intro to respiratory physiology

Question 1

describe pulmonary circulation

Answer 1

delivers carbon dioxide to the lungs and picks up oxygen

blood travels from the heart, to the lungs then back to the heart

Question 2

describe systemic circulation

Answer 2

delivers oxygenated arterial blood out to the peripheries

tissues use this oxygen and produce carbon dioxide which is returned back to the heart by the veins

Question 3

what is the function of the pulmonary vein

Answer 3

carries oxygenated blood back to the heart from the lungs

Question 4

define gas exchange

Answer 4

oxygen is added to the blood from the air and carbon dioxide is removed from the blood into the air

Question 5

why is gas exchange important

Answer 5

to produce energy via aerobic respiration

Question 6

what is the respiratory system responsible for?

Answer 6

acquiring oxygen and removing carbon dioxide.
This can’t be done w/o the CVS which transports the oxygen to and removes carbon dioxide from tissues
external respiration requires the integration of these two tissues

Question 7

where does gas exchange occur

Answer 7

in the lungs and at the systemic capillaries

Question 8

describe the relationship between net volumes exchanged at a steady state

Answer 8

the net volume of oxygen exchanged in the lungs per unit of time is equal to the net volume exchanged in the tissues (the same applies for carbon dioxide)

Question 9

average volume of oxygen exchanged per minute

Answer 9

250 ml oxygen consumed

200ml carbon dioxide produced

Question 10

average breathing rate

Answer 10

12-18breaths/min at rest

40-45 at max exercise in adults

Question 11

what are the 9 regions of the airways and lungs

Answer 11

nose
pharynx
epiglottis
larynx
trachea
bronchus
bronchioles
alveoli
diaphragm

Question 12

describe the nose

Answer 12

air enters here
cilia and mucus trap air particles
the air is warmed and moistened due to the large SA of the nose

Question 13

describe the pharynx

Answer 13

throat

shared with the digestive system

Question 14

describe the epiglottis

Answer 14

small flap of tissue that folds over the trachea

prevents food from entering the airway when we swallow

Question 15

describe the larynx

Answer 15

voice box

contains the vocal chords

Question 16

describe the trachea

Answer 16

made up of stiff, incomplete rings of cartilage for support

Question 17

describe the bronchus

Answer 17

trachea bifurcates into L and R 1y bronchi
these split again into the 2y bronchi: 2 on L and 3 on R going to the different lobes of the lung
these split again into 3y bronchi

Question 18

where are aspirated foreign bodies most commonly lodged and why

Answer 18

R bronchi

it is slightly wider and has a more vertical trajectory

Question 19

describe the bronchioles

Answer 19

3y bronchi divide into bronchioles
most of the bronchioles have walls too thick for gas exchange
the bronchioles eventually end as alveoli

Question 20

describe the alveoli

Answer 20

tiny sacs covered in a dense series of capillaries
walls are thin enough for gas exchange
surface is covered with elastic fibres allowing them to stretch and recoil

Question 21

describe the diaphragm

Answer 21

skeletal muscle

separates the abdominal from the thoracic cavity

Question 22

what is meant by a ‘patent’ airway

Answer 22

an open airway

the patency of an airway is maintained by the C-shaped rings of cartilage

Question 23

where does least resistance occur and why

Answer 23

further down the lungs where the diameter is smallest due to increased SA
airway diameter can be altered by the activity of bronchial smooth muscle - contract decreases diameter and increases resistance

Question 24

what are the two type of pneumocytes

Answer 24

Type I and Type II

Question 25

what is the role of type I pneumocytes

Answer 25

make up the majority of alveolar surface

very thin and allow gas exchange

Question 26

what is the role of type II pneumocytes

Answer 26

secrete surfactant which makes breathing easier

Question 27

what is the respiratory system divided into?

Answer 27

upper and lower
upper - larynx and above
lower - trachea and below

Question 28

what are the 4 functions of the respiratory system

Answer 28

gas exchange
acid base balance
protection from infection
communication via speech