Respiratory system: structure and function Flashcards
0
Q
Alveolar spaces are divided by tissue known collectively as (?) and it is a potential space for fluid and cells to accumulate
A
Interstitium
1
Q
Responsible for most of the lung’s volume
A
Alveolar spaces
2
Q
The respiratory system begins at the nose and ends in the most distal
A
Alveolus
3
Q
Major function of upper airway
A
To condition inspired air to be at body temp and fully humidified
4
Q
Functions to filter entrap and clear particles larger than 10 microns
A
Nose
5
Q
Surface area of the nose is increased by the (?), which are a series of 3 continuous ribbons of tissue that protrude into the nasal cavity
A
Nasal turbinates
6
Q
T or F
Nasal resistance decreases with viral infections and with increased airflow
A
F
Nasal resistance increases
7
Q
Produce important immunoglobulins, inflammatory mediators, and interferons
A
Secretory cells
8
Q
Paranasal sinuses (frontal, maxillary, sphenoid and ethmoid sinus) are lined by
A
Ciliated epithilium
9
Q
Facilitate the flow of mucus and clear the main nasal passages
A
Cilia
10
Q
Its major functions are
Lighten the skull
Offer resonance to the voice
A
Sinuses
Also for protection from frontal trauma
11
Q
Openings that are readily obstructed in the presence of nasal edema, and retention of secretions and secondary infection (sinusitis) may result
A
Ostia
12
Q
Major structures of the larynx (3)
A
Epiglottis
Arytenoids
Vocal cords
13
Q
1&2 cover the vocal cords during swallowing and under normal conditions 1&2 function to prevent aspiration of food and liquid into the lower respiratory tract
A
Epiglottis and arytenoids
14
Q
Both the right and left lungs are covered by a thin membrane called the (1) and are encased by another membrane called the (2)
A
1 Visceral pleura
2 parietal pleura
15
Q
Air between the visceral and parietal pleuras because of either trauma, surgery, or rupture of a group of alveoli creating a
A
Pneumothorax
16
Q
Fluid between the visceral and parietal pleuras create a
A
Pleural effusion
17
Q
Severe infection between the visceral and parietal pleuras
A
Empyema
18
Q
Region of the lung supplied by a segmental bronchus is the
A
Functional anatomic unit of the lung
19
Q
T or F
The airways continue to divide in a DICHOTOMOUS or ASYMMETRIC branching pattern until they form terminal bronchioles.
A
T
20
Q
T or F
Each branching of the respiratory bronchioles results in decreased diameter and the total surface area for that generation decreases in size but increases in number
A
F
The total surface area also increases in size
21
Q
The functional anatomic unit of the lung
A
Bronchopulmonary segment
22
Q
The basic physiologic unit of the lung which consists of the respiratory bronchioles, alveolar ducts and the alveoli is the
A
Respiratory or gas-exchanging unit (respiratory unit)
23
Q
Serve to move gas from the airways to the alveoli
A
Conducting airways
24
Conducting airways area of the lung is approximately (1) mL in volume and does not participate in gas exchange and forms the (2)
(1) 150 (or ~30% of a normal breath)
| (2) anatomic dead space
25
Which is TRUE
A) The respiratory bronchioles with alveoli and the area from the terminal or nonrespiratory bronchioles to the alveoli are where ALL gas exchange occurs.
B) This region is only approximately 5mm long and it is the single smallest volume of the lung
(1) T
| 2) F, it is the single largest volume of the lung (~2500mL
26
T or F
| Under normal conditions type I and type II epithelial cells exist in a 1:2 ratio.
F, 1:1 ratio
27
Occupies 96% - 98% of the surface area of the alveolus, and it is the primary site for gas exchange
Type I epithelial cell
28
T or F
| The thick cytoplasm of type I cells is ideal for optimal gas diffusion
F, thin cytoplasm
29
T or F
The basement membrane of type I cells and the capillary endothelium are separated, which maximizes the distance for gas diffusion and thereby facilitates gas exchange
F, are fused, which minimizes the distance
30
Occupies 2% - 4% of the surface area of the alveolus and is usually found in the corners
Type II epithelial cells
31
Type II synthesizes...
