Cardiovascular System And Respiratory ✅ Flashcards
What is diastole
Relaxation of atria and ventricles causes lower pressure within the heart
Blood then passively flows through the atria and into ventricles
Av valves are open, allows blood to move freely from atria to the ventricles
Semilunar valves are closed
What is systole
Atrial systole: atria contract, forcing blood into the ventricles
Ventricular systole: ventricles contract, AV valves close, semilunar valves open, blood pushed out of ventricles and into the large arteries leaving the heart.
How long is diastole, atrial systole and ventricular systole
Diastole: 0.4 seconds
Atrial systole: 0.1 seconds
Ventricular systole: 0.3 seconds
Describe the pathway of deoxygenated blood
BODY-Vena cava-right atrium-tricuspid valve- right ventricle-semilunar valve-pulmonary artery-LUNGS
Describe the pathway of oxygenated blood
LUNGS-pulmonary vein- left atrium- bicuspid valve- left ventricle- semilunar valve- aorta- BODY
Definition of heart rate
Number of times the heart beats per minute
Rest Untrained= 70-72
Trained= 50
Sub max untrained: 100-130
Trained: 95-120
Max untrained and trained: 220- age
What is the definition of stroke volume
Amount of blood ejected from left ventricle per beat
Rest Untrained= 70ml
Trained=100ml
Sub max untrained: 100-120ml
Trained: 160-200 ml
Max untrained: 100-120
Trained: 160-200ml
What is the definition of cardiac output
Amount of blood ejected from the left ventricle per minute
HR X SV= CO
Rest Untrained= 5L/min
Trained= 5L/min
Sub max untrained: 10-15L/min
Trained: 15-20
Max untrained: 20-30
Trained:30-30
What is bradycardia
A resting heart rate below 60bpm
What is the definition of max heart rate
Calculated by subtracting your age from 220
How can Stroke volume be able to increase
Increased venous return (due to skeletal muscle pump)
The Frank-Starling mechanism
What do arteries are arterioles do, how are they able to do this
Carry oxygenated blood from heart muscles and organs
Contain blood under high pressure
Large layer of smooth muscle and elastic tissue which can vasodilate and vasoconstrict
Arterioles have a ring of smooth muscle surrounding the capillary bed
What are capillaries
Capillary walls are 1 cell thick
Where gas exchange takes place, O2 passes through capillary wall and into the tissues; CO2 passes from tissues into blood through capillary wall
What do veins and venules do
These carry deoxygenated blood from muscles are organs back to the heart, have thin walls
They have a smaller layer of smooth muscle, allowing them to venodilate and venoconstrict
Contain blood under low pressure
Have 1 way pocket to prevent backflow of blood
What 5 things make up the conduction system
1: SA node- generates electrical impulses causing atria walls to contract (known as pacemaker, determines heart rate)
2: AV node- collects the impulse and delays it by 0.1 seconds to allow atria to finish contracting
3: bundle of his- located in septum, splits the impulse in 2, ready to be distributed to the ventricles
4: bundle branches: these carry impulses to base of each ventricle
5: Purkinje Fibres- these distribute the impulse through ventricle walls, causing them to contract
Learn the structure of the heart
Eg aorta, pulmonary vein, pulmonary artery, superior vena cava, R+L atrium, R+L ventricle, septum, tricuspid valve, bicuspid valve, inferior vena cava, aortic valve, pulmonary valve
What is the heart rate graph like for sub maximal exercise (aerobic)
Anticipatory rise before exercise
When exercise starts, rapid increase
Steady state (line is flat)
Exercise ends, rapid decrease
What is the heart rate graph like for to maximal (anaerobic) excerise
Anticipatory rise
As exercise starts, rapid increase, and then a slower increase
As exercise ends, rapid decrease and then a slower decrease
What is the heart rate graph like for fluctuating intensities of exercise
Anticipatory rise
As exercise starts constant increase and decrease of HR in fluctuating pattern
Why is SV able to increase by 40-60% working capacity, why does it plateau during sub max exercise
Increased venous return
Frank-starling mechanism
Increased HR does not allow enough time for ventricles to fill completely during diastolic phase, limiting Frank starling mechanism
What does the cardiac control center do
Controlled by autonomic nervous system (ANS) and determines the firing of SA node
Located in medulla oblongata
Responsible for regulating heart via motor neurons- sympathetic nervous system increases HR via accelerator nerve, parasympathetic nervous system decreases HR via vagus nerve
What are the 3 things that make up neural control
Proprioceptors: in muscles, tendons and joints, inform CCC that movement has increased
Chemoreceptors: located in aorta and carotid arteries, detect decrease in blood ph due to increase to lactic acid and CO2
Baroreceptors: located in blood vessel walls, inform CCC increased blood pressure
What are the 2 things that make up the intrinsic control
Temperature:: changes affect blood viscosity and speed of nerve impulse transmission
Venous return: changes affect the stretch in ventricle walls, force of contraction and SV
What makes up hormonal control
Adrenaline and noradrenaline: released from adrenal glands and increase SV and HR
What mechanism aid venous return
