Cardiovascular 1 Flashcards
What is the cardiac output for an average adult male at rest?
What can this increase to in exercise?
5L/min at rest
25L/min during exercise
Which organs need a constant supply of blood irrespective of exercise or rest. Which organs can have altered supply? Put some figures to these.
Brain
- at rest, 0.75L/min - the same during exercise
Heart
- at rest, 0.3L/min - during exercise, 1.2L/min
Kidney
- at rest 1.2L/min and same during exercise
Skeletal muscle
- 1.0L/min to 16L/min during exercise
Skin
- 0.2L/min to 2.5L/min during exercise - thermoregulation
What are resistance vessels and why are they necessary
In order to perfuse tissues that are hard to perfuse such as the brain, resistance vessels make it harder to perfuse some easy to perfuse tissues so blood is diverted away to the harder areas.
This is done by resistance vessels and in the cvs, the arterioles are the resistance vessels.
How man layers of the pericardial is there?
2:
Fibrous part
Serous part
Describe the different layers of the pericardial sac.
Fibrous
- tough external layer
- forms a ligament to sternum, the sternopericardial ligament, which holds the heart in place. Attaches to the posterior of the sternum.
Serous
- parietal - the outer layer - fused to the fibrous pericardium
- visceral - forms the epicardium
- extends to the beginning of the great vessels
- where the aorta/pa leave the heart and IVC/SVC/PV
enter it
Between the visceral and parietal pericardium, there is fluid to enable friction free movement.
Which nerves innervate the pericardium?
Phrenic nerves c3, c4 and c5
Pain sensed here is referred to C3-5 dermatomes hence get pain referred down the arm.
What are the borders of the heart?
Right border - right atrium
Left border - left ventricle
Inferior border - right ventricle.
How is the heart attached to the sternum and the diaphragm?
The anterior pericardium is connected to the posterior sternum by the sternopericardial ligament.
Inferior pericardial surface is fused with the diaphragm.
What are the first branches of the aorta and where do they arise?
The coronary arteries are the first branches of the aorta, and they arise from the aortic sinus, which is located at the base of the aorta, just superior to the aortic valve.
Describe the branches of the right coronary and what they supply
RCA - Right atrium, SAN/AVN (at the crux - junction of all 4 chambers).
RMA - right atrium
Posterior IV - R+L ventricles
What are the branches of the left coronary and what they supply
LCx - LA and LV
LMA - left ventricle
LAD - RV and LV
What 3 parameters influence diffusion?
Area - more area = more diffusion
Resistance - generally low - the lower the better
Concentration gradient - between the blood and tissues. Higher is better
