The Circulatory Sytem

• The heart: A muscular organ that pumps blood throughout the body, consisting of four chambers: the left and right atria, and the left and right ventricles.

Blood vessels 

Our body is made up of roads, and these roads are blood vessels. They go into different organs and parts of the body.  

Different sizes of different vessels include:

• The artery is a vessel that is connected to the heart and organs all over the body. It is made up of endothelium, smooth muscles, and connective tissue. The smooth muscles are larger in the artery since its needed in the transportation of blood molecules. 

• The vein is a vessel that is also connected from the heart to organs. It is made up of endothelium, smooth muscles and connective tissue. The smooth muscles in the vein are smaller than the artery.

• The capillary is also a vessel that connects the artery and the vein. An exchange takes place in the capillary. It exchanges nutrients, oxygen, and carbon dioxide. 

The Artery 

Artery transports oxygen from the heart to all of the body organs while the organs give carbon dioxide which is transported by the veins. It is elastic as it can stretch a huge amount and can snap which pushes the blood out of the heart and into the lungs.  

The Capillary

The capillary is where a the exchange between the artery and the vein occurs. They exchange oxygen, carbon dioxide, and nutrients. The capillary is found inside the organ/ on the border of the organ.

The cycle starts in the heart when it produces oxygen, then its transported through the artery into other organs where its exchanged with carbon dioxide, leaving the organ through the veins. 

The capillary connects the artery and the veins and its where the exchange between oxygen and carbon dioxide happens. 

A stroke happens when a lot of pressure is applied to the capillary. 

The vein

The vein inside is colored as blue since it transports carbon dioxide. However, inside your body, the vein is light red but not blue. It is colored as blue in diagrams to help students to identify the difference. They are called capacitance since they can stretch a high amount and can hold a large amount of blood. 64% of the blood in our body is found in the vein.

The heart

The heart contracts to release blood and relaxes to take in blood.

The blood does not go straight to the organs; it should always pass through the heart.

The vocab: 

• Valves

• Atria 

• Ventricles

• Aorta

The heart has 4 main chambers ;

The right atrium 

The right ventricle 

The left atrium

The left ventricle 

Notes of video 

Internal structure of the heart:

Each of the chambers have different names and different roles

The two chambers on the top are called atria each one is called an atrium

There is left atrium and a right atrium 

Under those are the ventricle chambers 

The walls of the ventricle are thicker than the walls of the atria because the pressure in the ventricle is much more thicker

The right atrium is going to take deoxygenated blood coming from the organs and sends it into the right ventricle. Then it moves outside the heart into the kidney to get oxygen.  

The role of the valve is to not allow the blood anymore to go back into the atrium. 

If the blood does go back into the right atrium, you wouldn’t be able to breath.

The valve is called a tricuspid valve

The heart then contracts to release the blood found in the right ventricle into the lungs with the help of veins and artery. 

 On the left side, the left atrium receives oxygenated blood from the lungs and passes it into the left ventricle which then the heart contracts moving the blood into the aorta which is found in the artery; moving it throughout the body. 

A wall called septum is found between the right atrium and ventricle and the left atrium and ventricle because one blood is oxygenated and one is deoxygenated. 

The semilunar valves are found on top make sure the blood does not come back. 

The aorta is a type of artery that connects the heart to the body and transports blood rich in  oxygen. 

• Cholestreol is a small diameter fractured in the body, it is mainly found on the edges of the heart

• The right atrium receives blood rich in CO2 and sends it to the right ventricle that pumps blood to the lungs where it becomes rich in O2 and then comes back to the left atrium 

• As much the heart is pumping, as much the oxygen is produced. Therefore, It is very important to have strong muscles inside the artery; to prevent the oxygen and blood to go back towards the heart.

Heartbeat

It is the contraction of the blood that makes the heart pump out blood. 

When the heart contracts, the valve that separate the ventricle from the vein opens to transport blood. 

The beeps are when the heart contracts and releases. 

The heart beats in a rhythm to help balance the amount of oxygen and carbon dioxide found in blood.

If it doesn’t beat in a rhythm, the amount of carbon dioxide could be higher or number of oxygen found could be higher. 

The heart beats faster during stress, adrenaline or sport. Because the organs need oxygen and thats why it beats faster since its pumping out more blood. 

The heart sends messages to the other organs with the usage of the nerve system. 

Blood pressure

Blood pressure is when the blood pumped out is either more or less than normal which effect the veins and artery. 

When a person has high blood pressure, its when the veins and at the arteries have more pressure than normal. And if continued, it could lead to veins popping. 

For example, if a persons blood pressure is 12/8; 12 stands for the number of times the heart contracts and 8 stands for the amount of time the heart relaxes. 

