# data[].attributes.body
Size of a clenched fist

Enclosed in a sac called the pericardium that is beneath the breastbone

Formed of three layers

1. Epicardium: contains many blood vessels

2. Myocardium: made of cardiac muscle tissue; works with contraction and relaxation of heart

3. Endocardium: innermost layer that lines the 4 chambers

# data[].attributes.headline
In order to transport these things, blood flows through a vast and complex system of closed tubes called blood vessels.

# data[].attributes.subject
In order to transport these things, blood flows through a vast and complex system of closed tubes called blood vessels.

# data[].attributes.body
Right & Left Atrium: receive blood from the veins leading to heart

The right side of the heart (from body to lungs); Deoxygenated blood (blue).

Right & Left Ventricle: force blood away from heart.

The left side of the heart (from lungs to body); Oxygenated blood (red).

# data[].attributes.body
Divides the right and left sides of the heart; prevents the mixing of oxygen-rich & oxygen-poor blood.

# data[].attributes.body
The heart can be thought as 2 pumps sitting side by side.

The right side of the heart pumps blood from the body into the lungs where oxygen poor blood gives up carbon dioxide & picks up oxygen.

The left side pumps oxygen rich blood from the lungs to the rest of the body

# data[].attributes.body
Large, thick vessels that carry oxygen and nutrient rich blood from heart/lungs to the body.

# data[].attributes.headline
Blood is made up of both solid and liquid components like plasma. The average blood an adult composes are approximately 5 liters (or 10 pints). 

# data[].attributes.subject
Blood is made up of both solid and liquid components like plasma. The average blood an adult composes are approximately 5 liters (or 10 pints). 

# data[].attributes.body
Large, but thinner vessels that carry oxygen and nutrient depleted blood from the body to the heart/lungs.

# data[].attributes.body
Small, very thin vessels that form woven networks of arterioles and venules (mini arteries & veins) where a direct exchange occurs between blood and body tissue cells.

# data[].attributes.body
Arteries, Veins, and Capillaries are over 60,000 miles long.

# data[].attributes.body
genetically determined proteins that mark each person's blood in a unique way.

If an antigen other than your own enters your body, the body recognizes it as foreign and triggers the immune system to release antibodies against it.

Exists on the surface of all of your RBC

Agglutination causes blood cells to rupture, releasing hemoglobin into the bloodstream which often blocks kidney tubules and results in kidney failure.

# data[].attributes.body
a condition that occurs when there are not enough red blood cells in our body or the cells are not normally shaped.
* May be caused by a decrease in red cell production, increased red cell production, or blood loss

Common symptoms include feeling tired, difficulty breathing, dizziness, difficulty sleeping, & headache.

Types of Anemia:

1. Aplastic Anemia is when the bone marrow is not producing RBC

2. Pernicious Anemia is when you have a deficiency of vitamin B12, which the RBC need

3. Hemolytic Anemia is when your body breaks down RBC too fast
*inherited

4. Hemorrhagic Anemia is what occurs during rapid blood loss

# data[].attributes.body
proteins contained in the blood plasma which identify foreign antigens and alert the immune system.

Once identified, antibodies bind to the foreign blood cells and causes them to clump, a process called agglutination.

Circulate in your blood plasma and ensure that only the blood cells of your blood type exists in your body.

# data[].attributes.body
A person experiencing a prolonged oxygen deficiency

Skin appears bluish (low oxygen levels)

Abnormally high deoxyhemoglobin (form of hemoglobin without oxygen)

Vessel constriction

# data[].attributes.body
Angina: symptom of ischemia when the heart muscle (myocardium) doesn't get as much blood (hence as much oxygen) as it needs. This usually happens because one or more of the heart's arteries is narrowed or blocked

# data[].attributes.body
Oxygen-poor blood from the body enters the right side of the heart through 2 large blood vessels called Vena Cava into the right atrium.

Superior Vena Cava: brings blood from upper part of the body to the heart

Inferior Vena Cava: brings blood from the lower part of the body to the heart

When the heart contracts, blood is squeezed from the right atrium into the right ventricle

Separated by the tricuspid valve

- Purpose of valves is to prevent back flow

When the heart contracts a 2nd time, blood is sent from the RV through the pulmonary valve into the pulmonary arteries into the lungs

# data[].attributes.body
occurs when the flow of blood from the heart decreases, or fluid backs-up behind the failing ventricle, or both.

- Can be caused by:

1. High Blood Pressure: increases the work of the heart. The heart has to pump blood against higher resistance & muster therefore generate more force.

1. Arrhythmias: Interrupt the normal filling & pumping cycle.

- Bradycardia: Heart beats too slowly (less than 60 bpm)
- Tachycardia: Heart beats fast (more than 100 bpm)
- Flutter: Very rapid heart rate (250-350 bpm)
- Fibrillation: Rapid, uncoordinated contractions

In any case, cardiac outpost is reduced causing the heart to fall

3. Pericarditis: When pericardium becomes inflamed. Layers become stuck together by adhesions.

4. Endocarditis: Most often caused by bacterial infection

Lasting effects by damage to the valves of the heart

# data[].attributes.body
When blood vessels are broken, blood loss can lead to weakness, shock and eventually death.

Loss of over 30% of a person's total blood volume can be fatal unless treated.

When giving a blood transfusion, it is essential to test the blood groups of both the donor and the recipient.

