Exam 3 Chapter 22 Flashcards
(113 cards)
1
Q
What is the function of vocal ligaments?
A
Attach arytenoid cartilages to thyroid cartilage Form core of vocal folds (true vocal cords)
2
Q
What are vestibular folds?
A
False vocal cords Superior to vocal folds No Part in sound production Help to close glottis during swallowing.
3
Q
How is voice produced?
A
Release of expired air while opening and closing glottis Pitch determined by length and tension of vocal cords Loudness depends on force of air Sound is shaped into language by muscles
4
Q
What is Valsava’s maneuver?
A
Glottis closes to prevent exhilation Abdominal muscles contract Intra-abdominal pressures rise Helps to empty rectum or stabalize trunk during heavy lifting
5
Q
The wall of the trachea is composed of what three layers?
A
Mucosa Submucosa Adventitia
6
Q
What structure connects posterior parts of cartilage rings and contracts during coughing to expel mucus?
A
Trachealis muscle
7
Q
What structure is located at the spar of cartilage on the last, expanded tracheal cartilage and marks the point where the trachea branches into two main bronchi?
A
Carina
8
Q
How many orders of branching does air passage undergo?
A
23
9
Q
What point of a lung do bronchi enter? What is the difference between the right and left main bronchi?
A
Enters at hilium of lung Right main bronchus is wider, shorter, and more vertical lan left
10
Q
What are the nine cartilages of the larynx?
A
Thyroid cartilage with laryngeal prominence Ring shaped cricoid cartilage Paired arytenoid, cuneform, and corniculate cartilages Epiglottis- elastic cartilage
11
Q
By what mechanism does gas exchange occur in respiratory membranes?
A
Simple diffusion
12
Q
What type of epithelium composes type 1 alveolar cells?
A
Single layer of squamous epithelium
13
Q
What cell type composes type 2 alveolar cells? What do they secrete?
A
Scattered cuboidal epithelium Secrete surfactant and antimicrobial proteins
14
Q
What are the functions of alveolar pores?
A
Connect adjacent alveoli Equalize pressure
15
Q
What is the difference between lung roots and costal surfaces?
A
Root- site of vascular and bronchial attachment to mediastinum Costal surface- anterior, lateral, and posterior surfaces
16
Q
How are the left lung’s superior and inferior lobes separated?
A
By oblique fissure
17
Q
How are the right lung’s lobes separated?
A
By oblique and horizontal fissures
18
Q
What blood vessels deliver systemic venous blood to the lungs for oxygenation?
A
Pulmonary arteries
19
Q
What enzyme activates blood pressure hormone?
A
Angiotensin converting enzyme
20
Q
What blood vessels provide oxygenated blood to all lung tissue except alveoli?
A
Bronchial arteries
21
Q
What structures does parietal plurae line?
A
Thoracic wall, superior face of diaphragm, around heart, between lungs
22
Q
What surfaces do visceral pleura line?
A
External lung surfaces
23
Q
What is the function of pleural fluids?
A
Provides lubrication and surface tension Assists in expansion and recoil
24
Q
What pressure is exerted by air surrounding the body?
A
Atmospheric pressure
25
What pressure describes the pressure in alveoli, fluctuates with breathing, and always eventually equalizes with atmospheric pressure?
Intrapulmonary pressure
26
What pressure describes pressure in the pleural cavity, fluctuates with breathing, and is always a negative pressure?
Intrapleural pressur
27
What happens intrapleural pressure becomes positive?
Lungs collapse
28
How is negative pressure maintained in the pleural cavity?
Opposing forces - two inward forces promoting lung collapse - one outward force enlarging lungs
29
What happens if Pip= Ppul or Patm
Lungs collapse
30
What pressure is described by (Ppulmonary-Pintrapleural) and Keeps airways open?
Transpulmonary pressure
31
What is lung collapse (atelectasis) due to?
Plugged bronchioles Pneumonothorax ( air in pleural cavity)
32
What is Boyle's law?
Relationship between pressure and the volume of gas
33
What is the relationship of volume and pressure as explained by Boyle's law?
P varies inversely with volume
34
Describe the active process of inspiration.
-inspiratory muscle contract - thoracic volume increases causing intrapulmonary pressure to drop - lungs stretch and increase intrapulmonary volume - air flows into lungs until pulmonary pressure equals atmospheric pressure
35
Describe the passive process of expiration.
- inspiratory muscles relax - thoracic cavity volume decreases - lungs recoil \> intrapulmonary vol decreses\> pulmonary pressure increases - air flows out until pulm press is zero
36
What three factors hinder air passage and pulmonary ventilation and require energy to overcome.
Airway resistance Alveolar surface tension Lung compliance
37
What is the major nonelastic source of resistance to gas flow
Friction
38
What is the relationship between gas flow changes and resistance?
Inversely related
39
Where is resistance the greatest?
In medium-sized bronchi
40
Where does airway resistance disappear?
