Respiration Flashcards
The respiratory system consists of what 6 parts of the body?
- Nasal cavity
- Pharynx
- Trachea
- Bronchi
- Bronchioles
- Alveoli
The respiratory system permits gaseous exchange between what and what?
Gaseous exchange between the external environment and the blood
There are 5 functions of the respiratory system, what are they?
- Gaseous exchange
- Sound production
- Abdominal compression
- Route for water/heat loss from body.
- Coughing and sneezing
Why is it important that one of the main respiratory functions is a route for water and heat loss from the body?
Moistening of inspired air is ESSENTIAL to prevent the alveolar linings form drying out.
Oxygen and carbon dioxide CANNOT diffuse through dry membranes.
What are the 3 types of respiration the body performs?
- External respiration
- Internal respiration
- Cellular respiration
What is ‘External Respiration’?
Process by which gases are exchanged between the air in the alveoli and blood within the pulmonary capillaries via diffusion.
What is ‘Internal Respiration’?
Process by which gases are exchanged between the blood and the cells.
What is ‘Cellular Respiration’?
Process by which cells use O2 for metabolism and give off CO2 as waste product.
O2 -> Mitochondria
CO2 From Mitochondria -> Blood Vessel (Waste)
What is the process from start to finish of the bronchial tree?
Trachea -> R/L Primary Bronchi -> Secondary Bronchi -> Tertiary Bronchi -> Bronchioles -> Alveolar ducts -> Alveolar sacs (Many Small Pulmonary Alveoli)
How does gas exchange occur with the blood of the circulatory system?
Through thin-walled, moistened pulmonary alveoli
What is the number of ‘pulmonary alveioli’ in the lungs and what is the approximate surface area?
300 million
6 times the surface area of the body
The surfactant in the alveoli is secreted by what kind of cells?
Type II alveolar cells
Why is a surfactant needed in the alveoli?
Lowers the surface tension inside alveolus
How are foreign materials removed from the lungs? (What kind of cells do this)
Alveolar macrophages
What are the mechanics of breathing? What causes air to move in and out of the lungs?
Pressure gradient changes
What happens during ‘INSPIRATION’ of the respiratory system? (i.e., diagphram/intercostal muscles/thoracic volume)
Diaphragm CONTRACTS and descends.
External Intercostal Muscles ELEVATE
(*Hint - INSPIRATION comes from EXTERNAL sources.)
Thoracic Volume INCREASES
What happens during ‘EXPIRATION’ of the respiratory system? (i.e., diagphram/intercostal muscles/thoracic volume)
Diaphragm RELAXES
Internal Intercostal Muscles CONTRACT
Thoracic Volume DECREASES
What is ‘hypoxia’?
A deprivation of oxygen in tissues and organs.
What is ‘eupnea’?
Normal breathing
What is ‘dyspnea’?
Difficult or labored breathing
What is ‘apnea’?
Temporary cessation of respiration that may follow hyperventilation.
What is ‘Cheyne-stokes’?
Periods of DYSPNEA followed by periods of APNEA
DEATH usually occurs close after this starts to occur
What is the ‘average respiration rate’?
12-15 times per minute
What is the ‘average Oxygen Consumption’ rate?
250 ml O2 per minute at rest
What are the 2 factors that affect airway resistance?
Bronchoconstriction
Bronchodilation
What are some of the characteristics of ‘bronchoconstriction’?
DECREASED radius
INCREASED resistance to flow
Allergy induced spasm of airways (histamine induced)
Parasympathetic stimulation may attribute in relaxed situations where demand for airflow is low.
Bronchiolar smooth muscle contraction = INCREASED airway resistance
What are some of the characterisics of ‘bronchodilation’?
INCREASED radius
DECREASED resistance to airflow
Sympathetic stimulation may attribute. Epi/Norepi hormonal control. Occurs when increased demands for oxygen uptake is required for the body.
What are the symptoms of ‘ASTHMA’ and what is it usually caused by?
Recurrent attacks of ‘DYSPNEA’ (difficulty breathing).
Usually via allergic response to plants, animals, food products.
Results in CONTRACTION of the bronchial muscles.
What are the symptoms of ‘PNEUMONIA’?
Acute infection and inflammation of the lungs with exudation (accumulation of fluid)
What are the symptoms of ‘CHRONIC BRONCHITIS’ and what is it usually caused by?
Long term inflammation of lower respiratory airways.
Triggered by frequent exposure to irritating cigarette smoke, polluted air or allergens.
What are the symptoms of ‘EMPHYSEMA’ and what is it usually caused by?
Collapse of smaller airways and breakdown of alveolar walls.
Caused by excessive release of destruction enzymes (i.e., TRYPSIN) from alveolar macrophages as a defense mechanism.
This is a response to chronic exposure of cigarette smoke or other irritants.
There are 8 values usually listed for lung volumes and capacities. What are they and their abbreviations?
- Tidal Volume (TV)
- Inspiratory Reserve Volume (IRV)
- Expiratory Reserve Volume (ERV)
- Residual Volume (RV)
- Minute Respiratory Volume (MRV)
- Alveolar Ventilation Volume (AVV)
- Total Lung Capacity (TLC)
- Vital Capacity (VC)
What is the definition of ‘TIDAL VOLUME’?
Volume of air moved into/out of lungs during NORMAL breathing (400-500 ml)
What is the definition of ‘INSPIRATORY RESERVE VOLUME’?
Maximum volume beyond the tidal volume that can be inspired in one deep breath (3000 ml)
What is the definition of ‘EXPIRATORY RESERVE VOLUME’?
Maximum volume beyond the tidal volume that can be forcefully exhaled following normal expiration (1100 ml)
What is the definition of ‘RESIDUAL VOLUME’?
Air that remains in the lungs following forceful expiration (1200 ml)
What is the definition of ‘MINUTE RESPIRATORY VOLUME’?
The volume of air moved in normal ventilation in one minute
(MRV = (tidal volume) x (respiratory rate)
**Normal Value = 6000 ml/min
What is the definition of ‘ALVEOLAR VENTILATION VOLUME’?
Volume of air that ACTUALLY ventilates the alveoli.
AVV = {(tidal volume) - (dead air)} x respiratory rate
**Normal Value = 4200 ml/min
What is ‘dead air’?
Portion of the inspired air that does NOT take part in gas exchange. This air fills passageways to ventilate the alveoli.
This is part of the Alveolar Ventilation Volume (AVV)
What percentage of the tidal volume is ‘dead air’?
30%
What is the definition of ‘TOTAL LUNG CAPACITY’?
The sum of the FOUR lung volumes
TLV = TV + ERV + IRV + RV
**Normal Value = ~5700 ml
What is the definition of ‘VITAL CAPACITY’?
Represents the total amount of air that can be exchanged by the lungs.
**Normal Value = ~4600 ml
What is a ‘spirogram’?
The recording of the pulmonary volumes and capacities.
There are 6 layers of the respiratory membrane (alveolar capillary membrane)?
- Surfactant
- Thin Layer of Fluid - WATER
- Alveolar Epithelium
- Interstitial Space
- Capillary Basement Membrane
- Capillary Endothelium
Sometimes newborn babies have collapsed alveolar sacs. Why does this occur?
They aren’t secreting surfactant