RESPIRATORY pp Flashcards
Respiratory track parts
Nose Pharynx = Naso P. / Oro P. / Laryngo P. Larynx = voice-box Trachea = windpipe Bronchi = airways Lungs Alveoli - site of gas exchange Locations of infections upper respiratory tract is above vocal cords lower respiratory tract is below vocal cords
Nasal structure external
Skin, nasal bones, & cartilage lined with mucous membrane
Openings called external nares or nostrils
Nasal structure internal
Large chamber within the skull
Roof is made up of ethmoid and floor is hard palate / Maxilla
Internal nares (choanae) are openings to pharynx
Nasal septum is composed of bone & cartilage
Conchae on lateral walls turbinate, moisten & warm air
Pharynx
Muscular tube (5 inch long) hanging from skull skeletal muscle & mucous membrane Extends from internal nares to cricoid cartilage passageway for food and air resonating chamber for speech production tonsil (lymphatic tissue) in the walls protects entry-way into body
anatomical regions
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
From choanae to soft palate openings of auditory (Eustachian) tubes from middle ear cavity adenoids or pharyngeal tonsil in roof
Passageway for air only
Oropharynx
From soft palate to epiglottis
fauces is opening from mouth into oropharynx
palatine tonsils found in side walls, lingual tonsil in tongue
Common passageway for food & air
Laryngopharynx
Extends from epiglottis to cricoid cartilage / post. to larynx
Epiglottis folds down to cover opening to trachea when swallowing
Common passageway for food & air & ends as esophagus inferiorly
Larynx
Cartilage & connective tissue tube
Anterior to C4 to C6
Constructed of 3 single & 3 paired cartilages
cartilages of larynx
Thyroid cartilage forms “Adam’s Apple”
Epiglottis—leaf-shaped piece of elastic cartilage during swallowing, larynx moves upward
epiglottis folds down to cover glottis when swallowing to divert food into esophagus and keep food out of trachea (wind pipe)
vocal cords
False vocal cords (ventricular folds) found above vocal folds (true vocal cords)
True vocal cords attach to arytenoid cartilages
airway epithelium
Ciliated pseudostratified columnar epithelium with goblet cells produce a moving mass of mucus / smoking destroys cilia
trachea
Size is 5 in. long & 1in. diameter
Extends from larynx to T5 anterior to the esophagus and then splits into bronchi at Carina
Layers:
mucosa = pseudostratified columnar with cilia & goblet
submucosa = loose connective tissue & seromucous glands
hyaline cartilage of 16 to 20 incomplete “C” rings
open side facing esophagus to accommodate swallowing
opening of “C” ring to the posterior
tracheostomy vs intubation
Re-establishing airflow past an airway obstruction
- crushing injury to larynx or chest
- swelling that closes airway
- vomit or foreign object
Tracheostomy is incision in trachea below cricoid cartilage of the larynx if larynx is obstructed
Intubation is passing a tube from mouth or nose through larynx and into the trachea
bronchi and bronchioles
Primary bronchi supply each lung / branch forming secondary br.
Secondary bronchi supply each lobe of the lungs (3 right + 2 left)
Tertiary bronchi supply each bronchopulmonary segment
Repeated branchings called bronchioles form a bronchial tree
Histology of Bronchial Tree
Epithelium changes from pseudostratified ciliated columnar to nonciliated simple cuboidal as pass deeper into lungs / smoking destroys cilia
Incomplete rings of cartilage replaced by rings of smooth muscle & then connective tissue
Sympathetic NS & adrenal gland release epinephrine that relaxes smooth muscle & dilates airways
asthma attack or allergic reactions constrict distal bronchiole smooth muscle
nebulization therapy = inhale mist with chemicals that relax muscle & reduce thickness of mucus
Lobue of lung structure
A lobule is formed by a compartment wrapped by elastic connective tissue
Terminal bronchiole branches to a Respiratory Bronchiole
Arteriole, venule & lymphatic vessel wrap around a Respiratory Bronchiole
Arterioles form alveolar capillaries and surround alveolar sacs / alveoli
Alveolar cell types
Type I alveolar cells
simple squamous cells where gas exchange occurs
Type II alveolar cells (septal cells)
secretes alveolar fluid containing surfactant
surfactant reduces the surface tension of the alveoli allowing them to open and receive air for gas exchange
reduced production of surfactant in premature baby causes Respiratory Distress Syndrome
Alveolar macrophages - lie Outside in air space
alveolar-capillary membrane
Respiratory membrane = 1/2 micron thick
Exchange of gas from alveoli to blood and from blood to alveoli
Membranes for gases to diffuse across type I & type II alveolar epithelial cells endothelial cells forming capillary wall the membrane of the RBC / oxygen inside RBC
Vast surface area provided by branching of alveolar capillaries = handball court
pleural membrane and cavity
Visceral pleura covers lungs — parietal pleura lines ribcage & covers upper surface of diaphragm
Pleural cavity is potential space between ribs & lungs
quiet inspiration
Diaphragm moves 1 cm & ribs lifted by muscles
Diaphragm innervated by Phrenic Nerve
Intrathoracic pressure falls and 2-3 liters inhaled
quiet expiration
Passive process with no muscle action
Elastic recoil of abdominal organs & lungs compresses the size of the lungs increasing the pressure by making volume smaller
Alveolar pressure increases & air is “pushed” out
Labored Breathing
Forced expiration abdominal m. force diaphragm up internal intercostals depress ribs lung volume is decreased emphysema “builds “up m.
