Cardiovascular Flashcards
What is the pericardium? What are its layers?
A tough, double-layered fibroserous sac which covers the heart.
It’s layers are:
- Fibrous pericardium: this is the most superficial layer, has loose and dense connective tissue and protects the heart, fixes it and prevent over filling
- Serous pericardium: has two layers, parietal (fused to the fibrous) and visceral (part of epicardium) both have a lubricating function
What artery supplies the Sino Atrial Node?
The right coronary artery (60%)
What artery supplies the Atrioventricular Node?
Posterior interventricular artery.
This arises from:
70% - Right coronary artery
20% - Right & Left coronary arteries
10% - Left coronary artery
Where can the apex beat be heard?
Left of the sternum, 5th intercostal space, mid-clavicular line
What is on the right heart border?
1) Superior Vena Cava
2) Right atrium
What is on the left heart border?
1) Aortic knuckle
2) Left pulmonary artery
3) Left auricle
4) Left ventricle
What is the anterior border of the heart?
Right ventricle
What is the posterior border of the heart?
Left atrium & pulmonary veins
What is the mediastinum?
Area between the right and left pleura
Where what divided the mediastinum into superior and inferior?
Plane between eternal angle & T4/5 vertebrae
How is the mediastinum into anterior, middle & superior?
By pericardium
Where would you find the SA node?
A long cresent shaped area in the crusts terminal is at the superior border of the right atrium
Where is the AV node located?
A small nodule just above the septal cusp of the tricuspid value in the inter-atrial septum
What is the thoracic duct?
A channel draining lump from below the diaphragm and above the diaphragm on the left side. It drains the lymph into the junction between the left subclavian vein and left internal jugular vein.
What is the nerve root of the greater splanchnic nerve? What does it supply?
T5-9
Supplies the foregut
What are the nerve roots of the lesser splanchnic nerve? What does it supply?
T10 & T11
Mid gut
What is the nerve root of the least splanchnic nerve? What does it supply?
T12
Hindgut
What level does the bifurcation of the aorta occur?
L4
Why is heart pain referred and where to?
Neck, shoulders, jaw, arms and stomach.
Because the heart’s sensory supply is from the cardiac plexus made up of spinal nerves T1-T4 so pain is felt in the dermatomes supplied by these nerves
What is involved in cardiac muscle contraction but not in skeletal muscle contraction (or to a lesser extent)
Calcium-induced calcium release: this is where an increase in Ca2+ in the cell causes more calcium release (part of the early plateau phase)
What are the two main baroreceptors?
1) Carotid sinus
2) Aortic Arch baroreceptors
What happens if the blood pressure decreases through baroreceptor detection?
Decreased pressure > decreased discharge rate > Fewer action potentials to medullary cardiovascular centre
This leads to:
- Increased hear rate (^symp)
- Increased contractibility (^symp)
- Arteriolar construction (^symp + angiotensin II & ADH release)
- Increased venous constriction (^symp)
What are the local factors that cause vasoconstriction?
1) Endorhelin - peptide produced by endothelium with causes constriction
2) myogenic contraction of blood vessels
What are the local factors for vasodilation?
Hypoxia Hypercapnia Decreased pH Bradykinin Increased K+ Nitric oxide Tissue breakdown products