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
- trachea divides into right, left bronchi as they enter lung
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
