1.2 cardiovascular and respiratory systems ✔️ Flashcards
what is the cardiac system
the heart its muscle blood vessels and the blood they contain - form a closed system
what is the pulmonary circuit
carries deoxygenated blood to the lungs and oxygenated blood back to the heart
what is the systemic circuit
carries oxygenated blood to the body and deoxygenated blood back to the heart
what separates the heart into two sides
the septum
where are the atrio-ventricular valves
valves in between the atria and ventricles
where are the semilunar valves located
between the ventricles and the blood vessels
what side of the heart is systemic
left side - thicker walls bicuspid higher pressure
what side of the heart is pulmonary
right side - tri-cuspid thinner walls less pressure
what vein is on the right atrium of the heart (deoxygenated)
vena cava - superior - blood from upper body
inferior vena cava - blood from lower body
what vein is on the right ventricle of the heart to the lungs (deoxygenated)
pulmonary artery - carries blood from the right ventricle to the lungs
what vein is on the left side of the heart in the left ventricle (oxygenated)
aorta - carries oxygenated blood from the heart to the rest of the body
what vein takes blood from the lungs to the left atrium (oxygenated)
the pulmonary vein - carries oxygenated blood from the lungs to the heart left atrium
what is myogenic
a muscles that starts the electrical impulses themselves that cause contractions
the conduction system
the rout that electrical impulses take through the heart 5 structures
where is the Sa node (pacemaker) found and what does it do
in the right atrial wall - generates the impulse and fires it through the atrial walls causing contraction - (pace of contractions makes heartrate)
what does the AV node do
receives the electrical impulse and delays it for 0.1 seconds to allow the atria finish contracting then releases it to the bundle of his
where is the bundle of his located and what does it do
it is located in the septum and splits the impulse in two to be distributed through each separate ventricle
bundle branches
carry the impulse to the base of each ventricle
purkyne fibres
these distribute the impulse through the ventricle walls causing them to contract
what is the cardiac cycle
the contractions of the cardiac muscle and the movement of blood through its chambers
- diastole
when the atria and ventricles relax they expand drawing blood into the atria the av valves open blood flows into the ventricles the sl valves shut
- ventricular systole
the ventricles contract closing the AV valves and the SL valves open forcing blood into the aorta and pulmonary artery
- atrial systole
atria contract forcing blood into the ventricles
what causes diastole
no electrical impulse (cardiac muscle relaxes)
what causes atrial systole
sa node fires the electrical impulse through the atria walls to the av node which delas the signal (atria contract)
what causes ventricular systole
the bundle of his splits the impulse into to two and passes it down the 2 bundle branches into the purkiyne fibres in both walls
what is the equation for max heart rate
220-age
what is bradycardia
a resting heart rate of lower than 60 beats per minute
untrained resting heart rate
72 BPM
cardiac hypertrophy
increase in the size of the cardiac muscle
stroke volume
the volume of blood ejected from the left ventricle per beat
untrained resting stroke volume
70 ml
venous return is
the volume of blood returning to the heart
cardiac output
amount of blood ejected from the left ventricle per minute (in L/PM)
cardiac output equation
stroke volume x heart rate
the untrained cardiac output
5 L/M
(same for athletes just have higher stroke vol but lower hr)
trained resting heart rate
50 bpm
trained stroke volume
100ml
submaximal exercise:
exercise at low to moderate intensity associated with aerobic work below the anerobic threshold
maximal exercise:
exercise at a high intensity above the anerobic threshold
what is starlings law?
stroke volume is directly related to venous return
why does stroke volume plateau when submaximal exercise
increased heart rate towards maximal intensity doesn’t allow ventricles to fill up fully (usually 40-60%)
untrained submaximal heart rate
100 - 130 bpm
untrained stroke volume (sub maximal and maximal)
100 - 120 ML
untrained sub maximal intensity cardiac output
10 - 15L
untrained maximal intensity cardiac output
20 - 30L
trained sub maximal heart rate
95 - 120 bpm
trained sub maximal intensity stroke volume
160 - 200 ml
sub maximal intensity trained athlete cardiac output
15-20 l/min
cardiac output trained athlete maximal intensity
30 - 40 l/m
what causes the heart to change beat even though its myogenic
THE Cardiac Control Centre
(CCC)
what are control mechanisms
the 3 main sources that send info to the CCC
- neutral
- intrinsic
- hormonal
what are the neutral controls
chemoreceptors - chemical changes - co2 / lactic acid
baroreceptors - in blood vessels walls inform the CCC of blood pressure changes
proprioceptors - in muscles and joints inform CCC of motor activity
what are the intrinsic responses
temperature changes - affect blood viscosity and speed of nerve transmissions
venous return - affect stretch in ventricle walls and force of contraction therefore stroke volume
what does the vagus nerve do
it decreases the heart rate
(parasympathetic)
what are the hormonal response
adrenaline and noradrenaline are released from the adrenal glands and increase force of ventricular contractions
what does the accelerator nerve do
it increases the heart rate and force of contraction
(sympathetic)
what are the two branches of the ANS (automatic nervous system)
- sympathetic
- parasympathetic
what does sympathetic do
Fight or Flight”
Prepares your body for stress (sport or danger)
what does parasympathetic do
Rest and Digest”
Calms your body down after activity.
what is the vascular system
a dense network of blood vessels which carry blood to every corner of the body
what is the make up of blood
45% cells 55% plasma
the 3 blood vessels:
artery’s
veins
cappillaries
arteries
carry oxygenated blood from the heart to the muscles and organs
what are arterioles
subdivisions of artery’s have large layer of smooth muscle which allows them to vasodilate and constrict
what is a pre capillary sphincter
a ring of smooth muscle surrounding the entry of a capillary’s
what are venules
small blood vessels that take blood from the capillaries to the veins
what do veins and venioles have and what does that allow them to do
they have a layer of smooth muscle which allows them to venoconstrict and venodialate to maintain the flow fo blood
what is venous return
return of blood back to the heart (right atrium)
mechanisms of venous return 1.