When someone has low blood pressure, the amount of oxygen inside the body is low and the organs will find it hard to function which could lead to dizziness and fainting. 

A Pulse 

You calculate a pulse by calculating how much beat occurs in a minute 

Experiment in class: For me - 1 minute = 68 pulse

When you get injured, in the place of the injury you could feel your pulse since the attention of the heartbeat is now on the injury which means that blood is being pumped/sent into the place of the injury.

Blood flow 

Blood flow is the movement of blood inside the body. It starts from the right atrium which is inside the heart then into the right ventricle then goes to the lungs then back to the left atrium and then left ventricle and then goes throughout all  the body. 

The color red means it is rich in oxygen, oxygenated blood and its the artery and the blue color is poor in oxygen which is deoxygenated and its the vein. 

The exchange of carbon dioxide and oxygen happens in the capillaries; therefore the color of the capillaries is both red and blue. 

The aorta is found in the artery and it is the first artery the blood leaves the heart from. It takes the blood from the heart and distributes it throughout the body. 

The heart contracts when it releases the blood, deoxygenated blood from the right ventricle into the lungs; transported by the veins and relaxes when its taking in blood but contracts again when it releases blood, oxygenated blood from the left ventricle into the body and relaxes again. 

• Heart to lungs : blood rich in CO2

• Heart to organs : blood rich in O2

• Lungs to heart : blood rich in O2

• Organs to heart : blood rich in CO2

the blood goes from the heart, to the lungs then goes back to the heart then to the organs then the cycle starts again. 

The heart is the center of the cycle; it starts in the heart and ends in the heart. Therefore, it is impossible for the blood flow to go from the lungs to the organs straight away.

Concentration in blood flow is the amount of oxygen found in your cell.

• High concentrated blood = more oxygen than carbon dioxide. 

• Low concentrated blood = more carbon dioxide than oxygen.

Oxygen poor or deoxygenated is when the blood is rich in carbon dioxide and blood rich in oxygen or oxygenated blood is when blood is rich in oxygen.

Blood Components 

Components of blood means nutrients, carbon dioxide, and oxygen

What blood is made up of means whats always found in blood; it is made up of platelets, white blood cell, red blood cell, and plasma. 

Plasma

The main function of plasma is the transportation and carrying of digested food; they move through the digested system to the organs since it carries nutrients with the help of digested food. 

More than 50% of blood in the body is made up of plasma; plasma is made up of 90% water and 10% dissolved materials. 

Red blood cells

The red blood cells carry oxygen through the blood and body and to all the body’s cells; they also carry carbon dioxide.

Job: transportation of oxygen and carbon dioxide throughout the body

White blood cells

White blood cells are involved in fighting diseases; they help keep the body stable and safe from diseases that are internal and external. 

Job: fighting off diseases

Platelets

Platelets involve in injuries; they help stop and slow down cuts and injuries with the usage of blood clots. They form blood clots on the injuries which slows it down and eventually stops the bleeding.

Job: stops blood from flowing during a cut.

Blood Groups 

There are 4 blood groups; A,B,O,AB

The genes classify your blood groups.

The antigen for A has square shapes

Antibody they fight antigens; they are the opposite of antigens

Antibody are also called white blood cells because they fight.

If a person has A antigens but B antibodies and another person donates to that person and their Antigen is B; they will fight since the antibodies don’t match and are opposites.

Blood group AB does not have antibodies since it doesn’t match with any other and will fight themselves. 

Antigen O is the disappearance of the antigens both A and B; its just a cell.

The most common blood type is A+; more than 55% of people have that blood type.

Donating blood 

Each person can donate blood to the same blood group;

A -> A ; B -> B ; O -> O ; AB -> AB

O is a universal donor and can give to each blood group and to everyone.

The antibodies of O wont work since antibodies are not taken from the blood. Therefore; the antibodies won’t work on it. 

Nowadays, doctors donate and prefer blood from the same rhesus and blood type and would leave the “O” blood type for last minute; since they believe that it could have affects on the blood. 

When we talk about receiving blood, we look at the antibodies; when we talk about giving blood we look at the antigens.

• “O” blood group is a universal donor. It has no antigens

• “AB” blood group is a universal recipient. It has no antibodies.  

Theres also an antigen that informs us if we are - or +

It is extremely important for girls since when a women gets pregnant, the blood type of the fetus and the women is very important. If a mother has different rhesus than her fetus; the blood will think its an intruder which would end the babies life and kill it. 

However, in the first pregnancy; the fetus is in the development region which means its not ready to fight; while in  the second pregnancy, the blood will be ready to fight; killing the baby. 

If a baby has a different RH; the baby cannot attack the mothers blood. 

Therefore, the doctors give the mother a siring to stop her white blood cells from attacking the fetuses red blood cells. 

Rhesus is the type of blood; If its positive or negative