At terminal bronchioles where diffusion drives gas exchange
41
What is the mechanism of surface tension?
Attracts liquid molecules to one another Resists any force that tends to increase surface area
42
What substance has high surface tension and reduces alveoli to their smallest size?
Water
43
What substance reduces surface tension and discourages alveolar collapse?
Surfactant
44
Insufficeint quantity of surfactant in premature infants causes?
Infant respiratory distress syndrome
45
What does lung compliance measure?
Change in lung volume that occurs with given change in transpulmonary pressure
46
What factors diminish lung compliance?
Fibrosis Reduced surfactant production Decreased flexibility of thoracic cage
47
What are some homeostatic imbalances that reduce compliance?
Thorax deformities Ossification of cartilage Paralysis of intercostal muscle
48
What are the different respiratory volumes used to assess respiratory status?
Tidal volume Insparatory reserve vol Expiratory reserve vol Residual vol
49
What are the different respiratory capacities?
Inspiratory capacity Functional residual capacity Vital capacity Total lung capacity
50
What is anatomical dead space?
Areas that do mot contribute to gas exchange but air remains in their passageways
51
What is a spirometer?
Instrument used for measuring respiratory volumes and capacities
52
What volumes or capacities might obstructive pulmonary disease increase?
Total lung capacity Functional residual capacity Reserve volume
53
What volumes and capacities are reduced by restrictive disorders like fibrosis?
Vital capacity Total lung capacity Functional residual capacity Residual volume
54
What volumes and capacities are used to measure the rate of gas movement?
Forced vital capacity Forced expiratory volume
55
How is alveolar ventilation rate determined?
Frequency x (total volume- dead space)
56
What are some effects of non-respiratory air movements? What are some examples
May modify normal respiratory rhythm Result from reflex actions such as coughing, sneezing, crying, laughing, hiccups, and yawns.
57
What law describes the total pressure exerted by mixture of gasses equal to the sum of pressures exerted by each gas?
Dalton's law of partial pressures
58
What is partial pressure and what is it directly proportional to?
Pressure exerted by each gas in a mixture Directly proportional to its percentage in mixture
59
What law does the following describe: Each gas dissolves in proportion to partial pressure At equilibrium, partial pressure in two phases will be equal And the amount of gas that will dissolve depends on solubility and temperature
Henry's Law of gasses
60
What factors influence external respiration?
Thickness and surface area of membrane Partial pressure gradients and gas solubilities Ventilation-perfusion coupling
61
Compare partial pressures of O2 to CO2. Which is more soluble in plasma?
O2 partial pressure gradient is steep in lungs. co2 is 20x more soluble in plasma
62
Define profusion
Blood flow reaching alveoli
63
Define ventilation
Amount of gas reaching alveoli
64
What causes ventilation and perfusion to never be balanced in all alveoli?
Regional variations due to effect of gravity on blood and air flow Some alveolar ducts plugged with mucous
65
Changes in O2 pressure cause changes in the diameters of which blood vessels?
Arterioles
66
Changes in CO2 pressure in alveoli causes changes in the diameter of which structures? Why?
Bronchioles Allows elimination of CO2 more rapidly
67
How are partial pressures and diffusion gradients in internal respiration compared to external respiration?
They are reversed compared to external respiration. (Tissue Po2 is lower than arterial blood so that oxygen diffuses from blood to tissue)
68
How is molecular oxygen transported in blood?
1.5% is dissolved in plasma 98.5% is bound to iron of hemoglobin
69
Why is the rate of loading and unloading of oxygen regulated?
To ensure adequate oxygen delivery to cells
70
How is hemoglobin saturation plotted against Po2?
S-shaped curve
71
Describe the concentration and saturation of hemoglobin in arterial blood.
Po2 is 100 mm Hg Contains 20% vol of o2 Hb is 98% saturated
72
Describe the concentration and saturation of hemoglobin in venous blood.
Po2 is 40 mm Hg Contains 15% vol oxygen Hb is 75% saturated
73
What factors influence hemoglobin saturation?
Increases in temp, H+, Pco2, and BPG
74
How do temp, H, Pco2' and BPG influence Hb saturation?
Modify structure of Hb to decrease its affinity for O2 Enhances o2 unloading from blood Shifts o2 Hb dissociation curve to the right
75
Decreases in factors influencing Hb saturation shift the curve in what direction?
To the left
76
What happens as cells metabolize glucose and use O2
Pco2 and H+ increase in capillary blood -\> declining blood pH and increasing Pco2 -\> Bohr effect
77
What is the Bohr effect?
Weakening of O2-Hb bonds
78
What is hypoxia?
Inadequate O2 delivery to tissues
79
What is ischemic hypoxia Histotoxic hypoxia Hypoxemic hypoxia?
Ischemic- impaired/blocked circulation Histotoxic- cells unable to use O2 Hypoxemic- abnormal ventilation
80
In what three ways is CO2 transported in blood?
~10% dissolved in plasma 20% bound to globin 70% transported as bicarbonate ions
81
What is acclimatization?
