RAA Physiology and Pathophysiology

Question 1

Aorta basic facts

Answer 1

Largest artery in the body.

The aorta begins at the top of the left ventricle, the heart’s muscular pumping chamber.

The heart pumps blood from the left ventricle into the aorta through the aortic valve.

The aorta is a tube about a foot long and just over an inch in diameter.

Question 2

Sections of aorta

Answer 2

1. Ascending Aorta
2. Aortic Arch
3. Thoracic Aorta
4. Abdominal Aorta

Question 3

Ascending Aorta

Answer 3

• Rises up from the heart
• 2 inches long.
• Coronary arteries branch off the ascending aorta to supply the heart with blood.

Question 4

Aortic Arch

Answer 4

• curves over the heart,

- giving rise to branches that bring blood to the head, neck, and arms.

Question 5

Thorcaic Aorta

Answer 5

travels down through the chest.

Its small branches supply blood to the ribs and some chest structures.

Question 6

Abdominal Aorta

Answer 6

• begins at the diaphragm,
• splitting to become the paired iliac arteries in the lower abdomen.
• Most of the major organs receive blood from branches of the abdominal aorta.

Question 7

Layers of the aorta

Answer 7

1. Intima
2. Media
3. Adventitia

Question 8

Aortic Intima

Answer 8

• innermost layer,

- provides a smooth surface for blood to flow across

Question 9

Aortic media

Answer 9

• middle layer with muscle and elastic fibres,

- allows the aorta to expand and contract with each heartbeat.

Question 10

Aortic Adventitia

Answer 10

• the outer layer,

- provides additional support and structure to the aorta.

Question 11

Physiology of aneurysm

Answer 11

• Aortic Aneurysm (AA) occurs where there is weakening of the vessel wall causing localised dilation of the vessel.
• The aorta is more at risk of aneurysm due to the constant high pressure
• Can occur at different points along the aorta
• 4/100 men and 1/100 women over 65yrs of age have a AAA in the UK
• Many are unaware
• Symptoms may present when aneurysm puts pressure on a nearby structure

Question 12

Physiology of ruptured aneurysm

Answer 12

• Often no knowledge of aneurysm - first sign is rupture, rapid exsanguination and death
• Sudden severe pain would indicate a rupture in the aneurysm
• The larger the aneurysm the higher likelihood of rupture
• Blood from ruptured aneurysm will bleed out into thoracic cavity (if thoracic Aortic aneurysm) or abdominal cavity (if AAA)

Question 13

Causes of Aortic Aneurysm

Answer 13

• Atherosclerosis, or hardening of the arteries, which weakens arterial walls.
• Hypertension (high blood pressure).
• Local injury to the artery.
• Congenital abnormality. …
• Aging.
• Syphilis used to be a common cause of thoracic aneurysms, but it is no longer as common.