Cariovascular and respiratory systems Flashcards
What is the Pulmonary circuit ?
Circulation of blood through the pulmonary artery to the lungs and pulmonary vein back to the heart
What is the systemic circuit ?
Circulation of blood through the aorta to the body and vena cava back to the heart
What happens if the body’s cardiovascular system is efficient ?
Greater the capacity to transport oxygen to the muscles and the greater the capacity to remove waste products from the muscles eg carbon dioxide and lactic acid
What are the chambers called in the heart ?
Atriums
Ventricles
Why is it important that the heart is separated ?
To keep the oxygenated and deoxygenated blood separate.
Describe the left side of the heart ?
Thick muscular wall which can contract with more force to circulate oxygenated blood from the lungs through the large systemic system circuit to muscles and organs
Describe the right side of the heart ?
Contracts to circulate deoxygenated blood from the body through the pulmonary circuit to the lungs
What is the path of the blood through the Heart ?
Left side of Heart - Blood is oxygenated at the lungs brought back to the left atria through the pulmonary vein.
Oxygenated blood moves from the left atria , through the left AV valve into the left ventricle. To be force out of the heart via the aorta.
Right side - Deoxygenated blood from the muscles and organs arrive back at the right atria through the vena cava. It moves right through the AV valve ( tricuspid ) into the right ventricle.
The blood is forced out by the pulmonary artery which carries blood back to lungs.
What is oxygenated blood ?
Blood saturated with oxygen and nutrients
What is deoxygenated blood ?
Blood depleted of oxygen , saturated with carbon dioxide an waste products
What is the conduction system ?
A set of structures in the cardiac muscle which create and transmit electrical impulses.
What is Myogenic ?
The capacity of the heart to generate its won electrical impulses, which cause cardiac muscle to contract.
What are the 5 structures in the conduction system ? ( in order)
SA node AV node Bundle of his Bundle of branches Purkyne fibres
SA node ?
Located in the right atria wall
generates electrical impulse and fires it through atria walls , causing them to contract.
Fire rate will determine heart rate
AV node ?
AV node collects impulse and delays it for 0.1 seconds to allow atria to finish contracting
Then releases impulse to bundle of his
Bundle of his ?
Located in the septum of the heart , the bundle of his splits the impulse in two.
To distribute to different ventricles
Bundle branches ?
Carry the impulse to the base of ventricle
Purkyne fibres ?
Distribute the impulse through ventricle walls causing them to contract
Define Diastole ?
The relaxation phase of cardiac muscle where the chambers fill with blood
Define systole
Contraction phase of cardiac muscle where the blood is forcibly ejected into the aorta and pulmonary vein.
What is the cardiac cycle ?
The process of cardiac muscle contracting and the movement of blood through its chambers.
How does diastole effect the cardiac cycle ?
Atria and ventricles relax , they expand drawing blood into the atria
The pressure in the atria increases opening valves
Blood passively enters the ventricles
SL valves are closed to prevent blood from leaving the heart
What are the three stages of the cardiac cycle ?
Diastole
Atrial systole
Ventricular systole
Atrial systole ?
The atria contract , forcing remaining blood from leaving the heart
Ventricular systole ?
Ventricles contract , increasing the pressure closing the AV valves to prevent backflow into the atria
SL valves are forced open as blood is ejected from the ventricles into the aorta and pulmonary artery
What is heart rate ?
The number of times the heart beats per minute
What is stroke volume ?
The volume of blood ejected from the left ventricle per beat
What is cardiac output ?
Volume of blood ejected from the ventricle per minute
Equation for cardiac output ?
HR X SV
What is bradycardia ?
A resting heart rate below 60 bpm
What is the venous return ?
The volume of blood returning to the heart. The greater the return of blood to the heart the greater the volume of blood available in the ventricles for ejecting
What is the equation for cardiac output ?
Heart rate X stroke volume
What is sub-maximal exercise ?
Exercise is at a low - moderate intensity within a performers aerobic capacity or below the anaerobic threshold. It is associated with aerobic work
What is the maximal exercise ?
Exercise is at a high intensity above a performer’s aerobic capacity , which will take a performer to exhaustion. It is associated with anaerobic work and fatigue.
