Chapter 13 Review Flashcards
Organs of respiratory pathway
- Nose
- Pharynx
- Larynx
- Trachea
- Main Bronchi
- Lungs
Define: Hyperventilation
Breathing more deeply and more rapidly
Define: Hypoventilation
Extremely slow or shallow breathing
Symptoms: Chronic Obstructive Pulmonary Disease (COPD)
- History of smoking
- Dyspnea becomes more severe
- Coughing
- Pulmonary infections are common
- Hypoxic
Causes: COPD
- Tobacco smoke
- Air pollution
Lung cancer
Symptoms: tons of coughing
Cause: Tobacco (nicotine and nitrosamine)
When are lungs filled with fluid?
In fetus, when all exchanges are made via placenta
When are lungs drained?
At birth
When do lungs fully inflate?
Not until two weeks after birth
What is required to transform nonfunctional respiration into functional respiration?
Surfactant
As we age, what happens to our lungs?
- Chest becomes more rigid and lungs slowly lose their elasticity
- By age 70, VC decreases by about 1/3
- More susceptible to sleep apnea
- Ciliary activity of the mucosa decreases
- More at risk for respiratory tract infections (pneumonia and influenza)
Define: Dyspnea
Difficult or labored breathing
Define: Apnea
Cessation of breathing
Why can’t we stop breathing voluntarily?
Respiratory centers will simply ignore messages from cortex (our wishes)
Physical factors that influence respiratory rate
- Exercise (more signals to resp. muscles)
- Increased body temperature (increase rate)
- Nonrespiratory movements
What does Pons do for respiratory system?
Smooth out basic rhythm of breathing set by Medulla
Eupnea
- Normal breathing rate
- 12-15 respirations/minute
What does Medulla do for respiratory system?
- Sets basic rhythm of breathing via pacemaker
- Stimulates diaphragm and intercostal muscles
- Helps maintain eupnea
Which nerves transmit respiratory messages from CNS?
- Phrenic
- Intercostal nerves
How is carbon dioxide transported in blood?
- Most transported in plasma as bicarbonate ion
- Smaller amount is transported in RBC, via attachment to hemoglobin
How is oxygen transported in blood?
- Most transported by RBC, via attachment to hemoglobin
- Very small amount is dissolved in plasma and transported that way
Nonrespiratory Movements: Yawn
Very deep inspiration
Nonrespiratory Movements: Hiccups
Sudden inspirations resulting from spasm in diaphragm
Nonrespiratory Movements: Laughing
Same as crying, in terms of air exhalations
Nonrespiratory Movements: Crying
- Release of air in a number of short expirations
- Primarily an emotionally induced mechanism
Nonrespiratory Movements: Sneeze
Same as cough, but upward air expels through nose
Nonrespiratory Movements: Cough
- Taking a deep breath, closing glottis, forcing air superiorly against glottis
- Glottis opens and blast of air is rushed upwards
- Acts to clear lower passageways
Residual air
Even after most strenuous expiration, 1200 mL of air still remains in lungs, and it cannot be voluntarily expelled
Inspiratory Reserve Volume (IRV)
The amount of air that can be taken in forcibly over the tidal volume
Expiratory Reserve Volume (ERV)
Amount of air that can be forcibly exhaled after a tidal expiration
Vital Capacity (VC)
- The sum of TV, IRV, ERV
- Total amount of exchangeable air
Process: Inspiration/Inhalation
Diaphragm/external intercostals contract –> thoracic cavity increases –> lungs adhere to thoracic walls –> intrapulmonary volume increases –> gases in lungs spread out –> decrease in gas pressure in lungs creates parietal vacuum, air is sucked into lungs until pulmonary pressure equals atmospheric
Process: Exhalation
Inspiratory muscles relax –> rib cage descends & lungs recoil –> thoracic volume decreases –> gases in lungs forced closer –> intrapulmonary pressure raises higher than atmospheric pressure –> gas flows out of lungs to equalize pressure
Description: Exhalation
- Exhalation
- Depends more on elasticity of lungs than on muscle contraction
Pulmonary respiration
- “breathing”
- Air moves in and out of lungs so that gases in alveoli are continuously refreshed
Internal respiration
At systemic capillaries, gas exchanges made between blood and tissue cells
External respiration
- Gas exchange between pulmonary blood and alveoli must take place
- Gas exchanges are being made between blood and body EXTERIOR
Cellular respiration
- Carbon atoms leave as CO2, and H atoms combine with O to form H2O
- Cornerstone of all energy-producing chemical reactions in body
Protective mechanism: surfactant
Lipid molecule that coats gas-exposed alveolar surfaces
Protective mechanism: laryngal cartilages
Protects pathways
Protective mechanism: epiglottis
Prevents food from entering larynx
Protective mechanism: tracheal cilia
Push bacteria/dust/particles superiorly, away from lungs
Protective mechanism: mucosa
- Moistens air
- Traps incoming foreign particles
Protective mechanism: Alveolar macrophages
- “dust cells”
- pick up bacteria, carbon particles, and other debris
Pathway of air from main bronchi to blood
Bronchi –> bronchioles –> terminal bronchioles –> alveolar duct –> alveoli
Lungs
- W/o mediastinum, lungs occupy entire thoracic cavity
- Site of gas exchange at respiratory membrane
- Apex is deep to clavicle; base rests atop diaphragm
- Covered with pulmonary/visceral serosa
- Stroma is mainly elastic connective tissue
Main Bronchi
- Formed by division of trachea
- Right bronchus is wider, shorter, and straighter
- Only warm, mostly cleansed, and well humidified air passes through bronchi
Nose
- Only exterior part of Resp. System
- First line of defense when filtering out air
- Palate separates it from oral cavity
- Sinuses lighten the skull
Pharynx
- Passageway for food and air, about 5 in.
- Nasopharynx>oropharynx>laryngopharynx>larynx
- Tonsils in nasopharynx and oropharynx
- Ear infections may follow sore throat
Larynx
- “Voice box”
- Routes food/air into proper channels
- Comprised of 8 cartilages & epiglottis
- Vestibular/Vocal folds formed by mucous membrane (Glottis between the two)
How is a cough triggered?
If anything other than air enters the larynx
Tidal Volume (TV)
Normal quiet breathing moves approximately 500 mL of air into and out of the lungs with each breath
Lobes on each side of lung
Left: Two lobes
Right: Three lobes
