Structure and Function of the Cardio-respiratory System Flashcards
What journey does the air take when we breather in?
nasal cavity/mouth, trachea, bronchi, bronchioles, alveoli
What increases the efficiency of gaseous exchange?
high surface area
moist, thin walls
short distance for diffusion
lots of capillaries
What is inspiration and expiration?
breathing in and breathing out
What happens to the diaphragm in inspiration?
it contracts and increases the cavity
What do the intercostals do in inspiration?
contract and lift the ribs up to increase thoracic cavity.
what does the diaphragm and intercostals do in expiration?
they relax
What is different about expiration at rest and in exercise?
at rest it is passive as muscles are relaxing, at exercise muscles like the abdominals contract to force out air
when oxygen attaches to haemoglobin, what is it called?
oxyhaemoglobin
What is tidal volume?
the volume of air breathed in and out at rest
In exercise which additional muscles help in inspiration?
the pectorals and sternocleidomastoid
What happens to tidal volume at exercise?
it increases
What does IRV stand for?
inspiratory reserve volume
What is IRV?
the additional volume of air taken in when exercising
What does ERV stand for?
Expiratory reserve volume
What is ERV?
the additional volume of air breathed out when exercising
What is the residual volume?
the volume of air left in our lungs after maximal breathing out
Why is there a residual volume?
the alveoli would scrunch in and damage if there wasn’t that air
What are the 3 blood vessels?
arteries, veins and capillaries
Describe the structure of an artery.
thick, smooth muscle layer
smaller lumen than veins
elastic walls
What is the function of the artery?
carry oxygenated blood at high pressure away from the heart
What is the lumen?
the space within the blood vessel through which blood travels
Describe the structure of veins.
thin muscle walls
larger lumen
valves
What is the function of veins?
carry deoxygenated blood at low pressure to the heart. They also prevent backflow of the blood
Describe the structure of capillaries.
1 cell thick
surround tissues
between arteries and veins
What is the function of capillaries?
gaseous exchange, removal of waste products
What makes capillaries efficient for gaseous exchange?
they are one cell thick, making the diffusion distance small
there are many so lots of diffusion can take place
they are partially permeable
they have a large surface area
What is the primary function of the heart?
to generate force to circulate blood
What is systole?
the contraction of the heart where it empties itself of blood
What is diastole?
the relaxation of the heart where it fills up with blood
Which side of the heart is oxygenated and which is deoxygenated?
the right side has deoxygenated blood, and the left side has oxygenated blood
What is stroke volume?
the amount of blood leaving the heart every time systole occurs
What is the average stroke volume?
70ml
how do you work out cardiac output?
stroke volume x heart rate
If my heart rate is 80 and my stroke volume is 60, what is my cardiac output?
80*60 = 4800ml = 4.8L
If my heart rate is 100 and my cardiac output is 5.2L, what is my stroke volume?
52ml
How do we increase cardiac output when exercising?
we increase our heart rate and stroke volume
