Respiratory System Flashcards
What are the two components of the respiratory system? (structurally)
Upper, lower
What parts does the upper respiratory system consist of? (4)
Nasal cavity, oral cavity, pharynx, larynx (voice box)
What parts does the lower respiratory system? (4)
Trachea, bronchi, bronchioles, alveoli
What are the two zones of the respiratory system? (functionally)
- Conducting zone: nose to bronchioles
- Respiratory zone: alveolar duct to alveoli (gas exchange)
What are the external structures of the nose? (4)
- Root (attachment to frontal bone)
- Apex (tip)
- Bridge (shaft)
- Nostrils (openings)
What are the main regions of the nasal cavity? (3)
- Vestibular (defense)
- Olfactory (smell)
- Respiratory (humidifier)
What is the nasal septum?
Divides nasal cavity into LT and RT sides
What is the vestibular region (vestibule) of the nasal cavity?
Region inside nostrils that contains hair w/ sebum to keep hair soft and trap particles
What is the olfactory region of the nasal cavity?
On the roof of the cavity to sample air
What is the respiratory region of the nasal cavity?
- Lined with mucosa that humidifies air
- Has 3 turbinates (superior, middle, inferior conchae)
What are the para-nasal sinuses? (4)
- Air-filled cavities connecting nasal cavity via small passageways
- Frontal, maxillary, sphenoidal, ethmoidal
What is the purpose of the nasal sinuses? (3)
- Helps to prolong/intensify sound produced w/ voice
- Lightens weight of head
- Warms and moisturizes air
Are we born with sinuses?
No, they develop as we do (which is why our facial features change)
What is the pharynx (throat)?
Hollow muscular structure starting behind the nasal cavity lined with epithelial muscle
What are the three sections of the pharynx?
Nasopharynx, oropharynx, laryngopharynx
What is the nasopharynx? (3)
- Upper most section of the the pharynx
- Contains the adenoids
- Passageway into the middle ear (eustachian/auditory tubes)
What is the oropharynx? (3)
- Center section of the pharynx
- Air, food, and fluid pass
- Has the palatine tonsils (back) and lingual (under tongue)
What is the laryngopharynx? (3)
- Lowermost section of the pharynx
- Connects to larynx where air enters trachea
- Connects to esophagus where food passes to the stomach
What are the larynx cartilages? (6)
- Thyroid
- Epiglottis
- Cricoid
- Arytenoid (pair)
- Corniculate
- Cuneiform cartilages
What is the largest cartilage in the larynx?
Thyroid (adam’s apple)
What is the purpose of the epiglottis?
Prevents food from entering larynx
What is the purpose of the cricoid cartilage in the larynx?
Connects larynx and trachea
The vocal cords divide…?
The upper from the lower respiratory tract
What are the true vocal cords?
Lower folds that produce sound
What is the purpose of the vocal folds?
- Produces high pitches when pulled and low pitches when relaxed (girl… if you don’t know this by now…)
- Sounds change with movements of pharynx, oral cavity, tongue, and lips
What is laryngitis?
Inflammation of the larynx usually caused by respiratory infections/irritants
What type of population can you find cancer of the larynx?
Almost exclusive to smokers
What is allergic rhinitis?
- Allergens trigger nasal mucosa to secrete excessive mucous
- Treat with anti-histamine medication and allergy injections
What are nasal polyps?
- Non-cancerous growths in nasal cavity
- May be related to chronic inflammation
- Can be surgically removed if large enough
What is the common cold?
- Also known as coryza
- Acute inflammation of upper respiratory mucous membranes
- Prevent with handwashing
What is sinusitis?
- Infection/inflammation of sinuses
- Pressure, pain, headaches
What is tonsillitis?
Inflammation, swelling, and pain in tonsils
What is pharyngitis?
Sore throat
What is laryngitis?
- Inflammation of voice box usually due to excessive voice use
- Hoarseness
What is epistaxis?
Nosebleed
- Causes can be unknown, nose picking, dry air, trauma, or foreign body
The trachea (windpipe) is anterior to the…?
Esophagus
The trachea extends from the […] to the primary […]
Larynx, bronchi
What is the trachea composed of and lined with? (3)
- Smooth muscle, C-shaped rings of cartilage
- Linked with pseudostratified ciliated columnar epithelium
What is the purpose of the cartilage rings in the trachea?
Keeps airway open
What is the purpose of the cilia in the trachea?
Sweeps debris away from lungs and back to the throat to be swallowed
What is the site of bifurcation in the trachea?
Carina
The trachea branches into a RT primary bronchus at…?