Pulmonary surfactant
32
Reduces surface tension in the alveolar fluid
Pulmonary surfactant
33
Responsible for regeneration of the alveolar structure subsequent to injury
Type II epithelial cells
34
Gas exchange occurs in the alveoli through a dense meshlike network of capillaries and alveoli called
Alveolar-capillary network
35
T or F
In response to injury and type II cell death, the type I cell replicates and differentiates into type II cells to restore normal alveolar architecture
F, type I cell death... Type II cell replicates and differentiate into type I cells
36
T or F
| During embryonic development the the epithelium of the alveolus is entirely composed of type I cells
F, type II cells
37
T or F
| Very late in gestation, type II cells differentiate into type I cells
T
38
- Prominent cells in the interstitium of the lung
| - Synthesize and secrete collagen and elastin
Fibroblast
39
Is the major structural component of the lung
Collagen
40
Component that limits lung distensibility
Collagen
41
Major contributor to elastic recoil of the lung
Elastin
42
A tough, resilient connective tissue that supports the airways of the lung
Cartilage
43
Encircles about 80% of the trachea
Cartilage
44
T or F
| The amount of cartilage decreases down the respiratory system and disappears at the level of the alveoli.
F, ...at the level of the bronchioles
45
Neuroendocrine cells found in clumps throughout the tracheobronchial tree and secrete biogenic amines
Kultschitzky cells
46
T or F
| Kultschitzky cells are more numerous in an adult than in a fetus
F, ...more numerous in fetus than in adults
47
Cells of origin for a rare bronchial tumor called bronchial carcinoid
Kulschitzky cells
48
Brings deoxygenated blood from the right ventricle to the gas-exchanging units for removal of CO2 and oxygenation
Pulmonary circulation
49
Arises from the aorta and provides nourishment to the lung parenchyma
Bronchial circulation
50
Largest vascular bed in the body
Pulmonary capillary bed
51
Capillary volume in the lung at rest is approximately (A) mL and increases and approaches (B) mL during exercise.
A 70
| B 200
52
T or F
| Open capillaries can enlarge as their internal pressure rises.
T
53
- Large numbers and thinner walls
- Provide a large reservoir for blood
- Can either increase or decrease their capacitance to provide constant left ventricular output
Pulmonary veins
54
T or F
| Pulmonary arteries and veins with diameters smaller than 50 microns are devoid of smooth muscle.
T
| Larger than 50 microns contain smooth muscle
55
- Provide a source of oxygenated, systemic blood to the lungs
- Accompany the bronchial tree and divide with it
- Nourish the walls of the bronchi, bronchioles, blood vessels, and nerves
Bronchial arteries
56
They perfuse the lymph nodes and most of the visceral pleura
Bronchial arteries
57
A third of the blood returns to the right atrium through the (1), whereas the remainder drains into the left atrium via (2).
(1) Bronchial veins
| (2) pulmonary veins
58
T or F
| In the presence of diseases the bronchial arteries decrease in size
F, ...increase in size (hypertrophy)
59
Somatic motor neurons innervate...
Skeletal muscles
60
Autonomic neurons innervate...(3)
Smooth muscle, cardiac muscle and glands
61
T or F
| The lung is innervated by the autonomic nervous system of the PNS, which is under CNS control.
T
62
Stimulation leads to airway constriction, blood vessel dilation, and increased glandular secretion
Parasympathetic system
63
Stimulation causes airway relaxation, blood vessel constriction, and inhibition of glandular secretion
Sympathetic system
64
T or F
| There is voluntary motor innervation in the lung and pain fibers.
F, ...no voluntary motor innervation..., nor are there pain fibers.
Pain fibers are found only in the pleura
65
Parasympathetic innervation of the lung originates from the...
Medulla in the brainstem (CN X)
66
T or F
Preganglionic fibers from the vagal nuclei descend in the vagus nerve to ganglia adjacent to airways and blood vessels in the lung. Postganglionic fibers from the ganglia complete the network by innervating smooth muscle cells, blood vessels, and bronchial epithelial cells.
T
67
T or F
Both preganglionic and postganglionic fibers contain excitatory (cholinergic) and inhibitory (nonadrenergic) motor neurons.
T
68
Neurotransmitters of excitatory motor neurons (2)
Acetylcholine and substance P
69
Neurotransmitters of inhibitory motor neurons (2)
Dynorphin and vasoactive intestinal peptide
70
T or F
| Parasympathetic innervation is greater in smaller airways, and it diminishes toward larger conducting airways
F, ...greater in larger airways, and it diminishes toward smaller conducting airways in the periphery
71
Response of the parasympathetic nervous sytem
Very specific and local
72
Response of the sympathetic nervous system
More general
73
Mucous glands and blood vessels are heavily innervated by (?); however, airway smooth muscle is not
Sympathetic nervous system
74
T or F
| Dopamine has no influence on the lung
T
75
T or F
| Stimulation of the parasympathetic nerves, increase the synthesis of mucus glycoprotein.
