Respiratory Physiology

Question 1

functions of breathing

Answer 1

-get oxygen to blood
-get carbon dioxide out the blood
-warm and humidify air
-protect the lung from hostile environment

Question 2

volume of oxygen absorbed per minute

Answer 2

250ml

Question 3

volume of carbon dioxide excreted per minute

Answer 3

200ml

Question 4

upper airways function

Answer 4

humidify, warm and filter

Question 5

epithelia found in respiratory

Answer 5

pseudostratified ciliated columnar

Question 6

asthmatic airway

Answer 6

muscle tightens, increased mucus and swelling

Question 7

glottis

Answer 7

vocal cords

Question 8

alveoli

Answer 8

series of tiny stretchy bubbles

Question 9

upper respiratory

Answer 9

nose, mouth and pharynx

Question 10

lower respiratory

Answer 10

larynx to alveoli

Question 11

nasal cavity and paranasal sinuses function

Answer 11

smell, warm and humidify air
- filter out large particles

Question 12

pharynx function

Answer 12

further warm, mix air and share cavity with digestive tract

Question 13

larynx function

Answer 13

protects entrance to respiratory tree and allows speech

Question 14

trachea and large bronchi

Answer 14

filters air, trap particles in mucus, macrophages involved in fighting infection

Question 15

cartilage function in trachea

Answer 15

maintains rigidity of airway

Question 16

alveoli cell types

Answer 16

type 1 and type 2

Question 17

bronchioles function

Answer 17

some filtration, cilia, macrophages and smooth muscle directs air flow

Question 18

type 1 epithelial cells

Answer 18

97% of alveolar surface, gas exchange and attracts water molecules

Question 19

type 2 epithelial cells

Answer 19

3% of alveolar surface, produces surfactant and reduce surface tension

Question 20

surfactant

Answer 20

amphipathic
binds to water and air within the alveoli - reducing the surface tension.
alveoli are able to expand to greater volumes

Question 21

amphipathic

Answer 21

able to bind to both hydrophobic and hydrophilic molecules simultaneously

Question 22

defence mechanisms

Answer 22

nose, cilia/mucus, bronch-constriction, constriction and dilation

Question 23

nose mechanism

Answer 23

stiff hair for filtration

Question 24

cilia and mucus mechanism

Answer 24

cilia moves mucus upwards to remove foreign material up the lumen - either coughed or swallowed

Question 25

broncho-constriction

Answer 25

constriction of smooth muscle narrows the lumen and relaxation widens airway

Question 26

constriction

Answer 26

mediated through ACh receptors and is triggered by irritants like dust and chemicals

Question 27

dilation

Answer 27

adrenergic receptors that are stimulated by adrenaline or noradrenaline - part of sympathetic response

Question 28

macrophages and lymphocytes in the lungs

Answer 28

arrive in lung from blood and migrate across membrane and attack micro-organisms

Question 29

under resting conditions

Answer 29

inspiration is active and expiration is passive

Question 30

inspiratory muscles

Answer 30

diaphragm and external intercostal muscles

Question 31

diaphragm

Answer 31

dome shaped muscle attached to lumbar vertebrae, ribs and xiphoid process - does most of the work of breathing

Question 32

external intercostal muscle

Answer 32

run infero-anterior from rib above to below; contraction pulls the ribs up

Question 33

accessory inspiratory mucles

Answer 33

used during strenuous exercise
- sternocleidomastoid and scalene

Question 34

sternocleidomastoid and scalene muscles

Answer 34

anterior part of the neck
-tension cause chest to be pulled up to head

Question 35

pectoralis major/minor

Answer 35

connect anterior chest to arm - contraction brings chest forwards

Question 36

expiratory muscles

Answer 36

passive due to elastic recoil of the lung
- internal intercostal and abdominal muscle

Question 37

internal intercostal

Answer 37

run infero-posterior from one rib to the one below
- contraction pulls ribs down reducing antero-posterior dimensions

Question 38

abdominal muscle
(six pack muscle)

Answer 38

large muscle which connects the pelvis to xiphisternum
-contraction pulls ribs down

Question 39

cough reflex

Answer 39

unlearned/automatic defence mechanism to get rid of harmful substances which requires:
-large volume of air
-fast flow of air

Question 40

step 1 (cough reflex)

Answer 40

-rapid deep inspiration
-brought about by contraction of the diaphragm (phrenic nerve) and the external intercostal muscles (spinal nerve)

Question 41

step 2 (cough reflex)

Answer 41

-closure of glottis (vagus nerve)
-relaxation of inspiratory muscles
- contraction of expiratory muscles

Question 42

step 3 (cough reflex)

Answer 42

-high intra-thoracic pressure
-opening of glottis
-rapid expulsion

Question 43

receptors which detect stimulus

Answer 43

found in pharynx and trachea
- rapidly adapting pulmonary stretch receptors

Question 44

afferent pathways

Answer 44

vagus nerve to medulla oblongata in the brainstem

Question 45

efferent

Answer 45

phrenic nerve and spinal motor nerve that travel to muscles

Question 46

gas exchange

Answer 46

absorb oxygen and excrete carbon dioxide by diffusion

Question 47

diffusion increased by

Answer 47

larger surface area
thin membrane
high conc gradient
high solubility of gas

Question 48

diffusion rates for oxygen and carbon dioxide

Answer 48

higher gradient generated for oxygen than for carbon dioxide
-carbon dioxide much more soluble in the alveolar membrane (diffusion rates similar)

Question 49

air components

Answer 49

21% oxygen
79% nitrogen