1.2 Cardiovascular and respiratory systems 3 Flashcards
What does the respiratory system consist of
-nose
-series of airways
-lungs
-respiratory muscles
Name the 2 functions of the respiratory system
-pulmonary ventilation- inspiration & expiration of air
-gaseous exchange- (external and internal)
What occurs in gaseous exchange
external respiration- movement of oxygen into the blood and CO2 into lungs
internal respiration- release of oxygen to respiring cells for energy production and collection of waste products
What are alveoli
clusters of air sacs covered in network of capillaries
-site for gaseous exchange
What is gaseous exchange
movement of oxygen from alveoli into blood stream and CO2 from bloodstream into alveoli
What is external respiration
movement of oxygen into blood stream and carbon dioxide into lungs
What is internal respiration
release of O2 to respiring cells for energy production
& collection of waste products
Name the 4 steps of the pathway of air through respiratory organs
- air into nasal cavity through nose
- travels down pharynx, larynx, trachea - the surface of these passageways have a mucus membrane and ciliated cells (covered in tiny hairs) which moisten, warm and filter the air
- trachea divides into right, left bronchi as they enter lung (the right lung has 3 lobes and the left has 2 to accomodate the heart)
4.bronchi divide into brochioles- end in alveoliar ducts
What occurs during inspiration (breathing in)
diaphragm contracts, moves downwards
intercostal muscles contract moving ribs upwards, outwards - increases size of chest- decreases air pressure inside it- sucks air into the lungs.
What occurs during expiration (breathing out)
diaphragm relaxes- returns to domed shape
intercostal muscles relax so the ribs move inwards, downwards- decreases size of chest- increases air pressure in chest- air is forced out lungs
Where does gaseous exchange occur and by what process
occurs in lungs
takes place by diffusion
What occurs in gaseous exchange
high concentration of oxygen in the alveoli and a low concentration of oxygen in the blood, so oxygen diffuses from the alveoli into the blood
high concentration of carbon dioxide in the blood and a low concentration in the alveoli, so carbon dioxide diffuses from the blood into the alveoli.
Name 2 ways oxygen can be transported
-blood plasma
-haemoglobin in red blood cells
What is oxygen
essential gas required for aerobic energy production in kmuscle cells
What is carbon dioxide
waste product of aerobic energy prdocyution in muscle cells
Name the 3 ways carbon dioxide can be transported
-carried as carbonic acid
-carried within haemoglobin
-disollved in plasma
What is tidal volume
volume of air inspired/ expired per breath
What is the formula for minute ventilation
tidal volume x breathing rate = minute ventilation
Explain the role of the respiratory system when responding to exercise snd recovery
-when we start to exercise- demand for oxygen by muscles increases
-respiratory systems role is to increase supply of air to alveoli and therefore oxygen for gaseous exchange
Explain what occurs to breathing rate in response to exercise
br increases until we reach our max (50-60 breathes per min)
sub-maximal- br can plateau- supply of oxygen meeting demand from muscles
Explain what occurs to tidal volume in response to exercise
tidal volume increases
Explain what occurs to minute ventilation in response to exercise
Describe what occurs in the mechanics of inspiration at rest
-active process
-external intercostal muscles between ribs CONTRACT -> pulls chest walls up & out
-diaphragm- CONTRACTS, FLATTENS -> increasing size of chest
Name the additional inspiratory muscles recruited for inspiration during exercise
-sternocleidomastoid
-pectoralis minor
How do the sternocleidomastoid and pectoralis minor increase breathing depth and volume during exercise
create greater up and outward movement of rib cage and sternum
greater movement ^ volume and decreases pressure inside thoracic cavity more than at rest
increases breathing depth and volume of air inspired#
What occurs during expiration at rest
external intercostals relax- lowers rib cage, sternum- down and in
diaphragm relaxes, returns to its dome shape
—> decreases vol of thoracic cavity- increases pressure above atmosphere outside body- air is pushed out of lungs
Name the process of expiration at rest
passive process
Name the process of expiration during exercise
active
