Chapter 1.2 The Respiatory System Flashcards
Name the passage of air
Nose Pharynx Larynx Trachea Bronchi Bronchioles Alveoli
What muscles are used in inspiration at rest (mention the pressure gradient)
Diaphragm contracts and flattens
External intercostals contract lifting the rib cage up and out
This decreases the pressure in the lungs and air is drawn into the lungs from the high pressure in the atmosphere.
What muscles are used at expiration at rest (mention the pressure gradient)
Diaphragm relaxes into a dome
Intercostal muscles relax
This increases the pressure on lungs, pushing the air out of the lungs
What muscles are used in inspiration DURING EXERCISE (mention the pressure gradient)
Diaphragm contracts and moves down External intercostals contract Sternocleidomastoid Scalene’s Pectoral is minor These muscles help to expand the rib cage lowering the pressure in the lungs, drawing air into the lungs
What muscles are used in expiration DURING EXERCISE (mention the pressure gradient)
Internal intercostals
Abdominals
They assist this passive process by increasing the pressure inside the lungs and expelling air out of the lungs
In gaseous exchange, __________ moves from the high concentration in the lungs into the capillaries which have a _____ concentration of oxygen.
Carbon dioxide diffuses from the _____ concentration in the capillaries to the ____ concentration in the ________ .
Oxygen, low
High, low, alveoli
Name the features that assist gaseous exchange/ diffusion
- Large surface area
- Thin walls
- Short diffusion pathway
- Lots of capillaries
- Large blood supply
What is the function of haemoglobin
Haemoglobin binds with oxygen in red blood cells to transport it to the working muscles.
It can also bind with CO2 to transport it out of the body.
Define tidal volume
Volume of air breathed in or out in a single breath
Define inspiratory volume
Volume of air that you can forcibly inspire after a normal breath
Define expiration volume
The amount of air that can be forcibly exhaled after a normal breath
Define Residual volume
Volume of air that stays in the lungs after maximal expiration
Define minute ventilation
GIVE EQUATION
Volume of air breathed in and out per minute
Number of breaths (per min) x tidal volume = minute ventilation
Why does minute ventilation increase during physical activity ?
The more demanding the physical activity, the higher demand for oxygen.
With a higher demand for oxygen, breathing increases to meet the extra demand
what is a spirometer
a device used to measure the volume of air inspired and expired by the lungs
define partial pressure
the pressure exerted by an individual gas when it exists in a mixture of gases
explain the diffusion gradient
explains how gases flow form an area of high pressure or concentration to an area of low pressure or concentration.
what 3 factors are involved in pulmonary ventilation during exercise
- neural control (parasympathetic and sympathetic nervous systems)
- chemical control (chemoreceptors)
- hormonal control (adrenaline)
explain how neural and chemical control regulates the rate of breathing
When the blood acidity is high (sensed by the chemoreceptors) nerve impulses are sent to the respiratory centre in the medulla oblongata. which then regulates the inspiration and expiration.
what is the order of neural/chemical control for inspiration
receptors (baro, chemo, proprioceptors> medulla > phrenic nerve >diaphragm and external intercostals
what is the order of neural/chemical control for expiration
receptors > medulla > intercostal nerve > abdominals and internal intercostals
what 2 areas does the respiration centre have and what are their roles
1- inspiratory centre is responsible for inspiration and expiration (via the phrenic nerve)
2- the expiratory centre stimulates the expiratory muscles during exercise (via the intercostal nerve)
the inspiratory centre sends out nerve impulses via the ______ nerve to the inspiratory muscles (the ______ and ______ __________) to cause them to contract. This stimulation acts for approximately _ seconds until the impulses stop and then passive _______ occurs due to the elastic recoil of the lungs.
phrenic, diaphragm, external intercostals, 2, expiration
what is the role of the chemoreceptors in neural and chemical control of pulmonary regulation
detect a change in the blood chemistry. For example when there is an excess of CO2 or lactic acid in the bloodstream chemoreceptors (located in the carotid artery and the aortic arch) will send nerve impulses to to the inspiratory centre to increase ventilation until blood acidity has been returned to normal.
identify and explain the other factors that affect neural control of breathing apart from chemoreceptors.
mechanical factors- proprioceptors are located in the muscles and joints and they detect increased muscle movement and send feedback to the respiratory centre to increase breathing during exercise
baroreceptors- detect a decrease in blood pressure resulting in increased breathing
stretch receptors- during exercise the lungs are stretched more. stretch receptors prevent over inflation by sending impulses to the expiratory centre which sends signal down the intercostal nerve to contract the expiratory muscles.
how does hormonal control regulate ventilation during exercise
adrenaline is a natural stimulant made in the adrenal gland in the kidneys. before we start exercise the brain sends impulses to the adrenal glands which then pump adrenaline into the bloodstream in anticipation for the increased need for oxygen and CO2 exchange. breathing rate increases.