Forced inspiration
sternocleidomastoid, scalenes & pectoralis minor lift chest upwards as you gasp for air
alveolar pressure changes
When alveolar pressure decreases air “rushes in
When alveolar pressure increases air “rushes out
pneumothorax
The pleural cavities are sealed cavities not open to the outside / lined with serous membrane
Injuries to the chest wall may let air enter the intrapleural space
collapsed lung on same side as injury
surface tension and recoil of elastic fibers within lung causes the lung to collapse / “pull” away from thoracic wall
the lung cannot inflate if it is not adhered to the thoracic cavity
pressure equalization causes a pneumothorax
compliance of lungs
Ease with which lungs & chest wall expand and recoil depends upon the elasticity of lungs & surface tension
airway resistance
Resistance to airflow depends upon airway Size
increase size of chest
airways Increase in diameter / Pressure decreases
contract or relax smooth muscles in airways (particularly the bronchioles)
asthma causes smooth muscle to contract
adrenalin / epinephrine like medicine opens airway by dilating bronchiole
lung volumes and capacities ADULT
Tidal volume = amount air moved during 1 breath ~ 500 cc
MVR= minute ventilation is amount of air moved in a minute
Reserve volumes —- amount you can breathe either in or out above that amount of tidal volume
Residual volume = 1200 mL permanently trapped air in system
Vital capacity & total lung capacity are sums of the other volumes
Hyperbaric Oxygenation
Use of pressure to dissolve more O2 into the blood
treatment for patients with anaerobic bacterial infections (tetanus and gangrene)
anaerobic bacteria die in the presence of O2
Hyperbaric chamber pressure raised to 3 to 4 atmospheres so that tissues absorb more O2
Used to treat heart disorders, carbon monoxide poisoning, cerebral edema, bone infections, gas embolisms & crush injuries
external respiration
Exchange of gas(O2&CO2) between Air & Blood
Gases diffuse from areas of high partial pressure to areas of lower partial pressure
Deoxygenated blood becomes saturated
Compare gas movements in pulmonary capillaries to tissue capillaries
internal respiration
Exchange of gases between blood & tissues
Conversion of oxygenated blood into deoxygenated blood
Note: diffusion of O2 inward
at rest 25% of available O2 enters cells
during exercise more O2 is absorbed
Note: diffusion of CO2 outward
gas transport
Oxyhemoglobin contains 98.5% chemically combined oxygen and hemoglobin inside red blood cells
Hgb + O2 = oxyhemoglobin is “bright red”
Deoxyhemoglobin is “blue”
only 1.5% of oxygen transported dissolved in blood
There are several factors affecting dissociation of O2 from hemoglobin / pH, CO2 levels, temperature
Remember - the Hbg has a lot of O2 to dissociate from and it must dissociate at the right time and place in body
carbon dioxide transport
- Is carried by the blood in 3 ways 1. 7% dissolved in plasma
- 23% combined with the Globin part of Hb molecule forming Carbamino-hemoglobin
- 70% as part of a Bicarbonate Ion
CO2 + H2O combine to form carbonic acid that dissociates into H+ and bicarbonate ion
CO2 + H2O H2CO3 H + HCO3(bicarbonate)
bicarbonate dissociates to CO2 in lungs
Acidity & Oxygen Affinity for Hb
As acidity increases, O2 affinity for Hb decreases
H+ binds to hemoglobin & alters it / O2 “falls” off Hb
O2 left behind in needy tissues
CO2 and acidosis
increaseCO2 = increaseacidosis
CO2 + H2O = H2CO3 = H + HCO3
carbonic bicarbonate
acid ion
HgbO2 + H causes O2 to be more “easily released” from the Hgb and the Hgb now binds to the H acting as a buffer forming HgbH
Buffers are compounds that combine to H ions
pCO2 & Oxygen Release
As pCO2 rises with exercise, O2 is released more easily
CO2 converts to carbonic acid & becomes H+ and bicarbonate ions & lowers pH.
Temperature & Oxygen Release
As temperature increases, more O2 is released
Metabolic activity & heat increases the release of O2 from the Hgb
hypoxia types
Hypoxia - A deficiency of Oxygen at the tissue level
4 Types
1. Hypoxic hypoxia - low oxygen in the blood from high altitude / airway obstruction / fluid in lungs
- Anemic hypoxia - reduced hemoglobin in blood from blood loss / anemia / Hgb combined to CO
- Ischemic hypoxia - blood flow to tissue is reduced from infart or cut vessel to organ
- Histotoxic hypoxia - blood delivers adequate oxygen but cells can not use it as from cyanide poisioning
CNS respiratory center
Involuntary respiration controlled by neurons in Pons and Medulla of the Brain Stem
regulation of respiratory center
Influences from Cortex of Cerebrum
voluntarily alter breathing patterns
limitations are buildup of CO2 & H+ in blood this will stimulate the respiratory center in the pons and medulla of the brain stem
fever and pain increase respiratory rate
if you hold your breath until you faint—-breathing will resume
chemical regulation of respiration
Central chemoreceptors in medulla
respond to changes in H ions(acid) or pCO2
hypercapnia = slight increase in pCO2 is noticed
Peripheral chemoreceptors
respond to changes in H ions(acid) , pO2 or PCO2
aortic body—in wall of aorta
nerves join vagus nerve
carotid bodies–in walls of common carotid arteries
nerves join glossopharyngeal nerve
