3.1.1.2 Structure and functions of the cardio-respiratory system Flashcards
The pathway of air steps
Mouth/nose
Trachea
Bronchi
Bronchioles
Alveoli
Gaseous exchange occurs in the
alveoli
The exchange of gas is
Oxygen to blood vessels, CO2 to alveoli
Features that help gas exchange in alveoli
Large surface area of alveoli
Moist thin walls of blood vessels
Short diffusion distance
Lots of capillaries
Large blood supply
In the red blood cells there is
Haemoglobin
Haemoglobin carries
Oxygen on the way to organs
Carbon dioxide on the way to lungs
Artery lumen size, wall thickness
Small lumen, thick elastic walls
Vein lumen size and wall thickness, other feature
Large lumen, thin walls, valves
Capillaries lumen size, wall thickness
Tiny lumen, one cell thick walls to allow for diffusion
Function of arteries
Always carries blood away from the heart. Oxygenated blood unless to the lungs to be oxygenated.
Carries at high blood pressure to get around the body fast.
Can vasoconstrict and dilate
Vasconstriction
Smaller lumen to redistribute blood to toher places more
Vasodilation
Larger lumen so that more blood gets to desired place
Vein function
Carry blood towards the heart always. Deoxygenated from body, oxygenated from lungs.
Low blood pressure, valves to prevent backflow.
Capillary function
To carry blood close to organs to allow the oxygen to diffuse out to organs through gas exchange.
Connect arteries and veins.
Allow co2 out of organs
Heart blood journey
Deoxygenated blood via Vena cava
Right atrium
Right ventricle
Deoxygenated blood via Pulmonary artery
Blood gets oxygenated in the Lungs by gas exchange
Oxygenated blood via Pulmonary vein
Left atrium
Left ventricle
Oxygenated blood via Aorta to rest of body
Systole
When the heart contracts to eject blood out of the ventricles
Diastole
When the heart relaxes to allow blood in to the atria
Cardiac output
The amount of blood pumped by the heart every minute
Heart rate
Amount of times the heart beats in a minute
Stroke volume
Amount of blood pumped by the heart every beat(contraction)
Cardiac output(Q)=
Heart rate(HR) x Stroke Volume(SV)
During inhalation at rest
Intercostals contract
The rib cage expands
Diaphragm contracts
During exhalation at rest
Intercostals relax
Rib cage shrinks
Diaphragm relaxes
During exercise, breathing in and out is called
Inspiration and Expiration
During inspiration whilst exercising
Pectorals and sternocleidomastoid contract
During expiration whilst exercise
pectorals and sternocleidomastoid relax. Abdominals contract to push air out quicker
Air pressure during inhalation
Air pressure decreases in lungs due to the chest cavity getting bigger, which means air rushes in
Air pressure during exhalation
Air pressure increases in the lungs due to chest cavity getting smaller, which means air rushes out ot the lower pressure in the surroundings
Spirometer traces show
Lung capacity
Tidal volume is
Amount of air breathed in with each normal breath
Inspiratory reserve volume
Maximum amount of additional air that can be be inhaled after a normal breath
Expiratory reserve volume
Maximum amount of additional air that can be forced out of the lungs after a normal breath
Residual volume is
The amount of air in the lungs after the expiratory reserve volume. Prevents the lungs collapsing
exercise effect on spirometer trace
Tidal volume gets larger and more breatsh are taken per miute
Inspiratory and expiratory reserve volume therefore get smaller
