Anatomy Flashcards
(125 cards)
What is the cardiovascular system comprised of?
Arterial System
Heart
Venous System
What are the 4 cardiac valves and where are they located?
- Tricuspid valve = RA + RV
- Pulmonary valve = RV + Pulmonary Trunk
- Mitral valve = LA + LV
- Aortic Valve = LV + Aorta
Describe the journey of blood through the heart
Blood flows in through the Superior or Inferior Vena Cava into the right atrium of the heart, through the tricuspid valve into the right ventricle.
Blood flows through the Pulmonary valve into the pulmonary trunk into the lungs and back through the pulmonary artery.
It passes into the left atrium through the mitral valve into the left ventricle through the aortic valve into the aorta.
What are the 3 layers of the heart (From external to internal)
- Epicardium (external)
- Myocardium
- Endocardium (Internal)
What happens in systole?
Contraction
What happens in diastole?
Relaxation
What chamber forms the right border of the heart?
Right atrium
What chamber forms the anterior border of the heart?
Right Ventricle
What chamber forms the posterior border of the heart?
Left Atrium
What chamber forms the left border of the heart?
Left Ventricle
What are the 3 layers of blood vessels (internal to external)?
- Tunica Intima
- Tunica Media
- Tunica Adventitia
Describe the conduction system of the heart.
- Electrical impulse starts at the SA node (Both atria contract)
- Travels to AV node at atrioventricular septum
- Travels down right and left bundles in interventricular septum
- Spreads out to myocardium through conducting fibres (both ventricles contract)
Describe features of arteries
- High pressure
- Pulsatile
- Carry oxygenated blood
What is an end artery?
only arterial blood supply to a given area of the body. Occlusion of an end artery results in infarction.
What is infarction?
irreversible cell death due to hypoxia.
Describe sympathetic Tone?
Sympathetic Tone is the background low level of contraction of smooth muscle in arterioles. This is due to tonic conduction of action potentials to arterioles by sympathetic nerves.
What is vasodilation?
Vasodilation is relaxation of the smooth muscle and widening of the lumen to increase blood flow.
What is vasoconstriction?
Vasoconstriction is the contraction of smooth muscle to reduce blood flow to the organ/tissue.
What is an anastomosis?
Anastomosis is where arteries connect with each other without intervening capillary network. This provides alternative routes for blood to flow to supply the cells distal to an arterial occlusion.
What is an example of an anastomosis?
The Circle of Willis in the brain
What are collateral arteries?
Alternative routes in an anastomosis.
What is a disadvantage of collateral arteries?
One disadvantage is that collaterals bleed from both sides of the cut.
What are the branches of the aorta?
- Brachiocephalic trunk
- Left common carotid artery
- Left subclavian artery
Describe features of veins
- Low pressure
- Deoxygenated blood
- Non-pulsatile