Respiratory system Flashcards
ventilation
getting air into the lungs
external respiration
gaseous exhange between the lungs and the blood
transport of gases
attaching to haemoglobin in red blood cells
internal repsiration
exchange of gases between the blood in capillaries and the body cells
cellular respiration
the metabolic reactions and process that takes place in a cel to obtain energy fuels such as glucose
resporatory structures
- nasal passage
- oral pharynx & larynx
- trachea
- bronchi & bronchioles
- alveoli
nasal passage
- nose cavity is divided into cartilaginous septum
- interior structures of the nose helps the repiratory process
- mucous membrane and blood capillaries moisten and warm the air
- ciliated epithelium filters and traps dust particles
- small bones (chonchae) increase the surface area
oral pharynx & larynx
- shared by both respiratory and alimentary tracts
- air enters the larynx passes over the vocal cords and into trachea
- when swalling - the larynx is drawn upwards and forward, prevents food entering
trachea
- 10cm in length
- lies infront of oesphagus
- composed with 18 horse shoe shaped rings of cartilage
- mucous membrane and ciliated cells
- provides protection from dust
bronchi & bronchioles
- divides into the right and left bronchi
- subdiveds into lobar bronchi
- airways form bronchioles
- enable air to pass into alveoli
- pulmonary diffusion occurs
alveoli
- exchange between lungs and blood
- walls are extremely thin
- composed of epithelial cells
- smooth passage for oxygen
- extensive cappilarries network
- blood squeezes into capilarries whcih gives the red blood cells the bioncave shape - increases surface area
inspirartion at rest - active
- diaphragm and external intercostal muscles contract
- diaphragm flattens/pushes down and ribs/sternum moved up and out - external intercostl muscles are contected to each rib, cause the ribcage to pivot about thoracic vertebral joints
- thoracic cavity volume increases
- lung air pressure decreases atmospheric air (outside)
- surface tension from pleural causes the lungs to push out - air rushes into lungs
expiration at rest - passive
- diaphragm and external intercostal muscles relax
- diaphragm pushes upwards and ribs/sternum move in and down
- thoracic cavity volume decreases
- lung air pressure rises above atmospheric air (outside)
- air rushes out of the lungs
inspiration during exercise - active
- diaphragm, external intercostal muscles, sternocleidomastoid, scalenes and pectoralis minor contracts
- diaphragm flattens with greater force which increases the lift of ribs and sternum
- increased thoracic cavity volume
- lower air pressure in lungs
- more air rishes into lungs
expiration during exercise - passive
- diaphragm and external intercostal muscles relax and rectus abdominis/obliques contract
- diaphragm pushed up harder with more force and ribs-sternum are pulled in and down - ribcage lowered into resting postiion
- greater decrease in thoracic cavity volume
- higher air pressure in lungs
- more air pushed out of lungs - forced out until equal pressure
the repiratory system - alveoli
- alveoli are responsible for gaseous exchange between the blood and the lungs
- structure helps gaseous exchange
- walls are one cell thick - short diffusion pathway
- many capillaries - excellent blood supply
- big surface area
mechanics of breathing
- lungs are surrounded by pleural sacs containing pleural fluid - reduces friction during respiration
- sacs are attached to the lungs and the thoracic cage -enables the lungs to inflate and defkate as the chest expands and flattens
- interrelationship between the lungs, the pleural sacs and throacic cage is central
diffusion
the movement of gas molecules from an area of high partial pressure to an area of low partial pressure
diaphragm
a dome shaped muscle sperating the abdominal and thoracic cavities
breathing during exercise
- demand of oxygen increases
- additonal muscles used
- sternocleidomastoid, perctorals minor and scaleni muscles - increases thoracic cavity
- expiration becomes active
how to measure lung volumes
- spirometer
- measure the volume of air in inspiration and expiration
tidal volume
- volume of air breathed in or out per breath
- increases during exercise
inspiratory reserve volume
- volume of air that can foricbly inspired after a normal breathe
- decreases during exercise
expiratory reserve volume
- volume of air that can be forcibly expired after a normal breath
- slight decrease during exercise
residual volume
- volume of air that remains in the lungs after maximum expirations
- remains the same
minute ventilation
- volume of air breathed in or out per minute
- big increase during exercise
