Respiratory System Flashcards
1
Q
“Breathing”; air moves in (inspiration) and out (expiration) of the lungs
A
Pulmonary ventilation (Respiratory system)
2
Q
Oxygen diffuses from lungs to blood; carbon dioxide diffuses from blood to lungs
A
External respiration (Respiratory system)
3
Q
Transport of respiratory gases
A
via the blood (cardiovascular system)
4
Q
Oxygen diffuses from blood to tissues; carbon dioxide diffuses from tissues to blood
A
Internal respiration (cardiovascular system)
5
Q
Anatomical Division
A
Upper respiratory system: nose to above the larynx
Lower respiratory system: larynx and everything below it
6
Q
Physiological Division
A
Conducting Zone and Respiratory Zone
7
Q
Conducting Zone
A
Respiratory passageways from nose to respiratory bronchioles
- -Rigid conduits for air to reach gas exchange sites
- –Conducting zone organs cleanse, humidify, and warm incoming air
8
Q
Respiratory Zone
A
Gas exchange sites
–respiratory bronchioles, alveolar ducts, alveoli
9
Q
5 Nose functions
A
1) Airway for respiration
2) Moistens and warms air
3) Filters and cleans
4) Resonating chamber for speech
5) Olfactory (smell) receptors
10
Q
Nose divided into
A
external nose and nose cavity
11
Q
noses differ in size due to
A
different nasal cartilage
12
Q
Nasal cavity is divided by
A
midline nasal septum (from septal cartilage anteriorly and skull bones posteriorly)
13
Q
Nasal cavity is continuous posteriorly with
A
nasopharynx via posterior nasal apertures
14
Q
separates nasal cavity from oral cavity
A
palate
- -Hard palate=anterior, made from facial bones
- -Soft palate=posterior, muscular
15
Q
Nasal vestibule is superior to nostrils (nares)
A
- -sweat and sebaceous glands, hair follicles
- -Hairs filter
16
Q
Small patch that contains smell receptors
A
olfactory mucosa
17
Q
Everywhere else; pseudostratified, ciliated columnar epithelium
A
respiratory mucosa
(goblet cells secrete mucus
Lamina propria contains seromucous nasal glands)
18
Q
- -Secrete mucus (traps junk)
- -Serous cells secrete watery fluid with lysozyme (enzyme destroys bacteria)
- -Defensins (which kill bacteria)
- -1 L of fluids per day humidify
A
Seromucous glands
19
Q
We get a drippy nose (Water condensation as we exhale also contributes)
A
cold weather, slow moving cilia, mucus to build up in the nasal cavity
20
Q
(BLANK)
A
under the nasal epithelium warm incoming air
21
Q
greatly increase mucosal surface area exposed to air
A
nasal conchae
22
Q
why colds travel from nose to throat to chest
A
Nasal mucosa is continuous with mucosa of other respiratory passageways
23
Q
Mucus formed drains into nasal cavity, which warms and humidifies
Lighten skull
Enhance voice
A
Paranasal sinuses
24
Q
connects nasal and oral cavities to the larynx and esophagus
Composed of skeletal muscle and mucosa
A
Pharynx
25
traps and destroys pathogens from air
Pharyngeal tonsil (adenoids)
26
air only
Continuous with nasal cavity via posterior nasal apertures
Pseudostratified ciliated epithelium propels mucus
nasopharynx
27
Drain middle ear and allow middle ear pressure to equalize with atmospheric pressure
Open into lateral walls of nasopharynx
Pharyngotympanic (auditory) tubes
28
protect from infections spreading superiorly from the nasopharynx
tubal tonsils
29
Swallowing
Soft palate and uvula move superiorly, closing off nasopharynx
30
oropharynx
soft palate to epiglottis
air and food
Stratified squamous epithelium accommodates friction and chemical trauma from hot or spicy food
31
you can see in the back of your throat
Palatine tonsils
32
covers posterior surface of tongue
Lingual tonsil
33
Laryngopharynx
```
Stratified squamous epithelium
air and food
Continuous with esophagus
posterior to larynx
Food => Esophagus
Air => Larynx
Food has“right of way”
```
34
Larynx (voice box)
