1.330 Flashcards
Primary function of the respiratory system?
Absorption of O2 and excretion of CO2
Level of respiration/ breathing
⬤ Breathing ( Pulmonary Ventilation): The way oxygen enters the lungs from the surrondings
⬤ External respiration: Gas exchange between the gas of the atmosphere and the lungs
⬤ Internal respiration: Gas exchange between tissue cells and systemic capillary blood
⬤ Cellular respiration: It is a series of chemical reactions that use O2 to break down food (glucose) to produce ATP(generate energy)
Function of the upper respiratory tract?
7 points
➢Conduction( Passageway for gas)
➢ Filtration
➢ Humidification
➢ Heater (warming of inhaled air)
➢Sense of small and taste (olfactory receptors)
➢Serves as a resonating chamber for speech
➢Protection of the lower airway
Definition of the URT?
What it’s composed of?
Defined as airways starting at the nose, extend to trachea
Composed of
➢Nasal cavities and sinuses
➢Oral cavity
➢ Pharynx
➢Larynx
Nasal cavity anatomical structure and their function?
5 points
⬤ External nares give entrance into cavities
⬤ Vestibules contain gross hairs working as filter (nasal cavity./septum)
⬤ Concha or turbinates: three shelflike bones projecting from lateral walls
Function: Increase surface area for filtering, warming, and humidifying inhaled gases
⬤ Contain olfactory cells providing sense of smell
⬤ Surface fluid is provided by goblet cells and submucosal glands in cavity and sinuses
Symptoms of diseases of the nose and paranasal sinuses?
8 points
❖ Nasal obstruction
❖Nasal discharge
❖Epistaxis
❖Hyposmia and anosmia
❖Headache
❖Snoring
❖Nasal septal deviation
❖Nasal polyps
What are sinuses, their sets, and function?
Def: Hollow spaces in the facial bones
Four sets of sinuses: Frontal, ethmoid, sphenoid, maxillary
Function of sinuses:
- Reduce weight of head
- Strengthen skull
- Modify voice during phonation
What is the oral cavity?
what is it composed of?
what does the posterior portion of the tongue has?
➢Forms common passage for air, food, and Fluids
➢Tip of soft palate, uvula, marks posterior aspect of cavity
➢Posterior portion of tongue has nerve endings triggering gag reflex to protect airway
Mallampati Score for intubation?
It measures how hard the intubation is from 1 to 4
Oral & nasal cavities open into the?
pharynx
The pharynx is composed of?
-Nasopharynx (from nasal cavity to uvula)
-Oropharynx (from uvula to tip of epiglottis)
Palatine tonsils (removed in tonsillectomy)
-Laryngopharynx (tip epiglottis to larynx)
Anatomic location where respiratory & digestive tracts divide
How many cartilages does the larynx has?
And their position
⬤ Contains nine cartilages
⮚ Thyroid (Adam’s apple)
⮚ Cricoid falls just below thyroid cartilage
⮚ Epiglottis attaches to thyroid cartilage
⮚ Three paired cartilages involved in phonation: Arytenoid, corniculate, cuneiform
What does the epiglottis do?
3 points
❖Closes laryngeal opening during swallowing, to create tight seal to prevent liquids and food from entering respiratory tract
❖Swallowing:
⮞ Muscular contractions resulting in early vocal cord closure and downward epiglottis movement
❖Folds connecting epiglottis and tongue form space called vallecula
⮞ Key landmark for oral intubation
Relative positions of oral cavity, pharynx, & larynx are major determinant of ………, particularly in ………….. patient
Relative positions of oral cavity, pharynx, & larynx are major determinant of patency, particularly in unconscious patient
How to keep patient upper airways open?
Head tilts forward, partial or total occlusion can occur
Extend head into “sniff position” to open airway & facilitate artificial airway insertion
(Correct is extended, flexed is the incorrect way)
What is the LRT?
What is it made of?
