respiratory system unit 3 Flashcards
function of the respiratory system
- provide oxygen to the muscle cells
- remove waste products such as carbon dioxide, heat and water vapour
function of the nasal cavity
- hairs filter out dust and pollen
- air is warmed and moistened
- mucous traps smaller foreign particles
function of the pharynx (throat)
- connects nasal cavity to the mouth
function of the larynx
- ridgid walls of cartilage and muscles
- constains vocal cords
function of the trachea
- rings of cartilage to prevent it from collapsing
- branches into right and left bronchi
function of the bronchus
- divided into reight and left bronchi
function of the bronchioles
- connect bronchi to alveoli
- doesnt contain cartilage
function of the diaphragm
- flat muscle beneath the lungs
- contraction of the diaphragm increases volume of chest cavity
- relaxation of the diaphragm decreses the volume of chest cavity
function of the pleura
- lubricates and reduces friction between lungs and thoracic cavity when breathing
MECHANICS OF BREATHING
inspiration at rest
1) DIAPHRAGM and EXTERNAL intercostal muscles CONTRACT
2) diaphragm FLATTENS and pushed down and ribs and sternum move UP + OUT
3) thoracic cavity volume INCREASES
4) lung air pressure DECREASES
5) air rushes INTO lungs
expiration at rest
1) DIAPHRAGM and INTERCOASTAL muscles RELAX
2) diaphragm MOVES UP into a DOME shape and ribs and sternum move DOWN + IN
3) thoracic cavity volume DECREASES
4) lung air pressure INCREASES
5) air rushes OUT of lungs
inspiration during exercise
1) more muscles are recruited to pull the rib cage UP +OUT more than at rest ( sternocleidomastiod, scalenes, pectoralis minor)
2) this INCREASES thoracic cavity volume more than at rest
3) this LOWERS lung air pressure more than at rest
4) allows more air to enter the lings than at rest
expiration during exercise
1) INTERNAL intercostal muscles pull the ribcage DOWN +IN more than at rest
2) abdominal muscles also CONTRACT to push against the diaphragm and RAISE ABDOMINAL air pressure
3) DECREASES thoracic cavity volume
4) INCREASES lung air pressure more than at rest
5) forces more air OUT of lungs than at rest
definition of tital volume
the volume of air inspired and expired in one breath
500ml to 5000ml
definition of inspiratory reserve volume
volume of oxygen which can be taken in more than usual
3000ml to 0ml
definition of expiratory reserve volume
the volume of oxygen which can be expelled more than usual
1500ml to 0ml
definition of residual volume
volume of air which is always in the lungs
1200ml to 1200ml
definition of vital capacity
maximum volume of air expired after a maximum inspiration
5000ml to 5000ml
definition of total lung capacity
complete volume of air in the lungs after a maximal inspiration
6200ml to 6200ml
neural control of breathing
1) breathing is controlled by the MEDULLA OBLONGATA which is called the RESPIRATORY CONTROL CENTRE in the brainstem
2) CHEMORECEPTORS located in the CAROTID ARTERY and AORTIC ARCH monitor levels of oxygen and carbon dioxide and ph in the blood
3) they DETECT an INCREASE in CARBON DIOXIDE and a decrease in OXYGEN, receptors SEND SIGNALS to the brain to INCREASE its BREATHING RATE
4) a MESSAGE IS SENT down the PHRENIC NERVE which STIMULATES the DIAPHRAGM and INTERCOSTAL MUSCLES to CONTRACT more than at rest
5) leads to an INCREASE in BREATHING RATE and increase in DEPTH OF BREATHING / TIDAL VOLUME
