respiration part 2

Question 1

Insects:

what are characteristics about their Tracheal system?

Answer 1

• air filled tubes called tracheae
• opens to outside via spiracle
• tracheae branch to form tracheoles
• contact abdominal muscles or thorax for tidal of unidirectional air flow
• gases diffuse n and out
• do not use circulatory system to deliver gas

Question 2

Birds:

characteristics of lungs?

Answer 2

Stiff and change little in volume

lungs are between a series of air sacs that act as bellows

Question 3

Birds

where does gas exchange occur?

Answer 3

Occurs as air flows through air capilaries in lungs

air flow through parabronchi is unidirectional

blood flow is crosscurrent and counter current

Question 4

Mammals:

what are the two parts of the respiritory system?

Answer 4

Upper:
mouth, nasal cavity, pharynx, trachea

lower:
bronchi and gas exchange surfaces (alveoli)

Question 5

Mammals:

where is the site of gas echange?

Answer 5

alveoli type 1

thin walled

Question 6

mammals:

Types 2 alveoli do what?

Answer 6

Secrete surfactant

Question 7

Mammals:

what is surfactant?

Answer 7

Lipids and protein reduce surface tension, prevent alveoli from collapsing, reduces work of breathing

Question 8

mammals:

what is the outer surface of alveoli covered in?

Answer 8

capillaries

Question 9

Surface tension and surfactants:

Surface tension is the force acting to do what?

Answer 9

acting to pull liquid’s surface molecules together at an air-liquid interphase

Question 10

What do surfactants reduce?

Answer 10

Reduce surface tension, thus less work is required to expand the alveolar volume

Question 11

Pleural Sac:

what do they surround?

Answer 11

each lung

Question 12

Pleural Sac:

characteristics of them?

Answer 12

two layers of cells with small space between them

Question 13

Pleural Sac:

What is the Plural cavity have in it?

Answer 13

Pleural cavity contains a small volume of pleural fluid

Question 14

Pleural Sac:

What is intrapleural pressure?

Answer 14

In subatmospheric

keeps lungs expanded

Question 15

Mammalian tidal ventilation: Inspiration

what are the steps in inhilation?

Answer 15

motor neurons stimulate inspiratory muscles

contractions of the external intercostals and diaphragm

ribs move outwatrd and the diaphragm moves downward

volume of thorax increase: intrathoracic pressure decrease

decrease in intrapleural pressure

transpulmonary pressure gradient increse

lungs expand, decrease alveolar pressure and air is pulled in

Question 16

Mammalian tidal ventilation: Exhalation

Steps of exhalation

Answer 16

Nerve stimulation of inspiratory muscles stops

muscles relax

rebs and diaphragm return to their original positions

intrapleural pressure increase

volume of thorax decrease intrathoracic pressure increase

passive recoil of the lungs decrease lung volume which increase alveolar pressure and results in air flowing out of lungs

during reapid, heavy breathing, forced exhalation is by contracting of the internal intercostal muscles

Question 17

Lung copliance and elasticity:

what is Lung compliance

Answer 17

How easily the lungs strech during inhalation

surface tension in alveolar fluid decrease compliance

Question 18

Lung copliance and elasticity:

Surfactants do what>

Answer 18

Reduce surface tension by disruptiong the cohesive forces between waer molecules; increase compliance

reduces tendency of alveolar walls and small airways to stick together makking the lung more compliant

less force required to expand alveoli in lungs

allows you to breather more easily

*in humans Surfactant synthesis does not begin until late gestation

Question 19

Lung compliance and elasticity:

What is lung elsticity?

Answer 19

The ability of the lung to return to resting volume after streched

Question 20

Lung compliance and elasticity:

low elasticity?

Answer 20

lungs do not readily return to resting volume when respiratory muscles relax

must actively expire, no longer passive expiration

Question 21

Lung Disease:

Fibrotic lung disease

Answer 21

Scarring of lung tissue

reduced lung compliance, inspiration difficult

shallow breathing

must breath more rapidly to obtain sufficient o2

Question 22

Emphysema

Answer 22

smoking

lung is less elastic, damaged elastin fibers and alveoli

lungs more compliant but tend to collapse, inflammation

lung is easily inflated but expend more energy to expire

Question 23

Asthma

Answer 23

chronic inflammatory disease of respiratory airway

bronchiospasm and constriction of airway

wheezing, coughing, shortness of breath

Question 24

Airway resistance:

Answer 24

Airway diameter affects resistance to air flow

as diameter decrease resistance increase

higher resistance requires a large transpulmonary pressure gradient

parasympathetic nerve stimulation causes bronchoconstriction

sympathetic nerve stimulation causes bronchodilation

Question 25

Dead space:

What is Tidal volume?

Answer 25

Volume of air moved in one ventilatory cycle

Question 26

What is dead space?

Answer 26

Air does not participate in gas exchange

Question 27

dead space

two components

Answer 27

Anatomical dead space:

colume of trachea and bronchi

alveolar dead space

volume of alveoli that are not perfused

Question 28

What is inspiratory reserve volume (IRV)

Answer 28

volume of air inhaled over and above resting tidal volume

Question 29

What is inspiratory capacity?

Answer 29

Tidal volume plus inspiratory volume

Question 30

What is expiratory reseve volume?

Answer 30

Max air that can be forcibly exhaled above resting tdal volume

Question 31

What is vital capacity?

Answer 31

max amount of air that can be moved in and out of lungs with one breath

Question 32

Total lung capacity

Answer 32

Sum of vital capacity pluys residual volume which is the volume of air that remains in lungs even after maximal exhalation