ch 22 the respiratory system Flashcards

1
Q

respiration: gas exchange

respiratory system

A

organ system that takes in air and expels it from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

respiration: gas exchange

respiration

A

refers to ventilation of the lungs (breathing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

respiration

gas exchange

A

O2 and CO2 exchanged between blood and air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

respiration

communication

A

speech and other vocalizations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

respiration

olfaction

A

sense of smell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

respiration

acid-base balance

A

influences pH of body fluids by eliminating CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

respiration

blood pressure regulation

A

assists with synthesis of angiotensin II

a hormone that regulates blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

respiration

blood and lymph flow

A

breathing creates pressure gradients between thorax and abdomen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

respiration

platelet production

A

more than 1/2 of platelets are made by megakaryocytes in lungs

not in bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

respiration

blood filtration

A

lungs filter small clots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

respiration

expulsion of abdominal contents

A

breath-holding assists in urination, defecation, childbirth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

organization of respiratory organs

principal organs of the respiratory system

A
  • nose
  • pharynx
  • larynx
  • trachea
  • bronchi
  • lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

organization of respiratory organs

conducting zone

A

passages that serve only for airflow
(no gas exchange)
* nostrils through major bronchioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

organization of respiratory organs

respiratory zone

A

regions that participate in gas exchange
* alveoli and nearby structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

organization of respiratory organs

upper respiratory tract

A

airway from nose through larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

organization of respiratory organs

lower respiratory tract

A

regions from trachea through lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

structure of the nose

nasal mucosa covered by a

A

respiratory epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

structure of the nose: respiratory epithelium

ciliated pseudostratified columnar epithelium contains what kind of cells

A
  • goblet cells
  • ciliated cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

strucutre of the nose: respiratory epithelium

goblet cells

A

produce most of the mucus, supplemented by mucous glands in lamina properia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

strucuture of the nose: respiratory epithelium

ciliated cells

A

have motile cilia that propel the mucus posteriorly toward pharynx to be swallowed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

strucuture of the nose:

olfactory epithelium

A

is involved in the sense of smell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

strucuture of the nose: olfactory epithelium

located at roof of each

A

nasal fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

strucuture of the nose: olfactory epithelium

immobile cilia bind

A

odarant molecules

do not propel nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

strucuture of the nose: olfactory epithelium

olfactory glands secrete serous fluid to assist

A

diffusion of odor molecules to receptors on the cilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

the pharynx

pharynx

A

muscular funnel extending about 13 cm (5 inch) from posterior nasal apertures to larynx

divided into 3 regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

the pharynx

nasopharynx

A

posterior to nasal apertures and above soft palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

the pharynx: nasaopharynx

receives auditory tubes and contains

A

pharyngeal tonsil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

the pharynx: nasaopharynx

90 degrees downward turn

A

traps large particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

the pharynx: oropharynx

space between

A

soft palate and epiglottis
* contains palatine tonsils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

the pharynx: laryngopharynx

posterior to

A

larynx, from epiglottis to cricioid cartilage
* esophagus begins at that points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

the larynx

cartilaginous chamber about

A

4 cm (1.5 inch) long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

the larynx

primary function is to keep

A

food and drink out of airway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

the larynx

also involved in

A

production of sound
* commonly known as “voice box”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

epiglottis

flap of tissue that guards

A

superior opening of larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

epiglottis

at rest stands almost

A

vertically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

epiglottis

during swallowing, extrinsic muscles pull

A

larynx upward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

epiglottis

tongue pushes epiglottis down to

A

meet it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

epiglottis

closes airway and directs food to

A

esophagus behind it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

epiglottis

vestibular folds of the larynx play greater role in keeping

A

food and drink out of the airway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

cartilages of the epiglottis

nine cartilages make up framework of

A

larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

cartilages of the epiglottis

first 3 are

A

solitary and relatively large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

cartilages of the epiglottis

epiglottic cartilage

A
  • most superior
  • spoon-shaped supportive plate in epiglottis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

cartilages of the epiglottis

thyroid cartilage

A
  • shield-shaped and largest laryngeal cartilage
  • contains laryngeal prominence (Adam’s Apple)
  • testosterone stimulates growth, larger in males
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

cartilages of the epiglottis

cricoid cartilage

A
  • ring-like shape
  • connects larynx to trachea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

cartilages of the epiglottis

what are the first 3 cartilages of the epiglottis

A
  • epiglottic cartilage
  • thyroid cartilage
  • cricoid cartilage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