Superior border of the 5th thoracic vertebra
The primary bronchi convert to…? (4)
- Lobar (secondary) bronchi
- Segmental (tertiary) bronchi
- Bronchioles
- Terminal bronchioles
The mucus membrane changes: (2)
Bronchi, terminal bronchioles
Describe bronchi
Ciliated pseudostratified epithelium with many goblet cells
Describe terminal bronchioles
- Nonciliated simple cuboidal epithelium
- No goblet cells, cartilage, cilia, or submucosal glands
The c-rings of the trachea are replaced by […] and eventually […] disappears completely in the […] bronchioles (3)
- Plates of cartilage (in the bronchi)
- Cartilage
- Distal
As the amount of cartilage decreases, the amount of smooth muscle…
Increases
What are the lungs enclosed and protected by?
Pleural membrane
What is in the outer layer of the pleural membrane?
Parietal pleura attached to wall of thoracic cavity
What is in the inner layer of the pleural membrane?
Visceral layer covering lungs
What the small potential space between the pleurae?
Pleural cavity containing serous lubricating fluid secreted by membranes
Where do the lungs extend from and lie against? (2)
- Extends from the diaphragm to slightly superior to clavicles
- Lies against ribs anteriorly and posteriorly
What happens in injuries to the chest wall?
Allows air to enter intrapleural space (pleural cavity fills up)
How many lobes and fissures are in the RT lung?
3 lobes separated by 2 fissures
How many lobes and fissures are in the LT lung?
2 lobes separated by 1 fissure and depression
What is the depression on the LT lung?
Cardiac notch
What bronchi supplies segments of lung tissue called bronchopulmonary segments?
Tertiary (segmental)
The bronchopulmonary segments consists of lobules containing? (8)
Lymphatics, arterioles, venules, terminal/respiratory bronchioles, alveolar ducts/sacs, alveoli
What is the hilum?
Root of lungs that connects them to supporting structures and the opening for pulmonary vessels
Where does actual gas exchange take place?
The alveoli
Terminal bronchioles become… (2)
- Alveolar ducts
- Then alveolar sacs (alveoli)
Alveolar have a single layer of…
Simple squamous epithelium
The respiratory membrane separates…
The air in the alveoli from the blood in surrounding capillaries
What does the alveolar wall consist of?
Pneumocyte type I/II/III cells
Pneumocyte type I cells
- Squamous pulmonary epithelial
- Allows easy gas molecule movement
Pneumocyte type II cells
- Septal
- Secretes alveolar fluid (surfactant) which lowers surface tension of fluid
- Prevents collapse of alveoli w/ each expiration
Pneumocyte type III
- Dust cells
- Alveolar macrophages ingest foreign particles
What are the layers of the alveolus? (4)
- Surfactant layer
- Tissue layer (alveolar epithelium)
- Interstitial space
- Endothelial layer
What is the first layer of the alveolus?
- Surfactant layer (liquid) lines alveoli
- Lowers surface tension in alveoli that would collapse
What is the second layer of the alveolus?
- Tissue layer
- Has all 3 cells (pneumocytes I/II/III)
What is the third layer of the alveolus?
- Interstitial
- Component of alveolar-capillary membrane
What is the fourth layer of the alveolus?
- Endothelial layer
- Capillary endothelial cells
What is pulmonary ventilation?
- Process of air flowing into lungs during inspiration/inhalation and out of lungs during expiration/exhalation
- Breathing
What three processes combine for respiration to occur?
- External/pulmonary respiration
- Internal/systemic respiration
- Cellular/mitochondrial respiration
70% of CO2 in the blood is transported as?
Bicarbonate ions (HCO3)
23% of CO2 in the blood is carried by hemoglobin inside RBCs as…
Carbaminohemoglobin
Most of the oxygen in the blood is carried by…
- Hemoglobin
- Some get dissolved in the plasma
What is pulmonary perfusion?
Amount of blood reaching lungs (alveoli via capillaries)
What is the V/Q ratio used for?
Ventilation/perfusion ratio to assess efficiency/adequacy of lungs
Why does air flow between the atmosphere and gases inside lungs?
Pressure differences
What is dead space in the lung?
Unfunctional area that does not participate in ventilation
At rest, when the diaphragm is relaxed, the alveolar pressure is […] the atmospheric pressure.
Equal to (no air flow)
When inhaling, what happens to the alveolar and intrapleural pressure?
- Alveolar pressure drops below atmospheric pressure (chest cavity expands)
- Intrapleural pressure goes down
When exhaling, what happens to the alveolar and intrapleural pressures?
- Alveolar pressure rises above atmospheric pressure
- Intrapleural pressure rises
Does atmospheric pressure change during pulmonary ventilation?
No, it stays at 760 mmHg
What is tidal volume? (TV)
The amount of air inhaled during a normal breath
What is inspiratory reserve volume? (IRV)
Maximal amount of air that can be inhaled above tidal volume (TV)
What is expiratory reserve volume? (ERV)
Maximal volume of air that can be exhaled from end-expiratory position
What is residual volume?
