The lungs

Question 1

functions of the respiratory system?

Answer 1

-Gas exchange (o2 in, CO2 out)
-Regulate pH (reduce acidity in blood)
-Protection from pathogens
-Allow us to talk (force air from lungs thru vocal chords)

Question 1

why do humans have an internal respiratory system

Answer 1

allows us to keep moist internal environment allowing for gas exchange

Question 2

what is external respiration

Answer 2

The movement of gases from the environment to the cells in the body

Question 3

what are the 4 processes of external respiration?

Answer 3

-Exchange of air between atmosphere and lungs
-Exchange of oxygen and CO2 between lungs and blood
-Transport of O2 and CO2 in the blood
-Exchange of gases between blood and cells

Question 4

describe what the external anatomy of the respiratory system consists of?

Answer 4

Both a muscular and bone system:
-Intercostal muscles (between ribs)
-Diaphragm (large flat muscle at bottom of rib cage)
-Scalenes & sternocleidomastoids (attach from neck to top of clavicle)
-Abdominal muscles

Question 5

What is the internal respiratory system split into?

Answer 5

split between upper and lower respiratory system

Question 6

what does the upper respiratory system consist of?

Answer 6

nasal cavity, larynx, vocal cords, tongue, pharynx, oesophagus

Question 7

what does the lower respiratory system consist of?

Answer 7

trachea, lungs, bronchus, bronchiole

Question 8

what occurs within the 2 pleural membranes in lungs and pleural cavity?

Answer 8

they fill with liquid

Question 9

What are functions of liquid in pleural cavity

Answer 9

-Provides slippery surface (prevents lungs from being damaged by touching the ribcage
-Holds the lungs close to ribcage (ensures lungs contract and expand fully along with the ribcage via surface tension)

Question 10

What happens within the airways?

Answer 10

-Warms air (ensures no cold air enters alveoli- could affect body temperature and damage alveoli)
-Adds water vapour (moisture) to air as it travels down respiratory system (moisture required for gas exchange later on)
-Layer of mucus filters out pathogens (pathogens stick to layer allowing mucus to be pushed out and removed)

Question 11

Describe the system within the airways?

Answer 11

-Conducting system(larynx, trachea which splits into 2 primary bronchus which then divide 22 more times into bronchiole finishing with alveoli cluster)

Question 12

Describe the function/ adaptations of alveoli in the lungs ?

Answer 12

-Allows gas exchange to take place
-Due to shape/ structure alveoli are able to increase SA of lungs, increasing gas exchange
-Large blood supply provided by surrounding capillaries (allows for efficiency of gas exchange)
-Thin membranes-1 cell thick-ensuring small diffusion distance, making it easier to get O2 in and CO2 out

Question 13

What does Boyles law suggest?

Answer 13

P1xV1= P2 x V2
-Pressure is created by collision of gases within a container
(is directly proportional to size of container- smaller container, more collisions, more pressure)
-Gases always move down pressure gradient In lungs: When we breathe out, volume decreases so pressure increases, forcing gases to move out
-We breathe in, volume increases so pressure decreases

Question 14

What does atmospheric pressure mean?

Answer 14

the sum of the pressures of the individual gases in the atmosphere (eg. Nitrogen, Oxygen, carbon dioxide and other gases)

Question 15

what does partial pressure mean?

Answer 15

the pressure of an individual gas
-Individual gases move down a concentration (partial pressure) gradient- continues into equilibrium is reached

Question 16

Describe the process of inspiration?

Answer 16

For air to move into alveoli pressure in lungs must be lower than atmospheric pressure:
-Diaphragm contracts and flattens, pulling bottom of lungs down increasing surface area for inspiration
-The ribs move up and out, increasing volume, reducing pressure allowing for air to be taken into lungs in order to equalise pressure gradient

Question 17

describe the process of expiration?

Answer 17

-Diaphragm relaxes causing lungs to drop and decrease volume, pressure increases and air is forced out
2 types:Quiet expiration (natural) and Active expiration (uses more muscles which contract and force air out)

Question 18

What is tidal volume?

