define systole
period of ventricular contraction
define diastole
period of ventricular relaxation
what is the role of haemoglobin in oxygen transportation?
haemoglobin binds with oxygen and carbon dioxide to transport them around the body
what happens to the oxygen atoms while they are diffusing?
they are also picking back up CO2 and returning it back to lungs so you can exhale it into the atmosphere
Haemoglobin + Oxygen =
oxyhaemoglobin
how many oxygen atoms can each haem hold up to?
4 oxygen atoms per haem
Where is haemoglobin found?
red blood cells
What is haemoglobin?
a globular protein that consist of 4 polypeptide chains and it allows oxygen to bind with red blood cells
what does each haem group contain?
iron
what are the 4 components of blood?
red blood cells, white blood cells, platelets, plasma
which component of the blood is responsible for the transport of oxygen?
red blood cells
give some features of a red blood cell:
no nucleusbiconcave shapelarge SA
what other substances are dissolved in the blood?
glucosehormonesureacarbon dioxideenzymesamino acids
explain what happens in cardiovascular drift during a marathon:
We begin to sweatAs we sweat our blood volume decreasesBc of decrease in blood volume, stroke volume decreases, therefore so does venous return cardiac output is equal to SV x HRHeart rate (HR) increases to compensate for the decrease in stroke volume (SV)Dehydration contributes to cardiovascular drift as blood is redirected to the skin to help temperature regulation
what 2 factors does cardiac output depend on?
heart ratestroke volume
what is the symbol for cardiac output?
Q
what is the abbreviation for heart rate?
HR
what is the abbreviation for stroke volume?
SV
What is cardiac output?
the volume of blood flowing into the heart from the left ventricle
what is resistance to flow?
the impedance offered by the blood vessels to the blood flow
what are the 2 factors that blood pressure depends on?
cardiac outputresistance to flow
how do you calculate blood pressure?
blood pressure = cardiac output x resistance
what do you use to measure blood pressure?
sphygmomanometer
where is blood pressure measured?
brachial artery
When is diastolic pressure recorded?
when the heart is relaxing and filling the blood
when is systole pressure experienced?
when the heart pumps blood into the system
what does the blood pressure reading show?
systolic value/diastolic value
what happens to systolic pressure during aerobic exercise?
increases
why does systolic pressure increase during aerobic exercise?
because of the increase in cardiac output
what happens to diastolic pressure during aerobic exercise?
remains constant
does blood pressure increase with age?
yes
what happens to systolic and diastolic pressure during anaerobic exercise?
both systolic and diastolic pressure rises due to increased resistance in blood vessels
what are the 2 responses to exercise?
immediate (short term effects)chronic (long term effects)
what happens to stroke volume during exercise? (short term)
SV increases because more blood is returning to the heart
when does maximal stroke volume occur? (short term)
during sub maximal work
what happens to heart rate during exercise? (short term effects)
HR increases as exercise intensity increases
Define tachycardia
maximum heart rate
what happens to systolic pressure during exercise? (short term effects)
increase because of the increased cardiac output
immediate response to exercise?
short term responses that only last for the duration of the exercise and the recovery period
chronic response to exercise?
long term adaptations to exercise
what happens to blood plasma volume during exercise? (short term effects)
blood plasma volume decreases, especially in hot weather (because of increased sweating)
what happens to the blood's acidity during exercise? (short term effects)
blood acidity increases because of the amount of lactic acid circulating the body
what happens to muscle glycogen content during exercise? (short term effects)
decrease in muscle glycogen content because its being used as a primary energy source
principal structures of the ventilatory system
Nose, mouth, pharynx, larynx, trachea, bronchi, bronchioles, lungs and alveoli
function of the nose
Humidifies the air entering and filters particles
Function of bronchioles
smallest and thinnest air tubes in the lungs that carry air into the alveoli
function of pharynx
the tube at the back of your nose and mouth that allows air to pass into the trachea.
what is the pharynx also known as?
throat
function of the alveoli
tiny air sacs in the lungs that take oxygen from the air and put it into the blood
function of the lungs
the 2 breathing organs where gas exchange occurs in the body
function of the nasal cavity
entrance for air that is also used for smelling and carries air into pharynx
function of the larynx
-voice box-protects the trachea from invasion of foods and fluids
function of the pharynx
Air passes through the 3 parts of the pharynx which offers a low resistance path for airflow into the larynx and then finally into the trachea.
function of the trachea
ai passage in your throat that leads to the lungs
what is the trachea also known as?
windpipe
function of the bronchi
passages that allow air to travel from your windpipe into your lungs
mechanisms of breathing
inspiration and expiration
describe inspiration in terms of pressure
pressure must be low in the lungs than the air we are breathing in from the atmosphere
why does the pressure need to be lower inside the lungs than the air we are breathing in from the atmosphere?
because air moves from an area of high pressure to an are of low pressure
what does a greater different in pressure mean?