What happens during sub-maximal exercise ?
Heart rate can plateau as we reach a comfortable , steady state. This plateau represents the supply meeting demand for oxygen delivery and waste removal.
What happens during maximal exercise ?
Heart rate doe not plateau as exercise intensity continues to increase. There is a growing demand for oxygen and waste removal which HR must continually strive to meet
What is frank-starling mechanism ?
Increased venous return leads to an increased stroke volume , due to an increased stretch of the ventricle walls and therefore force of contraction
What us the cardiac output response to exercise ?
Cardiac output increases in line with exercise intensity and plateaus during maximal exercise. In recovery , there is a rapid decrease followed by a slower decrease to resting levels
Cardiac control centre ( CCC) ?
A control centre in the medulla oblongata responsible for HR regulation
Sympathetic nervous system ?
Part of the automatic nervous system responsible for increasing HR
Parasympathetic ?
Part of the automatic nervous system responsible for decreasing HR
What is the vascular system ?
The dense network of blood vessels and the blood which they carry in one direction around every corner of the human body
What does blood consist of ?
45 % cells
55% plasma
Function of blood ?
transport nutrients such as oxygen and glucose
Protect and fight diseases
maintain the internal stability of the body and regulate temp
Define vasodilate ?
Widening of arteries , arterioles and pre - capillary sphincters
Define vasoconstrict ?
Narrowing of arteries , arterioles and pre-capillary sphincters
What is the main artery ?
The aorta and carries blood at high pressure directly from the left ventricle
Arteries ?
Large layer of smooth muscle and elastic tissue to cushion and smooth the blood flow
Arterioles ?
Large layer of smooth muscle allowing both vessels to vasodilate and vasoconstrict to regulate blood flow and control blood flow
Have a ring of smooth muscle , it dilates and constricts to control the blood flow through the capillary bed
Capillaries ?
Brings blood slowly into close contact with the muscle and organ cells for gaseous exchange
Capillary walls are composed of a single layer of cells , thin to allow quick diffusion
What is the job of veins and venules ?
Transport deoxygenated blood from the muscles and organs back to the heart.
Venules leaving the capillary bed reconnect to form veins
What is the main vein ?
The vena cava which carries slow-moving blood at low pressure back to the right atria
Describe the veins and venules ?
Have small layer of smooth muscle allowing them to vasodilate and vasoconstrict to maintain blood flow
Veins have one-way pocket valves which prevent the backflow of blood as it travels against gravity
What are the mechanisms of venous return ?
Pocket valves - one way valves located in the veins which prevent back flow
Smooth muscle - The layer of smooth muscle in the vein wall vasoconstricts to create venomotor to aid movement
Gravity - Blood from the upper body , above the heart is helped by gravity
muscle pump - Skeletal muscles contract compressing the veins , squeezing blood back to the heart
Respiratory pump - during inspiration and expiration a pressure difference is created which squeezes blood back to the heart
What is inspiration ?
Drawing air into the lungs
What is expiration ?
expelling of air from the lungs
blood pooling ?
Accumulation of blood in the veins due to gravitational pull
Active recovery ?
Low - intensity activity post exercise to maintain elevated heart and breathing rate
What is the Vascular shunt mechanism ?
The redistribution of cardiac-output around the body from the rest to exercise which increases the percentage of blood flow to the skeletal system
What are arterioles ?
blood vessels carrying oxygenated blood from the arteries to the capillary beds, which can vasodilate and vasoconstrict to regulate blood flow
At rest where does most of the cardiac output go ?
to the organs
What are pre-capillary sphincters ?
rings of smooth muscle at the junction between arterioles and capillaries
What happens to arterioles and pre-capillary sphincters during exercise ?
Arterioles and pre-capillary sphincters serving the capillary beds surrounding the muscle cells dilate , maximising blood flow , nutrient and gaseous exchange
What is Vasomotor control ?
The control in the medulla oblongata responsible for cardiac output distribution
What is the vasomotor tone ?
The partial state of smooth muscle constriction in the arterial walls
Where does the VCC receive information ?
