# data[].attributes.body
3 layers-

1. Inner- Epithelial cells

2.  Middle- Smooth muscle

3. Outer- connective tissue

# data[].attributes.body
Carries oxygen rich blood from the lungs through the pulmonary vein back to the heart

Carries oxygen poor blood from the rest of the body back to the heart

# data[].attributes.body
Single layer of epithelial cells

# data[].attributes.body
Where diffusion takes place in- exchanges gasses

Example- In the lungs, oxygen travels from the lungs (high concentration) to the capillaries (low concentration) through while the carbon dioxide travels from the capillaries (high concentration) to the lungs (low concentration)

# data[].attributes.headline
                                        Structure

# data[].attributes.subject
                                        Structure

# data[].attributes.body
3 layers-

1. Inner- Epithelial cells

2.  Middle- Smooth muscle

3. Outer- connective tissue

# data[].attributes.body
1. Carries oxygen poor blood from the right ventricle through the Pulmonary arteries to the lungs

2. Carries oxygen rich blood through aorta (which branches out into many arteries) to the rest of the body

3. Regulating blood flow- arteries become bigger or smaller based on how much blood the organ needs. When it needs more blood, the artery expands and when it needs less blood, it contracts.

# data[].attributes.body
1. Arteries:
- Arteries are deep under the skin
- There are 5 arteries in your leg
- 2 arteries go to the brain
- larger arteries tend to be elastic and smaller ones tend to be muscular

# data[].attributes.body
2. Capillaries-
- capillaries are a tenth of the diameter of a human hair
- there are 10 billion capillaries in the body
- capillaries are smaller than a dot on a piece of paper
- capillaries are about 600 microns long

# data[].attributes.body
3. veins-
- there's at least 34 main veins in your body
- women are 4 times more likely to develop a vein problem than men
- up to 70% of your body's entire blood supply is located within the vein
- As you get older, your veins start to lose elasticity and valves, making them less efficient.