.It then comes back to the heart in the pulmonary vein which enters the left
atrium.
When the atria contract, the blood is pushed through the bicuspid o mitral
valve into the left ventricle.
5.The ventricles contract and this pushes the blood through the aortic valve to the
main artery of the body, aorta.
6.Blood is pushed out to all around the body.
Left
atrium
Left
ventricle
pulmonary vein
From the lungs

22. 3. The Lymphatic System
It carries lymph from the lymphatic tissues and organs to the blood.
Functions
To mantain a
liquid balance
in the body
To transport
lymphocytes
(white blood
cells)
To transport
fats
(tonsils, spleen, thymus, bone marrow…)

23. This condition refers to an obstruction of the lymph vessels, mostly located in the
lower limbs. It is caused by a protozoan infection transmitted by the larvae of certain
insects.
An enlargement of the affected area characterises this condition, making the leg look a
bit like an elephant leg. In Spain this condition does not occur given that the insects
that carry the protozoa are located in tropical regions.
An illness related to the lymphatic system: elephantiasis

24. 4. The Excretory System
It is the system that eliminates the waste products produced by cells.
Main waste products:
 Carbon dioxide
 Urea and uric acid
 Toxic substances
Organs and
systems involved
in excretion
Liver Toxic substances
Respiratory
system
Carbon dioxide
Sweat glands
Toxic substances
and urea
Urinary
system
Urea and uric acid

25. 4.1 Urinary System
Components
Kidneys
Ureters
Bladder
Urethra

26. Men’s urethra belongs to both systems: urinary and reproductive
Women have 2 different ducts:
- the urethra (urinary)
- and the vagina (reproductive)

27. Kidney structure

28. Nephrons
They are the structural and functional units of the kidneys. They
are responsible for filtering blood and forming urine. They
also regulate water and mineral content in the blood.
Each kidney is formed by over a million nephrons.

30. 4.2 Urine formation
URINE = liquid obtained from blood composed of water,
minerals and waste products (urea and uric acid).
Stages
Glomerular
filtration
Blood from the
glomerulus is filtered 
blood plasma passes to
the Bowman’s capsule.
Tubular
reabsorption
Useful substances (water
and nutrients) are
reabsorbed.

31. Water is reabsorbed in the
Loop of Henle and other
substances are reabsorbed in
the proximal tube.

32. Arteriosclerosis
Accumulation of substances (fats, calcium…) in the arteries, which causes them
to narrow and restricts the blood flow.
http://www.youtube.com/watch?v=qRK7-DCDKEA  atherosclerosis
(a common form of arteriosclerosis in which fatty substances form a deposit of plaque on the inner lining
of arterial walls)

33. Thrombosis
Blood clots formed in a blood vessel. It is especially dangerous in the brain
or in the heart
http://www.youtube.com/watch?v=OxY4BphpGqo  Thrombosis

34. Heart attack and angina
Angina pectoris: narrowing or partial obstruction of the coronary arteries,
which produces a lack of oxygen in the myocardium.
Heart attack: total obstruction of the coronary arteries.
Arteries which carry blood to the cardiac cells

36. Cystitis
Bladder and kidney stones
Page 78, activity 26, 27 and 29
Page 83, activities 41 and 42

37. IN PAIRS
Activities 6, 8, 12, 22 pages 69 and following
4 minutes
Discuss the following activities with your partner
HW: Activities 48, 52 page 84
Healthy habits: read page 80 and
do activity 31.