respiratory system unit 3

Question 1

function of the respiratory system

Answer 1

• provide oxygen to the muscle cells
• remove waste products such as carbon dioxide, heat and water vapour

Question 2

function of the nasal cavity

Answer 2

• hairs filter out dust and pollen
• air is warmed and moistened
• mucous traps smaller foreign particles

Question 3

function of the pharynx (throat)

Answer 3

• connects nasal cavity to the mouth

Question 4

function of the larynx

Answer 4

• ridgid walls of cartilage and muscles
• constains vocal cords

Question 5

function of the trachea

Answer 5

• rings of cartilage to prevent it from collapsing
• branches into right and left bronchi

Question 6

function of the bronchus

Answer 6

• divided into reight and left bronchi

Question 7

function of the bronchioles

Answer 7

• connect bronchi to alveoli
• doesnt contain cartilage

Question 8

function of the diaphragm

Answer 8

• flat muscle beneath the lungs
• contraction of the diaphragm increases volume of chest cavity
• relaxation of the diaphragm decreses the volume of chest cavity

Question 9

function of the pleura

Answer 9

• lubricates and reduces friction between lungs and thoracic cavity when breathing

Question 10

MECHANICS OF BREATHING

inspiration at rest

Answer 10

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

Question 11

expiration at rest

Answer 11

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

Question 12

inspiration during exercise

Answer 12

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

Question 13

expiration during exercise

Answer 13

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

Question 14

definition of tital volume

Answer 14

the volume of air inspired and expired in one breath
500ml to 5000ml

Question 15

definition of inspiratory reserve volume

Answer 15

volume of oxygen which can be taken in more than usual
3000ml to 0ml

Question 16

definition of expiratory reserve volume

Answer 16

the volume of oxygen which can be expelled more than usual
1500ml to 0ml

Question 17

definition of residual volume

Answer 17

volume of air which is always in the lungs
1200ml to 1200ml

Question 18

definition of vital capacity

Answer 18

maximum volume of air expired after a maximum inspiration
5000ml to 5000ml

Question 19

definition of total lung capacity

Answer 19

complete volume of air in the lungs after a maximal inspiration
6200ml to 6200ml

Question 20

neural control of breathing

Answer 20

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