respiration

Question 1

at equilibrium what can you say about partial pressures and concentrations of gases in aqueous and gaseous phase

Answer 1

the concentration of gases is not the same but the partial pressures is the same

Question 2

O2 moves into the cell by diffusion because

Answer 2

PO2 in the interstitial fluid is greater than PO2 in the cell
O2 in a cell is used for oxidative phosphorylation in mitochondria so its concentration in the cell is low

Question 3

CO2 moves out of the cell because

Answer 3

PCO2 in the cell is greater than PCO2 in interstitial fluid (product of oxidative phosphorylation)

Question 4

Difference in exchange of gasses for aquatic animals and terrestrial animals

Answer 4

Aquatic animals exchange with dissolved gasses, and its environment will be in equilibrium with atmospheric gas

Terrestrial animal is exchanging gases directly with the atmosphere
The surface of the lungs is covered with water so the movement of gases between phases is taking place here

Question 5

Problems with gases only moving by diffusion

Answer 5

Diffusion is slow

Partial pressure drops off with the square of the distance

Question 6

what is the solution to diffusion being too slow and Partial pressure drops off with the square of the distance

Answer 6

increase surface area on which gases can exchange → lungs and gills

Reduce distance gases must travel

Question 7

Insects tracheal system

Answer 7

Network of air-filled tubes
Increases surface area of gas exchange

Question 8

Fish gills

Answer 8

Lots of close proximity capillaries
Countercurrent exchange
Water and blood flow in opposite directions
Brand-new oxygenated water is meeting blood that is leaving the capillaries
Partial pressures equilibrate better

contain arterioles, capillaries, and venules

Question 9

Frogs
gas exchange

Answer 9

Exchange gases through skin
Lungs
Create positive pressure to force air into their lungs \

Question 10

how do frogs create positive pressure to force air into their lungs

Answer 10

Expands buccal cavity and brings in air
Glotis opens and buccal cavity contracts → lungs expand
Buccal cavity expands and lungs contract
Glotis closes and buccal cavity contracts

Question 11

Birds respiration

Answer 11

When they inhale they fill up air/posterior sacs
Exhale sends gas from sacs to the lungs and exchange gases at capillaries then send to anterior sacs and out

Question 12

why is bird respiration more efficient than human respiration

Answer 12

humans have remaining air from previous inhale/exhale cycle
Birds don’t have that issue due to one way direction of air across the parabronchi

Question 13

why do mammals not have the one way passage of air

Answer 13

the trachea and bronchioles don’t participate in gas exchange

Question 14

Mammalian lungs
The nose, mouth, and pharynx all lead to the __ which connects to the __

Answer 14

Larynx, trachea

Question 15

Trachea

Answer 15

stiff large tube
Stiff to maintain open passage

Question 16

how does air flow in humans?
describe where it passes through

Answer 16

Air enters the thoracic cage and divides into two major bronchi
Each bronchus leads to a lung
The bronchi branch into smaller tubules called bronchioles
The bronchioles are wrapped in smooth muscle
Bronchioles continue to branch into smaller and smaller tubes that lead into the alveoli
Alveoli covered in capillaries

Question 17

Alveolus

Answer 17

One alveoli
Most of the alveolus is just air (hollow)

at the terminals of bronchioles
covered in capillaries

Air sacs clustered at the tips of the tiniest bronchioles

Question 18

pharynx

Answer 18

intersection where the paths for air and food cross
links mouth and nose to larynx and esophagus

Question 19

What happens when food is swallowed

Answer 19

The larynx (upper part of respiratory tract) moves upward and tips the epiglottis over the glottis
This allows food to go down the esophagus to the stomach

Question 20

what is the glottis and what is its resting state

Answer 20

The glottis is the opening of the trachea, or windpipe

Typically the glottis is open which allows for breathing

Question 21

The epithelium lining the major branches of the respiratory tree(system of air ducts) is covered by is Cilia and thin film of mucus

the Purpose of mucus and cilia is

Answer 21

Traps dust pollen and other particulate contaminants
the beating cilia move the mucus upward to the pharynx where it can be swallowed into the esophagus
Plays a crucial role in cleansing the respiratory system

Question 22

what prevents surface tension from collapsing alveoli(alveoli is hollow)

Answer 22

Surfactant
Mixture of phospholipids and proteins
Breaks up water strictures and prevent too much surface tension

Question 23

How do humans breathe
inhalation and exhalation

Answer 23

Negative pressure breathing

Diaphragm contracts(moves down)
Increasing the volume of the lung (Patm>Plung –> air moves into lung)

