Lecture 48 - Cardiovascular System 2 Flashcards
We’re do the coronary vessels run?
In the grooves of the exterior surface of the heart
Where does the heart get its blood?
Coronary arteries
First two branches of the aorta
How does the name of the aorta change?
Changes according to its position
No clear demarcation
- Ascending aorta
- Aortic arch (upwards, backwards, to the left)
- descending thoracic aorta
What does the aorta arch over?
Left lung route
Where does the descending thoracic aorta run?
Down the left side of the vertebral column
Through the diaphragm
What happens to the aorta once it goes through the aorta
T12: becomes the abdominal aorta
Only name changes
What are the first branches of the ascending aorta?
Coronary arteries
Literally just above the attachments of the aortic valves
What are the two bits of the coronary arteries?
Left coronary artery: posterior surface of the heart
Right coronary artery: anterior surface of the heart
Runs in anterior AV groove (coronary groove)
Supplies right atrium and ventricle, as well as SA and AV node
Describe the features of the right coronary artery
Right coronary artery:
- anterior surface of the heart
- Runs in anterior AV groove (coronary groove)
- Supplies right atrium and ventricle, as well as SA and AV node
Describe the features of the left coronary artery
Left coronary artery:
- Posterior surface of the heart
- Runs in anterior interventricular groove
- Supplies left atrium and ventricle
Draw the paths of the coronary arteries
Slide 8
What are the regions where the left and right arteries connect?
Anastomosis
What happens if there is a sudden occlusion in the left coronary artery?
The right coronary arteries cannot supply the left side, because the anastamoses are too small (capillary sized)
Whatever is supplied by the blocked artery dies
Are the coronary arteries end arteries?
Yes
What is myocardial infarction?
Sudden occlusion of a coronary artery
No blood flow to the tissue supplied distal to the clot
What happens in slow occlusion
Anastomotic channels can open up
Some blood can get through and supply the tissue
Why do an angiogram before surgery?
Determine where the block is
Find out where the arteries are –> natural variation in humans
What does the arch of the aorta branch into?
1\ Brachiocephalic trunk:
- right common carotid
- right subclavian
2\ Left common carotid
3\ Left subclavian
How many branches are there off the aortic arch?
Three
What happens beneath the arch of the aorta?
Pulmonary trunk divides into right and left branches
How can blood bypass the lungs?
- Foramen ovalis
- Ductus arteriosus
What happens to the ductus arteriosus after birth?
Constricts –> non functional
We see a remnant:
Fibrous cord called:
- ligamentum arteriosum
What are the branches of the descending thoracic aorta?
What does each branch supply?
Intercostal arteries (chest wall)
Bronchial (lung tissue)
Pericardial branches (pericardium)
Oesophageal (oesophagus)
What does the IVC travel through to the right atrium?
Central ligament of the diaphragm
What drains blood from the head?
Left and right
Internal jugular veins
IJV
What drains blood from the upper limb?
Subclavian veins
Where do the subclavian veins run?
Anterior to the subclavian arteries
Describe the IJV and subclavian veins uniting
Draw this
Left IJV and left subclavian unite –> left brachiocephalic
Right IJV and right subclavian unite –> right brachiocephalic
Slide 13
Is there a difference in path between the left and right brachiocephalic veins?
Yes
Right: shorter
Left: longer
How is blood drained from the walls of the thoracic wall
Azygos system of veins
Describe the Azygos system of veins
Highly variable
There is always a final azygos vein that receives blood from everything else (oesophagus, pericardium, walls)
This enters into the SVC
