Respiration Flashcards
(106 cards)
1
Q
What are the 4 processes of respiration?
Which belongs to the respiratory and which belongs to circulatory system?
A
Respiratory
- Pulmonary ventilation (breathing
- External respiration (exchange of O2 and CO2 between LUNGS and BLOOD)
Circulatory
- Transport: of O2 and CO2 in blood
- Internal respiration: (exchange of O2 and CO2 between systemic blood vessels and tissues
2
Q
What is considered upper respiratory and lower respiratory?
A
upper: Pharynx and above
Lower: Larynx and below
3
Q
What is the role of the larynx? (3)
A
- prevent food from entering lower respiratory tract
- voice production
- provides patent airway
4
Q
What are the main sites of gas exchange and help reduce surface tension in the lung
A
alveoli
5
Q
What is the role:
- respiratory mucosa
- Seromucous nasal glands
A
Respiratory mucosa
- contain goblet cells
Seromucous nasal glands
- Provide protection from antigens (secretions contain lysozyme and defensins)
6
Q
Role of nasal conchae during
Inhalation
Exhalation
A
Inhalation
- filter, heat, and moisten air
Exhalation
- reclaim heat and moisture
7
Q
Explain rhinitis
A
Inflammation of nasal mucosa
- can cause a sinus headache
8
Q
What type of muscle is the pharynx composed of?
A
Skeletal muscle
9
Q
What closes the nasopharynx during swallowing (2)
A
- Soft palate
- uvula
10
Q
What is the opening to oral cavity called?
A
Isthmus of fauces
11
Q
What is the role of the adenoids (pharyngeal tonsil)?
What happens if they get infected and swollen?
A
Role
- builds mucus to cough out
When infected:
- adenoids can block air passage in the nasopharynx, allowing only breathing through mouth
- as a result, air is not properly moistened, warmed, or filtered before reaching lungs
12
Q
What are the 2 zones of the lower respiratory system?
A
Conducting zone:
- transport gas to and from gas exchange sites
- First 20 orders of branching (no gas exchange)
Respiratory zone: site of gas exchange
- microscopic structures such as: bronchioles, alveolar ducts, alveoli
- last 3 orders of branching (gas exchange)
13
Q
What are the 9 cartilages of the larynx
A
- Thyroid cartilage
- Cricoid cartilage
- & 4. Paired arytenoid cartilages
- & 6 paired cuneiform cartilages
- & 8. paired corniculate cartilages
- Epiglottis
14
Q
What cartilage form’s the adam’s apple?
What’s it called?
A
- Thyroid cartilage
- Laryngeal prominence
15
Q
What is the role of vestibular folds? (false vocal cords)
A
- No part in sound
- help to close glottis during swallowing
16
Q
What kind of fibers are in the vocal folds?
What 2 cartilages do they attach together?
A
Elastic
- arytenoid cartilage & cricoid cartilage
17
Q
Which cartilage in the larynx is embedded in muscle?
A
Cuneiform cartilage
18
Q
How is speech produced?
A
intermittent release of expired air during opening and closing of glottis
19
Q
How is pitch determined?
How is loudness determined?
A
Pitch
- length and tension of vocal cords
Loudness
- force of air
20
Q
What works together to amplify and enhance sound quality?
A
pharynx and oral, nasal, and sinus cavities
21
Q
How is sound “shaped” into language
A
By muscles of pharynx, tongue, soft palate, and lips
22
Q
Explain Laryngitis
A
- inflammation of the vocal folds that interfere with vibrations
- caused by viral infections
- can be also due to overuse of voice, dry air, bacterial infections
23
Q
What are the 3 layers of the trachea wall?
A
- Mucosa:
- goblet cells - Submucosa:
- seromucous glands supported by 16-20 C shaped cartilage to prevent collapse of trachea - Adventitia:
- outermost layer made of connective tissue
24
Q
What is the role of the trachealis smooth muscle?
A
- contracts during coughing to expel mucus
25
How is violent coughing triggered?
If any foreign object makes contact with CARINA (last tracheal cartilage with highly sensitive mucosa)
26
What is the Heimlich maneuver?