| 3 major functions
1) open (“patent”) airway
2) switching mechanism to route air and food
3) Voice
35
larynx made of how many hyaline cartilages
8, connected with ligaments and membranes
36
Adam's apple
Laryngeal prominence of the thyroid cartilage
37
Below vocal folds, larynx has pseudostratified, ciliated columnar epithelium
Cilia mucus up toward pharynx away from lungs
| “clear our throat,” mucus up/out of larynx
38
elastic cartilage
open in breathing
When swallowing, larynx moves superiorly, and epiglottis covers it
Anything other than air in larynx triggers=cough reflex
Epiglottis
39
Mucosa-covered ligaments attach arytenoid and thyroid cartilages
Vibrate make sound
Vocal Cords
40
Vocal folds + opening between them
Glottis
41
Nosound production
| Help close the glottis in swallowing
Vestibular glottis
42
During speech, glottis
opens and closes
43
Pitch changes with length and tension of vocal folds
Tenser=faster vibration=higher
| looser=slower vibration=lower
44
loudness
strength of vibration
45
vocal folds only produce
buzzing sounds
46
Voice and speech quality are also determined by
pharynx, oral and nasal cavities, paranasal sinuses, tongue, soft palate, and lips
47
laryngitis
Inflammation of vocal folds, interferes with vibration
48
Trachea "windpipe"
larynx to bronchi
4 in long, ¾ in wide
Hyaline cartilage, connective tissue, and pseudostratified, ciliated epithelium
Cilia sweep mucus toward pharynx
Smoking inhibits and destroys cilia, so smokers cough to prevent mucus from accumulating in the lungs
49
Mucosa layer (ciliated) supported by submucosa, which (contains seromucous glands)
Submucosa (supported by 16-20 C-shaped hyaline cartilage rings)
The “open” part of the rings are located posteriorly expands with food
Trachea Anatomy
50
Smooth muscle helps expel mucus with greater force (e.g., coughing) reducing trachea’s diameter; 100 mph!!!
Trachealis
51
Cartilage is surrounded by
adventitia, the outermost connective tissue layer
52
Spar of cartilage on last tracheal cartilage
where trachea splits into two main bronchi
Mucosa is very sensitive; if anything touches it, violent coughing occurs
Carina
53
Bronchial tree branches about how many times?
23
54
Trachea divides into
right and left main (primary) bronchi
55
Trachea enters lung at the
hilum (medial depression)
56
inhaled objects tend to get stuck in which side
right side
57
< 1 mm diameter (and no cartilage)
bronchioles
58
< 0.5 mm diameter
Cuboidal epithelium; sparse mucus and cilia
Macrophages in alveoli remove debris
terminal bronchioles
59
Terminal bronchioles => Respiratory bronchioles =.> Alveolar ducts
Respiratory Zone
60
Each individual air sac
alveolus
61
cluster of alveoli
alveolar sac
62
Lung contains 300 million alveoli, which are covered in
capillaries
63
Type 1 alveolar cells
Simple squamous epithelial cells=>alveolar walls
64
Respiratory membrane
Alveolar and capillary walls with fused basement membranes
0.5-μm thick blood-air barrier
gas exchange by diffusion (O2 into blood, and CO2 into alveoli)
65
Type II alveolar cells
Cuboidal cells secrete fluids containing surfactant and antimicrobial proteins
Surface tension shrinks alveoli, so surfactant prevents alveoli from collapsing
Premature babies not enough surfactant; require a mechanical ventilator
66
surfactant
(detergent-like substance that reduces surface tension)
67
Alveolar pores
- -Connect alveoli
- -equalize pressure
- -alternate route if bronchi collapsed or obstructed
68
Alveolar macrophages
Gobble debris and pathogens on internal alveolar surfaces
Alveolar surfaces sterile because antimicrobial proteins and macrophages
Dead macrophages are swept up in cilia to pharynx swallow 2 million alveolar macrophages per hour!
69
lungs combined weigh how much?
2.2 lbs.
