Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
The Circulatory System
Cardiovascular System Facts The average person has nearly 100,000 km of blood
vessels running through them.
The larger the organism, the slower the heart beats (a
woman’s heart will beat faster than a man’s)
A blue whale’s heart beats 5 times per minute while a
hummingbird’s beats closer to 1400 times
Blood in your veins is not blue! They look blue due to
the way the light is absorbed and reflected in your
skin.
Your heart produces enough pressure to shoot blood
nearly 30 feet.
The Heart
The heart is the pump in our body which
stimulates the movement of the blood.
In an adult, it is about the size of a fist.
It is located roughly in the middle of the chest
between the lungs.
It is composed of 4 chambers.
The Heart
The four chambers of the heart are:
Right atrium
Right ventricle
Left atrium
Left ventricle
The Heart
The Heart
The atrium and ventricle on the respective sides
are directly linked
The left and the right side have no direct link.
They are separated by a partition, the septum.
For the left and right side, blood flows into the
heart through the atrium and is pushed out
through the ventricle.
The Heart
To prevent blood from flowing backwards in the
heart, valves are present in the heart
These valves are called the atrioventricular
valves.
Without these, blood would flow backwards
through the heart.
The Heart There are 5 major blood vessels connected to the
heart.
Superior and inferior vena cava
Pulmonary vein
Pulmonary artery
Aorta
The Heart
Function of the Heart The heart pumps blood to the entire body
First phase of a heart beat is diastole
The heart is at rest and the atriums fill with blood.
Next the atriums contract, pushing blood into the ventricles.
The final phase is when the ventricles contract, pushing blood out into the arteries.
This phase is called systole.
The Heart
Blood Pressure When you take your blood pressure, you always get 2
numbers
The systolic pressure it he higher number and
indicate the pressure caused by the contraction of the
heart
The diastolic pressure is the pressure between beats.
It is better to have lower blood pressure, within reason
Your Pulse
When taking your pulse, the pulse you feel is the
systole.
An average heart beats around 75 times per
minute.
This number varies depending on age, gender,
physical fitness and physical activity.
Types of circulation.
The heart is a double pump.
There are two circulatory routes which the blood
takes.
The right side is responsible for the pulmonary
circulation.
The left side is responsible for the systemic
circulation.
Circulatory Routes
Pulmonary Circulation This circulation brings blood to and away from the
lungs.
Right side of the heart is responsible for this
circulation.
Blood is pushed out of the heart by the right ventricle
through the pulmonary artery.
The blood then passes through the capillaries and
then returns to the heart through the pulmonary vein.
Systemic Circulation This is the circulation which sends blood out to the
body systems (except the lungs).
The blood is pushed out the of heart by the left ventricle through the aorta.
The aorta splits and sends blood out through different parts of the body.
The blood then gives its oxygen, nutrients and other goodies to the body tissues through the capillaries.
The blood then returns to the heart through the veins.
Blood Vessels
Now that we understand how the heart works and
we know where the blood goes, let’s talk about
the pathways it takes.
There are three types of blood vessels in our
bodies.
Arteries
Veins
Capillaries
Arteries
Arteries are the largest blood vessels in our
bodies
They carry blood from the heart to other parts of
the body.
Their walls are very thick.
This helps them withstand high pressures.
Arteries
Veins
Veins carry blood back to the heart from the body
systems.
They are thinner than arteries.
They also have small valves in them to prevent
the blood from falling back down.
The pressure is lower than in arteries.
Veins
Veins
Capillaries
Capillaries are small vessels which are only 1 cell
thin.
This is the site of gas and nutrient exchange.
They are the bridge between the veins and
arteries.
Where else have we seen capillaries?
Capillaries
Comparing Blood Vessels
Comparing Blood Vessels
Diseases of the Heart
We are going to discuss 5 diseases of the heart
and vessels.
Arteriosclerosis
Atherosclerosis
Angina
Heart attack
Stroke
Arteriosclerosis This is a condition where the arteries thicken and
become harder.
This causes them to be less flexible. Less flexible means that it puts more pressure on the heart.
This is caused by age, smoking, bad diet, drugs and a poor lifestyle
There are currently no proven medical treatments for this condition as of yet.
Atherosclerosis
This conditions is caused by a build up of plaque
inside the arteries.
These plaques are caused by too much fat and
cholesterol in an individuals diet.
Treatments are improved diet and exercise.
There are some medications which can be taken,
but exercise and diet at the first to be tried.
Atherosclerosis
Angina This is also referred to as angina pectoris.
This is a sharp chest pain.
This is caused by ischemia to the heart, which means a lack of oxygen to the heart.
This is caused by a blockage of the coronary artery, meaning atherosclerosis of the arteries around the heart.
Treatments include nitroglycerin, a strong vasodialator.
Angina Treatments include nitroglycerin, a strong
vasodialator.
A vasodilator is something which dilates, opens up, the blood vessels. This allows more blood and thus more oxygen through.