faster air flow
Describe the nervous and chemical control of ventilation during exercise
-breathing is controlled by the nervous system-increases/decreases the rate, depth and rhythm of breathing-nerve impulses are sent via the phrenic nerve-intercostal nerves are sent to the respiratory muscles (intercostals and diaphragm)-Stretch receptors in the lungs and bronchioles help to prevent over inflation of the lungs
Define pulmonary ventilation
movement of air in and out of the lungs
Define total lung capacity
vital capacity + residual volume
Define vital capacity
Maximum volume of air that can be inhaled and exhaled out.
define tidal volume
The volume of air inhaled and exhaled per breath
Define expiratory reserve volume
volume of air in excess of tidal volume that can be exhaled forcefully
Define inspiratory reserve volume
additional inspired air over and above tidal volume
what happens to tidal volume during exercise?
increases
what happens to expiratory reserve volume during exercise?
slight decrease
what happens to inspiratory reserve volume during exercise?
decrease
what happens to residual volume during exercise?
no change
what happens to total lung capacity during exercise?
slight decrease
define residual volume
amount of air remaining in the lungs at the end of maximal expiration
Mechanics of Ventilation
inspiration and expiration
what percentage of blood do red blood cells occupy?
43%
what is the role of leucocytes and phagocytes
to defend body's immune system
how much of blood do platelets and leucocytes take up?
less than 1%
how much of the blood does the plasma take up?
55%
What are Enthrocytes?
red blood cells
What are enthrocytes responsible for?
O2 distribution
how is body heat maintained?
by the plasma
What is plasma made of?
90% water and 10% dissolved substances
Is oxygen soluble in blood?
no, its insoluble
where is carbon dioxide dissolved?
plasma
what does some of the carbon dioxide bond with?
haemoglobin
carbon dioxide + enthrocytes =
hydrogen carbonate
explain the events of the cardiac cycle
during diastole the heart muscles are relaxedblood enters atriaduring atrial systole the atria contracts and blood moves into ventriclespressure in ventricles causes biscupid/triscupid valves to closeclosing of valves causes first heart sound
relationship between pressure and volume
as volume increases, pressure decreases
What are erythrocytes also known as?
red blood cells
What are leucocytes also known as?
white blood cells
Importance of accessory muscles during exercise
Accessory muscles are located in the neck, these supply to the work of breathing during exercise. these muscles pull the rib cage upwards, which makes lung expansion and gas exchange easier.
process of gas exchange at the alveoli
alveoli are small hollow sacs gases move by a passive process called diffusion from an area of high concentration to an area of low concentrationoxygen travels from the alveoli, in the lungs, into the blood via diffusionlungs have a very thin total distance between the alveoli and the blood oxygen attaches to haemoglobin which is then dissolved in the blood plasma carbon dioxide goes from the blood plasma into the alveoli(co2 and o2 changes places)
when we inhale was happens?
External intercostal muscles contract Ribcage moves upwards and outwardsDiaphragm contracts and flattens increase in volume of chest cavityPressure decreases air is forced into the lungs
when we exhale what happens?
diaphragm relaxesexternal intercostal muscles relaxesinternal intercostal muscles contractsribcage moves downwards and upwarddecrease in volume of chest cavitypressure increasesair rushes out of lungs
journey of a red blood cell
enters the heart via the superior vena cava, containing deox. bloodthe deox. RBC enters the RA and then the RV by going through the right atrioventricular valveRBC is pumped up through the semilunar valve in the lungsfrom the lungs the RBC becomes oxygenated and enters the LA via the pulmonary veinRBC travels to LV through the left atrioventricular valve and the RBC is pumped back through the left semilunar valve into aorta which pumps blood to the rest of the body
Veins carry blood
toward the heart
Capillaries function
Serve as exchange vessels for nutrients, wastes, fluids.
Arteries carry blood
away from the heart
Why do ventilation rates increase
-breathing rate increases during exercise as the expiratory centre sends impulses to the expiratory muscles (internal intercostals) which speeds up the expiratory process;-increase CO2 causes the acidity of the blood to increase (decrease blood pH)/a change in acidity of the blood is detected by chemoreceptors which send nerve impulses to the respiratory muscles which increase the rate of ventilation (faster/deeper);
What is pulmonary circulation?
circulation between heart and lungs
Describe pulmonary circulation
the portion of the cardiovascular system that carries oxygen-depleted blood away from the heart and to the lungs and then returns it, oxygenated, back to the heart.
describe systematic circulation?
the portion of the cardiovascular system that carries the oxygenated blood away from the heart and delivers it to the body. It also carries the deoxygenated blood after use back to the heart to be re-oxygenated.
Define systolic blood pressure
the force exerted by the blood on the arterial walls during ventricular contraction
Define diastolic blood pressure
the force exerted by the blood on the arterial walls during ventricular relaxation
Why does Diastolic blood pressure increase during static exercise?
-The pressure on the arterial walls is increased even during relaxation-The vasoconstriction creates an increase in pressure-Muscles squeeze the veins to promote venous return, by doing so increases pressure -During static exercise, breathing is more constricted, there is less oxygen and more carbon dioxide, the heart must work harder to pump the blood it does have to supply the muscles with sufficient oxygen to continue the static exercise