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Topic 2 - Exercise Physiology :check: - Coggle Diagram
Topic 2 - Exercise Physiology :check:
VENTILATORY SYSTEM
Components of the ventilatory system:
Nose
Mouth
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
Outline function of the conducting airways
Low resistance pathway for air flow in and out of the lungs
Warm and moisten the air as it enters the body
Protect the lungs from harmful substances breathed in
Define - PV; TLC; VC; TV; ERV; IRV; RV
Pulmonary ventilation
- the breathing of air in to the lungs from the atmosphere
Total lung capacity
- the total amount of air in the lungs after maximal inhalation
Vital capacity -
amount of air that can be exhaled after maximal inhalation
Tidal volume
- the total amount of air inhaled after normal breathing
Expiratory reserve volume
- volume of air in the lungs that can be exhaled forcibly after tidal volume is exhaled
Inspiratory reserve volume -
volume of air in the lungs to be inhaled forcibly after tidal volume is inhaled
Residual volume
- amount of air left in the lungs after maximal exhalation
Explain the mechanics of ventilation in the human lungs
Inhalation:
Diaphragm contracts
- moves down and flat
External intercostal muscles
contract
Moves
ribs up and out
Increasing thoracic volume
of the lungs - thereby
decreasing pressure
Allows
air to flow into the lungs
from the atmosphere
Exhalation:
Diaphragm relaxes
- moves up
Internal intercostal muscles
contract
Moves
ribs down and in
Reduces thoracic volume
of the lungs - thereby
increasing pressure
This
forces air out of the lungs
and the pressure decreases until it matches atmospheric pressure
Process repeats
Describe nervous and chemical control of ventilation during exercise
During exercise there is an increase in use of working muscles, therefore more oxygen is required to facilitate these muscles and the oxygen usage in the body increases.
Therefore, carbon dioxide concentration in the blood also increases.
This acidity level is recognised by the respiratory centre (NOT NERVOUS SYSTEM) via muscle proprioreceptors and chemreceptors.
This then causes an increase in breathing rate and depth to intake more oxygen from the atmosphere to reduce blood acidity levels and increase levels of oxygen in the blood
BLOOD
State and describe 4 components of the blood:
Plasma
- transports blood cells and other components of the blood around the body
Platelets
- clots blood to prevent infection from external harmful substances - also prevents blood loss from a wound
Luecocytes
- defend the body from harmful cells and pathogens (white blood cells)
Erythrocytes
- transport oxygen around the body via hemoglobin (red blood cells)
Explain the role of hemoglobin in oxygen transportation
Hemoglobin is what carries the oxygen in red blood cells; it is carried as oxyhemoglobin.
Hemoglobin is a protein which contains a central ion which can bind with up to 4 oxygen atoms at a time.
This is what allows the oxygen to be transported and then diffused into the muscle when the target cells are reached by the erythrocytes.
Explain the process of gaseous exchange at the alveoli
Oxygen in the alveoli diffuses across the membrane and into the pulmonary capillary beds from a high concentration of oxygen in the lungs to a low concentration of oxygen in the blood. This oxygen can then be distributed to the rest of the body via red blood cells.
On the contrary, carbon dioxide in the blood capillaries diffuses into the alveoli from a high concentration in the blood to a low concentration in the lungs. This CO2 can then be breathed out of the lungs via exhalation.
ANATOMY OF THE HEART
4 valves in order from left to right
:
Tricuspid
valve - separates right atrium from the right ventricle
Pulmonary valve
- separates the right ventricle and the pulmonary artery to deliver de-oxygenated blood to the lungs
Aortic valve
- separates blood from the left ventricle and the aorta to deliver oxygenated blood to the rest of the body
Bicuspid valve
- separates the left atrium from the left ventricle
4 Chambers:
Left atrium
- moves blood into the left ventricle
Left ventricle
- moves blood through the pulmonary valve to be transported to the lungs via the pulmonary artery to be oxygenated
Right atrium
- moves blood into the right ventricle
Right ventricle
- moves blood through the aortic valve to be have oxygenated blood distributed to the rest of the body via the aorta
4 main blood vessels
:
Pulmonary artery
- delivers de-oxygenated blood from the heart to the lungs
Aorta
- delivers oxygenated blood from the heart to the rest of the body
Vena cava
- delivers de-oxygenated blood to the right atria of the heart to be sent to the lungs
Superior vena cava
- carries blood from the head, neck , arms and chest
Inferior vena cava
- carries blood from the legs, feet and organs
Pulmonary vein
- delivers freshly oxygenated blood back to the left atria of the heart from the lungs
Describe the intrinsic and extrinsic regulation of heart rate and the sequence of excitation of the heart muscle
The heartbeat is controlled by a pacemaker in the heart which produces tiny electrical currents which cause the heart muscle to contract - this is known as the sino-atrial node
Sino-atrial node (SAN)
- produces an electrical impulse which causes excitation across the atria, causing the muscles in the left and right atria to contract simultaneously - moving blood from the atria into the ventricles during atrial systole. This impulse also stimulates the AVN as the atrioventricular walls are non-conducting.