cartilages of the epiglottis

what are the 3 smaller, paired cartilages

A
  • arytenoid cartilages
  • corniculate cartilages
  • cuneiform cartilages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

cartilages of the epiglottis

arytenoid cartilages

A

posterior to thyroid cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

cartilages of the epiglottis

corniculate cartilages

A

attached to arytenoid cartilages like a pair of little horns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

cartilages of the epiglottis

cuneiform cartilages

A

support soft tissue between arytenoids and epiglottis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

cartilages of the epiglottis

extrinsic ligaments connect the

A

larynx to external structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

cartilages of the larynx: extrinsic ligaments

thyrohyoid membrane

A

suspends larynx from hyoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

cartilages of the larynx: extrinsic ligaments

cricothyroid ligament

A

connects cricoid and thyroid cartilages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

cartilages of the larynx: extrinsic ligaments

cricotracheal ligament

A

suspends trachea from larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

cartilages of the larynx: extrinsic ligaments

what are the 3 extrinsic ligamnets

A
  • thyrohyoid membrane
  • cricothyroid ligament
  • cricotracheal ligament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

cartilages of the larynx

intrinsic ligamens hold

A

laryngeal cartilages together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

vocal structures

interior wall has 2 folds on each side that extend from

A

thyroid cartilage in front to arytenoid cartilages in back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

vocal structures

vestibular folds

A

play no role in speech but close the larynx during swallowing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

vocal structures: vestibular folds

supported by the

A

vestibular ligaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

vocal structures

vocal cords
(vocal folds)

A

produce sound when air passes between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

vocal structures: vocal cords

contain vocal ligaments covered with

A

stratified squamous epithelium
suited to endure vibration and contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

vocal structures: vocal cords

glottis

A

the vocal cords and the opening between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

vocal cords

adult male vocal cords when compared to female cords

A
  • usually longer and thicker
  • vibrate more slowly
  • produce lower-pitched sound
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

vocal cords

loudness determined by the force of

A

air passing between the vocal cords

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

vocal cords

vocal cords produce crude sounds that are formed into words by actions of

A
  • pharynx
  • oral cavity
  • tongue
  • lips
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

the trachea

tube that connects

A

larynx to bronchi

commonly called “windpipe”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

the trachea: strucure

rigid tube that is how long and what is the diameter

A

12 cm (4.5 inch) long
2.5 cm (1 inch) in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

the trachea: strucure

supported by

A

16 to 20 C-shaped rings of hyaline cartilage
* prevents collapse during inhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

the trachea: strucure

opening in cartilage rings faces

A

posteriorly toward esophagus
* allows esophagus to expand as swallowed food passes by

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

the trachea: strucure

trachealis

A

muscle spans opening in rings
* contracts or relaxes to adjust airflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

the trachea: strucure

carina

A

lowermost tracheal cartilage has internal median ridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

the trachea: histology

lined by

A

pseudostratified columnar epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

trachea: histology of pseudostratified columnar epithelium

contains

A
  • mucus-secreting cells
  • ciliated cells
  • stem cells
73
Q

trachea: histology of pseudostratified columnar epithelium

mucociliary escalator

A
  • mechanism for debris removal
  • mucus traps inhaled particles, upward beating cilia moves mucus to pharynx to be swallowed
74
Q

trachea: histology

connective tissue beneath the tracheal epithelium contains

A
  • lymphoid nodules
  • mucous and serous glands
  • tracheal cartilages
75
Q

trachea: histology

adventitia

A
  • outermost layer of trachea
  • fibroud connective tissue that blends into adventitia of other nearby organs (esophagus)
76
Q

tracheotomy

tracheotomy

A

to make a temporary opening in the trachea and insert a tube to allow airflow

77
Q

tracheotomy

prevents asphyxiation due to

A

upper airway obstruction

78
Q

tracheotomy

potential problems include

A
  • inhaled air bypasses the nasal cavity and is hot humidified
  • if left for long, will dry out mucous membrane
  • become encrusted and interfere with clearance of mucus from tract, thereby promoting infection
79
Q

tracheotomy

intubation

A

when a patient is on a ventilator air is introduced directly into trachea
* air must be filtered and humidified

80
Q

lungs and bronchial tree

each lung is a conical organ with the following landmarks

A
  • base
  • apex
  • costal surface
  • mediastinal surface
  • hilum
  • root of lung
81
Q

lungs and bronchial tree

base

A

broad concave portion resting on diaphragm

82
Q

lungs and bronchial tree

apex

A

tip that projects just above the clavicle

83
Q

lungs and bronchial tree

costal surface

A

pressed against the ribcage

84
Q

lungs and bronchial tree

mediastinal surface

A

faces medially toward the heart

85
Q

lungs and bronchial tree

hilum

A

slit through which the lung receives the
* main bronchus
* blood vessels
* lymphatics
* nerves

