Lecture 19 - The Respiratory System

Question 1

what are the functions of the respiratory system?

Answer 1

• exchange of gas between the atmosphere and the blood
• filtration
• temperature regulation
• humidification of air
• olfaction (sense of smell)
• production of sound

Question 2

what is the arbitrary boundary between the upper and lower parts of the respiratory system?

Answer 2

the vocal cords

Question 3

what are the two portions of the respiratory system?

Answer 3

conducting and respiratory

Question 4

contains all the vessels that carry air to the sites of gas exchange

Answer 4

the conducting portion of the respiratory system

Question 5

contains the sites of gas exchange with the blood

Answer 5

the respiratory portion of the respiratory system

Question 6

list the nine main portions of the upper respiratory system

Answer 6

• external nares (nostrils)
• nasal vestibule
• conchae
• internal nares
• nasopharynx
• eustachian tube
• oropharynx
• epiglottis
• laryngopharynx

Question 7

the site of air humidification, filtration, and warming

Answer 7

conchae

Question 8

two holes at the back of the conchae which serve as the connection between the nasal cavity and pharynx

Answer 8

internal nares

Question 9

an opening in the nasopharynx which equalizes pressure in the middle ear

Answer 9

eustachian tube

Question 10

what are the three main functions of the upper respiratory system?

Answer 10

• allows movement of air in and out of the body
• warms and humidifies air
• trap particulates and pathogens

Question 11

closure of the epiglottis is complex, but upward movement of _____ and posterior movement of _____ are important

Answer 11

the larynx, the tongue

Question 12

true or false: the vocal cords close while swallowing

Answer 12

true

Question 13

the midline tube with stiff cartilage rings that prevents collapse

Answer 13

the trachea

Question 14

the site where blood vessels, lymphatics, nerves, and bronchi enter and leave the lungs

Answer 14

the hilum

Question 15

the structures that meet at the hilum in the lungs form:

Answer 15

the root of the lungs

Question 16

why do all of the vessels in the lung enter and exit through the same spot?

Answer 16

leaves the lungs free for movement

Question 17

how many lobes are present in the right lung and what are their names?

Answer 17

three lobes (superior, middle, and inferior)

Question 18

how many lobes are present in the left lung and what are their names?

Answer 18

two lobes (superior and inferior)

Question 19

where is the apex of the lungs located?

Answer 19

at the top point

Question 20

true or false: the base of the lungs are flat

Answer 20

false: they are concave and mould to the shape of the diaphragm

Question 21

how many fissures does the right lung have, what are their names, and where are they located?

Answer 21

two fissures, the oblique fissure which separates the superior and middle lobes from the inferior lobe, and the middle fissure which separates the superior and middle lobes

Question 22

how many fissures are present in the left lung, what are their names, and where are they located?

Answer 22

one fissure, the oblique fissure which separates the superior and inferior lobes

Question 23

which lung contains the lingula and where is it?

Answer 23

the left lung, located underneath the cardiac notch

Question 24

which lung contains the cardiac notch?

Answer 24

the left lung

Question 25

true or false: you could remove a lobe from the lung and the rest would still remain functional

Answer 25

true

Question 26

the serous membrane that covers the lungs

Answer 26

the visceral pleura

Question 27

the serous membrane that covers the inside of the body wall in the thoracic cavity

Answer 27

the parietal pleura

Question 28

a small amount of _____ is present between the pleural layers of the lungs

Answer 28

serous fluid

Question 29

the pleural cavities extend ______ below the inferior border of the lung, giving rise to ______; these allow space for the lungs to ______

Answer 29

~2 rib levels, recesses, expand

Question 30

do the lungs fully fill the pleural cavity recesses when they expand?

Answer 30

no, this is only a potential space

Question 31

like the lungs, the pleaural cavities/recesses sits on top of the:

Answer 31

diaphragm

Question 32

list the major airways in the lungs

Answer 32

- trachea - primary bronchi - secondary and tertiary bronchi - bronchioles - terminal bronchioles

Question 33

how many secondary bronchi are in the right lung?

Answer 33

3 (corresponds with the number of lobes)

Question 34

how many secondary bronchi are in the left lung?

Answer 34

2 (corresponds with the number of lobes)

Question 35

the trachea is surrounded by specialized C-shaped:

Answer 35

cartilage rings

Question 36

why are the cartilage rings on the trachea C-shaped and not full rings?

Answer 36

because we don't want the stiff cartilage to protrude into the esophagus, which is supposed to move around a lot

Question 37

instead of having cartilage at the back of the trachea, there is a layer of:

Answer 37

smooth muscle

Question 38

at what point do the airways have no cartilage?

Answer 38

the bronchioles

Question 39

why is it that bronchioles have smooth muscle instead of cartilage?

Answer 39

easier to expand and contract the airways (better regulated)

Question 40

do the smaller bronchi have cartilage rings?

Answer 40

no, they have fragmented bits of catrilage

Question 41

do the respiratory bronchioles have alveoli?