Procedure in which air in victim's lungs is used to "pop out" an obstructing piece of food
27
Why should smokers with respiratory congestion avoid medications that inhibit cough reflex?
- smoking inhibits and destroys cilia
- without ciliary activity, coughing is the only way to prevent mucus from accumulating in lungs (which is their only option)
28
What is the difference between right main (primary) bronchus and the left?
Right = wider, shorter, vertical
29
What is the difference between left and right lobar bronchi?
3 on right
2 on left
30
What are the 3 changes that occur in the conducting zone?
1. Support structures change
- cartilage rings become irregular plates
- in bronchioles, elastic fibers replace cartilage altogether
2. Epithelium type changes
- pesudostrat columnar--> cuboidal
- cilia and goblet cells become more spars
3. Amount of smooth muscle increases
- allows bronchioles to provide more resistance to air passage
31
What does the respiratory membrane consist of?
Blood air barrier that consists of alveolar and capillary walls along with their fused basement membranes
- allows gas exchange across by simple diffusion
32
What do alveolar walls consist of? (2)
What does type II alveolar cells secrete?
1. Single layer of squamous (type I alveolar cells)
2. Scattered cuboidal type II alveolar cells;
- secrete surfactant and antimicrobial proteins
33
What are alveoli surrounded by?
- fine elastic fibers
- pulmonary capillaries
34
What are the roles of alveolar pores?
- connect adjacent alveoli
- equalize pressure throughout lung
- provide alternate routes in case of blockages
35
What keep alveolar surfaces sterile?
alveolar macrophages
- 2 mill dead macrophages/hour carried by cilia to throat and swallowed
36
What can fluid to do respiratory membrane?
make membrane levels bigger to decrease amount of O2 diference
37
How many segments are in each lobes of the lungs?
What tissue are they separated by?
Right:
- Superior: 3
- Middle: 2
- Inferior: 5
Left
- Superior: 4
- Inferior: 5
Connective tissue septa
38
Explain pulmonary circulation.
- pulmonary arteries & veins
Pulmonary circulation
- LOW pressure, HIGH-volume system
- re-oxygenate the blood
Pulmonary arteries (away from heart)
- deliver system venous blood from HEART TO LUNGS - lacking oxygen
- Lots of branching to feed into pulmonary capillary networks
Pulmonary veins
- carry oxygenated blood from respiratory zones back to heart.
39
Explain bronchial circulation.
- Bronchial arteries & veins
Bronchial circulation
- HIGH pressure, LOW volume
- systemic circulation
- arise from aorta enter lungs at hilum
Bronchial arteries
- provides oxygen to all lung tissue expect the alveoli
(alveoli is diffusion)
Bronchial veins
- anastomose with pulmonary veins
40
Where do nerves enter through?
What do parasympathetic and sympathetic fibres cause?
Enter through pulmonary plexus and run along bronchial tubes and blood vessels
Parasympathetic fibers
- bronchoconstriction
Sympathetic fibers
- Brocnhodilation
41
Explain Pleurisy.
Inflammation of pleurae that results in pneumonia
- becomes rough and can cause friction which has pain with each breath
- pleurae may produce excessive amount of fluid which may exert pressure on lungs, hindering breath
42
What other fluids can accumulate in a pleural cavity?
( other than what it produces during pleurisy)
- Blood: leaked from damaged blood vessels
- Blood filtrate: watery fluid that oozes from lung capillaries when left-sided heart failure occurs
43
What does Atmospheric pressure relate to (Patm)?
Explain negative, positive, zero pressure?
Pressure exerted by air surrounding body
- 760 mm Hg at seal level = 1 atm
Negative: less than Patm
Positive: MORE than Patm
Zero: Equal to Patm
44
What is Intrapulmonary pressure (Ppul)
Characteristic?
Pressure in alveoli
- Always eventually equalizes with Patm
45
What is Intrapleural pressure (Pip)
Characteristic?
Pressure in pleural cavity
- ALWAYS NEGATIVE pressure
(less than Patm and Ppul)
- usually 4 mm Hg less than Ppul (-4 mm Hg)
46
What happens to Pip if excess fluid accumulates?