pocket valves - small valves in the veins that prevent blood backflow
mechanisms of venous return 2.
smooth muscle - the muscle (involuntary) in the vein walls that allow it to Vaso and venoconstrict
mechanisms of venous return 3.
gravity - for blood above the heart
mechanisms of venous return 4.
muscle pump - during exercise skeletal muscle (actual voluntary muscle) contracts compressing the veins located between them
mechanisms of venous return 5.
respiratory pump during inspiration and expiration a pressure difference between the thoracic cavity and abdominal cavity is created
what is the vascular shunt mechanism
the redistribution of blood during exercise
during exercise what vaso dilates
arterioles and pre capillary sphincters to the organs
what controls the vascular shunt mechanism
the vasomotor control centre
where does the VCC get its info from
the barro receptors and chemoreceptors
what does the VCC do
increases or decreases sympathetic stimulation which allows Vaso dilation or constriction
order of the respiratory system
nasal cavity
pharynx
larynx
trachea
bronchi
bronchioles
alveoli
what do the airways have to filter air
ciliated cells (tiny hairs) filter warm and moisten the air
mucous - traps dust pathogens ect
how is carbon dioxide carried 70%
dissolved in water and transported as carbonic acid
how is carbon dioxide transported 23%
binds with haemoglobin to form carbaminohaemoglobin
how is carbon dioxide transported 7%
dissolved in blood plasma
how is oxygen transported 97%
binds to haemoglobin to form oxyhaemoglobin
how is oxygen transported 3%
dissolved in the blood plasma
breathing rate:
the amount of breaths take in 1 minute
average resting breathing rate is:
12 - 15
what is tidal volume
the amount of air inspired or expired in one breath
what is the average tidal volume:
500ML
how can BR and TV be measured
using a spirometer
what is minute ventilation formula
minute ventilation = tidal volume x breathing rat e
minute ventilation
the amount of air inspired/expired per minute
breathing rate trained
11-12
minute ventilation trained
5.5 - 6 L/M
minute ventilation untrained
6 - 7 L/M
what happens to breathing rate when exercising
increases up to the maximum 50-60 BPM
what happens to tidal volume
increases up to a point sub maximal plateaus not enough time and muscular strength to increase further
why does breathing rate plateau sub-maximal
demand from the muscles is met
minute ventilation during submaximal exercise
plateaus as demand is met
what is anticipatory rise
when breathing rate and heart rate increase in anticipation of exercise
exercising trained breathing rate:
50-60 BPM
maximal intensity trained tidal volume
3-3.5 L
maximal intensity trained minute ventilation
160-210 L
maximal intensity not trained minute ventilation
100 - 150 L/M
maximal intensity not trained tidal volume
2.5-3L
exercising not trained breathing rate:
40 - 50 BMP
muscles responsible for inspiration at rest
External intercostals
the diaphragm
inspiration at rest answer-
the external intercostals contract pulling the ribs up and out the diaphragm contracts and flattens this increases the volume of the thoracic cavity decreasing the pressure air rushes in down the concentration gradient into the lungs
mechanics of breathing during exercise inspiration
additional muscles are recruited
- sternocleidomastoid
- pectoralis minor
created a created upward and outward movement increasing the volume and decreasing the pressure more than at rest
muscles of expiration at rest
the external intercostals and diaphragm
mechanics of expiration at rest answer
the external intercostals relax lowering the ribcage and sternum down and in the diaphragm relaxes and returns to its dome chape
mechanics of expiration during exercise
becomes an active process and the internal intercostals and rectus abdominals are recruited creating and stronger downward and in force more air can be expired faster
what controls breathing
the respiratory control centre (RCC)
what are the 2 centres in the RCC
the inspiratory centre rest and exercise and the expiratory centre just exercise
(both stimulate muscles)
what nerves does the IC use
it uses the phrenic nerve - diaphragm and the intercostal nerve - external intercostals
why is the expiratory centre not involved at rest
because of the natural relaxation of the diaphragm and external intercostals
what receptors send info to the rcc ec and ic
chemoreceptors
baroreceptors
proprioceptors
thermoreceptors
what is partial pressure
the pressure exerted by an individual gas held in a mixture of gasses
what is the internal site
gas exchange between the blood capillary’s and the muscles
what is the external site
gas exchange between the alveoli and capillary
pressure gradient
the difference in the pressure of two sides greater the gradient the faster the diffusion
what is dissociation of o2
when a haemoglobin releases (oxygen)
what is association
when haemoglobin binds to o2
how many molecules of o2 can oxygen hold
4
what happens when the ppo2 is high
it readily associates
what happens when the ppo2 is low
more readily dissociates
what does the oxyhaemoglobin dissociation curve show
relationship between the ppo2 and percentage saturation of haemoglobin
what is the ppo2 at rest
75%
as exercise increases what happens to the ppo2 in muscles
it decreases which mean the o2 more readily dissociates from the haemoglobin
what factors affect increase dissociation of exercise
increase temperature
increase production of co2 raising ppco2
increase production of lactic acid and carbonic acid (lowers ph)
what does carbonic acid and lactic acid do
Lactic acid and carbonic acid increase H⁺ (hydrogen ion) concentration.
what way does the bohr shift move
to the right
what does the Bohr shift show
o2 more readily dissociates
what percent of o2 is released during exercise
75%
what happens when recovering
it shifts to the left meaning it more readily associates meaning the blood stream can become saturated again to remove waste
