Cardiorespiratory System Flashcards
Tidal volume
Volume of air breathed in or out with each normal breath
Inspiratory reserve volume
The maximum amount of air that can be inhaled after a normal inhalation
Expiratory reserve volume
The maximum amount of air that can be exhaled after a normal exhalation
Residual volume
The volume of air remaining in the lungs after a maximal exhalation - prevents alveoli from collapsing/becoming damaged
Name the apparatus used to measure the volume of air inspired and expired by the lungs
Spirometer
Describe the pathway of air
Nasal cavity (air is warmed) –> Trachea –> Bronchi –> Bronchioles –> lungs –> Alveoli
Describe what happens in the body during inhalation (at rest)
- Diaphragm contracts and moves downwards
- Intercostal muscles contract and move the ribs upwards and outwards
- This increases the size of the chest, decreasing air pressure inside it which sucks air into the lungs
Describe what happens in the body during inhalation (during exercise)
- Inspiration is assisted by pectoral muscles and the sternocleidomastoid which help to life the ribs up and out even further
Describe what happens in the body during exhalation (at rest)
- Diaphragm relaxes and moves back into its dome shape
- Intercostal muscles relax, so the ribs move inwards and downwards under their own weight
Describe what happens in the body during exhalation (during exercise)
- Abdominals pull the ribs downwards and inwards even further
Explain the role of haemoglobin
Haemoglobin carries oxygen to be exchanged at the working muscle and carbon dioxide to be exchanged at the lung.
Explain gaseous exchange
- High concentration of Oxygen in alveoli, low concentration of oxygen in capillary
- So, the oxygen diffuses from an area to high concentration to low concentration into the blood
- High concentration of carbon dioxide in the blood and low concentration in the alveoli
- So, carbon dioxide diffuses into the alveoli to be breathed out
What factors help gaseous exchange?
- Alveoli has large surface area
- Alveoli has one cell thick moist walls (short distance for gas to diffuse)
- Semi permeable membranes
- Lots of capillaries
Explain how oxygen and carbon dioxide are transported
- Oxygen diffuses into the blood from the alveolus and binds to haemoglobin (iron rich protein)
- This forms oxyhaemoglobin
- It is then transported to the working muscle to be exchanged
- Haemoglobin carries carbon dioxide to be exchanged at the lung
What’s the equation for Cardiac Output? - and define all the parts to it
Cardiac output L/m = Heart Rate bpm x Stroke Volume L
Cardiac output: amount of blood pumped from the heart every minute
Heart rate: number of times the heart beats in one minute
Stroke volume: volume of blood pumped out of the heart with every beat
Explain the structure and function of the body’s blood vessels.
Arteries:
- Carry blood away from the heart
- This requires high pressure, so they have thick muscle and outer wall with narrow lumen to force blood around the body
Veins:
- Carry blood to the heart
- Carries it at low pressure due to wide lumen and thin muscle and outer wall
- Have valves to prevent backflow of blood
Capillaries:
- Carry blood to and from the body’s cells + site of gaseous exchange
- Narrow lumen, one cell thick walls
- Medium blood pressure
Why does tidal volume increase during exercise?
Tidal volume increases due to an increased depth of rate breathing (1)
Due to a higher demand for oxygen (1)
(to supply more oxygen to working muscles)
Explain how EPOC is caused
Caused due to vigorous (anaerobic) exercise (1)
Lactic acid is built up (1)
Need to maintain an elevated breathing rate (1)
To repay the oxygen debt (1)
what causes anticipatory rise?
Release of hormone adrenaline
Which blood vessels in the heart are arteries? - what do they do?
Aorta (carries oxygen rich blood to the rest of the body)
Pulmonary Artery (carries deoxygenated blood from the heart to the lungs to become oxygenated)