- Positive Pip
- Lung collapses
47
What are the 2 inward forces that promote lung collapse due to opposing forces of negative Pip?
1. Lungs' natural tendency to recoil because of elasticity (always try to assume the smallest size)
2. SURFACE TENSION of alveolar fluid pulls on alveoli to try to reduce alveolar size
48
How is Negative Pip maintained?
By strong adhesive force between parietal and visceral pleurae
49
What is transpulmonary pressure?
- Pressure that keeps lung spaces open and keeps lungs from collapsing
- the greater this pressure, the larger the lungs
Ppul - Pip = 0 - (-4) = 4 mm Hg
50
What pressures can lungs collapse?
Pip = Patm
Pip = Ppul
51
What does volume and pressure changes lead to for pulmonary ventilation?
Volume changes:
- lead to pressure changes
Pressure changes:
- lead to flow of gasses to equalize pressure
52
What is boyle's law?
P1V1 = P2V2
- pressure is inverse with volume
53
What occurs to the diaphragm and external intercostal muscles during quiet inspiration?
Diaphragm
- Contracts
- Moves inferiorly = increase in thoracic volume
External intercostals
- contract
- rib cage lifted up and out = increase in thoracic volume
54
What occurs to Ppul and Pip during quiet inspiration?
Ppul
- drops by 1 mm Hg
Ppul < Patm
until air flows into lungs, down its pressure gradient to equal Ppul=Patm
Pip
- lowers about 6 mm Hg less than Patm (-6 mm Hg)
- becomes more negative
55
Explain quiet expiration.
Passive process
- Diaphragm and external intercostals relax
- lungs recoil
56
What occurs to Ppul & Pip during quiet expiration?
Volume decreases.. causing:
Ppul to increase +1 mm Hg
Ppul > Patm until air flows out of lungs down its pressure gradient until Ppul= Patm
Pip: goes back to -4 mm Hg
57
What are 3 physical factors that influence the ease of air passage?
1. Airway resistance
2. Alveolar surface tension
3. Lung compliance
58
Explain DELTA P in airway resistance
Pressure gradient between atmosphere (Patm) and alveoli (Ppul)
- 2 mm Hg or less during normal quiet breathing and is sufficient to move 500mL
59
What are the 2 reasons factor of airway resistance is insignificant?
1. Diameters or airways in first part of conducting zone is huge
2. progressive branching of airways as they get smaller leads to an increase in total cross-sectional area
60
Where is the highest airway resistance
In medium-sized bronchi
61
Explain alveolar surface tension factor.
What helps it?
The attraction of liquid molecules to one another at a gas-liquid interface
- resists any force that tends to increase SA of liquid
- water has a very high surface tension and can cause alveoli to shrink to smallest size/collapse
Helps
- Surfactants which is produced by Type II alveolar cells
62
Explain what happens in infant respiratory distress syndrome (IRDS)
Not enough quantity of surfactant
- results in collapse of alveoli after each breath
63
Explain lung compliance factor.
Why is this number normally high? (2)
How much stretch the lung has with given change in transpulmonary pressure
1. Distensibility of lung tissue
2. Surfactants (decreases alveolar surface tension)
Lowest pressure that increase lung compliance is the best
64
What is the mathematical equation of lung compliance?
Compliance = Change in lung volume / (Ppul- Pip)
65
How can lung compliance be diminished? (3)
1. Nonelastic scar tissue replacing lung tissue (fibrosis)
2. Reduced production of surfactant
3. Decreased flexibility of thoracic cage
66
What does in the following make up:
inspiratory capacity
Functional residual capacity
Vital capacity
Total lung capacity
inspiratory capacity: Insp + Tidal
Functional residual capacity: Exp + residual
Vital capacity: Insp + Exp + Tidal
(volume to breathe in & out)
Total lung capacity
- everything
67
What are the average volumes for the following?
Tidal
Inspiratory reserve volume
Expiratory reserve volume
Residual volume
Tidal: 500 mL
Inspiratory reserve volume: 3100 mL
Expiratory reserve volume:
1200 mL
Residual volume: 1200 mL
68
Explain obstructive pulmonary disease (bronchitis).