T
76
T or F
| Stimulation of parasympathetic nerves in mucous glands increases water secretion.
F, stimulation of sympathetic nerves...
77
Main control center for respiration
Brainstem
78
Composed of several groups of cells in the brainstem that have the property of a pacemaker
Central pattern generator (CPG)
79
Integrates peripheral input from stretch receptors in the lung and O2 receptors in the carotid body with central input from the hypothalamus and amygdala
Central pattern generator (CPG)
80
Major muscles of respiration (3)
Diaphragm
External intercostals
Scalene
81
T or F
| In skeletal muscles, force of contraction increases when they are stretched and decreases when they are shorten
T
82
Inspiration is initiated by
Contraction of the diaphragm
83
The diaphragm protrudes into the abdominal cavity and moves the abdomen outward to create (?) pressure inside the chest
Negative
84
Lung volume increases at (inspiration / expiration) and oxygen is taken (into / away) the lung.
Inspiration, into
85
During exhalation the diaphragm (contracts / relaxes), pressure inside the chest (decreases / increases) and carbon dioxide and other gasses flow passively out of the lungs
Relaxes, increases
86
Major muscle of respiration
Diaphragm
87
Contraction of the diaphragm (increases / decreases) the vertical dimension of the chest and creates a pressure difference between the thorax and abdomen.
Increases
88
During quiet breathing the diaphragm moves approximately (?) cm
1
89
During deep-breathing maneuvers the diaphragm can move as much as (?) cm.
10
90
The diaphragm is innervated by the right and left (?) which have their origins at the (3) cervical segments of the spinal cord
Phrenic nerves
| C3, C4, C5
91
Muscles of inspiration which pull the ribs upward and forward
External intercostal muscles
92
T or F
| Paralysis of the external intercostal muscles has significant effect on respiration
F, because respiration is primarily dependent on the diaphragm
93
T or F
| It is only when the injury is above C5 that individuals are completely dependent on a ventilator.
F, C3
94
T or F
| Accessory muscles of inspiration do not contract during normal breathing.
T
95
T or F
| Accessory muscles of inspiration do not contract during exercise and when airway obstruction is significant
F, do contract
96
T or F
| Respiratory muscle can be trained to do work, but there is a finite limit to the work that they can perform
T
97
(1) & (2) are components of the mucocilliary clearance system, which aids in the removal of particulates, and line the epithelium of the conducting airways from the trachea to the terminal bronchioles
Periciliary fluid and mucus
98
Lines the epithelium of the alveolus and provides an antistick function that decreases surface tension in the alveolus
Surfactant
99
Ratio of goblet cells to ciliated cells
1:5 ratio
100
T or F
| Submucosal tracheobronchial glands are absent wherever there is cartilage in the tracheobronchial tree.
F, present
101
T or F
| Clara cells are found at the level of bronchioles, where the goblet cells and submucosal glands are.
F, where the goblet cells and submucosal glands have disappeared
102
The alveoli are lined with a predominantly lipid-based substance called
Surfactant
103
Is a force by water molecules at the air-liquid interface that tend to minimize surface area
Surface tension
104
T or F
| Higher pressure is required to fully inflate the lung with air than with saline
T, because of the higher surface tension forces in air-filled versus saline-filled lungs
105
T or F
| Surfactant does not allow surface tension to increase as the alveoli becomes larger
F, allows because it can change its surface tension at different lung volumes
106
Small openings in the alveolar walls connect adjacent alveoli
Pores of Kohn
107
Connect the terminal airways to adjacent alveoli
Canals of Lambert
108
Major phospholipid in surfactant is (1) and is present as (2)
(1) Phosphatidylcholine (approximately 75%)
| 2) dipalmitoyl phosphatidylcholine (DPPC
109
Is the major surface-active component of surfactant and decreases surface tension
Dipalmitoyl phosphatidylcholine (DPPC)
110
Second most abundant phospholipid in surfactants which is about 1% to 10% of total surfactant and has spreading properties
Phosphatidylglycerol (PG)
111
Account for the majority of neutral lipids in surfactants (1&2)
Cholesterol and cholesterol esters
112
- Expressed in alveolar type II cells and in Clara cells
- Involved in the regulation of surfactant turnover, in immune regulation within the lung and in the formation of tubular myelin
SP-A
113
- May be involved in tubular myelin formation and the surface activity of surfactant
- May increase the intermolecular and intramolecular order of phospholipid bilayer
SP-B
114
May be involved in spreading ability and surface tension activity of surfactant
SP-C
115
4 specific surfactant proteins
SP-A, SP-B, SP-C, SP-D