86
Q

lungs and bronchial tree

strucutures near hilum constitute

A

root of lung

87
Q

lungs and bronchial tree

left and right lungs are not

A

symmetrical

88
Q

lungs and bronchial tree: right lung

shorter than left because

A

liver rises higher on the right

89
Q

lungs and bronchial tree: right lung

has 3 lobes

A
  • superior
  • middle
  • inferior
90
Q

lungs and bronchial tree: right lung

horizontal fissure

A

seperated superior and middle lobes

91
Q

lungs and bronchial tree: right lung

oblique fissure

A

seperates middle and inferior lobes

92
Q

lungs and bronchial tree: left lung

tall and narrow because the heart

A

tilts toward the left and occupies more space on this side of mediastinum

93
Q

lungs and bronchial tree: left lung

cardiac impression

A

has indentation to accommodate heart

94
Q

lungs and bronchial tree: left lung

has 2 lobes

A
  • superior and inferior lobes
  • seperated by a single oblique fissure
95
Q

lungs and bronchial tree

bronchial tree

A

a branching system of air tubes in each lung

96
Q

lungs and bronchial tree: bronchial tree

extends from main bronchus to

A

65,000 terminal bronchioles

97
Q

lungs and bronchial tree

main (primary) bronchi arise from

A

fork of trachea

98
Q

lungs and bronchial tree: main (primary) bronchi

right main bronchus

A

is wider and more vertical than left main bronchus
* right is 2 to 3 cm long, left about 5 cm long

99
Q

lungs and bronchial tree: main (primary) bronchi

aspirated (inhaled) foreign objects lodge in the

A

right main bronchus more often than in the left

100
Q

lungs and bronchial tree

the main bronchi divide into

A

lobar (secondary) bronchi

101
Q

lungs and bronchial tree: lobar (secondary) bronchi

a lobar bronchus serves each

A

lobe of each lung

102
Q

lungs and bronchial tree: lobar (secondary) bronchi

right main bronchus gives off 3 branches

A
  • superior
  • middle
  • inferior lobar bronchi
103
Q

lungs and bronchial tree: lobar (secondary) bronchi

left main bronchus gives off 2 branches

A
  • superior
  • inferior lobar bronchi
104
Q

lungs and bronchial tree

lobar bronchi branch into

A

segmental (tertiary) bronchi

105
Q

lungs and bronchial tree: segmental (tertiary) bronchi

segmental (tertiary) bronchi

A
  • 10 in right lung
  • 8 in left lung
106
Q

lungs and bronchial tree: segmental (tertiary) bronchi

bronchopulmonary segment

A

functionally independent unit of lung ventilated by segmental bronchus

107
Q

lungs and bronchial tree

bronchioles

A

continuations of airway that lack supportive cartilage and are 1mm or less in diameter

108
Q

lungs and bronchial tree: bronchioles

pulmonary lobule

A

portion of lung ventilated by one bronchiole

109
Q

lungs and bronchial tree: bronchioles

have ciliated cuboidal epithelium and

A

well-developed layer of smooth muscle

110
Q

lungs and bronchial tree: bronchioles

each bronchiole into

A

50 to 80 terminal bronchiles

111
Q

lungs and bronchial tree: terminal bronchioles

final branches of

A

conducting zone

112
Q

lungs and bronchial tree: terminal bronchioles

measure 0.5 mm or

A

less in diameter

113
Q

lungs and bronchial tree: terminal bronchioles

have no mucous

A

glands or goblet cells

114
Q

lungs and bronchial tree: terminal bronchioles

have cilia that move mucus by

A

mucociliary escalator

115
Q

lungs and bronchial tree: terminal bronchioles

each terminal bronchiole gives off

A

2 or more smaller respiratory bronchioles

116
Q

lungs and bronchial tree: respiratory bronchioles

these have alveoli budding from their

A

walls

117
Q

lungs and bronchial tree: respiratory bronchioles

considered the beginning of the respiratory zone since the

A

alveoli participate in gas exchange

118
Q

lungs and bronchial tree: respiratory bronchioles

each respiratory bronchiole divides into

A

2 to 10 alveolar ducts

119
Q

lungs and bronchial tree: respiratory bronchioles

elongated thin-walled passages with

A

alveoli along their walls

120
Q

lungs and bronchial tree: respiratory bronchioles

end in alveolar sacs

A

clusters of alveoli around a central space (atrium)

