Respiratory System (LAB PRACTICAL) Flashcards
Upper division of respiratory system
Structures found in head and neck:
-External nose
-Nasal cavity
-Paranasal sinuses
-Pharynx
Lower division of respiratory system
Larynx and structures below:
-Larynx
-Trachea
-Bronchi
-Lungs
Functions of nasal cavity
-Filters, warms, and moistens air
-Resonates chamber for the voice
-Smell
Included structures of the nasal cavity
-External nares (nostrils)
-Inferior, middle, and superior conchae
-Sinuses
Pharynx function
Connects nasal and oral cavities to larynx and esphagus
Regions of the pharynx
-Nasopharynx: Superior and only involved in respiration
-Oropharynx: Middle portion from soft palate to epiglottis. Both respiratory & digestive function
-Laryngopharynx: Most inferior region from epiglottis to larynx. Both respiratory & digestive function
Larynx function
-Prevents food/fluid from entering lungs
-Permits the passage of air and produces sound
-Composed of cartilaginous and membranous structures
Thyroid cartilage
-Hyaline
-Forms framework of larynx
-Contains laryngeal prominence/adams apple
Cricoid cartilage
-Hyaline
-Attaches larynx to trachea
Arytenoid cartilage
-Hyaline
-Anchors the vocal folds
Epiglottis
-Elastic cartilage
-Closes opening of the trachea when swallowing.
Vocal folds
-True vocal cords
-Vibrate with expired air to produce sounds
-Composed of elastic fibers covered with mucous membrane
Glottis
Slit-like passageway between the folds
Vestibular folds
-False vocal cords
-Protects vocal folds
-Located superior to vocal folds
-Composed of elastic fibers covered with mucous membrane
Trachea function & composition
-Connection of larynx to bronchi
-Lined with pseudostratified ciliated columnar epithelium
-Goblet cells produce mucus
-Cilia move mucus away from lungs and to the throat
Bronchi
-Series of branching respiratory tubes
-Trachea divides into left and right primary bronchus
-Each bronchus divides to secondary, tertiary, etc…
-Terminal bronchioles divide into respiratory bronchioles
-Respiratory bronchioles divide into alveola ducts, terminating in alveolar sacs
C-Rings
-Reinforcement rings of hyaline cartilage for the trachea
-Allows expansion during swallowing
-Provide structure to maintain an open airway
Alveolar ducts
Divide from respiratory bronchioles
Alveolar sacs
Clusters of alveoli
Alveoli
-Balloon-like pockets at the end of alveolar ducts
-Sites of gas exchange, which occurs by simple diffusion
-Densely covered with pulmonary capillaries
-Composed of a single layer of simple squamous epithelium overlying a basal lamina
Blood air barrier/Respiratory membrane
-Alveolar and capillary walls with their fused basement membranes
Lung lobes
-Long fissures that divide lungs
-Left lung: 2 lobes
-Right lung: 3 lobes
Lungs
-Soft spongy organ
-Some elastic CT allowing for expansion and contraction
Cardiac notch
Concavity of left lung to provide space for the heart
Expiration
-Air moves out of the lungs
-Inspiratory muscles relax
-Thoracic cavity decreases in size
-Intrapulmonary volume decreases
-Intrapulmonary pressure increases
-Air flows to area of lowest pressure (Out of lungs)
Lung pleura
-Double layed serous membranes surrounding each lung
-Parietal pleura: Outer layer attaches to thoracic wall or diaphragm
-Visceral pleura: inner layer, covering the external surface of lungs
Tidal volume (TV)
Amount of air inhaled or exhaled with each breath under resting conditions
Inspiration
-Air moves into the lungs
-Inspiratory muscles contract
-Intrapulmonary volume increases
-Intrapulmonary pressure decreases
-Air flows to area of lowest pressure
Inspiratory reserve volume (IRV)
Amount of air that can be forcefully inhaled after a normal tidal volume inspiration
Residual volume (RV)
Amount of air remaining in the lungs after forced expiration
Expiratory reserve volume (ERV)
Amount of air that can be forcefully exhaled after a normal tidal volume expiration
Vital Capacity (VC)
-Maximum amount of air that can be expired after a maximum inspiratory effort
-VC=TV+IRV+ERV
Total lung capacity (TLC)
-Maximum amount of air contained in lungs after a maximum inspiratory effort
-TLC = TV+IRV+ERV+RV
Inspiratory capacity (IC)
-Maximum amount of air that can be inspired after a normal tidal volume expiration
-IC = TV +IRV
Functional residual capacity
-Volume of air remaining in the lungs after a normal tidal volume expiration
-FRC = ERV + RV
How to use a spirometer
-Breath in outside of spirometer
-Exhale into the mouthpiece of the spirometer
-Spirometer records the volume of air expired
Bronchial sounds
Produced by air rushing through the large respiratory passageways (Trachea & Bronchi)
Vesicular breathing sounds
-Result from air filing the alveolar sacs
-Sounds like rustling leaves
Rasping sound with stethoscope
Rales
Whistling sound with stethescope
Wheezing
Obstructive respiratory diseases
-Increased resistance in the airways
-Normal vital capacity but decreased rate of air flow due to bronchocontriction
-Ex. Asthma & Chronic bronchitis
Restrictive respiratory diseases
-Decline in lung capacity
-Decreased vital capacity
-Ex. Polio & Tuberculosis
Forced vital capacity
-Volume of air expelled when subject takes deepest possible breath and then exhales forcefully and rapidly
-Reduced in restrictive pulmonary disease
Forced expiratory volume
-Similar testing procedure to FCV
-Looks at percentage of the vital capacity that is exhaled during specific time intervals
-Healthy individuals can expire 75-85% of FVC in the first second
-Will be reduced in obstructive pulmonary disease`
Rate of respiration control
-Neural centers in the medulla and the pons control rhythm & rate
Normal rate of respiration
-12-18 breathes/minute
-Modified by physical phenomena
-Influenced by chemical factors such as O2/CO2 conc. in blood & pH
Arterial blood pH
7.4 ±0.02
Carbonic acid/Bicarbonate buffer system
- CO2 diffuses into blood from tissues
- In RBC’s CO2 combines with H2O to form H2CO3/Carbonic acid (Facilitated by carbonic anhydrase)
- H2CO3 breakds down into HCO3/Bicarbonate & H+
- H+ are neutralized by attaching to hemoglobin
- HCO3 moves into plasma (Down its gradient)
Chloride shift
To balance negative charge of HCO3 leaving the erythrocytes CL- is drawn from plasma into erythrocytes
Buffer system if pH decrease/Increase in H+
-H+ combines with HCO3 to form H2CO3
-Removes free H+ to buffer decreases in pH
Buffer system if pH increases/Decrease in H+
H2CO3 dissociates into H+ and HCO3- releasing H+ ionto the blood to buffer against an increasing pH
Hyperventilation impact
-Decreased carbonic acid production in RBC’s
-Less H+ produced by dissociation
-Respiratory alkalosis (Higher than normal pH)
Hypoventilation
-Co2 not properly removed from body
-Increased carbonic acid production
-More H+ produced by dissociation
-Results in respiratory acidosis (Lower pH than normal)
What can impact respiration rate
-Physical phenomena: Talking, yawning, coughing, exercise
-Chemical factors: O2/CO2 concentrations and pH fluctuations