Atrio-ventricular node (AVN) -
there is a short stall to where the impulse is held in the AVN to allow the completion of atrial systole - then the AVN sends the electrical signal to the Purkinje fibres (bundle of his) to begin ventricular systole
Purkinje fibres (bundle of his)
- the electrical impulse is conducted down the interventricular septum along the branches of the bundles of his to the apex. Then it travels along the Purkinje fibres which extend up the walls of the ventricles. This causes the muscles of the ventricles to contract simultaneously from the bottom up, causing tri/bicuspid valves to shut but semi-lunar valves to open for oxygenated blood to flow to the rest of the body via the aorta and deoxygenated blood to the lungs via the pulmonary artery during ventricular diastole.
1 - SAN produces electrical impulse
2 - atrial systole
3 - stimulates AVN
4 - sent down atrioventricular septum via branches of BoH
5 - reaches apex and is sent along Purkinje fibres along walls of ventricles (contracts bottom up)
6 - ventricular diastole
Describe the 3 stages of the cardiac cycle
:
1) Atrial systole -
both atria contract, forcing blood into the ventricles of the heart - back flow of blood is prevented by the closing valves in the veins
2) Ventricular systole -
both ventricles contract and the atrio-ventricular valves close while the semilunar valves of the pulmonary artery and the aorta open - allowing blood to flow into the blood vessels
3) Ventricular diastole -
both the atria and the ventricles relax - meanwhile allowing for blood from vessels to flow through the atria and into the ventricles
Outline relationship between pulmonary and systemic circulation
Pulmonary circulation:
Pulmonary artery
Carries deoxygenated blood from the heart to the lungs
Pulmonary vein
Then takes oxygenated blood from the lungs back to the heart
Systemic circulation:
Aorta
Carries oxygenated blood from the heart to the rest of the body
Vena cava (superior and inferior)
Carries deoygenated blood back from the body to the heart
Brain, neck, chest and arms = superior
Back from the legs, feet and internal organs = inferior
Receptors in the body which connect to the respiratory centre
What do they detect?
All factors require a change in heart rate for stabilisation
Baroreceptors -
blood pressure
Chemoreceptors -
pH levels, carbon dioxide concentration and oxygen concentration
How is blood pressure regulated?
1) A change in blood pressure is detected by
baroreceptors in the aorta and carotid artery.
2) A nerve impulse is then sent along sensory neurones to the
cardioregulatory centres in the medulla oblongata
3a)
Blood pressure is high - cardioinhibitory centre
sends nerve impulses to the SAN along parasympathetic neurones to decrease heart rate
3b)
Blood pressure is high - cardioacceleratory centre
sends nerve impulses to the SAN along sympathetic neurones to increase heart rate
Parasympathetic neurones - contain acetylcholine
Acetylcholine binds with the receptors in the SAN - causing a decrease in the amount of electrical signals produced
Thereby reducing heart rate
Sympathetic neurons - contain noradrenaline
Noradrenaline binds with receptors in SAN - causing an increase in the amount of electrical signals produced
Thereby increasing heart rate
Systolic blood pressure
- blood pressure on arterial walls during ventricular contraction
Diastolic blood pressure
- blood pressure on arterial walls during ventricular relaxation
At rest:
Systolic blood pressure is higher than diastolic blood pressure
During exercise:
Both blood pressures increase but systolic increases far more than diastolic does because the heart is working harder to provide sufficient oxygen and glucose to muscles due to increased strain on the muscles
How are acidity levels regulated?