# data[].attributes.body
A: A agglutinogen, anti B agglutinin
B: B agglutinogen, anti B agglutinin
AB: A & B agglutinogen, neither A nor B agglutinin
O: neither A & B agglutinogen, both A & B agglutinin

# data[].attributes.body
During a blood transfusion, only certain types of donor blood will successfully transplanted in a recipient.
Example: Type A can receive type A OR type O blood.

# data[].attributes.body
*Type AB is universal recipient *Type O is the universal donor

# data[].attributes.body
Rh+: This means they have Rh antigen on their RBC's

Rh-: This means they do not have the Rh antigen. If they come in contact with Rh+ blood they will start producing anti Rh+ antibodies that will attack

# data[].attributes.body
1 in 3 is O+
1 in 15 is O-
1 in 3 is A+
1 in 16 is A-
1 in 12 is B+
1 in 67 is B-
1 in 29 is AB+
1 in 167 is AB-

# data[].attributes.body
Oxygen-rich blood leaves the lungs and returns to the heart by the way of blood vessels called pulomary veins

Only veins that carry oxygen rich blood

Returning blood enters the left atrium & passes through a flap tissue to left ventricle
- Through Mitral (bicuspid) valve

From the left ventricle, blood is pumped through the aortic valve into the aortic artery that carries it to every part of the body (except lungs)

Aortic valve prevents back flow

# data[].attributes.headline
Blood is unique in that is the only fluid body tissue.

# data[].attributes.subject
Blood is unique in that is the only fluid body tissue.

# data[].attributes.headline
Blood is a connective tissue composed of solid elements suspended in fluid called plasma.

# data[].attributes.subject
Blood is a connective tissue composed of solid elements suspended in fluid called plasma.

# data[].attributes.headline
About 55% is made up of plasma, with the remaining 45% made up of solid elements. 

# data[].attributes.subject
About 55% is made up of plasma, with the remaining 45% made up of solid elements. 

# data[].attributes.body
Erthocytes: red blood cells that function in oxygen transport and make up the large majority of the solid matter of the blood.

Hemoglobin - an oxygen binding protein that contains iron that gives red blood cels their color.

- Hemoglobin contains iron, which is what gives red blood cells their color.
- The more hemoglobin molecules a red blood cell contains, the more oxygen the cell is able to carry.
- The amount of hemoglobin produced by the body can vary dependent on elevation and physical training.
- One RBC contains @ 250 million hemoglobin molecules. Each can bind to 4 oxygen molecules, so each cell can carry @ 1 billion molecules of oxygen total.

Leukocytes: white blood cells that protect your body from disease by either phagocytizing (eating) bacteria or producing substances that destroy infectious particles.

- Every 1,000 RBC, there are 1-2 WBC
- Colorless, larger RBC, there are 1-2 WBC
- When white blood cells are needed to defend against a foreign agent, the body speeds up their production.
- Destroyed while fighting infection.

Types of Leukocytes
Granulocytes:

1. Neutrophils - targets bacteria and fungi

2. Eosinophils - target is parasites and work with alle reactions

3. Basophils - work with allergic reactions

Arganulocytes:

1. Monocytes - develop into macrophages to fight future pathogens (long-term clean-up team)

2. Lymphocytes - fight pathogens

Thrombocytes/Platelets: Cell fragments that function in blood clotting.

Plasma: Liquid portion of blood.

- However, dissolved in the plasma are many important elements being transported by the blood.
- Vitamins, proteins, hormones, and antibodies, etc.

Hematopoiesis: Blood formation

- Occurs in the red bone marrow of:
Flat bones - skull pelvis, ribs, sternum
Epiphyses of humerus and femur
- All cells originally formed are stem cells that develop into a specialized blood cell.

# data[].attributes.body
The tricuspid valve regulates blood flow between the right atrium and right ventricle.

The pulmonary valve controls blood flow from the right ventricle into the pulmonary arteries, which carry blood to your lungs to pick up oxygen.

The mitral valve (bicuspid) lets oxygen-rich blood from your lungs pass from the left atrium into the left ventricle.

The aortic valve opens the way for oxygen-rich blood to pass from the left ventricle into the aorta, your body's largest artery, where is is delivered to the rest of your body.

# data[].attributes.body
Systole: heart contraction

Diastole: heart relaxation

The contraction and relaxation of the ventricles, unless otherwise noted.

Blood pressure readings are recorded as systolic pressure over diastolic pressure, which refer to the pressure in the arteries during contraction and relaxation, respectively.

- A typical blood pressure reading is around 120/80

# data[].attributes.body
Cardiac muscle can contract independently, even if it's severed from all nerve connections.

Two systems act to regulate heart activity:

The nerves of the nervous system act to decrease and increase heart rate in response to environmental changes.

The intrinsic conduction system (nodal system) built into the cardiac muscle tissue, this sets the heart basic rhythm.

4 major parts that make up the intrinsic conduction system:

Sinoatrial (SA) Node - tissue located on the right atrium which starts each heartbeat and sets the pace for the whole heart. Also known as the pacemaker.

Atrioventricular (AV) Node - tissue located at the junction of the atria and ventricles, this causes the atria to contract.

Atrioventricular (AV) Bundle - groups of fibers located on the interventricular septum.

Purkinje Fibers - spread throughout the muscle of the ventricle walls.

**These cause the ventricle to contract