Respiratory and hematopoietic adjustments to long term move to high altitude - chemoreceptors become more responsive to Pco2 when Po2 declines
82
Is acclimatization always lower or higher Hb saturation levels? Why?
Lower because there is less O2 available
83
What is COPD?
Chronic obstructive pulmonary disease - irreversible decrease in ability to force air out of lungs - most develop respiratory failure (hypoventilation) accompanied by respiratory acidosis, hypoxemia
84
What is emphysema?
Permanent enlargement of alveoli; destruction of alveolar walls; decresed lung elasticity - exhaustion of accessory muscles\> hyperinflation\> flattened diaphragm \> reduced ventilation efficiency \> damaged pulmonary capillaries \> enlarged right ventricle
85
COPD symptoms and treatments?
Different symptoms in diff patients - pink buffers: thin near normal blood gasses - blue bloaters: stocky; hypoxic Treated with bronchodilators, corticosteroids, oxygen, sometimes surgery
86
Describe asthma
Reversible COPD Characterized by coughing, dyspnea, wheezing, chest tightness - active inflam of airways precedes bronchospasms
87
Descibe TB
Infectious disease caused by myobacterium tuberculosis -symptoms- fever night sweats, weight loss, racking cough, coughing up blood -treatment- 12 mo course of antibiotics
88
What are the three most common types of lung cancer? Describe
Adenocarcinoma- originates in peripheral lung areas (bronchial glands, alveolar cells) Squamous cell carcinoma- in bronchial epithelium Small cell carcinoma- contains lymphocyte like cells that originate in primary bronchi and subsequently metastasize
89
By what week can a premature baby breath on its own?
28
90
Descibe the developmental aspects of the lungs.
During fetal life- lungs filled with fluid and blood bypasses lungs - gas exchange takes place in placenta - at birth resp centers activated, alveoli inflate, lungs begin to function
91
How many weeks after birth before lungs are fully inflated?
2
92
Cystic fibrosis?
Most common lethal genetic disease in north amer Abnormal Viscous mucous clogs passagways - cause abnormal gene for Cl membrane chann Treatment- mucous dissolving drugs; manipulation to loosen mucus,antibiotics
93
What causes a chloride shift in systemic capillaries?
Bicarbonate quickly diffusing from RBCs into plasma
94
What occurs once bicarbonate ions move into RBCs within pulmonary capillaries?
HCO3 binds with H+ to form H2CO3 which is split into carbon dioxide and water CO2 then diffuses into alveoli
95
What encourages CO2 exchange in tissues and lungs?
Haldane effect
96
Describe the carbonic acid- bicarbonate buffer system
Resists changes in blood pH HCO3 is alkaline reserve that changes when H+ concentration becomes too high or low
97
How do changes in respiratory rate and depth affect blood pH?
Slow, shallow breathing \> increased CO2 in blood \> pH drop Rapid deep breathing \> decreased CO2 in blood \> pH rise
98
What structures in brain control respiration?
Neurons in reticular formation of medulla and pons.
99
How does ventral respiratory group in medulla control respiration?
Sets eupnea (normal respiratory rhythm and rate) Inspiratory neurons excite muscles via phrenic and intercostal nerves
100
How do dorsal respiratory group in medulla control respiration?
(Near cranial nerve 9) Integrates input from peripheral stretch and chemoreceptors to send info to visceral respiratory group
101
What is the most widely accepted hypothesis regarding respiratory rhythm?
Reciprocal inhibition of two sets of interconnected pacemaker neurons in medulla that generate rhythm.
102
How is breathing depth determined?
By how actively respiratory centers stimulates respiratory muscles
103
How is breathing rate determined?
By how long inspiratory centers are active
104
What happens if blood Pco2 levels rise?
(Hypercapnia) CO2 accumulates in the brain leading to a drop in pH
105
How does hyperventilating cause dizziness and fainting?
Increased depth and rate of breathing \> decreased CO2 levels \> cerebral vasoconstriction and cerebral ischemia \> dizziness and fainting
106
Do peripheral chemoreceptors in aortic and carotid bodies cause and increase or decrease in ventilation?
Increase
107
At what level must PO2 fall to in order to stimulate an increase in ventilation?
At least 60 mm Hg
108
What might decreased pH reflect?
CO2 retention, accumulated lactic acid, excess ketones
109
What controls act through limbic system to modify rate and depth of respiration?
Hypothalamic
110
What controls direct signals from cerebral motor cortex that bypass medullary controls such as that occurs in voluntary breath holding?
Cortical
111
How do receptors in bronchioles respond to irritants?
By communicating with respiratory centers via vagal nerve afferents.
112
What three neural factors cause increase in ventilation as exercise begins?
- psychological stimuli - simultaneous cortical motor activation of skeletal muscles and respiratory centers - excitatory impulses to respiratory centers in moving muscles, tendons, joints
113
When does ventilation decline suddenly?
As exercise ends because the three neural factors shut off