1)
Increase in exercise
causes an
increase in carbon dioxide concentration
in the blood
2) Change in blood acidity
detected by chemoreceptors
and a nerve signal is sent to the
medulla oblongata
3) Medulla oblongata secretes
noradrenaline
4) Noradrenaline binds to the
receptors of the sinoatrial node
and causes an increase in the amount of electrical signals it produces
5)
Heart rate is increased
to increase breathing rate to allow more oxygen into the lungs and increase
exhalation of carbon dioxide
6) Carbon dioxide levels in the blood
drop again
7) This is detected by
chemoreceptors
again which send a signal to the
medulla oblongata
8) Medulla oblongata secretes different hormone called
acetylcholine
9) Acetylcholine binds to
receptors of the sinoatrial node
and causes a decrease in electrical signals
10) Leading to a
decreased heart rate
HEART RATE, STROKE VOLUME AND CARDIAC OUTPUT
Equation:
Cardiac output = stroke volume x heart rate
An athlete will have a:
Lower resting heart rate
Higher stroke volume
Higher cardiac output than a non-athlete during exercise
Same cardiac output as a non-athlete during rest
Larger heart and left ventricle due to cardiac hypertrophy
Increased capillarisation of the heart muscle
Cardiovascular drift:
Describes the physiological changes in heart function during prolonged exercise -
E.g - stroke volume steadily
decreases
and heart rate steadily
increases
meaning cardiac output
stays the same
Cardiovascular drift is caused by
:
1) Increase in exercise causes an
increase in body temperature
2) This then causes an
increase in sweating
to regulate body heat
3) The water for sweat is
taken from the plasma
in the blood
4) This causes an increase in the
viscosity of the blood
5) Which therefore results in
reduced arterial pressure and lower stroke volume
Define maximal oxygen consumption:
This is when the body and the working muscles are utilizing oxygen as fast as it can, meaning even if exercise intensity were to increase, the body's oxygen consumption would stay the same
Someones VO2 max is mostly determined by genetics but can also be increased via training
It can be measured using specialised equipment
Variability in VO2 max in trained individuals and in different modes of exercise
Trained individuals:
Although VO2 max is mainly genetic it can be increased via consistent cardiovascular training and exercise
Different modes of exercise:
VO2 max may vary over different forms of exercise depending on their exercise intensity and how much cardiovascular support is required
E.g - long distance runner may have a higher VO2 max than a sprinter due to the varying duration of exercise, despite both being high in intensity
Vasodilation and constriction
Chemoreceptors and sympathetic/parasympathetic neurons cause either vasodilation or vasoconstriction of arterioles
Vasodilation widens the arterioles
which allows for increased flow of blood - flushing out unwanted chemicals such as carbon dioxide - therefore this will occur when blood acidity levels get too high or carbon dioxide levels are increased
Vasoconstriction is when there is reduced flow
through the arterioles, meaning the adverse has happened and blood acidity levels are too low - they react to chemical changes of the local tissues
Explain the effect on systolic and diastolic blood pressure during dynamic and static exercise
During dynamic exercise:
Systolic and diastolic blood pressure
both increase
as dynamic exercise puts a
large strain on the muscles due to a high intensity of movement
However,
systolic raises more
than diastolic does
Static stretches
do not require a high intensity of movement
and therefore
do not put a high stress on the heart
Therefore,
dynamic stretches increase blood pressure more than static stretches do
(both systolic and diastolic)
During steady state exercise heart rate steadily increases and stroke volume steadily decreases meaning cardiac output stays the same
Compare the distribution of blood at rest and the redistribution of blood during exercise
At rest:
Blood flow to the
brain is constant
While the blood flow to the
internal organs is prioritised
over blood flow to skeletal muscle
During exercise:
Blood flow to the
brain remains the same
Blood flow is redirected away from the internal organs to
prioritise the working muscles
during exercise
Cardiovascular adaptations resulting from endurance training:
Left ventricular volume
increases
Stroke volume
increases
Resting heart rate
decreases
Heart rate during exercise
decreases
Capillarisation
to muscles increases
Arterio-venous oxygen difference
increases