The Respiratory System

Question 1

primary function of the respiratory system

Answer 1

• provide a large surface area for gas exchange between the atmosphere and the bloodstream
• move the air to and from the exchange surface

Question 2

secondary functions of the respiratory system

Answer 2

• the production of sound

- facilitation of the sense of smell

Question 3

two areas of the respiratory tract

Answer 3

• upper respiratory tract

- lower respiratory tract

Question 4

upper respiratory tract

Answer 4

the nose, nasal cavity, and pharynx; exposed to everything

Question 5

lower respiratory tract

Answer 5

the larynx, the trachea, and the lungs; only exposed to air, more delicate as it contains a huge amount of membrane surface within the lungs

Question 6

infections

Answer 6

upper respiratory not too concerning, lower can be a greater cause for concern

Question 7

respiratory mucosa

Answer 7

the respiratory tract is lined with a moist respiratory mucosa; this moistens the air and provides protection, which includes three layers: stratified squamous epithelium, pseudostratified ciliated columnar epithelium, and simple squamous epithelium

Question 8

stratified squamous epithelium

Answer 8

found in areas of the upper respiratory tract; designed to resist abrasion as food and liquids pass by

Question 9

pseudostratified ciliated columnar epithelium

Answer 9

found in parts of the nasal cavity and most of the lower respiratory tract; designed to catch small particles that come in with the air. particles get stuck on the mucus of the cilia, and the cilia all wave to push the particle/mucous out of the respiratory tract

Question 10

simple squamous epithelium

Answer 10

lines the delicate alveolar surface

Question 11

nose and nasal cavity

Answer 11

designed to “clean and process” the air before it reaches the delicate surfaces of the inner lungs

Question 12

structures of the nose and nasal cavity

Answer 12

-external nares - opening to the outside
-internal nares - opening to the pharynx
-olfactory epithelium - sense of smell
-palate - hard in the front, soft in the back
nasal conchae - scroll-shaped projections that fill most of the nasal cavity

Question 13

primary functions of the nasal cavity

Answer 13

warm the air, moisten the air, filter the air

Question 14

pharynx

Answer 14

simple passageway that connects from the nasal cavity to the beginning of the trachea (the larynx); also connects the oral cavity to the esophagus. it is a common passageway for both the respiratory system and the digestive system (commonly called the throat)

Question 15

larynx

Answer 15

acts as a “gatekeeper” allowing air to pass into the trachea, but preventing food and fluid from entering the trachea.

Question 16

epiglottis

Answer 16

it normally sticks up, but when swallowing occurs, it is pushed down to cover the opening into the trachea

Question 17

trachea

Answer 17

“windpipe” a relatively rigid tube that runs down the neck into the lungs; it’s function is to conduct air to the lungs

Question 18

lungs

Answer 18

consist of the following components: bronchial tree, alveoli, capillary network, elastic connective tissue

Question 19

bronchial tree

Answer 19

a series of branching air passageways, become smaller and more numerous with each branch; some bronchial branches have specific names

Question 20

primary bronchi

Answer 20

the first branches, right and left, from the trachea

Question 21

secondary bronchi

Answer 21

the next set of branches, which go to individual lung lobes

Question 22

tertiary bronchi

Answer 22

the next set of branches, going to specific segments with lobes

Question 23

bronchioles

Answer 23

the smallest, microscopic branches which lead to the alveoli

Question 24

alveoli

Answer 24

microscopically small chambers where gas exchange occurs

Question 25

capillary network

Answer 25

surrounding all of the alveoli; exchange gases with the bloodstreams

Question 26

elastic connective tissue

Answer 26

allows the lungs to expand and recoil during breathing

Question 27

receptors

Answer 27

found in the wall of the bronchioles, respond to epinephrine and norepinephrine; if stimulated, will inhibit muscle cell contraction which causes air passageways to dilate, which allows easier flow

Question 28

albuterol

Answer 28

a chemical that binds to the very same receptors (mimicking epinephrine); inhalation will result in a very rapid dilation of the respiratory passageways, which can be important if a patient is having an allergic asthma attack, an exercise-induced asthma attack, or a COPD attack

Question 29

gas exchange

Answer 29

all exchange occurs at the interface between the alveoli and the blood capillaries

Question 30

alveolus

Answer 30

very small; simple squamous epithelium

Question 31

diffusion

Answer 31

the key principle in action at the alveolar/capillary interface

Question 32

breathing

Answer 32

a mechanical action that centers around changing the volume of the thoracic cavity; gases will always move from an area of higher pressure to an area of lower pressure