Name the additional expiratory muscles recruted to give larger force of contraction in expiration during exercise
internal intercostals
rectus abdominis
—> creates greater down, inward movement of rib cage and sternum- decreases vol, increases pressure insude thoracic cavity- increases br and vol of air expired
What is the respiratory control centre (RCC)
control centre in medulla oblongata responsible for respiratory regulation
What is minute ventiliation
volume of air inspired/ expired per minute
What is respiratory control
when exercise/ recovery occurs- brain gets involved to regulate br
Name the 2 centres within the respiratory control centre (RCC)
inspiratory centre (IC)- stimulates inspiratory muscles to contract at rest and during exercise- INSPIRATION
expiratory centre (EC)- inactive at rest- stimulates additional expiratory muscles to contract during exercise- EXPIRATION
What occurs in terms of regulatory regulation at rest
inspiratory centre is responsible for rhymic cycle of breathing
-nerve impulses are generated and stimulate inspiratory muscles causing them to contract via:
-intercostal nerve to external intercostals
-phrenic nerve to diaphragm
causes thoracic cavity vol to be increase lowering lung air pressure
expiratory centre = inactive
What occurs in terms of regulatory regulation during exercise
breathing rate & depth increases to meet demand for oxygen
sensory nerves relay info to RCC where response initiated by IC and EC
chemoreceptors in aorta and carotid arteries pick up increase in blood acidity, increase in CO2 conc and decrease O2 conc
Name the 3 different neural controls
thermoreceptors- inform of increase in blood temp
proprioceptors- inform of motor activity in muscles and joints
barorecptors- located in lung tissues, bronchioles
Explain what occurs in the inspiratory centre which has been informed on what to do by the RCC during respiratory regulation during exercise
chemo, thermo, propriorecpetors inform IC
–> increases stimulation of phrenic nerve so diaphragm contracts with more force
-IC also increases stimulation of intercostal nerve so external intercostals contract with more force
-stimulates additional muscles to contract – sternocleidomastoid & pectoralis minor
increases volume of thoracic cavity and decreases pressure in lungs more than at rest.
more air rushes in - increasing depth of breathing.
Explain what occurs in the experiatory centre which has been informed on what to do by the RCC during respiratory regulation during exercise
barorecptors inform expiratory centre on extent of lung inflation
stimulates additional muscles to contract – internal intercostals & rectus abdominis
this decreases volume of thoracic cavity and increases pressure in lungs more than at rest.
more air rushes out - increasing rate of breathing.
Meaning of partial pressure
pressure exerted by individual gas held in mixture of gases
define gaseous exchange
the movement of gases across a membrane
define partial pressure
the pressure exerted by an individual gas held in a mixture of gases
what are the units for partial pressure?
mmHg
define diffusion
the movement of gases across a membrane down a gradient from high to low pressure
define diffusion gradient
the difference in areas of pressure from one side of membrane to the other
the blood is made up of…
45% blood cells
55% plasma
how is CO2 carried in the body?
70% dissolves in H2O as carbonic acid
23% combined with haemoglobin to make carbaminohaemoglobin
7% blood plasma
O2 is carried as…
97% with haemoglobin to make oxyhemoglobin
3% in blood plasma
minute ventilation =
TV x f
what is breathing rates response to exercise?
It increases proportionally to the intensity of the exercise, until reaching max
what is tidal volumes response to exercise?
Increase depth of breathing initially in proportion to exercise
what is minute ventilations response to exercise?
increases in line with intensity when TV and f increase
what happen to minute ventilation at sub max…
- Anticipatory rise
- Rapid increase.
- Steady state
- Rapid then gradual decrease
what happen to minute ventilation at maximal exercise?
- ME doesn’t plateau
- growing demand for O2 strives to meet
- TV will plateau will ME continues to rise due to breathing rate
what happens to minute ventilation during recovery…
rapid then gradual decrease to resting levels
describe the mechanics of inspiration at rest:
diaphragm contracts and flattens
external intercostals contract.
Rib cage moves up and out.
vol of thoracic cavity increases.