121
Q

lungs and bronchial tree

alveoli

A

microscopic air pouches in the lungs
each about 0.2 to 0.5 mm in diameter

122
Q

lungs and bronchial tree: alveoli

480 million alveoli in each

A

lung
providing 70 msquared of surface for gas exchange

123
Q

lungs and bronchial tree: alveoli

cells of the alveoli

A
  • squamous (type 1) alveolar cells
  • great (type 2) alveolar cells
  • alveolar macrophages (dust cells)
124
Q

lungs and bronchial tree: cells of the alveoli

squamous (type 1) alveolar cells

A
  • thin cells allow rapid gas diffusion between air and blood
  • cover 95% of alveolus surface area
125
Q

lungs and bronchi tree: cells of the alveoli

great (type 2) alveolar cells

A
  • round to cuboidal cells that cover the remaining 5% of alveolar surface
  • repair the alveolar epithelium when the squamous (type 1) cells are damaged
  • secrete pulmonary surfactant
126
Q

lungs and bronchi tree: cells of the alveoli–> great alveolar cells

pulmonary surfactant

A

mixture of phospholipids and proteins that coats the alveoli and prevents them from collapsing during exhalation

127
Q

lungs and bronchi tree: cells of the alveoli: alveolar macrophages

alveolar macrophages
(dust cells)

A
  • most numerour of all cells in the lung
  • wander lumens of alveoli and connective tissue between them
  • keep alveoli free from debris by phagocytizing dust particles
  • millions of dust cells die each day as they ride up the mucociliary escalator to be swallowed and digested with their load of debris
128
Q

lungs and bronchi tree:

respiratory membrane

A

thin barrier between the alveolar air and blood

129
Q

lungs and bronchi tree: respiratory membrane

each alveolus surrounded by a basket of

A

capillaries supplied by the pulmonary artery

130
Q

lungs and bronchi tree: respiratory membrane

gases exchanged across respiratory membrane which

A

consists of 3 layers

131
Q

lungs and bronchi tree: respiratory membrane

3 layers

A
  • sqamous alveolar cells
  • endothelial cells of blood capillary
  • their shared basement membrane
132
Q

pulmomary circulation

lungs receive both

A

pulmonary and systemic blood supplies

133
Q

pulmomary circulation

pulmonary circuit

A
  • pulmonary trunk
  • pulmonary arteries
  • lobar arteries
  • capillaries surrounding alveoli
  • pulmonary veins
134
Q

pulmomary circulation: pulmonary circuit

serves to unload carbon dioxide from blood so it can be

A

exhaled and pick up oxygen from inhaled air

135
Q

pulmomary circulation:

systemic blood supply

A
  • bronchial arteries arise from aorta
  • supply lung tissue (pleura, bronchi, bronchioles, larger vessels) with blood supply
136
Q

pulmomary circulation: systemic blood supply

bronchial veins drain this blood into

A

azygos vein of thorax

137
Q

pulmomary circulation

right-to-left shunt

A

some bronchial venous blood mixes with pulmonary venous blood
* dilutes oxygen contetn somewhat

138
Q

pulmomary circulation

gases diffuse too slowly through

A

liquid to sufficiently aerate the blood

139
Q

pulmomary circulation: to prevent fluid accumulation

alveoli are kept dry by

A

low blood pressure in capillaries

140
Q

pulmomary circulation: to prevent fluid accumulation

mean blood pressure is

A

10 mm Hg
(compared to 30 mm Hg at the arterial end of the average capillary elsewhere)

141
Q

pulmomary circulation: to prevent fluid accumulation

reabsorption (osmotic uptake of water) overrides

A

filtration and keeps the alveoli free of excess fluid
* the low capillary blood pressure also prevents rupture of the delicate respiratory membrane

142
Q

pulmomary circulation: to prevent fluid accumulation

lungs have more extensive lymphatic drainage than any other

A

organ in the body

143
Q

the pleurae

pleura

A

serous membrane that lines thoracic wall and forms surface of lung

144
Q

the pleurae

visceral pleura

A

forms surface of the lung

145
Q

the pleurae

parietal pleura

A

adheres to
* mediastinum
* inner surface of the rib cage
* superior surface of the diaphragm