Since the cause is blockages of the arteries, taking care of those blockages is the first priority.
Again, diet and exercise!
Heart Attack
This is also called a myocardial infarction.
A heart attack is caused by a lack of oxygen to
the heart.
This causes part of the heart to die.
The lack of oxygen is caused by a blockage in the
coronary arteries (the vessels which feed the
heart).
Heart Attack Symptoms of a heart attack are chest pain, numbness
in either arms, nausea, shortness of breathe, etc.
Nitroglycerin can be administered to help prevent
further damage.
Without needing to said, heart attacks can be quite
deadly.
The older you are when you have a heart attack, the
more likely you are to survive.
Heart Attack
Stroke A stroke is caused by a blood vessel in the brain
either bursting or becoming blocked.
This can lead to loss of brain function, ability to move one or more limbs, loss of speech or many other past abilities.
This is due to the lack of oxygen to the brain.
The effects could be permanent or temporary and there is no way to know.
Stroke Risk factors for a stroke are old age, high blood
pressure, diabetes, high cholesterol and smoking.
In this case, the smoking can lead to arteriosclerosis which makes the vessels more prone to breaking.
Prevention is the best defense against strokes.
Once a patient is cleared of the danger of a stroke, the recovery is a long process.
Stroke
Circulatory System Facts The heart beats around 3 billion times in the
averages person's life.
About 8 million blood cells die in the human body every second, and the same number are born each second.
It takes about 20 seconds for a red blood cell to circle the whole body.
Red blood cells make approximately 250,000 round trips of the body.
Red blood cells may live for about 4 months circulating throughout the body.
Blood
Blood is composed of different constituents.
It is also the only liquid tissue in the body.
A man’s body contains approximately 5-6 L of
blood and a woman’s contains 4-5 L.
Although it seems like a homogeneous mixture,
blood is a solution of components suspended in a
liquid.
Blood after centrifugation
Plasma
The liquid component of the blood.
It is 90% water in which has substances
dissolved into it such as:
Hormones
Nutrients
Antibodies
Waste
It is used for transportations of substances.
Blood Plasma
Blood Constituents
Red Blood Cells are red-coloured cells in the form
of a biconcave disk.
They have no nucleus and very few organelles.
There are about 4-6 billion per mL
They responsible for carrying oxygen through the
use of hemoglobin.
Red Blood Cells
Blood Constituents
White blood cells are transparent cells.
There about 4-11 million per mL of blood.
Their role in the body is for our immune system.
They seek out and attack intruders in our bodies.
Types of White Blood Cells
Blood Constituents
Platelets are irregular cell fragments.
There are between 150-400 million per mL of
blood.
They help in blood clotting.
With a low platelet count, one could bleed to
death from a simple paper cut.
Platelets
Blood Types Humans have 4 different blood types.
A
B
AB
O
The blood type is determined by surface proteins on
the red blood cells.
There is also one other substance on their surface
The Rh factor
Rh Factor
The Rh factor is known as the rhesus factor
because it was first discovered on the red blood
of rhesus monkeys, also known as macaques.
Surface Proteins
There are proteins on the surface of the red blood
cells.
The red blood cells are what determine an
individuals blood type.
There are three different surface proteins
A
B
Rh
What’s your blood type?
Blood Type A+ A- B+ B- AB+ AB- O+ O-
Su
rface p
rote
in
A X X X X
B X X X X
Rh X X X X
Blood Types in Quebec
A 42%
B 9%
AB 3%
O 46%
Distribution of types A, B, AB and O
Rh Negati
ve 15%
Rh Positi
ve 85%
Distribition of Rh Positive and Rh
Negative
Distribution of the Eight Blood Types
in Quebec
O+ 39%
A+ 36%
B+ 7%
AB+ 3%
O- 7%
A- 6%
B- 3%
AB- 1%
Distribution of the Eight Blood Types
Blood Transfusions
A blood transfusion entails the injection of blood
into a person.
A donor is defined as the person who gives blood
for the purpose of a transfusion
A recipient is a person who receives blood from a
transfusion
Blood Transfusions
Before the discovery of blood types in 1902,
many transfusions resulted in the death of the
recipient.
We are well aware of the rules of blood
transfusion.
What do you think this rule is?
The Blood Rule
Remember the surface proteins on the red blood
cells.
Those are the key to safe blood transfusions.
To safely receive blood, you must not receive
something you don’t already have.
You cannot receive something which you don’t
have!
Blood Compatibility Donor
O- O+ A- A+ B- B+ AB- AB+
Recip
ien
t
O- X
O+ X X
A- X X
A+ X X X X
B- X X
B+ X X X X
AB- X X X X
AB+ X X X X X X X X
Blood Compatibility Remember, way for a blood transfusion to work
safely the recipient must not receive something which they do not have.
If you are blood type A-, you can’t receive B or +.
This means that O-, which is “empty” is the universal donor.
AB+ is the universal recipient because it already has everything.