Transport

A 1.3

Three main systems in oxygen transport

• lungs

• heart

• muscles

Respiratory system

• first stage in oxygen transport system

• mostly involuntary process

• flow from area of high pressure to low pressure - Diffusion

air movement

done through repeated contraction and relaxation of the diaphram

Exhalation

• passive process

• diaphram relaxes and moves up

• pressure in lungs is increased which allows for more air to come in

Inhalation

• active process

• diaphram contract and moves down

• during exercise, extra muscles will be used to help breath in more air

lung function

• place where gas exchange occurs

• millions of alveoli so more surface area for gas exchange

• strong blood supply to carry gas quickly

• wall is very thin allowing for better gas transport through alveoli wall

Alveoli

• where gas exchange happens

• oxygen goes into blood and CO2 comes out, to be breathed out

vital capasity

total amount of air exhaled after maximal inhalation

residual volume

air that remains in lungs after maximum forceful exhalation

cardiovascular drift

• when heart rate increases and stroke volume decreases

• ex: marathon runners have increasing HR but decreased SV due to dehydration

VO2 Max

• maximum rate at which an individual can take in and use oxygen

• measuring the gas concentration and volume of air being inhaled and exhaled

• measure of aerobic capacity

VO2 Max equation

VO2 Max = maximum cardiac output x maximum arterio-venous oxygen difference

arterio-venous oxygen difference

• the difference in oxygen content between arterial and venous blood

• shows how much oxygen is extracted by the muscles

tital volume

amount of air that moves in or out of the lungs with each respiratory cycle

total lung capasity

volume of air in the lungs upon the maximum effort of inhalation

inspiratory and expiratory reserve volumes

Inspiratory

• amount of air that can be taken into the lungs upon forced inhalation

Expiratory

• amount of air that can be pushed out of the lungs upon forced expiration

factors affecting lung volume

• age, sex, body size

• females usually have smaller lung volumes than males

• taller people usually have bigger lung volume than shorter people

measuring lung function

• speed you can breath out is a good sign of lung health

• common test is FEV - air forced out in one second

gas exchange

• happens through diffusion

• oxygen and co2 move from where more of them are to where less of them are

• oxygen transported from lungs to blood which is then pumped around body while co2 is transported from blood to lungs to be breathed out

minute ventiliation (VE)

the volume of air being exhaled per minute

VE= VT x BF

VT - tidal volume

BF - breathing frequency

factors affecting breathing

• gas levels ( O2 + CO2)

• acidity

• temp

• hormones

blood

• transports gas, nutrients, waste products, hormones, and heat to and from various tissues

• 5 litres for person weighting 70 kg

major components of blood

• plasma

• platelets

• white blood cells

• red blood cells

plasma

• 55% of blood volume

• mixture of water and dissolved substances

platelets

• 1% of blood volume

• helps in repairing after injury

• vital role in blood cloting

white blood cells

• 1% of blood volume

• immune system so they protect body from infection

red blood cells

• 40-50% of blood volume

• carry oxygen from lungs to rest of body, then carry CO2 back to lungs

blood vessels

• blood is transported through them

• three types: arteries, capillaries, veins

arteries

• large vessels with thick muscular wall to help with high pressure of moving oxygenated blood away from heart

• take blood away from heart to rest of body

• arteries branch to arterioles

capillaries

• very narrow vessels with thin walls

• large branching network through tissues of the body

• blood moves from arterioles to capillaries

veins

• deliver deoxygenated blood back to heart

• less muscular and fibrous than arteries as pressure is lower

• contain valves to prevent back-flow

pulmonary circulation

delivers deoxygenated blood from right side of heart to the lungs for oxygen and then to the left side of heart

systemic circulation

• delivers oxygenated blood from left side of heart to the other tissues of the body where oxygen is needed, then deoxygenated blood is moved back to right side of heart

heart attack results

• any disruption to the coronary arteries

• cardiac muscles starved for oxygen so cannot function correctly

the cardiac cycle

• events happening in one heartbeat

• ensures efficient blood pumping throughout the body

heart

• four chamber pump

• each side has atrium that recieves blood and ventricles that eject blood

• four chambers with two atriums and two ventricles

Systolic blood pressure

measure of pressure within arteries while heart beats

Diastolic blood pressure

measurement during pause between heartbeats

healthy blood pressure

systolic - 90-120mm

diastolic - 60-80 mm

blood flow distrobution

• blood vessels diameter and capillary flow are regulated to maintain blood pressure and support cardiovascular function

• regulation is involuntary

cardiac output

• amount of blood ejected from left side of heart in litres per minute to supply the whole body except the lungs

• cardiac output = (heart rate x stroke volume) / 1000