Respiratory System Flashcards
Name the correct passage of air
Nose, Larynx, trachea, bronchi, bronchioles, alveoli
How does Oxygen and Carbondioxide move from the alveoli to the blood capillaries
Diffusion occurs from an area of high concentration to an area of low concentration.
Define Diffusion?
The movement of gas molecules from an area of high concentration or partial pressure to and area of low conentration or partial pressure
Define Gaseous exchange?
The movement of oxygen from the air into the blood, and carbondioxide from the blood into the air.
During inspiration which muscles are used at rest and during exercise
at rest- Diaphragm, External intercostal muscles
During exercise - Diaphragm, External Intercostal muscles, Sternocleidomastoid, scalenes, pectoralis major.
During expiration which muscles are used at rest and during exercise
at rest - Passive: diaphragm and external intercostal muscles just relax
during exercise- intercostal muscles abdominals
Explain the process of inhalation and exhalation
Inhalation- Ribcage moves up and outwards, diapragm contracts and is pulled flat. Thoracic cavity increases in size lowing the air pressure inside the lungs. air moves from an area of high concentration in atmospheric air to a low concentration in the alveioli. - air taken in
Exhalation - Ribcage falls, diaphragm relaxes and rises to dome shaped position decreasing the thoracic cavity causing the pressure inside the lungs to be greater than atmospheric air - air forced out.
How do the extra muscles that are used help inhalation and exhalation during exercise?
During exercise
Inhalation -Sternocleidomastoid, scalenes, pectoralis major help to increase the size of the thoracic cavity even more so the concentration gradient is larger than at rest so more air moves into the lungs more rapidly.
Exhalation - Abdominals contract actively forcing the diaphragm to relax back into a dome shape and the intercostal muscle contract to make the cavity smaller.
Define the following terms and state what happens to them during exercsie: Tidal volume Inspiratory Reserve Volume Expiratory Reserve volume Residual volume Minute ventilation
Tidal volume - Volume of air breathed in or out per breath - Increses during exercise
Inspiratory Reserve Volume - Volume of air that can be forcibly inspired after a normal breath- decreases during exercise
Expiratory Reserve volume - Volume of air that can be forcibly expired after a normal breath- decreases during exercise
Residual volume -Volume of air that remains in the lungs after maximum expiration -Remains the same during exercise
Minute ventilation -Volume of air breathed in or out per minute - Big increase during exercise
What is a spirometer? How does it show the changes in tidal volume during exercise?
A device that is used to measure the volume of air inspired and expired by the lungs.
Lines become longer and closer together, showing that the rate and depth of breathing has increased.
Explain how the movement of oxygen from the alveoli to the muscles occur
By a process of diffusion the gas moves from an area of high concnetration to an area of low concentration. The partial pressure of oxygen is higher in the alveoli (104mmHg) and lower in the capillaries(40mmHg) so the oxygen diffuses from the alveoli to the capillaries which transport it to the muscles. At the muscles the partial pressure of oxygen is higher in the capillaries (100mmHg) than in the muscles (40mmHg)so the oxygen diffuses down the concentration gradient from the capillaries to the muscles.
Explain how the corbondioxide moves from the muscle to the alveoli
By a process of diffusion the gas moves from an area of high concnetration to an area of low concentration. The partial pressure of Carbon dioxide is higher in the Muscles and lower in the capillaries so the carbondioxide diffuses from the muscles to the capillaries which transport it to the lungs. At the Lungs the partial pressure of carbondioxide is higher in the capillaries than in the alveoli so the carbondioxide diffuses down the concentration gradient from the capillaries to the alveoli.
How does an increase in blood carbondioxide change the breathing rate?
The increase in carbon dioxide is detected by chemorecptors in the carotid arteries/aortic arch/ medulla. The chemoreceptors send nerve impulses to the respiratory control centre in the medulla in the brain. The medulla then sends nerve impulse to the breathing muscles via the phrenic nerve/sympathetic system. This increases the rate of contraction of the diaphragm and external intercaostal muscles, so breathing increases.
How are the characteristics of the alveoli designed to help gaseous exchange?
Wall are very thin - short diffusion Pathway
Extensive capillary network so have an excellent blood supply for greater uptake of oxygen and carbondioxide.
Alveoli have a large surface arera for a greater exchange of oxygen and carbondioxide.
What other factors beside chemical chnages in the blood affect the neural control of breathing?
Mechanical factors - Proprioceptors located in the joints and muscles provide feedback to the respiratory centre to increase the breathing rate.
Baroreceptors - a decrease in blood pressure detected by baroreceptors in the aorta and carotid arteries results in an increase in Breathing rate.
Stretch receptors - during exercsie the lungs are stretched more. stretch receptors prevent over inflation of the lungs by sending an impulse to the expiratory centre and then down the intercostal nerve to the expiratory muscles (abdominals and internal inercostals so expiration occurs.