Amount of air left in lung at all times
What is inspiratory capacity? (IC)
Sum of IRV (inspiratory reserve volume) + TV (tidal volume)
What is expiratory capacity?
Sum of ERV (expiratory reserve volume) + TV (tidal volume)
What is vital capacity? (VC)
Volume of air breathed out after deepest inhalation
What is total lung capacity? (TLC)
- Volume in lungs at maximal inflation
- Sum of VC (vital capacity) + RV (residual volume)
What is surface tension in pulmonary ventilation?
- Inwardly directed force in alveoli which must be overcome to expand lungs during each inspiration
What affects surface tension in pulmonary ventilation?
Levels of surfactant
What is elastic recoil in pulmonary ventilation?
Relaxation of inspiratory muscles allowing increased alveolar elastic recoil to decrease volume of alveoli leading to alveolar pressure > atmospheric pressure
What is compliance in pulmonary ventilation?
How easy it is for lungs and thoracic wall can be expanded
What is resistance in pulmonary ventilation?
- Walls of respiratory passageways (bronchi, bronchioles, etc) offer resistance to air flow into lungs
- More pressure with obstructions
What is coughing?
- Long-drawn and deep inhalation followed by closure of rima glottidis
- Rima glottidis gets forced open when air gets suddenly exhaled
- Caused by foreign body in larynx/trachea/epiglottis
What is sneezing?
- Spasmodic contraction of muscles that forcefullt expels air through nose/mouth
- May be caused by irritations in nasal mucosa
What is sighing?
Long-drawn/deep inhalation followed by shorter/forceful exhalation
What is yawning?
Deep inhalation through widely open mouth
(can be stimulated by drowsiness or someone’s yawning)
What is sobbing?
Convulsive inhalations followed by single prolonged exhalation
(glottis closes faster after each inhale so little air enters lungs)
What is crying?
Inhalation followed by short convulsive exhalations
(glottis remains open and vocal folds vibrates)
What is laughing?
Sam basic movements as crying but facial expressions differ
What is hiccuping?
Spasmodic contraction of the diaphragm followed by closure of the glottis (makes a sound)
Caused by irritation of sensory nerve endings of digestive canal
What is valsalva maneuver?
Forced exhalation against closed glottis (like when straining or… defecating)
What is the affinity of hemoglobin affected by? (4)
- Temperature
- Hydrogen ions (pH)
- Intraerthocytic 2,3-DPG (salt that dissociated Hb from O2)
- Hype of Hb (fetal hemoglobin has higher O2 binding affinity than maternal hemoglobin)
Where are the respiratory control centers in the brain stem?
- Pons respiratory center
- Medullary respiratory center
What controls voluntary respiration?
Motor cortex in cerebral cortex (can be overriden by involuntary– chemoreceptor stimulus, hypothalamus stress response)
Need conscious control to avoid inhaling noxious gases or water
Centers of this work together to control breath rate
Pons
What sends signals to the muscles that intiate inspiration/expiration and controls non-respiratory air movement reflexes?
Medulla
What is the purpose of the ventral respiratory group?
Controls voluntary forced exhalation and increases force of inspiration
What is the purpose of the dorsal respiratory group?
Controls inspiratory movement and timing
What detects levels of O2 and CO2?
Central (medulla) and peripheral (systemic arteries) chemoreceptors
- Aortic bodies in aortic arch branches detect CO2 levels
- Carotid bodies sense CO2 levels
What is the purpose of proprioceptors of joints and muscles?
Activates dorsal respirtoary group to increase ventilation
What is the purpose of the inflation reflex?
Detects lung expansion with stretch receptors and limits it depending on need or prevention of damage
How does aging impact the respiratory system?
Decreased…
- Vital capacity
- Blood O2 level
- Alveolar macrophage activity
- Ciliary action of respiratory epithelia
What is dyspnea?
Feeling of uncomfortable breathing or short of breath
What is hemoptysis?
Coughing up blood or bloody secretions
What is hypercapnia?
Increased CO2 in blood
Hypoventilation vs hyperventilation
- Hypoventilation (inadequate ventilation) leads to respiratory acidosis from hypercapnia
- Hyperventilation (too much ventilation) leads to respiratory alkalosis from hypocapnia
What is cyanosis?
Blue discoloration of skin and mucous membranes (desaturated hemoglobin)
What is emphysema?
Destruction of alveolar walls and loss of lung elastic coil
What is pneumonia?
Inflammation of lung due to infections (fluid in alveoli)
What is respiratory distress syndrome?
Premature fetal delivery, surfactant in lungs hasn’t developed and alveoli needs to be forced open
What is flail chest?
Segment of chest wall breaks under extreme stress and detaches from wall (lung bruising)
