1 - Introduction to CVS Flashcards
How do single-celled organisms get oxygen and nutrients from their environment?
By diffusion across the cell membrane
Why do large multi-cellular organisms need a cardiovascular system?
For oxygen and nutrients to diffuse, there needs to be a system for these substances to get close to the cells
What is the structure of a capillary?
Single layer of endothelial cells surrounded by basal lamina
What is the function of the cardiovascular system?
- Take oxygen and nutrients to the tissue capillaries so diffusion can take place and pick up carbon dioxide and waste products for excretion
- Cellular signalling via hormones
- Protection of the body from pathogens via the immune system and protection from blood loss via clotting
- Homeostasis of pH, temperature and water balance
Why are coronary vessels required when the heart already contains blood in it’s chambers?
- The distance of cells in the muscle wall from the source of oxygen and nutrients is too large for diffusion to take place
- Only the left side of the heart carries oxygenated blood
Infarcted tissue is caused by a ………. in a coronary vessel. In pathology, the tissue will appear ………….
Blockage
White (scar tissue)
The conorary arteries branch from the ………
Aorta
In the anatomical position, the ……… ………… forms the anterior surface of the heart
Right ventricle
What are the two main branches of the coronary arteries that leave the aorta?
- Right coronary artery
- Left coronary artery
What two branches come off of the left coronary artery?
- Anterior interventricular (left anterior descending)
- Circumflex
Which of the coronary arteries is most commonly blocked in a myocardial infarction?
Anterior interventricular (left anterior descending)
Coronary arteries have few anastomoses, what does this mean?
- They are end arteries and don’t link together very much
- Anastomoses allow blood supply to continue even if one pathway was blocked - coronary arteries cannot do this
Describe the location of the apex of the heart from the surface anatomy.
- 5th intercostal space
- mid-clavicular line
Where is the base of the heart?
- At the superior border, where the great vessels emerge
Where is the right border of the heart, relative to the surface anatomy?
~1cm lateral (right) from the sternum along the 3rd costal cartilage
Where is the right border of the heart, relative to the surface anatomy?
~1cm lateral (right) from the sternum along the 3rd costal cartilage
Where is the right inferior border of the heart, relative to the surface anatomy?
~1cm lateral (right) from the sternum along the 6th costal cartilage
The heart lies within a sac called the ……………
Pericardium