What capacity/volumes are affected? (3)
Increased airway resistance
(issue with getting air out)
Total capacity TC
Functional residual capacity FRC
Residual volume RV
- may increase because of hyperinflation of lungs
69
Explain restrictive disease.
(tuberculosis, fibrosis)
What capacity/volumes are affected? (4)
Reduced TLC due to disease (tub.) or exposure to environmental agents (fibrosis)
- issue with getting air in)
TLC
VC
FRC
RV
- all decrease because lung expansion is comprimized
70
Explain forced vital capacity
Amount of air you can move out fast after taking a deep breath
71
Explain FEV1.
What should we expect for obstructive vs restrictive disease?
FEV1
- amount of air expelled during a specific time interval of FVC (1 second)
Healthy: 80%
Obstructive: less than 80%
restrictive: 80%+
72
What is the best indicator of effective ventilation?
What is the equation?
Alveolar ventilation rate
TV - dead space vol x respiratory rate
73
What causes significant increase in AVR?
Decrease?
significant AVR increase is due to increase in TV not frequency
Rapid shallow breathing deceases AVR
74
Differentiate between external and internal respiration
External
- diffusion of gases between BLOOD AND LUNGS
Internal
- between blood and tissues
75
What happens to partial pressure in high vs low altitude
High altitude
- partial pressure declines
Low altitude (under water)
- partial pressure increase
76
Differential between O2 and CO2 partial pressure gradients in external respiration.
Inspired air
PO2: 160 mm Hg
PCO2: 0.3 mmHg
Alveoli of lungs
PO2: 104 mmHg
PCO2: 40 mmHg
77
Differentiate between Perfusion and Ventilation in external respiration.
What do PO2 and PCO2 control? How?
Perfusion: blood -> alveoli
Ventilation: gas -> alveoli
PO2 controls PERFUSION by changing ARTERIOLAR diameter
PCO2 controls VENTILATION by changing BRONCHIOLAR diameter
(breathing rate)
78
What do changes in PO2 in alveoli influence on perfusion?
At lungs?
at tissues?
Directs blood to go to alveoli, where O2 is high, so blood can pick up more O2
Lungs:
- Where alveolar O2 is HIGH, arterioles DILATE
Where alveolar O2 is low, arterioles constrict
Tissues = opposite
79
What do changes in PCO2 in alveoli influence on ventilation?
Allows elimination of CO2 more rapidly
- When alveolar CO2 is HIGH, bronchioles DILATE
- When alveolar CO2 is low, bronchioles constrict
80
Why is ventilation-perfusion never balanced in external respiration? (2)
1. variations in region; due to effect of GRAVITY on blood and air flow
2. Occasionally, alveolar ducts plugged with mucus; causes unventilated areas
81
Differentiate between Tissue PO2 and tissue PCO2 compared to arterial blood in internal respiration
- Tissue PO2 is always lower than in arterial blood
(oxygen moves from blood into tissues) (100 -> 40)
- Tissue PCO2 is always higher than in arterial blood
(CO2 moves from tissues into blood) (40 --> 45+)
82
Compare arterial blood and venous blood in hemoglobin saturation
Arterial blood
- PO2 is 100 mm Hg
- Hb 98% saturation
Venous blood
- PO2 is 40 mm Hg
- Hb is 75% saturated
83
What other factors on hemoglobin decreases for Hb's affinity for O2
Temperature, H+, PCO2, and BPG
84
Bohr effect
More CO2 you have, the more likely you are to unload O2
85
Explain hypoxia
Inadequate O2 delivery to tissues
86
Describe the 3 forms CO2 is transported in blood.
1. 7-10% is dissolved in plasma as PCO2
2. 20% of CO2 bound to the globin part of hemoglobin
3. 70% is transported as HCO3
87
Explain the CO2 transport in tissues (RBC)
RBCs have the enzyme carbonic anhydrase that make bicarbonate.