Everything distal to larynx
Made up of:
-Conducting airways⎯first 15 generations
-Purpose: convey gas from URT to area of gas exchange (lung parenchyma)
-Respiratory airways
-Microscopic airways distal to conducting zone
-Participate in gas exchange with blood
Trachea extension, supported by, and the muscles
Trachea: extends below cricoid cartilage to sternal angle
Anterior & sides supported by 16 to 20 C-shaped cartilage
Trachealis muscle connects tips of C-shaped cartilage & forms posterior wall
Bronchi is bifurcated into…….. at ………?
The degree of each one?
Right & left mainstem bronchi bifurcate at carina
Right bronchus branches at 20- 30-degree angle
Due to angle, most foreign aspirate goes to right lower lobe
Left bronchus branches at 45- 55-degree angle
Lobar and Segmental Pulmonary Anatomy of each lung
Each lung is divided into lobes and segments
Right lung has 3 lobes and 10 segments
Left lung has 2 lobes and 8 or 10 segments
Each segment of the lungs is supplied by?
These further divide numerous times until conducting airways end in ……………
Each segment is supplied by segmental bronchus.
These further divide numerous times until conducting airways end in terminal bronchioles
All airway up to to terminal bronchioles constitute ………… and it is ………………………….. with the law of?
Dead space
~2 ml/kg of lean body weight, typically 150 ml
Deadspace to Tidal Volume Ratio (VD/VT)**
(VD/VT) = (PaCO2 –PECO2) / PaCO2
The wall of the conducting airways (trachea to bronchioles) made of 3 layers
Inner layer ( a mucous membrane) called a mucosa
- Composed of epithelia
- Pseudostratified, ciliated, columnar epithelia⎯most numerous cell type
Submucosa⎯composed of connective tissue, bronchial glands & smooth fibers wrap around airway
Adventitia⎯outer covering of connective tissue, cartilaginous rings
The conducting airways has basal cells that?
3 points
Contribute to appearance of pseudostratified cellular layer
Mature into pseudostratified cells
Thought to play role in repair of mucous membrane following diseases
The conducting airways has Neuroendocrine cells that?
5 points
Connected to vagus nerve
Are thought to function during lung development
Hypoxia & stress-strain sensors
Secrete bioactive chemicals (e.g., serotonin, calcitonin, & gastrin releasing peptide)
Mixed with lymphocytes & thought to be migratory in nature
Respiratory bronchioles arise from terminal bronchioles & have 2 functions
- Conduct gas deeper into respiratory zone
- Participate in gas exchange: Bronchiole walls sprout alveoli
All structures distal to one terminal bronchiole form primary lobule or acinus, each composed of:
➢ Respiratory bronchioles, alveolar ducts, alveolar sacs, & about 10,000 alveoli
Alveoli are ? 4 points
saclike growths that sprout on walls of respiratory bronchioles, alveolar ducts, & alveolar sacs
Primary function is gas exchange
Around 270 – 790 million of alveoli in adults, (increase with individual’s heights),
The diameter of the alveoli in the apical regions are greater then in the basal regions of the lungs! Q
Alveoli types 1 cells and macrophages?
Type I pneumocytes: very flat & cover about 93% of alveolar surface
Very thin facilitating gas exchange
Form very tight joints, which limits movement of materials into alveolar space
Alveolar macrophages provide defense
Alveoli types 2 cells?
Type II pneumocytes are cuboidal
Twice as many as type I cells
Manufacture & storage of surfactant
-It is a mixture of several phospholipids, proteins, and ions.
-Reduces surface tension & alveolar tendency to collapse
-Increases compliance & decreases work of breathing
-In humans, surfactant appears at about week 28 (a full-term pregnancy is 40 weeks).
-Deficiency of surfactant → Respiratory Distress Syndrome (RDS).
Have “Stem” cell like action
-Can differentiate into type I cells, so as to repopulate & repair damaged alveolar surface
Blood-gas barrier
O2 & CO2 diffuse from alveoli through: 7 points
A/C membrane provides area for gas exchange (typically about 140 m^2 and 1 µm thick)
O2 & CO2 diffuse from alveoli through:
- Surfactant layer
- Type I cell
- Basement membrane
- Interstitial space containing basement membrane, elastin & collagen fibers, & capillaries
- Capillary endothelial cells
- Plasma
- Finally, into erythrocytes (RBCs)