Answer 41

yes, they have sparse alveoli

Question 42

the alveolar ducts act as the _____ for a cluster of _____

Answer 42

stems, grapes

Question 43

true or false: alveoli are open to the central space in the alveolar sac (look like a half sphere)

Answer 43

true

Question 44

why is alveolar tissue so thin?

Answer 44

to maximize the interface between air and blood you need to minimize all the extra stuff

Question 45

alveoli are capable of _____ and _____, which is important for breathing

Answer 45

stretching, recoiling

Question 46

what is the purpose of the conducting airways?

Answer 46

warms, moistens, and conducts air

Question 47

what is the purpose of the respiratory airways?

Answer 47

both conducts air and respires

Question 48

found in large airways and helps to keep them open

Answer 48

cartilage

Question 49

tissue that predominates in smaller airways, controlling the diameter of the airways

Answer 49

smooth muscle

Question 50

predominates in smaller airways and the respiratory portion of the lungs, elastic recoil provides for expiration

Answer 50

elastic fibres

Question 51

smooth muscle constriction in the bronchioles is caused by:

Answer 51

parasympathetic nerve stimulation

Question 52

what is the effect of histamine during an asthmatic attack?

Answer 52

histamine (mediator of allergic reactions) release causes spasms and contractions of the already inflamed airways

Question 53

breakdown of alveolar walls which produces abnormally large air spaces

Answer 53

emphysema

Question 54

what are the effects of emphysema on the lung?

Answer 54

lowered surface area for gas exchange and reduced elastic fibres

Question 55

what are the causes of emphysema?

Answer 55

smoking and other irritants such as pollutants and dust

Question 56

type of epithelium that is found in the nasal cavity, nasopharynx, and large airways

Answer 56

pseudostratified epithelium

Question 57

what is the function of the cilia in the respiratory system?

Answer 57

moves fluid and debris along to be swallowed or spit out

Question 58

type of epithelium found in the oropharynx

Answer 58

stratified squamous epithelium

Question 59

type of epithelia found in the smaller respiratory tubes

Answer 59

simple columnar, simple cuboidal, and simple squamous

Question 60

what are type I alveolar cells?

Answer 60

very thin cells (simple squamous epithelium) that form the walls of the alveoli

Question 61

how many plasma membranes does an oxygen molecule cross to pass from air space to bind a hemoglobin molecule in a red blood cell?

Answer 61

five

Question 62

what are type II alveolar cells?

Answer 62

cells which secrete surfactant and can act as stem cells to regenerate type I and type II alveolar cells

Question 63

lowers the surface tension of alveolar fluid and prevents alveolar walls from sticking together and collapsing

Answer 63

surfactant

Question 64

cells which ingest debris in the alveoli

Answer 64

alveolar macrophages

Question 65

what is the path that alveolar macrophages follow through the lungs?

Answer 65

- enter airways - become trapped in mucus sheets - carried toward pharynx by ciliary action - expectorated or swallowed

Question 66

where in the lungs are the pulmonary arteries found?

Answer 66

they travel with the airways and branch with the airways

Question 67

where in the lungs are the pulmonary veins found?

Answer 67

travel in the interlobular connective tissue

Question 68

where in the lungs are the lymphatic vessels found?

Answer 68

travel in the interlobular connective tissue (like pulmonary veins)

Question 69

in the lungs, capillaries are often sandwhiched between:

Answer 69

two alveoli (maximizes efficiency)

Question 70

which muscle are involved in quiet breathing (eupnea)?

Answer 70

external intercostals and the diaphragm

Question 71

contraction of external intercostals and diaphragm increases the volume of:

Answer 71

the pleural cavity

Question 72

what drives lung expansion?

Answer 72

negative pressure (from increased volume of the pleural cavity)

Question 73

relaxation of the external intercostals and diaphragm decreases the volume of:

Answer 73

the pleural cavtiy

Question 74

when the volume of the pleural cavity decreases, this causes:

Answer 74

exhalation

Question 75

_____ of the alveoli is also important during exhalation

Answer 75

elastic recoil

Question 76

what are the muscles of forced inhalation?

Answer 76

- scalenes - pectoralis minor - sternoclaidomastoid

Question 77

how do the accessory muscles help with forced inhalation?

Answer 77

they elevate the rib cage to make the pleural membrane as big as possible

Question 78

what are the muscles of forced exhalation?

Answer 78

- internal intercostal muscles - abdominal wall muscles

Question 79

how do the muscles of forced exhalation work?

Answer 79

they depress the rib cage

Question 80

contraction of the diaphragm increases the ______ of the thoracic cavity

Answer 80

vertical diameter

Question 81

the external intercostals lift the ribs ______ and move the sternum ______

Answer 81

superiorly, anteriorly

Question 82

what is the function of the sternocleidomastoid during forced inspiration?

Answer 82

elevates the sternum

Question 83

what is the function of the scalenes during forced inspiration?

Answer 83

elevates ribs 1 and 2

Question 84

what is the function of the pectoralis minor during forced inspiration?

Answer 84

elevates ribs 3-5