The Cardivascular System (P1) Flashcards
What is the Arterio-Venous Difference?
The difference between the oxygen content of the arterial blood arriving at the muscles and the venous blood leaving the muscles.
When is their a high arterio venous difference and when is their a low difference ? And why?
There is a high difference during exercise because more oxygen is needed from the blood for muscle contractions. There is a low difference during rest because as not much oxygen is required by the muscles.
How does a high difference in the Arterial-Venous Difference affect gaseous exchange?
This affects gaseous exchange at the alveoli as more oxygen is taken in and more carbon dioxide is removed.
How is oxygen transported? As a percentage.
97% is transported with haemoglobin in oxyhemoglobin.
3% with blood plasma
What is haemoglobin and myoglobin?
An iron containing pigment found in the red blood cells.
Myoglobin is the ‘muscle haemoglobin’. An iron containing muscle pigment in slow twitch muscle fibres which has a higher affinity for oxygen than haemoglobin.
.When partial pressure (concentration) of oxygen is high e.g in the lungs how many molecules of oxygen can a haemoglobin molecule carry?
.When partial pressure is low e.g in muscle tissue what happens to oxygen molecules?
. What is this called ?
.4 molecules
. Oxygen is released from oxyhaemoglobin
. Oxyhaemoglobin association/dissociation curve
Where does the oxygen go when it dissociates from haemoglobin?
Myoglobin takes oxygen away from haemoglobin into the muscle cell and stores it until it is needed by the mitochondria for aerobic respiration and energy production.
Who has large amounts of myoglobin and mitochondria and why?
Endurance athletes as a result of training.
What is the oxyhaemoglobin dissociation curve?
It helps us to understand how haemoglobin in our blood transports and releases oxygen. The curve shows the relationship between oxygen and haemoglobin.
What is a Bohr Shift?
During exercise, the s-shaped curve shifts to the right because when muscles require more oxygen, the dissociation of haemoglobin in blood capillaries to the muscle tissue occurs more readily.
What are the four reasons why a Bohr shift occurs?
- Increase in blood and muscle temperature during exercise
- Decrease in the partial pressure of oxygen- muscles use more oxygen to provide energy
- Increase in the partial pressure of carbon dioxide- muscles produce more carbon dioxide as a by-product.
- Lower pH- The increase in lactic acid/increased co2 in muscles/blood acidity
What is the vascular shunt mechanism?
The redirecting of blood to the areas that most need it. During exercise the skeletal muscles require more oxygen so more blood needs to be redirected to them.
What may occur if a performer eats less than an hour before exercise?
A full gut would result in more blood being being directed to the stomach instead of the working muscles .
What is the cardiovascular system?
The body’s transport system.
In the heart, what does the dual action pump do?
Pumps blood to two destination. Heart and lungs.
What does the right side of the heart do?
Pumps deoxygenated blood towards the lungs.
What does the left side of the heart do?
Pumps oxygenated blood towards the body.
What is the name of the mucular wall that seperates the two chambers?
The septum.
Each half contains two chambers which are called….
which are bigger?
Atrium and ventricles. Ventricles are bigger
What does the atria do?
Atria push blood down into the ventricles which does not require much force so they have thinner muscular walls.
What do ventricles do?
They have thicker muscular walls so they need to contact with more muscular force to push blood out of the heart.
What do the superior/inferior vena cava do?
Carry deoxygenated blood from the body to the right atrium.
What does the pulmonary vein do?
Carries oxygenated bloodfrom the lungs to the left atrium.
What does the aorta do?
Carries oxygenated blood from the left ventricle to the whole body.
What seperates atria from the ventricles?
2 AV (atrioventricular) valves
What is the main role of the valve?
To prevent backflow.
What are the two names of the valves of the heart?
Tricuspid and bicuspid.
What side if the tricuspid valve?
Right
What side is the bicuspid valve?
Left
What is the journey of the red blood cell in order?
Vana cava, right atrium, tricuspid valve, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, bicuspid valve, left ventricle and aorta.
What is a cardiac impulse?
An electrical impulse responsible for strimulating the heart to contract (systole).
What does myogenic mean?
The capacity of the heart to generate its own impulses.
What is the order of the cardiac conduction system?
SA Node Atrial systole AV Node Bundle of his Bundle his branches Purkinje fibres Ventricular systole
What is the SA node?
It generates the heart rate. Also called a pacemaker.
What is atrial systole?
An elctrical impulse through the walls of the atrial causing them to contract.
What is AV node?
This node relays the impulse between ther upper and lower sections of the heart.
What is the bundle of his?
A collection of heartt muscle cells that transmit electrical impulses from the AV node via the bundle branches.
What is the purkinje fibres?
Muscle fibres that conduct impulses in the walls of the ventricles.
What does CCC stand for?
Cardiac Control Centre
Where is the CCC found?
Medulla Oblongata (brain)
What do chemoreceptors detect? Where are the found?
Detects changes in blood acidity caused by an increase or decrease in the levels of carbon dioxide. Carotid arteries and aorta.
What will happen if there is an increase in the levels of carbon dioxide in the blood?
The chemoreceptors will detect the increase in co2 in the blood. The CCC will stimulate the sympathetic nervous system to send sympathetic nerve impulses to the SA node and then the heart will beat faster.
What will happen with a decrease in the levels of carbon dioxide?
The chemoreceptors will detect the decrease in co2 in the blood.The CCC will stimulate the parasympathetic nervous system to send parasympathetic nerve impulses to the SA node which will decrease heart rate.
What do the baroreceptors detect and where are they found?
They respond to changes in blood pressure to either increase or decrease heart rate. Found in the aorta, heart and pulmonary vessels.
What happens if there is an increase in blood pressure?
Baroreceptors detect the increase and the CCC will stimulate the parasympathetic nervous system to send parasympathetic impulses to the SA node which will decrease heart rate.
What happens if there is an decrease in blood pressure?
Baroreceptors detect a decrease and the CCC will stimulate the sympathetic nervous system to send sympathetic impulses to the SA node which will increase heart rate.
What are proprioceptors?
sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement.
What happens when an increase in movement is detected?
The proprioceptors send a signal to the CCC which stimulates the sympathetic nervous system to send sympathetic impulses to the SA node which will increase heart rate.
What happens when an decrease in movement is detected?
The proprioceptors send a signal to the CCC which stimulates the parasympathetic nervous system to send parasympathetic impulses to the SA node which will decrease heart rate.
What type of control are chemoreceptors, baroreceptors and proprioceptors?
Neural control