Inhalation (also known as inspiration) happens when oxygen from the air enters the lungs.
Contents
- 1 Inhalation of air
- 2 Other substances – accidental
- 3 Other substances – deliberate
- 3.1 Recreational use
- 3.2 Medical use
- 3.2.1 Diagnostic
- 3.2.2 Therapeutic
- 3.3 Suicide
- 4 Mechanism of inhalation
- 5 Hyperaeration
- 6 See also
- 7 References
Inhalation of air
Inhalation of air, as part of the cycle of breathing, is a vital process for all human life. As such, it happens automatically (though there are exceptions in some disease states) and does not need conscious control or effort. However, breathing can be consciously controlled or interrupted (within limits).
Breathing allows oxygen (which humans and a lot of other species need for survival) to enter the lungs, from where it can be absorbed into the bloodstream.
Other substances – accidental
Examples of accidental inhalation includes inhalation of water (eg. in drowning), smoke, food, vomitus and less common foreign substances[1] (eg. condoms,[2] tooth fragments, coins, batteries, small toy parts, needles).
Other substances – deliberate
Recreational use
Legal - helium, nitrous oxide ("laughing gas")
Illegal - various gaseous, vaporised or aerosolized recreational drugs
Medical use
Diagnostic
Various specialized investigations use the inhalation of known substances for diagnostic purposes. Examples include pulmonary function testing (eg. nitrogen washout test, diffusion capacity testing (carbon monoxide, helium, methane)) and diagnostic radiology (eg.radioactive xenon isotopes).
Therapeutic
Gases and other drugs used in anaesthesia include oxygen, nitrous oxide, helium, xenon, volatile anaesthetic agents. Medication for asthma, croup, cystic fibrosis and some other conditions.
Suicide
Carbon monoxide from vehicle exhaust emissions.
Mechanism of inhalation
Inhalation begins with the contraction of the muscles attached to the rib cage; this causes an expansion in the chest cavity. Then takes place the onset of contraction of the diaphragm, which results in expansion of the intrapleural space and an increase in negative pressure according to Boyle's Law. This negative pressure generates airflow because of the pressure difference between the atmosphere and alveolus. Air enters, inflating the lung through either the nose or the mouth into the pharynx (throat) and trachea before entering the alveoli.[citation needed]
Other muscles that can be involved in inhalation include:[3]
- External intercostal muscles
- Scalene muscles
- Sternocleidomastoid muscle
- Trapezius muscle
Hyperaeration
Hyperaeration or hyperinflation is where the lung volume is abnormally increased, with increased filling of the alveoli. This results in an increased radiolucency on X-ray, a reduction in lung markings and depression of the diaphragm. It may occur in partial obstruction of a large airway, as in e.g. congenital lobar emphysema, bronchial atresia and mucous plugs in asthma.[4]
It causes one form of overexpansion of the lung. Overexpansion, however, can also be caused by increase in lung mass itself.[citation needed]
See also
|
Look up inhalation or sniffing in Wiktionary, the free dictionary. |
- Exhalation
- Inhalant – psychoactive drugs consumed through inhalation
- List of terms of lung size and activity
- Respiratory system
- Smoking - a specific inhalation route
- Ventilation (physiology)
- Work of breathing
References
- ^ Passàli, D; Lauriello, M; Bellussi, L; Passali, GC; Passali, FM; Gregori, D (2010). "Foreign body inhalation in children: an update". Acta Otorhinolaryngol Ital. PMC 2881610. PMID 2881610.
- ^ Arya, CL; Gupta, R; Arora, VK (2004). "Accidental condom inhalation". Indian J Chest Dis Allied Sci. PMID 14870871.