Pocket valves- within veins prevent back flow of blood
Smooth muscle- is in wall of each vein so can venocontrisct, helps push blood back towards heart
Gravity- blood from upper body above heart, aided by gravity in its return
Muscle pump- many veins situated between skeletal muscles; during exercise they squeeze on veins and help push blood back towards heart
Respiratory pump- helps return blood in thoracic cavity and abdomen back to heart, during exercise inspire and expire quicker and deeper, this rapidly changes pressure within thorax between high and low to help squeeze blood in area back to heart
What is vascular shunt
As we start exercise, muscles demand more oxygen, so blood flow diverted to working muscles and away from non essential organs
How does the vascular shunt mechanism work
At rest:
Arterioles to organs vasodilate, increasing blood flow, arterioles to muscle vasoconstrict to limit blood flow
Pre capillary sphincters dilate, opening up capillary beds to allow more blood flow to organ cells, beds of muscle construct
During exercise: opposite
What is vasomotor control
Located in medulla onlongata
VCC alters level of stimulation send to arterioles and pre capillary sphincters at different sites in body allowing for vascular shunt
Receives information from: chemoreceptors and barorecptors
Increases sympathetic stimulation limits blood flow, decrease does opposite
What are 2 main functions of respiratory system
Pulmonary ventilation
Gaseous exchange
What is pathway of air during inhalation
Nasal cavity-pharynx-larynx-trachea-primary bronchi-bronchiole-alveoli
What % if oxygen and carbon dioxide transported in blood
O2
97% in hameoglobin, 3% blood plasma
CO2
70% dissolved in water carried as carboinic acid,23% hemoglobin, 7% dissolved in blood plasma
What is breathing rate
Number of inspirations or expirations per minute
Untrained Resting 12-15
Trained 11-12
Untrained max value- 40-50
Trained 50-60
What is tidal volume
Volume of air inspired or expired per breath
Untrained resting 500ml
Trained 500ml
Max untrained 2.5-3L
Trained 3-3.5L
What is minute ventilation
Volume of air inspired or expired per minute VE=TVxf
Resting untrained 6-7.5L/min
Trained 5.5-6
Max untrained 100-150L/min
Trained 160-210
Describe what happens during inspiration at rest
External intercostal muscles contract, pulling chest up and our
Diaphragm contracts and flattens increasing size of chest
Increasing thoracic cavity decreases pressure causing air to move in
What happens during inspiration at excericse
External intercostal muscles and diaphragm contract still
Sternocleidomastoid lifts sternum
Scalene and pectoralis minor contract and lift ribs up more
Volume of thoracic cavity increases, creating large concentration gradient between inside lungs and outside body, more air enters quicker
What happens during expiration at rest
External intercostal muscles relax and diaphragm relaxes
Thoracic volume decreases increasing pressure forcing air out
What happens during expiration at exercise
Diaphragm and external intercostal muscles relax
Internal intercostal muscles contract
Rectus abdominus contracts
Decrease in volume of thoracic cavity increases pressure forcing air out quicker cause of larger concentration gradient
What does the inspiratory center do
Stimulates muscles to contract at rest and during exercise
What does the expiratory center do
Inactive at rest, stimulate additional expiratory muscles to contract during exercise
What is the respiratory control center responsible of
Located in medulla oblongata
Respiratory regulation
How does the respiratory regulation center receive information
Chemical: chemoreceptors, located in aorta and arteries, detect changes in blood acidity, increases in CO2 decreases In O2
Neural:
Thermoreceptors, inform of increase in blood temp
Proprioceptors, inform of motor activity in muscles and joints
Baroreceptors, located in lung tissue and bronchioles, inform of state of lung inflation
Is the partial pressure of oxygen and carbon dioxide higher or lower before and after entering the capillaries
Before
pO2=40
pCO2=46
After
pO2=100
pCO2=40
What is external respiration
During exercise Deoxygenated blood reruns to lungs has lower pO2 and higher pCO2 than at rest, O2 and CO2 diffusion gradient steepens in alveoli
What is internal respiration
Internal respiration is exchange of gases at muscle cells between oxygenated blood that arrives in capillaries and carbon dioxide producing muscle cells
Describe the oxyhaemoglobin curve
Haemoglobin % saturation on y axis
PO2 on x axis
Resting tissue:40mmHg is 75% and 100 lungs is 100%
Exercise tissue is 15mmHg and 25% lungs 100 and 100%
What is the Bohr shift and what are the effects
The effects move oxyhaemoglobin curve to the right
Increase in blood and muscle temperature
Increase in pp of CO2 (raising pCO2)
Increase in production of lactic acid and carbonic acid (lowering pH)
What is the impact on performance of the Bohr shift
At any given pO2 for exercising muscle tissue, % saturation of oxyhaemoglobin is far lower therefore dissociation of O2 to respiring tissue is greater
Enhances volume of O2 available for diffusion therefore aerobic production of exercise
why would the oxyhaemoglobin curve shift to the right or left
Shift right:Increase in temperature, increase in CO2, decrease In pH
Left is the opposite