70
lung root
```
lungs to heart and trachea via the hilum
blood vessels (pulmonary and bronchial), bronchi, lymphatic vessels, nerves that enter lungs
```
71
left lung to accommodate the heart
cardiac notch
72
Each lobe contains pyramid-shaped
bronchopulmonary segments
right: 10 segments
left: 8-10 segments
73
Each segment (of bronchopulmonary segment) is served by its own
artery and vein and tertiary bronchus
Lung disease often limited to one or a few segments
Segments separated connective tissue; they can be removed without damaging nearby segments
74
Pulmonary circulation
Oxygen-poor blood leaves heart (via pulmonary arteries) => exchanges gases in lungs => Returns to heart (via pulmonary veins)
Low pressure, high volume
75
Supplies the lung tissue itself
Bronchial circulation
76
Oxygen-rich blood from the aorta enters the lungs via
bronchial arteries
77
Blood supplies all lung tissue except
alveoli
78
Tiny bronchial veins return some blood to heart, but most of the blood actually returns via
pulmonary veins due to anastomoses between the two circulations
79
pleurae
fold back on themselves
Prevents organs from interfering with each other
Prevents infections from spreading
80
lung pressure relative to
atmospheric pressure
atmospheric (760 mmHg)
zero (760 mmHg)
positive pressure=greater than 760 mmHg
negative pressure=less than 760 mmHg
81
Intrapulmonary (intra-alveolar) pressure (Ppul)
0 mmHg
82
Intrapleural pressure (within pleural cavity, Pip)
-4 mmHg
83
Pip must be negative relative to
Ppul
84
Lung collapse (atelectasis) occurs when:
- -plugged bronchiole (ex: pneumonia)
| - -Associated alveoli absorb all of their air and collapse
85
Air enters pleural cavity (BLANK) due to chest wound or rupture of visceral pleura
pneumothorax
86
the most important muscle contributing to the change in volume of the thoracic cavity.
diaphragm
87
Expiration is mostly a passive process that depends on
lung elasticity and muscle relaxation.
88
Amount of air that moves in/out of lungs with each breath (500 mL)
tidal volumes
89
Forcibly inhaled volume beyond tidal
Inspiratory reserve volume
90
Forcibly exhaled volume beyond tidal
Expiratory reserve volume
91
Amount of air in lungs that cannot be exhaled; prevents lung collapse
Residual volume
92
Anatomical dead space
all 500 mL of the air in each breath is “usable” because 150 mL remains in the conducting zone and does not contribute to gas exchange in alveoli
93
alveoli collapse or are blocked by mucus
contribute to total dead space
94
obstructive pulmonary diseases
in which airway resistance increases
--cannot exhale 80% of vital capacity in 1 second
95
restrictive diseases
in which total lung capacity is reduced
--Patients can exhale 80% of VC in 1 second, but VC is lower
96
Normal respiratory rate (12-16 breaths/min)
Eupnea
97
amount of air reaching your alveoli, breathe slowly and deeply
alveolar ventilation
98
slide 41
yes
99
Alveoli have less O2 and more CO2 and H2O than air. Why?
- -O2 goes into blood and CO2 comes out of blood)
- -Humidification
- -Mixing of gas as we inhale and exhale
100
External respiration (pulmonary gas exchange) relies on three factors
1) Partial pressure gradients and gas solubilities
2) Thickness and surface area of respiratory membrane
3) Ventilation-perfusion coupling (See Slide #45)
Ventilation (amount of gas reaching alveoli) is matched to perfusion (blood flow in pulmonary capillaries)
101
What determines areolar diameter?
Po2
102
PO2 is low, arterioles constrict, bypassing the alveoli
PO2 is high, arterioles dilate and fill with blood
103
PCO2 is high, bronchioles dilate to eliminate the gas
PCO2 is low, bronchioles constrict
104
factors influnence shape of hemoglobin and change its ability to bind to O2
temperature increase,
--CO2, or H+ decreases hemoglobin’s ability to carry O2 (which helps hemoglobin unload O2) in the tissues
This makes sense because in the tissues where active metabolism is occurring
- -higher temp
- -CO2 =waste product
- -H+ acid is being produced as CO2 dissolves in plasma
105
hypoxia
Inadequate oxygen to body tissues
| Skin turns bluish (cyanosis) when O2 saturation is below 75%
106
Anemic hypoxia
Lack of RBCs
107
Ischemic hypoxia
Blocked circulation
108
Tissues cannot use O2 (even though supply is adequate) due to poison, such as cyanide
Histotoxic hypoxia
109
Reduced arterial PO2
| -- cause: pulmonary disease reduces ventilation, breathing air with little O2, or carbon monoxide poisoning