Chemoreceptors - chemical changes eg co2 and lactic acid during exercise ?
baroreceptors - regarding pressure changes on the arterial walls
What are the two main functions of the respiratory system ?
Pulmonary ventilation
Gaseous exchange
What is external respiration ?
The movement of oxygen into the blood stream and carbon dioxide into the lungs
What is internal respiration ?
The release of oxygen to respiring cells for energy production and collection of waste products
What are alveoli ?
Clusters of tiny air sacs covered in dense network of capillaries which together serve as the external site of gaseous exchange
What is gaseous exchange ?
The movement of oxygen from the alveoli into the blood stream and carbon dioxide from the blood stream into the alveoli
What is breathing rate ?
The number of inspirations or expirations per minute
What is tidal volume ?
The volume of air inspired or expired per breath
What is minute ventilation ?
The volume of air inspired or expired per minute
What is the breathing rate response to exercise ?
Breathing rate increases
In sub-maximal exercise steady state exercise breathing rate can plateau
What is tidal volume response to exercise ?
It increases initially
Tidal volume reaches a plateau during sub maximal intensity because increased breathing rate towards maximal intensities does not allow enough time and requires too much muscular effort
What are the mechanics of inspiration at rest ?
The external intercostals contract lifting the rib cage and sternum up and out
The diaphragm contracts and flattens
What happens to the volume inside the thoracic cavity ?
It increases
This lowers the pressure below the atmosphere outside the body
All gases move from an area of high to low pressure , so air rushes into the lung
What are the mechanics of inspiration during exercise ?
The external intercostals and diaphragm
Sternocleidomastoid
Pectoralis minor
Creates a greater up and outward movement of rib cage and sternum. The greater movement increases the volume and decreases the pressure inside the thoracic cavity more at rest. This increase the depth of breathing and the volume of air inspired
What are the mechanics of expiration at rest ?
Passive process
The external intercostals relax , lowering rib cage and sternum down and in
The diaphragm relaxes and returns to its dome shape
What are the mechanics of expiration during exercise ?
external intercostals and diaphragm not enough contraction
Internal intercostals
Rectus abdominals
This creates a greater down and inward movement of the rib cage and sternum
The greater movement decreases the volume and increases the pressure inside the thoracic cavity more than at rest. This increases the rate of breathing and volume of air expired per minute
Define respiratory control centre ?
A control centre in the medulla oblongata responsible for respiratory regulation
Define inspiratory centre ?
A control centre within the RCC responsible for inspiration
Define expiatory centre ?
A control centre within the RCC responsible for expiration
What is partial pressure ?
The pressure exerted by an individual gas held in a mixture of gases
What is diffusion ?
The movement of gases across a membrane down a gradient from an area of high pressure
What is diffusion gradient ?
The difference in areas of pressure from one side of a membrane to the other
What is external respiration ?
The exchange of gases at the lungs between the deoxygenated blood that arrives in the capillaries
What is internal respiration ?
The exchange of gases at the muscle cells between the oxygenated blood that arrives in the capillaries with the carbon dioxide producing muscle cells
Gaseous exchange during exercise ? ( External )
External respiration - The 02 diffusion gradient steepens and 02 diffuses from the high P02 in the alveoli to the lower P02 in the capillary blood at a greater rate
The C02 diffusion gradient steepens and C02 diffuses from the higher pC02 in the alveoli at a greater rate
Gaseous exchange during exercise ? ( Internal )
The 02 diffusion gradient steepens and 02 diffuses from the high p02 in the capillary blood to lower p02 in the muscle cell
The C02 diffusion gradient steepens and C02 diffuses from the higher Pc02 in the muscle cell to the low Pc02 in the capillary cell
Define association ?
The combining of oxygen with haemoglobin to form oxyhaemoglobin
Define dissociation ?
The release of oxygen from haemoglobin for gaseous exchange
What is the dissociation of oxygen from haemoglobin during rest ?
At rest , PO2 in the muscle is 40 mmHg and approximately 25 % of oxygen has dissociated , 75% remains associated
What is the dissociation of oxygen from haemoglobin during exercise ?
Po2 levels lower in the muscle cell and more oxygen dissociates from the haemoglobin for diffusion