Exhalation
Diaphragm relaxes (moves up)
Decrease the volume of the lung (Patm<Plung –> air moves out the lung)

uses diaphragm and rib muscles

Question 24

what pressure keeps the lungs inflated

Answer 24

lungs are Suspended in our pleural cavity
Partial pressure inside pleural cavity is slightly less than in the lung

Question 25

If pleural cavity or lung was punctured the lung would

Answer 25

deflate
collapsed lung

Question 26

Control of respiration is done
Primarily through

Answer 26

monitoring CO2 not O2
and especially through monitoring pH
When CO2 levels rise, blood pH falls in cerebrospinal fluid
Sensors in major blood vessels detect decrease in blood pH
Medulla receives signals from major blood vessels
Signals from medulla to rib muscles and diaphragm increase rate and depth of ventilation

Question 27

why does CO2 level in the blood affect pH

Answer 27

Carbonic anhydrase turns CO2 and H2O into carbonic acid which lowers pH

Question 28

What occurs during respiration

Answer 28

gases move due to partial pressure differences
In atmosphere there is a lot of O2 and not a lot of CO2
O2 is breathed in and CO2 is released

Question 29

when you inhale what is the partial pressure difference that is observed

Answer 29

you are inhaling used air along with the new air so there is a slightly higher PCO2 and lower PO2 in alveoli when inhaled

Oxygen just moves down partial pressure difference

Question 30

blood entering the alveolar capillaries is going through what circulation

Answer 30

pulmonary circulation (lung)

Question 31

in the alveoli, blood entering the alveolar capillaries from pulmonary circulation(old gas) has what sort of gas concentration

Answer 31

higher PCO2 and lower PO2 (compared to inhaled)
this is blood returning from systemic circulation (deoxygenated)

Question 32

the air in the alveolar space(inhaled/new air) has what sort of pressure differences and how does it move

Answer 32

higher PO2 and lower PCO2

down pressure gradient

O2 moves into the blood and CO2 moves into the alveolar space(out the blood)

Question 33

Why are alveoli highly susceptible to contamination and what is its defense measure

Answer 33

They lack cilia or significant air currents to remove particles from their surface

They do have white blood cells that patrol the alveoli and engulf foreign particles

Question 34

Neurons mainly responsible for regulating breathing are in the

Answer 34

Medulla oblongata
Near the base of the brain

Question 35

in the body tissues/where the systemic capillaries meet the body tissues, what is the pressure gradient like

Answer 35

blood entering the systemic capillaries from the pulmonary veins and systemic arteries has a high PO2 and low CO2

the interstitial fluid in the tissues have high PCO2 and low PO2 which results in O2 movement into the interstitial fluid and CO2 into the blood

Question 36

as blood moves up the pulmonary arteries and systemic veins, what is the pressure like? where do the gases move

Answer 36

PCO2 is high and PO2 is low

CO2 leaves alveolar capillaries and is exhaled out while O2 is maintained in capillaries as old air to be used again

Question 37

what comes first, the pulmonary veins or pulmonary arteries?

Answer 37

pulmonary veins

Question 38

what comes first, systemic arteries or systemic veins

Answer 38

systemic arteries

Question 39

If a molecule of CO2 is released into
the blood in your left toe is exhaled from your nose, it
must pass through all of the following except

a. the pulmonary vein.
b. the trachea.
c. the right atrium.
d. the right ventricle

Answer 39

a. pulmonary vein
it already went through pulmonary vein and needs to go through pulmonary artery

Question 40

The amount of O2 that can directly dissolve in the blood is very low. So, we evolved

Answer 40

Erythrocytes (red blood cells)

Question 41

Erythrocytes (red blood cells) and its function

Answer 41

Filled with hemoglobin that bind blood

When O2 goes into a red blood cell it binds to hemoglobin, due to this it no longer contributes to the partial pressure, allowing O2 to continue flowing in

They greatly increase the amount of O2 that can be carried in the circulatory fluid

contain respiratory pigment, hemoglobin which can carry four O2 molecules

Question 42

Why is hemoglobin especially efficient at delivering O2 to tissues actively consuming O2

Answer 42

it can bind 4 O2
Where Co2 production is greater, the hemoglobin releases more O2(pH increases)
As the partial pressure of O2 increases, the amount of O2 bound to hemaglobin will increase
The binding of the first O2 increases the affinity for O2 binding of the next and so on

Question 43

If only 7% of the CO2 released by respiring cells is transported in solution in blood plasma, what happens to the rest of it

Answer 43

The rest diffuses from plasma into erythrocytes and reacts with water to form H2CO3.
Minimizes change in blood pH

Most of CO2 is converted to carbonic acid by the enzyme carbonic anhydrase in the erythrocytes
Carbonic acid is pumped out of the cell and dissociates to ions that can diffuse out easier