Pressure of thoracic cavity decreases.
air dishes in from high-pressure outside to low pressure inside the lung
describe the mechanics of expiration at rest…
diaphragm relaxes and returns domed
external intercostals contract
Rib cage moves down and in
vol of thoracic cavity decreases
Pressure of thoracic cavity increases
air forces out from a high pressure inside lungs to a low pressure outside
describe the mechanics of inspiration during exercise
diaphragm contracts and flattens more than at rest
External intercostals contract more than at rest
Sternocleidomastoid recruited
Rib cage moves up and out further than the rest
Volume of thoracic cavity increases more than the rest
Pressure of thoracic cavity decreases more than a rest
More air moves from a high-pressure to low-pressure
ACTIVE PROCESS
describe the mechanics of expiration during exercise
diaphragm and external intercostals relax
rectus abdominous and internal intercostals contract
Rib cage moves down and in more than at rest
Volume of thoracic cavity decrease is more than at rest
Pressure of thoracic cavity increase as more than at rest
More air moves from high to low pressure
what does the respiratory control centre do?
Receives information from sensory neurons and sends directions through motor neurons to change the rate of respiratory muscle contraction
what does the inspiration center (IC) do?
stimulates inspiratory muscles to contract at rest and exercise
what does the expiratory centre (EC) do?
stimulates additional extra expiratory muscles during exercise
during rest the IC…
generates intercostal neves causing external intercostals to contract
phrenic never generated causing the diaphragm to contract
which receptors send info to the IC?
proprioreceptors
thermoreceptors
which receptors send information to the EC during exercise?
baroreceptors
during exercise the IC and EC send information to the…
RCC
during exercise the RCC causes…
diaphragm and ext. intercostals contract with more force
recruits pec minor and sternocleidamastoid
increases breathing depth
int. intercostals and rectus abdominals contacts
reduces volume and increases pressure of thoracic cavity more than at rest
describe gaseous exchange at rest…
imbalance of pO2 and pCO2 between alveoli and capillaries causes pressure gradient and allows passive movement of gases
external respiration is..
the exchange of O2 and CO2 between the lungs and blood
internal respiration is…
exchange of O2 and CO2 between blood and muscle tissues
define breathing rate
the number of inspirations or expirations per minute
define tidal volume
the volume of air inspired or expired per breath
define minute ventilation
the volume of air inspired or expired per minute
the average breathing rate of an untrained person at rest is…
12-15 breaths per minute
the average breathing rate of an untrained person during max exercise is…
40-50 breaths per minute
the average breathing rate of a trained person at rest is…
11-12 breaths per minute
the average breathing rate of a trained person duing max exericse is…
50-60 breaths per minute
the average tidal volume for an untrained person at rest is…
500ml
the average tidal volume for an untrained person during max exercise is…
2.5-3 litres
the average tidal volume for a trained person at rest is….
500 ml
the average tidal volume for a trained person during max exercise is…
3-3.5 litres
the average minute ventilaton of an untrained person at rest is…
6-7.5 litres per minute
the average minute ventilation of an untrained person during maximal exercise
100 - 150 litres per minute
the average minute ventilation of a trained person at rest is…
5.5 - 6 litres per minute
the average minute ventilation of a trained person during maximal exercise
160 - 210 litres per minute
is inspiration at rest active or passive?
active
is expiration at rest active or passive?
passive
is insipration during exercise active or passive?
passive
is expiration during exercise active or passive?
active
define dissociation
oxygen unloading from haemoglobin
define Bohr shift
a move in the oxyhaemoglobin dissociation curve to the right caused by increased acidity in the bloodstream
what effects does Bohr shift have on the body?
- increased blood and muscle temperature
- increase in partial pressure of CO2
- increased lactic acid and carbonic acid production
what impact does Bohr shift have on performance?
dissociation of oxygen to tissues is higher, therefore there is more oxygen available for diffusion and aerobic energy production for exercise
what factors affect tidal volume?
- age
- fitness level
- gender
- respiratory conditions
- size of lungs & thoracic cavity
define diffusion
the movement of substances down the concentration gradient across a membrane
heart rate increases prior to exercise, explain how
adrenaline is released from the adrenal gland
by stimulating the SA node
so its firing rate increases
