topic 10 powerpoint 10.0

Question 1

Two primary operating features of gas exchange

Answer 1

The respiratory medium refers to the air or water that is involved in the exchange of gases. The respiratory surface, on the other hand, is the wetted epithelium where gas exchange takes place. Ex: gil

Question 2

What is the respiratory surface in mammals?

Answer 2

lungs

Question 3

What is ventilation?

Answer 3

Ventilation refers to the flow of the respiratory medium (air or water) over the external side of the respiratory surface.
Ex: air moves into and out of the lungs

Question 4

What is perfusion?

Answer 4

Perfusion refers to the flow of blood or other body fluids on the internal side of the respiratory surface.
Ex: movement of blood through the capillaries surrounding the alveoli in the lungs, where gas exchange occurs.

Question 5

Optimal gas exchange depends on

Answer 5

-A large respiratory surface is a wetted epithelium where gas exchange takes place, thus larger area means more gas exchange
-simple diffusion, process gases move from high concentration areas to lower area, determined by SA available for exchange

Question 6

In mammals, the lungs carry out what extra features to prevent drying of respiratory surface?

Answer 6

-lungs are invaginated, meaning they have pockets or folds. These pockets help to keep the lungs from drying out by minimizing the exposure of the respiratory surface to dry air. AKA prevent evaporation
-Lungs allow air to become saturated with
water before it reaches the respiratory surface

Question 7

What are the two types of ventilation?

Answer 7

-positive pressure breathing(frog), the air is forced into the lungs by muscle contractions, air pressure inside is greater than outside

-negative pressure breathing(mammals), air is pulled into lungs by muscle contractions that expand lungs and lowering air pressure inside, air pressure inside is lower than outside

Question 8

If you had a highly infectious disease, such
as Covid- 19, should you stay in a hospital room that has a positive pressure ventilation system or a negative pressure ventilation system?
A. Positive
B. Negative

Answer 8

negative pressure in the room
Air is being pulled into the room, so the Coronavirus is not being pushed out of
the room to infect others)

Question 9

What if you had a severely compromised
immune system?
A. Positive
B. Negative

Answer 9

positive
The air pressure in the room is greater than that outside of it, so it
pushes potential infection agents or chemicals away from the patient.
Air flows from the room to the outside adjacent space, so germs from the
outside are not being pulled into the room

Question 10

What are some characteristics of the Mammalian Respiratory System?

Answer 10

1. airways connecting exterior to lungs, filter, moisten, and warm entering air
   2.Contractions of the diaphragm and muscles between the ribs
   ventilate the lungs
2. The volume of inhaled and exhaled air varies.
3. The centers that control breathing are located in the brain stem(medulla oblongata)

Question 11

Describe air passageway in lungs

Answer 11

1.nasal passages: chamber for air wash
2.pharynx(throat): connects nasal passages to mouth, expect air + food +liquid
3. epiglottis: closes larynx during swallowing
4.larynx(voice box)
5. trachea(windpipe): airway that connects the larynx to two bronchi that lead into the lungs
6. lungs: elastic organ that exchanges gases between internal and external air
7. bronchi are branched airways that become bronchioles, leading into alveoli surrounded by networks of blood capillaries

Question 12

food travels down the __ not the ___

Answer 12

esophagus, trachea

Question 13

intercostal muscle

Answer 13

skeletal muscle between ribs that contract to fill and empty lungs

Question 14

diaphragm

Answer 14

muscle sheets between chest cavity and abdominal cavity that contracts to fill lungs

Question 15

T/F Gas exchnage has a small area

Answer 15

false: Large area for gas exchange: 150 million alveoli, each
surround by a dense network of capillaries

Question 16

Larynx, trachea and large bronch have what in common?

Answer 16

are non-muscular tubes; have rings of cartilage around them for support

Question 17

What controls the diameter of the Small Bronchi and bronchiole?

Answer 17

smooth muscle cells

Question 18

bronchi has what two features?

