CV System

• What is heart rate?

  Number of ventricular contractions (beats) per minutes
• What is stroke volume?

  Volume of blood ejected from the left ventricle per beat
• What is cardiac output?

  The volume of blood ejected from the left ventricle per minute
• What is venous return?

  The return of blood to the heart
• What is starling‘s law?

  Increased venous return, increases the stretch of the ventricle walls and force of contractions so stroke volume increases
• what is myogenic? 


  the capacity of the heart to generate its own electrical impulse
• What is the cardiac cycle?

  the process of cardiac muscles contracting and the movement of blood through the chambers. Atrial systole, ventricular systole and cardiac diastole
• what is the conduction system?

  Electrical system that transmits an impulse to the atria and ventricles to contract
• What is the SA node?

  Generates the electrical impulse to initiate the conduction system and sends it through the atria walls causing them to contract
• What is the AV node?

  Receive the signal from the SA node and delays it to allow blood to catch up
• What is The ‘bundle of his’?


  Structures in the septum that branches left and right. It receives the signal from the AV node and send it to the pirkinji fibres
• What are purkinji fibres?

  Distributes the electrical impulse through the hearts ventricular walls, causing them to contract
• What is the cardiac control centre (CCC) responsible for?

  Regulation of heart rate
• Where is the cardiac control centre located?

  In the medulla oblongata
• What is the function of pocket valves in veins?

  Prevent backflow of blood
• What does the medulla oblongata regulate?

  Basic functions of the autonomic nervous system
• How does smooth muscle in vein walls assist blood movement?

  By vasoconstricting to aid blood flow
• How does gravity assist venous return from the upper body?

  Helps blood return to the heart
• What does the autonomic nervous system control?

  Bodily functions like heart rate
• What is the muscle pump mechanism during exercise?

  Skeletal muscles contract to compress veins
• What do chemoreceptors detect?

  Chemical changes like O2 and CO2
• How does the respiratory pump aid venous return?

  Creates pressure difference during breathing
• What do proprioceptors detect

  Detect changes in environment (Located In muscles, tendons, and joints)
• What is blood pooling?

  Accumulation of blood in veins
• What do baroreceptors detect?

  Pressure changes in blood pressure
• How do temperature changes affect blood viscosity?

  They affect thickness and nerve impulse speed
• What is the vasomotor control centre responsible for?

  Distribution of cardiac output
• What is vasomotor tone?

  Partial smooth muscle constriction in arteries
• How does adrenaline affect the heart?

  Increases force of ventricular contraction
• What is the vascular shunt mechanism?

  Redistribution of cardiac output during exercise
• What does the sympathetic nervous system do?

  Increases heart rate during exercise
• What are arterioles?

  Blood vessels from arteries to capillaries
• What does the parasympathetic nervous system do?

  Decreases heart rate during recovery
• What are pre-capillary sphincters?

  Rings of smooth muscle at arterioles
• What is vasoconstriction?

  Narrowing of arteries and arterioles
• What is vasodilation?

  Widening of arteries and arterioles