Respiratory System

Question 1

Pathway

Answer 1

Nasal cavity -> trachea -> bronchi -> bronchioles -> alveolar ducts + alveoli -> pulmonary capillaries (0.5 um)

Question 2

Epithelial surfaces are made of ___ cells

Answer 2

Pseudostratified ciliated columnar cells

Question 3

Mucus beats towards ____

Answer 3

pharynx

Question 4

Phagocytes + simple cuboidal cells are in

Answer 4

Lower airway

Question 5

Functions

Answer 5

1. O2/CO2
2. Speech sounds in humans
3. Defend against microbes
4. Traps and dissolves blood clots
5. Metabolic

Question 6

Metabolic functions

Answer 6

1. Dipalmitoyl lecithin synthesis
2. Prostacyclin release (lung injury)
3. Angiotensin 1 -> angiotensin 2 (vasoconstrictor)
4. Inactivation and removal of toxic substances

Question 7

Inspiration

Answer 7

1. Inrapleural pressure must be elastic recoil lung and chest wall
2. When inspiratory muscles increase, thoracic dimensions of lungs increase because change in intrapleural pressure

Question 8

Boyle’s law

Answer 8

Pressure within alveoli drops below atmosphere

Question 9

Expiration

Answer 9

Completely passive at rest -> depends on relaxation of inspiratory muscles and recoil of stretched lungs

Question 10

Under certain conditions expiratory intercostal muscles…

Answer 10

contract with abdominal muscles to actively decrease thoracic dimensions

Question 11

VT

Answer 11

Tidal volume - volume of gas passing into and out of respiratory tract

Question 12

FRC

Answer 12

Functional residual capacity - volume of gas remaining in lungs + airways following normal expiration

Question 13

TLC

Answer 13

Total lung capacity - volume of gas after max inspiration

Question 14

RV

Answer 14

Residual volume - volume of gas after max expiration

Question 15

VC

Answer 15

Vital capacity - volume of gas exhaled between points of max inspiration and max expiration

Question 16

Largest possible volume =

Answer 16

TLC - RV

Question 17

IC =

Answer 17

Inspiratory capacity = TLC - FRC

Question 18

IRV =

Answer 18

Inspiratory reserve volume = TLC - (VT + FRC)

Question 19

ERV =

Answer 19

Expiratory reserve volume = FRC - RV

Question 20

Dynamic lung volume

Answer 20

FVC = VC, FEV1

Question 21

Compliance is the measure

Answer 21

of ease at which lungs can be inflated, the smaller the delta P to produce a given delta P

Question 22

Compliance depends on

Answer 22

1. elasticity

2. surface tension forces at the gas/ liquid interface

Question 23

Laplace’s equation

Answer 23

P = 2T/r

transpulmonary pressure = 2 tension of alveolus wall / radius of alveolus

Question 24

Surfactant

Answer 24

Produced by type 2 alveolar cells : a phospholipid which reduces cohesive forces on alveolar surface

Question 25

How does surfactant reduce surface tension?

Answer 25

Surface tension is at the air/water interface with alveoli. Expansion requires energy to overcome surface tension of water lining of alveoli. Surfactant increases lung compliance and prevents lung collapse.