- HCO3 goes out of the RBC
- Chloride goes in via transport protein (antiport)
Oxygen release and CO2 pickup at tissues
88
Explain the CO2 transport in lungs (RBC)
in pulmonary capillaries
- HCO3 goes in RBC (to transport CO2 out of lungs)
- Chloride goes out of RBC
Oxygen pickup and CO2 release in lungs
89
What does the haldane effect encourage?
Encourage CO2 exchange at tissues and at lungs
- as more CO2 enters blood, more O2 dissociates from Hb (bohr effect)
90
How does slow, shallow breathing affect pH?
How does rapid, deep breathing affect pH?
Slow shallow
- increase CO2, drop pH
Rapid deep
- Decrease CO2, pH rise
91
Explain what the ventral respiratory group (VRG) does in the Medullary respiratory centres.
What do their inspiratory and expiratory neurons do?
- sets eupnea: normal breathing rate
- inspiratory neurons excite inspiratory muscles (diaphragm, intercostal nerves)
- expiratory neurons inhibit inspiratory neurons
92
Explain what the Dorsal respiratory group (DRG) does?
Integrates peripheral sensory input and modifies the rhythms generated by the VRG
93
Explain what Pontine respiratory centres do?
Act to smooth out transition between inspiration and expiration by modifying activity of VRG
94
What is the most widely accepted hypothesis for neural mechanisms in generating a respiratory rhythm
Reciprocal inhibition of 2 sets of interconnected pacemaker neurons
95
What are the 4 factors influencing breathing rate & depth?
Which is the most important factor?
1. Chemical factors (most important)
2. Influence of higher brain centers
3. Pulmonary irritant reflexes
4. Inflation reflex
96
Explain the influence of PCO2 in breathing rate & depth. in steps. what type of receptors?
(MOST INFLUENTIAL, CONTROLLED)
1. Arterial PCO2 increases
2. Increase in PCO2 decreases pH
3. Increased H+ stimulates CENTRAL chemoreceptors which synapses with respiratory regulatory centres
4. Respiratory centers increase depth and rate of breathing, which lower PCO2 and pH rises to normal levels
97
Explain the influence of PO2 in breathing rate & depth.
- PERIPHERAL chemoreceptors (in aortic & carotid bodies) sense arterial O2 levels
- Declining O2 normally has only slight effect of ventilation due to HUGE O2 reservoir bound to Hb
- requires drop below 60 mm Hg to stimulate chemoreceptors to cause respiratory centers to increase ventilation
98
Explain influence of arterial pH? what type of receptors?
- pH can modify respiratory rate and rhythm even if CO2 and O2 levels are normal
- mediated by PERIPHERAL chemoreceptors
99
How does blood PO2 affect breathing?
Directly/indirectly
What type of receptor? How?
Indirectly by influencing PERIPHERAL chemoreceptor sensitivity to changes in PCO2
100
What do hypothalamic controls influence?
act through limbic system to modify rate and depth of respiration
- ex: breath holding that occurs in anger or gasping with pain
101
What do corticol controls influence?
Direct signals from cerebral motor cortex that bypass medullary controls
- ex. voluntary breath holding
102
Explain pulmonary irritant reflexes.
- Receptors in bronchioles respond to irritants such as dust, accumulated mucus, or noxious fumes
- promote reflexive constriction of air passages
103
Explain the Hering-Breuer reflex (inflation reflex).
Mechanical stretch receptors in pleurae and airways are stimulated by lung inflation
- send inhibitory signals to medulla respiratory to end inhalation and allow expiration (protective response)
104
What is the issue with COPD?
irreversible decrease in ability to force air out lungs
105
Explain emphysema and the 3 consequnces
(COPD)
Permanent enlargement of alveoli and destruction of alveolar walls resulting in decreased lung capacity
3 consequences
1. Accessory muscles leading to exhaustion (using more energy to breathe)
2. Trapped air causes hyperinflation, which flattens diaphragm, and causes expanded barrel chest, both of which reduces ventilation efficiency
3. Damaged pulmonary capillaries lead to enlarged right ventricle
106
Explain asthma.
- Acute, not chronic
- Active inflammation of airways precedes bronchospams
- airways thickened
