gas exchange in humans

Question 1

What is ventilation in humans?

Answer 1

inspiration and expiration, controlled by the diaphragm, internal and external intercostal muscles and ribcage

Question 2

what are the components of the gas exchange system in mammals?

Answer 2

trachea bronchi bronchioles alveoli

Question 3

what is the dome shaped muscle below your lungs and heart?

Answer 3

diaphragm

Question 4

5 steps of inhalation

Answer 4

-external intercostal muscles contract
-ribcage raises
-volume of chest cavity increases
-pressure in chest cavity drops below atm. pressurr
-air rushes down a pressure gradient

Question 5

5 steps of exhalation

Answer 5

-external intercostal muscles relax
-ribcage lowers
-volume of chest cavity decreases
-pressure in chest cavity rises above atm. pressure
-air rushes out down a pressure gradient

Question 6

what are the 4 components of structures in the exchange system?

Answer 6

-cartilage
-smooth muscle
-cilia
-goblet cells

Question 7

describe cartilage in the trachea

Answer 7

-trachea supported by rings of strong, flexible cartilage
-incomplete C shape so that food can move down oesophagus
-stops trachea from collapsing

Question 8

describe cartilage in bronchi

Answer 8

-bronchi supported by strong, flexible cartilage that are smaller than in the trachea
-cartilage incomplete

Question 9

cartilage in bronchioles

Answer 9

-smaller bronchioles have no cartilage rings

Question 10

describe smooth muscle in trachea

Answer 10

non existent

Question 11

describe smooth muscle in bronchi

Answer 11

-patchy smooth muscle

Question 12

describe smooth muscle in bronchioles

Answer 12

-walls contain smooth muscle
-contracts to constrict bronchioles
-relaxes to dilate

Question 13

describe cilia in trachea

Answer 13

-lines trachea and branches
-beat and move mucus with trapped microorganisms, usually into throat

Question 14

describe cilia in bronchi

Answer 14

-lines bronchi
-beat and move mucus with trapped microorganisms

Question 15

describe cilia in bronchioles

Answer 15

very few

Question 16

describe goblet cells in trachea

Answer 16

-between and below epithelial cells
-secrete mucus onto lining on trachea

Question 17

describe goblet cells in bronchi

Answer 17

-secrete mucus to trap microorganisms and dust

Question 18

describe goblet cells in bronchioles

Answer 18

-very few

Question 19

what components are in the alveoli?

Answer 19

none of

Question 20

what type of cells do cilia attach to?

Answer 20

epithelial

Question 21

how many alveoli in each lung?

Answer 21

300 million

Question 22

what is plural of alveolus?

Answer 22

alveoli

Question 23

what shape are alveoli?

Answer 23

rounded for large SA

Question 24

what type of cell are alveoli made of

Answer 24

squamous epithelial

Question 25

what are alveoli surrounded by?

Answer 25

capillaries

Question 26

what cells make up capillaries?

Answer 26

endothelial cells

Question 27

what gases are exchanged in alveoli?

Answer 27

Co2 leaves alveoli and lowers concentration Co2 diffuses in from a higher concentration in capillaries O2 enters alveoli and increases concentration O2 diffuses out to a lower concentration in capillaries

Question 28

how is a steep concentration gradient maintained?

Answer 28

-constant supply due to breathing in air -constant supply due to circulation of blood

Question 29

what does Ficks law state?

Answer 29

diffusion is proportional to: (SA x difference in concentration) / length of diffusion path

Question 30

what are the ideal conditions of Ficks law to be most efficient

Answer 30

(large SA x steep concentration gradient) / short diffusion pathway