Answer 18

Ronchi have cilia and mucus-secreting cells. Mucus traps dust, pollen, bacteria; cilia move material up to the throat

Question 19

Air is exhaled passively due to:

Answer 19

-relaxation of diaphram + intercostal muscle
-Elastic recoil of lungs (pleural membranes)

Question 20

Explain mechanism of inhalation

Answer 20

diaphragm contracts downward
external intercostal muscle contract,increase volume lifting rib cage upward and outward-decrease pressure-
lung volume expands- draw air into lungs

Palv(lung pressure)< Patm

Question 21

explain mechanism of exhalation

Answer 21

Exhalation during breathing or rest. Diaphragm and external intercostal muscles return to the resting positions. Rib cage moves down. decrease in volume-Lungs recoil passively-increase pressure- expel air

Palv(lung pressure) > Patm

Question 22

pleura

Answer 22

double layer of epithelial tissue
that covers the lungs
Visceral: inner layer that’s attached to lung surface
Parietal: outer layer that attaches to surface of the chest cavity
liquid in between layers help to prevent friction and abrasion between the lungs and the chest wall.

Question 23

negative pressure

Answer 23

refers to a situation in which an enclosed area has lower
pressure than the area around it

Question 24

What keeps lungs in contact with chest wall?

Answer 24

negative pressure in intrapleural space, liquid in space between visceral and parietal in pleura

Question 25

T/F Lungs are inelastic and stiff

Answer 25

false; that’s why there is a pleura, to prevent friction when lungs moved upward and downward
They are compliant (stretchy)

Question 26

tidal volume

Answer 26

Amount of air moved in and out of lungs during an
inhalation and exhalation

Question 27

vital capacity

Answer 27

total volume of air a person can inhale and exhale by
breathing as deeply as possible

Question 28

residual volume

Answer 28

Air remaining in the lungs after as much air as possible is
exhaled

Question 29

What is the ideal gas law?

Answer 29

PV=nRT
*air flows from areas of higher to lower pressure

Question 30

What is Boyle law?

Answer 30

P1V1=P2V2 pressure of gas is inversely proportional to volume

Question 31

What does it mean by “Pathways in and out of lungs offer low resistance to flow”?

Answer 31

The airways are designed to be wide and open, allowing for smooth and unobstructed airflow.

Question 32

What is ventilation in mammals?

Answer 32

exchange of air between the atmosphere
and alveoli in the lungs

Question 33

F= change in pressure/ R , how do we calculate change in pressure?

Answer 33

Palv- Patm

lungs, Palv is less than and greater than Patm

Question 34

What do you think would happen…
When the pressure in the alveoli is less
than the atmospheric pressure?

Answer 34

Air flow into lungs (Inspiration)

Question 35

When the pressure in the alveoli is greater than the
atmospheric pressure?

Answer 35

Air flows out of lungs (Expiration)

Question 36

Why does the lung expand when the chest
cavity expands since they are not directly
attached?

Answer 36

negative pressure in the intrapleural space that keeps the lungs in contact with the chest wall

Question 37

Ptp

Answer 37

Ptp: transpulmonary pressure: difference in pressure between the
inside and outside of lungs
Ptp= Palv-Pip
Palv: alveolar pressure: pressure in the alveoli
Pip: intra pleural pressure: pressure in the pleural space

Question 38

According to Ptp= Palv-Pip, which is always positive and which is always negative? Which changes?

Answer 38

• transpulmonary pressure is always positive;
  -intrapleural pressure is always negative,
  -alveolar pressure moves from slightly positive to slightly negative as a person breathes

Question 39

Relate inspiration to Ptp= Palv-Pip

Answer 39

Breathe in, chest wall expands, pip has negative pressure aka lowerring pressure
when pip is lower, ptp increases and expands lungs.
Palv- Patm
Palv is less than Patm, air rushes in

Question 40

What happens between breathes (at the end of an expiration) in terms of
pressure?

Answer 40

End of expiration, no air flow palv=patm
lungs lways have air in them so, ptp is positive and pip is negative. This negative intra pleural pressure “holds” the lungs open and the chest wall in.

Question 41

In between breaths, we can expect who two things to be a zero? And what to be negative?

Answer 41

Alv and patm, pip is negative(-4)

Question 42

expansion of the chest wall (increase in volume) at the end of
inspiration, the Pip has gone

Answer 42

from -4 to -7

Question 43

Two Determinants of lung compliance:

Answer 43

1.“Stretchability” of the lungs.
The greater the lung compliance, the easier it is to expand
the lungs at any given change in transpulmonary pressure.
2. Surface tension:
surfactant on alveolar cells forms layer of fluid over it to reduce surface tension, which increases lung compliance

Question 44

What would happen if there was no surfactant?

Answer 44

The tendency of the water molecules to attract (and form
a droplet) can cause the alveoli to collapse, thus
producing a fluid filled alveoli with smaller volumes than
an air filled alveoli. (Surfactant prohibits this)