146
Q

the pleurae

pleural cavity

A

potential space between pleurae

147
Q

the pleurae: the pleural cavity

normally no room between the membrances, but contains a film of

A

slippery pleural fluid

148
Q

the pleurae: the pleural cavity

pleural effusion

A

pathological seepage of fluid into the pleural cavity

149
Q

functions of pleurae and pleural fluid

reduction of friction

A

allow lungs to move with minimal friction

150
Q

functions of pleurae and pleural fluid

creation of a pressure gradient

A

pressure gradient assists with lung inflation

151
Q

functions of pleurae and pleural fluid

compartmentalization

A

prevents spread of infection from one organ in mediastinum to others

152
Q

pulmonary ventilation: breathing

breathing is a repetitive cycle of

A

inspiration (inhaling) anf expiration (exhaling)

153
Q

pulmonary ventilation: breathing

respiratory cycle

A

one complete breath
inspiration and expiration

154
Q

pulmonary ventilation: breathing

quiett respiration

A

breathing while at rest
effortless and automatic

155
Q

pulmonary ventilation: breathing

forced respiration

A

deep or rapid breathing such as during exercise or playing an instrument

156
Q

pulmonary ventilation: breathing

flow of air in and out of lung depends on a

A

pressure difference between air within lungs and outside body

157
Q

pulmonary ventilation: breathing

respiratory muscles change

A

lung volumes and create differences in pressure relative to the atmosphere

158
Q

respiratory muscles

principal muscles of respiration are the

A

diaphragm and intercostal muscles

159
Q

respiratory muscles

diaphragm

A

prime mover of respiration

160
Q

respiratory muscles: diaphragm

contraction flattens diaphragm enlarging

A

thoracic cavity and pulling air into lungs

161
Q

respiratory muscles: diaphragm

relaxation allows diaphragm to bulge

A

upward again compressing the lungs and expelling air

162
Q

respiratory muscles: diaphragm

accounts for 2/3 of

A

airflow

163
Q

respiratory muscles

internal and external intercostal muscles

A

assist diaphragm

164
Q

respiratory muscles: internal & external intercostal muscles

located between

A

ribs

165
Q

respiratory muscles: internal & external intercostal muscles

contribute to enlargements and contraction of

A

thoracic cage

166
Q

respiratory muscles: internal & external intercostal muscles

add about 1/3 of the air that ventilates the

A

lungs

167
Q

respiratory muscles:

accessory muscles of respiration act mainly in

A

forced respiration

168
Q

respiratory muscles:

accessory muscles of respiration include

A
  • sternocleidomastoid
  • pectoralis major
  • pectorlais minor
  • erector spinae
  • scalenes
  • serratus anterior
  • serratus posterior superior muscles
169
Q

respiratory muscles: accessory muscles

aid in

A

deep inspiration

170
Q

respiratory muscles:

normal quiet expiration

A

energy-saving passive process
achieved by the elasticity of the lungs and thoracic cage
* As muscles relax, structures recoil to original shape and original
(smaller) size of thoracic cavity
* Results in airflow out of lungs

171
Q

The Respiratory Muscles

Forced expiration:

A
  • Rectus abdominis, internal intercostals, and other lumbar,
    abdominal, and pelvic muscles
  • Greatly increased abdominal pressure pushes viscera up against
    diaphragm increasing thoracic pressure, forcing air out
172
Q

The Respiratory Muscles

Valsalva maneuver

A

breathing technique used to help
expel contents of certain abdominal organs

173
Q

Neural Control of Breathing

Breathing depends on repetitive stimulation of skeletal
muscles from brain and will cease if spinal cord is severed
high in neck

A
  • Skeletal muscles require nervous stimulation
  • Multiple respiratory muscles require coordination
174
Q

Neural Control of Breathing

Breathing is controlled at two levels of the brain

A
  • One is cerebral and conscious
  • Other is unconscious and automatic
175
Q

Neural Control of Breathing

Brainstem respiratory centers

A
  • Automatic, unconscious breathing is controlled by
    respiratory centers in reticular formation (medulla
    oblongata and pons)
  • Two pairs of respiratory centers in the medulla and one
    pair in pons
176
Q

Neural Control of Breathing: brainstem respiratory centers

Ventral respiratory group (VRG)

A
  • In medulla
  • Primary generator of the respiratory rhythm
  • Reverberating circuits of inspiratory (I) neurons and expiratory
    (E) neurons
  • Produces a respiratory rhythm of 12 breaths per minute
177
Q

Neural Control of Breathing: Brainstem respiratory centers

Dorsal respiratory group (DRG)

A
  • In medulla
  • Modifies the rate and depth of breathing
  • Receives influences from external sources (pons, medulla,
    receptors in lungs, and higher brain centers
178
Q
A