Hypoxemic hypoxia
110
CO2 transported to the lungs (3 ways)
1) Dissolved in plasma (10%)
2) Bound to hemoglobin (20%)
CO2 bound to hemoglobin protein
3) As bicarbonate ions in plasma (70%)
111
carbonic acid-bicarbonate buffer system
CO2 dissolves in plasma => Enters RBCs => Converted to carbonic acid (H2CO3) by enzyme (carbonic anhydrase) => Acid is unstable and breaks down to H+ + HCO3- (bicarbonate)
Reaction: CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO3-
112
Chloride shift
Via facilitated diffusion, bicarb ions from RBC into plasma, and Cl- ions take their place inside RBCs (chloride-bicarbonate antiporter)
process reversed in lungs
113
Generates the respiratory rhythm
| Thought to involve reciprocal inhibition of neuronal networks
Ventral respiratory group (VRG)
114
Opioids and alcohol turn this part of the brain stem “off” Breathing stops
medulla oblongata
115
Integrates input from peripheral stretch and chemoreceptors and sends info to VRG
Dorsal respiratory group (DRG)
116
Pontine respiratory centers smooth inspiration/expiration transitions
Fine-tunes breathing rhythm set by VRG
Pons
117
Located in brain stem
central chemoreceptors
118
: Located in aortic arch and carotid arteries
Peripheral chemoreceptors
119
Chemoreceptors monitor
O2, CO2, and H+ (i.e., pH)
120
cannot cross blood-brain barrier, so a drop in pH is detected by peripheral chemoreceptors
Blood that is too acidic can be caused by too much CO2, exercise (lactic acid), or diabetes
Regardless of the cause, increased breathing eliminates CO2 (and carbonic acid), raising pH
H+
121
Strong emotions and pain can change breathing
Hypothalamus
122
consciously control our breathing
cerebral cortex
123
Cerebral motor cortex sends signals to motor neurons that stimulate respiratory muscles
Can’t hold your breath forever
high levels of CO2 cause brain stem to initiate breathing
124
Pulmonary irritants trigger
bronchoconstriction, coughing, sneezing
125
Stretch receptors (during breathing) tell the medulla to
stop inspiration
126
removes excess CO2, which:
- -Constricts cerebral blood vessels, causing dizziness or fainting
- -Increases pH, tingling and muscle spasms due to blood Ca2+ levels falling
Hyperventilation
127
Why swimmers shouldn't hyperventilate before swimming
PCO2 can be lowered to such an extent that it takes a while before the brain decides to initiate breathing again
128
Debunking junk: oxygen masks for athletes
During exercise, ventilation and perfusion are still (nearly) perfectly matched, which means respiratory functions are efficient
129
Results in an irreversible decrease in ability to force air out of lungs
Chronic obstructive pulmonary disease (COPD)
130
COPD symptoms: Dyspnea
Difficult or labored breathing (“shortness of breath”) that gets progressively worse
131
COPD symptoms: Coughing and frequent pulmonary infections
yes
132
COPD symptoms: Hypoventilation
Insufficient ventilation to provide O2 and reduce CO2 Respiratory acidosis & hypoxemia
133
Other COPD symptoms:
emphysema and chronic bronchitis
134
Enlargement of alveoli and destruction of alveolar walls; lungs lose elasticity; air trapped in lungs and breathing very difficult
Emphysema
135
Chronic production of excessive mucus due to lung irritation; infection more likely because bacteria in stagnant mucus
Chronic bronchitis
136
Reversible obstructive disease with acute episodes and symptom-free periods
Asthma
137
Asthma symptoms
- -Coughing, wheezing, dyspnea, chest tightness
- -Allergic asthma is most common, which is mediated by IgE antibodies
- -Inflammation persists even during symptom-free periods
- -Allergens trigger bronchospasms (sudden constriction of bronchioles)
138
Tuberculosis symptoms
Mycobacterium tuberculosis
1/3 of the world population is infected, but most don’t develop disease
Most people form tubercles contain bacteria
In others, bacteria “break free” and cause active infection
139
leading cancer killer
More deaths than prostate, breast, and colorectal cancer combined
About 90% of cases are due to smoking
Most patients die within 1 year of diagnosis
5-year survival is 17%
lung cancer
140
Adenocarcinoma
40% of cases
| Cancer arises from epithelial glands of bronchi
141
Squamous cell carcinoma
25-30% of cases
| Cancer arises from bronchi epithelia
142
Small-cell carcinoma
20% of cases
arise from neuroendocrine cells
release hormones=>other problems
