CV and respiratory systems Flashcards
Untrained HR at rest
60-75
HR
number of beats per min
SV
volume of blood ejected from left ventricle per beat
CO
volume of blood ejected from left ventricle per min
Bradeycardia
resting HR below 60bpm
Diastole
relaxtion of atria and ventricles = low pressure in heart
Blood passively flows through atria into ventricles
AV valves are open
Semilunar valves are closed
Atrial systole
atria’s contract , forcing blood into ventricles
Ventricular systole
Ventricles contract
AV valves close
Semilunar valves open
Blood pushed out ventricles into large arteries
how long is one cardiac cycle
0.8 seconds
Myogenic
heart generates own impulse
CV drift
gradual rise of HR towards end of exercise as SV drops to give heart time to fill but CO needs to remain the same
Why does CV happen
blood becomes more viscous as plasma is sweated out which is harder to pump around body
SV during recovery
maintained during early stages of recovery
HR during recovery
decreases fast
CO during recovery
rapid decrease
3 neural control
propio receptors , chemoreceptors , baroreceptors
2 intrinsic control
Temperature , Venous return
Hormonal control
adrenaline and noradrenaline
How is HR regulated during exercise
receptors detect changes , sends to CCC in medulla , decrease HR sent via vegas nerve , Increase HR sent via accelerator nerve which increases SA node firing
Vascular shunt is
redistribution of blood to working muscles and organs during exercise
Vascular shunt mechanisms
vasodilation and open of capilary sphincteres of arteries to working muscles , vasoconstriction and closing of capilary sphincteres of arteries to non working muscles
Why vascular shunt occurs
VCC in medulla recieves info from receptors, stimulates sympathetic NS
5 veneous return mechanisms
Pocket valves
muscular pump
Gravity
respiratory pump
smooth muscle
veneous return - pocket valves
one way so prevent backflow
veneous return - muscular pump
muscles contract and squeezes on veins
veneous return - smooth muscle
in walls of veins , contract causing blood to flow back to heart
veneous return - respiratory pump
cause pressure difference in thorasic cavity which aids movement of blood
veneous return - gravity
blood above heart returns with help of gravity
transport of 02
97% in haemoglobin
3% dissolved in plasma
tidal voume
volume of air breathed in or out per breath
breathing frequency
number of breaths per min
MV
volume of air breathed in or out per min
Inspiration at rest
Diaphragm contracts and flattens
External intercostals contract
Rib cage up and out
Increases volume of thoracic cavity - decreases pressure
air rushes in
Expiration at rest
passive
diphragm relaxes and domes
external intercostals relax
rib cage moves down and in
decreases volume of thoracic cavity - increases pressure
air rushes out
Inspiration during exercise
diphragm flattens more
external intercostals contract more
sternocloidmastoid + pectoralis are recruited to move ribs up and out futher
volume of thoracic cavity increases futher
futher pressure decrease
more air rushes in
expiration during exericise
active
diphragm relaxes
external interostal relax
rectus abdominus, internal/external obliques pull ribs in and down futher
thoracic cavity decreases futher
pressure increases more
more air rushes out
How is breathing controlled during exercise ( inspiration)
Chemoreceptors detect increase acidity send message to ICC in medulla causing increase inspiration
How is breathing controlled during exercise ( expiration)
propio/thermo receptors detect changes. Baroreceptors detect strtech in lungs , send message to ECC, increase expiration
02 in alveoli during exercise
high P02 in alveoli , low P02 in pulmonary capillary. Steep concentration gradient, 02 from alveoli goes into blood.
C02 in alveoli during exercise
low PC02 in alveoli, high PC02 in pulmonary capillary , steeper concentration gradient, C02 diverts from blood to alveoli
Muscle site at rest
high p02 in blood , low p02 in muscles.
02 goes from blood to muscles
c02 is opposite of this
muscle site during exercise
high p02 in blood, lower p02 in msucles , steeper gradient so more 02 diffuses into muscle cell
BOHR shift ( Dr TACO)
Dissociation curve shifts right
Temp increases in blood tissue and muscles
Acidity increases in blood tissue and muscle
C02 has stepper diffusion gradient between muscle tissue and blood
02 has stepper diffusion gradient between muscle tissue and blood
This means less dissociation but at a quicker rate
Conduction system
SA Node initiates impulse , sends to AV node which holds for a sec causing atrial systole, AV then sends it to Bundle of HIS to Punjiknjee fibres causing ventricular systole
BF resting/maximal value
R- 12-16
M- 40+
MV - resting/maximal value
R- 6-8
M- 200
untrained HR at rest
60-75
trained HR at rest
50
untrained SV at rest and maximal
rest- 70ml
maximal - 100-120
trained SV at rest and maximal
rest- 100ml
maximal - 160-200ml
max HR
220-age
TV at rest and Maximal
rest- 0.5l
max- 3-5l
Untrained CO at rest and maximal
rest- 5l
max- 20-30l/min
trained CO at rest and maximal
rest - 5l
max- 30-40l/min
sympathetic NS
increases heart rate
vagus nerve
decreases HR
accelerator nerve
increases adrenaline
increases SA node firing
features of arteries
oxygenated blood away from heart
high pressure
features of capillaries
one cell thick
where gas exchange takes place
features of veins
deoxygenated blood towards heart
low pressure
vasoconstriction
smooth muscle contracts reducing lumen diameter and reducing blood flow
vasodilation
smooth muscle relaxes which increases lumen diameter and increases blood flow
VCC
located in medulla oblangata
receives info from receptors
will either stimulate parasympathetic or sympathetic NS
pulmonary ventilation
inspiration and expiration of air from atmosphere
gaseous exchange
extraction of oxygen from air to blood to muscles
% transport of oxygen
97% to haemoglobin
3% disolved in plasma
% transport of c02
70% dissolved in water - carbonic acid
23% combines with haemoglobin
7% dissolved in blood plasma
TV
Volume of air breathed in or out per breath
breathing freqency
number of breaths per min
MV
volume of air breathed in or out per min
Bohr shift on graph ( Dr TACO)
Dissociation curve shifts right
Temperature increases in blood and muscles tissue
Acidity increases in blood and muscle tissue
C02 increases in blood and muscle tissue
Oxygen has a steeper diffusion gradient between blood and muscle tissue
Oxygen affinity is reduced
reason for Bohr shift
less saturation of 02 at lungs but at quicker disociation to working muscles for aerobic energy production
