Introduction to the respiratory system

Question 1

what is internal (cellular) respiration?

Answer 1

the use of oxygen by a cell

Question 2

what is external respiration?

Answer 2

the transfer of gas from the atmosphere to cells and vice versa

Question 3

what are the 3 key functions of the respiratory system?

Answer 3

• gas exchange
• host defence
• metabolism

Question 4

what are the 2 major areas of the respiratory system?

Answer 4

• Conducting zone (left) involved in moving gases to and from the atmosphere and the lungs.
• Respiratory zone (right) Where gases are exchanged.

Question 5

what 7 things does the airway consist of?

Answer 5

-nasal cavity
-mouth
-pharynx
-larynx
-trachea
-bronchi
-bronchioles

Question 6

what is the function of the airway?

Answer 6

Facilitates the movement of air, but also conditions the air that will be received by the respiratory zone. (Air is warmed, filtered (large particles and pathogens) and moistened.)

Question 7

what are the 2 key things that remove inhaled particles?

Answer 7

mucus and cilia

Question 8

what is the function of the goblet cells?

Answer 8

secrete mucus

Question 9

what is the function of the cilia?

Answer 9

have hair like projections (move trapped particles)

Question 10

what is the function of the serous glands?

Answer 10

secrete watery anti-bacterial substance

Question 11

what is the nasal cavity crucial for?

Answer 11

Crucial to the humidification, warming and filtering of air (very efficient)

Question 12

how many bones is the nasal cavity made up of? why?

Answer 12

3 bones to provide a large surface area

Question 13

what is the function of the oropharynx?

Answer 13

provides the common path for both food and air

Question 14

what does the larynx connect?

Answer 14

the oropharynx to the trachea

Question 15

what contains the vocal cords? how do they work?

Answer 15

the larynx contains the vocal cords
they vibrate to allow speech

Question 16

what is the key function of the larynx?

Answer 16

to direct food/drink and air by action of the epiglottis

Question 17

what is the function of the epiglottis?

Answer 17

to keep air and food going to the right place

Question 18

what does the trachea connect?

Answer 18

larynx to lungs

Question 19

what is the function of the trachea?

Answer 19

facilitates movement of air and clearance of particles

Question 20

how does the trachea not collapse?

Answer 20

C-shaped cartilage rings

Question 21

what allows for coughing in the trachea?

Answer 21

smooth muscle that contracts the rings

Question 22

how long is a human trachea?

Answer 22

10-16cm

Question 23

the trachea branches to form 2 ______

Answer 23

bronchi

Question 24

what does the right primary bronchus split into?

Answer 24

3 smaller secondary bronchi

Question 25

what does the left primary bronchus split into?

Answer 25

2 smaller secondary bronchi

Question 26

what are the 3 futher divisions after secondary brochi?

Answer 26

-tertiary bronchi
-bronchioles
-teminal bronchioles

Question 27

where does gas exchange take place?

Answer 27

in lobules of the lung (smallest functional unit of the lungs)

Question 28

what do lobules consist of?

Answer 28

respiratory bronchioles and alveolar ducts

Question 29

how many alveoli are in an adults lung?

Answer 29

300 million

Question 30

why do alveoli have a rich blood supply?

Answer 30

to allow efficient exchange

Question 31

describe type I alveoli cells

Answer 31

Thin squamous epithelia, flatten themselves to form a minimum barrier to diffusion. (95% of alveoli cells)

Question 32

describe type II alveoli cells

Answer 32

Small cuboidal cells, secrete surfactant to stop alveoli collapsing. (5% of alveoli cells)

Question 33

what is the function of alveolar surfactant?

Answer 33

• Coats the alveoli to protect
• Lowers surface tension and stabilises structure.
• This acts to reduce work of breathing

Question 34

what are lungs encased in?

Answer 34

A gas tight seal formed by two membranes:
- Parietal pleura layer contacts thoracic wall.
- Visceral pleura layer contacts lungs.

Question 35

what is the function of the pulmonary arteries?

Answer 35

carry deoxygenated blood from the heart to alveoli (via pulmonary capillaries) to be oxygenated

Question 36

define ventilation

Answer 36

exchange of gases in the respiratory system

Question 37

what is the name for the top of the lung?

Answer 37

apex

Question 38

what is the name for the bottom of the lung?

Answer 38

base

Question 39

is the pressure in the pulmonary capillaries high or low?

Answer 39

low
22/8 mm Hg

Question 40

what is hypoxia-induced vasoconstriction?

Answer 40

Pulmonary vessels constrict at low oxygen to divert blood to oxygen rich areas