Cardio System Flashcards
What are the Blood vessels and valves in the head
Vena cava
Pulmonary artery
Aorta
Pulmonary vein
Aortic semi lunar valve.
Pulmonary aortic semi lunar valve.
Tricuspid valve.
Bicuspid.
What are the four components of the conduction system?
SA node
AV node
Bundle of his
Purkinje fibres
What are the four chambers of the heart?
Right atrium Left atrium
Right ventricle Left ventricle
What are the four components of the blood?
Platelets
White blood cells
Plasma
Red blood cells
What is Venous return?
Venous return is the return of blood to the heart during the cardiac cycle.
What is starlings law?
There are two problems that might delay or slow down venous return.
One is the blood pressure in the veins is very low. Most of t the blood has been distributed lower than a heart, and therefore has a fight against the gravity to make its way back to the heart.
What are the solutions for starlings law?
Solution one is veins, have pocket valve to prevent backflow of blood.
Solution to his skeletal muscle pumps – when muscles in the lower leg contract, they squeeze the surrounding veins and forth of blood back to the heart .
Solution three is smooth, muscle veins aligned with muscles, so can vino constrict and force the blood back towards the heart.
Solution for is a respiratory pump – as the diaphragm flattens, and we inhale depression of the thoracic cavity is increased and forces blood back to the heart. This happens more the higher are breathing rate is.
Solution five is gravity blood from above the heart returns, via gravity.
How do we regulate heart rate during exercise?
We use neural and hormonal and intrinsic.
What are the neural factors?
Chemoreceptors, barrow, receptors, proprioreceptors and thermoreceptors.
Where are chemoreceptors and what do they do?
They are in the blood, and they measure O2 and CO2 levels.
Where are baroreceptors and what do they do?
These are in the arteries, and they measure blood pressure.
Where are proprioreceptors and what do they do?
They measure muscle contraction, they send information to the VCC, and this increases stimulation of the SA node via the sympathetic nervous system, which intern increases heart rate.
What do Thermo receptors do and whereabouts are they in the body?
They’re everywhere and they measure temperature.
What are the hormonal factors?
Adrenaline is released prior to exercise.
What does the adrenaline being released prior to exercise do for the body?
It stimulates the sympathetic nervous system, which increases stimulation of SA node, which in turn increases heart rate. Adrenaline also increases forces of cardiac contractions, increasing stroke, volume and cardiac output (Q).
What are the intrinsic factors (inside the heart)?
Increase temperature increased venous return.
What does an increase in temperature do?
This causes increased speed of nerve transmission, which intern increases stimulation of the SA node which intern increases heart rate.
What does an increase in VR do?
An increase in the volume of blood, returning to the heart, stretches the walls of the heart, which increases stimulation of the SA node, which in turn increases HR.
Hence what will a decrease in temperature cause?
A decrease in temperature will decrease the speed of no transmission and so the VR slows down and intern the heart rate slows down as well.
What happens to the neural factors when a person slows down that exercise?
Receptors detect a change the other way messages sent to the VCC. And use of the parasympathetic nervous system is used to slow down the SA node and so slow down that HR.
What is the vascular shunt mechanism?
This is a vasodilation and vasoconstriction, and this happens when exercise occurs.
What happens at rest?
The abundant capillaries on organs will be full of blood as the valves connecting to the main artery will be open to allow maximum blood flow to the organs.
However, for the muscles, the valves will be closed so the abundant capillaries on muscles at rest won’t have much blood at all in them and the blood will just go through the main pre-capillary.
What happens during exercise in the vascular shunt mechanism? Lol
For the organs the capillaries will vasoconstrict, the valves from the pre-capillary will close, and the abundance of capillaries covering the organs will not have much blood flow, and it will only be going through that one capillary. However, for the muscles the capillaries will vasodilate to allow more blood through and the valves will open and the abundant capillaries will fill with blood to allow more oxygen to go to the working muscles. This is known as blood shunting.
What is the cardiac cycle?
This is the sequence in which blood is pumped in.