- number of breaths per min (approx 12) x tidal volume = minute ventilation
vital capacity
- the toal sum of both your inspiratory reserve volume and your expiratory reserve volume
- remains the same during exercise
regulation of pulmonary ventilation (breathing) - during exercise
- the respiratory control centre is locted in the medulla oblongata
- controls rate and depth of breathing
- 3 factors involded during exercise - neural control, chemical control ( blood acidity), hormonal control
neural control in regulation of breathing during exercise
- involves the brain, nervous system and chemical control
- when blood acidity is high - the brain is informed and sends impulses to nervous syetm to increase breathing
- detected by chemoreceptors
- sends message through phrenic nerve to stimulate more inspiration
- pulmonary ventilaion is controlled automatically by the sympathatic and parasympathic nervous system
- proprioceptors, barorecptors and stretch receptors detects change in body
two main areas in respiratory system
- inspiratory centre - responsible for inspiration and expiration
- sends nerve impulses via phhrenic nerve to the diaphragm and external intercostal muscles
- muscles contract for 2s and the impulse stops
- passive expiration occurs
- expiratory centre - stimulates expiratory muscles during exercise (internal intercostal muscles and abdominals)
hormonal control in regulationof breathing during exercise
- before exercise brain sends an impulse to the renal gland
- pumps adrenaline into the blood in anticipation of needing more oxygen
- breathing increases
proprioceptors (mechanoreceptors)
increase in movement of joints and muscles sends feedback to respiratory centre - increase breathin rate
baroreceptors
detects a decrease in blood pressure from in the aorta and vena cava - increases breathing rate
stretch receptors
prevents over inflation by sending impulses to the expiratory centre to the expiratory mucles
smoking - effects on respiratory system
- decreased elasticity of respirary structures
- damadge to trachea and bronchi
- damadge to cell linings - cilia is meant to push up mucus but when damadge it blocks causing smokers cough
- excuss mucus in the airways are called brochitis
- chronic obstructive pulmonary disease
- tar increases asma
- emphysema - alveoli are damaged and create greater air sacs which reduce gaseous exchange - irreversable
smoking - effects on cardiovascular system
- atherosclerosis
- arteriosclerosis
- angina
- heart attack
- hypertension
- caner
- pneumonia
- blood clots
- stroke
- kidney failure
smoking - effects on performance
- lungs
- decrease in lung volumes
- decrease in tidal volume
- reduction in surface area in gaseous exchange
- carbon monoxide
- haemoglobin has higher affinity for carbon monoxide
- haemoglobin combines with carbon monoxide instead of oxygen
- reduces association of oxygen with haemoglobin
- oxygen delivery
- reduces partial pressure of oxygen
- gaseous exchange
- decrease diffusion and concentration gradient of oxygen
- less effient
- increase diffusion distance
gaseous exchange
- the replenshiment of oxygen
- all gases exert partial pressure
- partial pressure needs to be siccessively lower when air moves from the alveoli to the blood to the muscles
external respiration (alveoli)
- air that enters the alveoli has high partial pressure of oxygen compared to deoxygeanted blood in alveoli
- oxygen diffuses alveoli into the blood of cappilaries to be transported back to left atrium
- carbon dioxide diffuses from the capillry blood into the alveoli of lungs when its expired
- the difference between high and low pressure is called diffusion/concentration gradient
internal respiration (tissue)
- oxygentated blood is pumped around the systemic circulation until it reaches the cappilaries
- capillary blood has high partial pressire of O2 and low CO2 compared to muscle tissue
- oxygen passed into muscle cells is transferred from haemoglobin in blood cappillaries to myoglobin in muscles tissues
external respiration during exercise
- venous blood returning to the lungs has high partial pressure of CO2
- alveolar has high partial pressure of O2
- has an increased diffusion gradient
- haemoglobin is fully saturated
- will diffuse until partial pressure is equal - greater the diffusion gradient , the greater the amount of oxygen and carbon dioxide exhancge
internal respiration during exercise
- greater oxygen dissociation in the muscle tissues
chemical control in regulation of breathing in exercise
• controlled with chemoreceptors in the aorta and medulla oblongata
• chemoreceptors stimulate increased breathing via the ICC
•detection of changes in blood acidity levels, caused by carbon dioxides