- ^ Physiology: 4/4ch2/s4ch2_10 - Essentials of Human Physiology[dead link]
- ^ "Hyperinflation". Medcyclopaedia. GE. [dead link]
Routes of administration, Dosage forms
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Oral |
Digestive
tract (enteral)
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Solids
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- Pill
- Tablet
- Capsule
- Pastille
- Time release technology
- Osmotic delivery system (OROS)
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Liquids
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- Decoction
- Elixir
- Electuary
- Emulsion
- Extended-release syrup
- Effervescent powder or tablet
- Herbal tea
- Hydrogel
- Molecular encapsulation
- Powder
- Softgel
- Solution
- Suspension
- Syrup
- Syrup Concentrate for dilution and/or addition of carbonated water
- Tincture
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Buccal (sublabial), sublingual
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Solids
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- Orally disintegrating tablet (ODT)
- Film
- Lollipop
- Sublingual drops
- Lozenges
- Effervescent buccal tablet
- Chewing gum
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Liquids
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- Mouthwash
- Toothpaste
- Ointment
- Oral spray
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Respiratory
tract
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Solids
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- Smoking device
- Dry-powder inhaler (DPI)
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Liquids
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- Anaesthetic vaporizer
- Vaporizer
- Nebulizer
- Metered-dose inhaler (MDI)
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Gas
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- Oxygen mask and Nasal cannula
- Oxygen concentrator
- Anaesthetic machine
- Relative analgesia machine
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Ophthalmic,
otologic, nasal |
- Nasal spray
- Ear drops
- Eye drops
- Ointment
- Hydrogel
- Nanosphere suspension
- Insufflation
- Mucoadhesive microdisc (microsphere tablet)
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Urogenital |
- Ointment
- Pessary (vaginal suppository)
- Vaginal ring
- Vaginal douche
- Intrauterine device (IUD)
- Extra-amniotic infusion
- Intravesical infusion
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Rectal (enteral) |
- Ointment
- Suppository
- Enema
- Murphy drip
- Nutrient enema
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Dermal |
- Ointment
- Topical cream
- Topical gel
- Liniment
- Paste
- Film
- DMSO drug solution
- Electrophoretic dermal delivery system
- Hydrogel
- Liposomes
- Transfersome vesicles
- Cream
- Lotion
- Lip balm
- Medicated shampoo
- Dermal patch
- Transdermal patch
- Contact (rubbed into break in the skin)
- Transdermal spray
- Jet injector
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Injection,
infusion
(into tissue,
blood)
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Skin
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- Intradermal
- Subcutaneous
- Transdermal implant
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Organs
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- Intracavernous
- Intravitreal
- Intra-articular injection
- Transscleral
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Central nervous system
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- Intracerebral
- Intrathecal
- Epidural
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Circulatory, musculoskeletal
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- Intravenous
- Intracardiac
- Intramuscular
- Intraosseous
- Intraperitoneal
- Nanocell injection
- Patient-Controlled Analgesia pump
- PIC line
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Category Commons WikiProject
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Respiratory physiology
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Respiration |
- breath
- respiratory rate
- respirometer
- pulmonary surfactant
- compliance
- elastic recoil
- hysteresivity
- airway resistance
- bronchial
- hyperresponsiveness
- constriction
- dilatation
- mechanical ventilation
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Control |
- pons
- pneumotaxic center
- apneustic center
- medulla
- dorsal respiratory group
- ventral respiratory group
- chemoreceptors
- pulmonary stretch receptors
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Lung volumes |
- VC
- FRC
- Vt
- dead space
- CC
- PEF
- calculations
- respiratory minute volume
- FEV1/FVC ratio
- Lung function tests
- spirometry
- body plethysmography
- peak flow meter
- nitrogen washout
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Circulation |
- pulmonary circulation
- hypoxic pulmonary vasoconstriction
- pulmonary shunt
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Interactions |
- Perfusion (V)
- ventilation (Q)
- ventilation/perfusion scan
- zones of the lung
- gas exchange
- pulmonary gas pressures
- alveolar gas equation
- alveolar–arterial gradient
- hemoglobin
- oxygen–haemoglobin dissociation curve (Oxygen saturation
- 2,3-BPG
- Bohr effect
- Haldane effect)
- carbonic anhydrase (chloride shift)
- oxyhemoglobin
- respiratory quotient
- arterial blood gas
- diffusion capacity (DLCO)
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Insufficiency |
- high altitude
- oxygen toxicity
- hypoxia
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