Answer 18

the amount of air that goes in and out of lungs with each breath
(at rest-½ L- 1L per breath)

Question 19

what is inspiratory reserve volume?

Answer 19

how much more air we could breathe in (at rest 2 1/2L- 3L)

Question 20

what is expiratory reserve volume?

Answer 20

how much more air that could be exhaled (1l-1 1/2L at rest)

Question 21

What is vital capacity?

Answer 21

the largest breath possible (the largest inspiration + largest expiration)

Question 22

what is Total lung capacity compared to vital capacity?

Answer 22

will always be larger than vital capacity- due to always being a slight residual volume left over

Question 23

what is residual volume?

Answer 23

(around 1l)- air that is left in the lungs (decreases with age)

Question 24

what does dynamic lung volume mean?

Answer 24

How much air can be forced out in a certain amount of time

Question 25

What can dynamic lung volume tell us?

Answer 25

whether we have normal lungs or problems with restriction or obstruction

Question 26

what is restriction?

Answer 26

lower forced vital capacity(lower elasticity)

Question 27

what is obstruction?

Answer 27

lower FEV1 (volume of air that can be exhaled in 1 second) is lower but overall forced vital capacity is the same

Question 28

what is Minute ventilation and the formula for it?

Answer 28

-the amount of air going in and out of lungs within 1 minute Minute ventilation = Tidal vol x breathing rate

Question 29

State the general values of breathing rate, tidal vol and minute ventilation at rest

Answer 29

BR=12, TV=0.5, MV=6

Question 30

State the general values of breathing rate, tidal vol and minute ventilation in moderate exercise

Answer 30

BR=30, TV=2.5, MV= 75

Question 31

State the general values of breathing rate, tidal vol and minute ventilation in vigorous exercise

Answer 31

BR=50, TV=3, MV= 150

Question 32

Why can't minute ventilation indicate how much fresh air reaches alveoli?

Answer 32

Due to dead space (150ml)- is old air and can’t be used for gas exchange

Question 33

formula for alveoli ventilation?

Answer 33

Alveoli ventilation= Ventilation Rate x (tidal volume- dead space)

Question 34

Describe the journey of oxygen within gas exchange?

Answer 34

-Oxygen enters alveoli and moves from pulmonary capillaries into the system -The heart then pumps it around the body and reaches the tissues (reaches muscle tissue and capillaries within it) -Oxygen then moves into cells where cellular respiration can take place

Question 35

describe the journey of CO2 within gas exchange?

Answer 35

-CO2 goes back into systemic capillaries and through the system and heart into the pulmonary capillaries -its then exchanged and taken out through the alveoli and expelled with air being exhaled

Question 36

what is exchange process driven by?

Answer 36

-partial pressure (gas moves from area of low to high partial pressure): -Atmosphere has high partial pressure of oxygen wheare blood reaching alveoli has lower oxygen partial pressure

Question 37

what are the factors influencing alveolar gas exchange

Answer 37

-resistance within airways, lung compliance and rate/ depth of breathing influence alveolar ventilation which affects oxygen reaching the alveoli -Composition of inspired air -Barrier thickness, amount of fluid can influence diffusion distance -Diffusuion distance and SA can influence gas diffusion between alveoli and blood

Question 38

Diffusion formula

Answer 38

Diffusion = Surface Area x Barrier permeability/ distance

Question 39

what is emphysema?

Answer 39

destruction of alveoli means less surface area for gas exchange

Question 40

what is fibrotic lung disease?

Answer 40

thickened alveolar membrane slows gas exchange, loss of lung compliance may decrease alveolar ventilation

Question 41

what is pulmonary edema

Answer 41

fluid in interstitial space increases diffusion distance

Question 42

what is asthma?

Answer 42

increased airway resistance decreasing alveolar ventilation

Question 43

what is transport of oxygen within the lungs influenced by?

Answer 43

by solubility of oxygen within a liquid

Question 44

describe the effect of haemoglobin within oxygen transport in the lungs?

Answer 44

-Haemoglobin is able to bind to oxygen causing it to diffuse into the blood, each red blood cell is able to take on 4 oxygen molecules -This then allows for more room so more oxygen can move into and dissolve the blood, increasing uptake of oxygen