Question 33

inspiration

Answer 33

process of moving air into the lungs; key muscles are diaphragm and certain rib muscles

Question 34

diaphragm

Answer 34

the most important muscle for inspiration; located at the bottom of the thoracic cavity

Question 35

certain rib muscles

Answer 35

aligned in such a way that they pull the ribs up and away, creating greater thoracic volume

Question 36

expiration

Answer 36

process of moving air out of the lungs; a passive process

Question 37

forced expiration

Answer 37

certain rib muscles and abdominal wall muscles help with this process

Question 38

gas exchange

Answer 38

the law of diffusion governs the movement of each gas; oxygen will move from the higher concentration in the alveoli to the lower concentration in the blood

Question 39

partial pressures

Answer 39

a system that allows us to compare how much of a gas is present in the air (a mixture of gases) and how much is present as a dissolved gas in liquid (the bloodstream)

Question 40

total pressure of atmosphere = 760 mm Hg

Answer 40

• Nitrogen = 75%
• Oxygen = 14%
• Carbon Dioxide = 5%
• Water Vapor = 6%

Question 41

P O2 = Partial Pressure O2

Answer 41

14% of 760 mm Hg = 104 mm Hg

Question 42

P CO2 = Partial Pressure CO2

Answer 42

5% of 760 mm Hg = 40 mm Hg

Question 43

P O2 in lung capillary (just arriving at interface)

Answer 43

40 mm Hg

Question 44

P CO2 in lung capillary (just arriving at interface)

Answer 44

45 mm Hg

Question 45

tissue capillaries

Answer 45

blood coming into the tissue capillaries will have lots of oxygen and lower levels of carbon dioxide; the tissue fluids will have relatively low concentrations of oxygen (the cells have been using it) and relatively high concentrations of carbon dioxide

Question 46

oxygen

Answer 46

the vast majority of oxygen is carried in the bloodstream by hemoglobin; no less than 97% of oxygen in bound to hemoglobin molecules while in the bloodstream; the remaining 3% of the oxygen is transported as a dissolved gas in the plasma

Question 47

carbon dioxide

Answer 47

also dissolves in the blood plasma fluid; 8% of the carbon dioxide is carried as a dissolved gas

Question 48

hemoglobin molecules

Answer 48

also have the ability to carry some carbon dioxide; about 20% is carried this way

Question 49

CO2 + H20 –> H2CO3 (carbonic acid)

Answer 49

first, carbon dioxide combines with water to form carbonic acid; carbonic acid is much more soluble in water, so a very large quantity can be carried in the bloodstream

Question 50

H2CO3 –> H+ + HCO3- (bicarbonate ion)

Answer 50

mass quantities of the bicarbonate ion are carried through the bloodstream all the time; once it gets to the lungs, the reactions are reversed and carbon dioxide is released; responsible for moving 72% of all carbon dioxide through the bloodstream

Question 51

carbonic anhydrase

Answer 51

an enzyme made to speed up the process

Question 52

brain stem respiratory centers

Answer 52

controls the rate and depth of breathing; clusters of cells within the brain stem

Question 53

respiratory centers receive sensory input from a variety of sources

Answer 53

• carbon dioxide levels in the blood
• blood pH
• sympathetic and/or parasympathetic stimulation
• emotional state
• hormones
• oxygen levels in the blood

Question 54

respiratory distress syndrome

Answer 54

particularly a problem for premature infants; they don’t yet have surfactant which reduces water tension and would otherwise cause the moist walls to stick together after expiration

Question 55

asthma

Answer 55

caused by an obstruction of air flow through the bronchioles; most commonly a result of:

• excessive mucus secretion
• inflammation
• smooth muscle spasms in the walls of the bronchioles

Question 56

histamines

Answer 56

will contribute to asthma; they stimulate the constriction of the air passageways; they are released in response to pollen or similar substances, to minimize the number of particles that get deep into the lungs

Question 57

emphysema

Answer 57

common and deadly respiratory disorder; lung tissue is destroyed, creating fewer and larger alveoli, limiting surface area for gas exchange. it makes the air harder to get out

Question 58

COPD

Answer 58

caused by emphysema and severe chronic bronchitis; inadequate gas exchange and developed high levels of carbon dioxide in the blood

Question 59

pulmonary fibrosis

Answer 59

a result of the accumulation of fibrous connective tissue in the lungs; most often caused by small particles that irritate the delicate bronchioles and alveoli. asbestos fibers in the air can potentially create this problem; coal dust is notorious for causing this disease “black lung”