Respiratory System Flashcards
Functions of the Respiratory System
- supply the body with oxygen
- disposes of carbon dioxide
4 Processes of Respiration
- Pulmonary Ventilation (inhalation and exhalation)
- External Respiration (pick up O2 in lungs)
- Transportation of Respiratory Gases (via blood)
- Internal Respiration (O2 given to tissues)
The Two Zones of the Respiratory System
Conducting Zone - progressively smaller passages which warm, moisten and clean air as they convey it into the lungs
Respiratory Zone - the site of gas exchange within the lungs
Organs of the Conducting Zone
(from outermost to innermost)
Nasal Cavity
Nasopharynx
Larynx
Trachea
Bronchi
Bronchioles
Terminal Bronchioles
Organs of the Respiratory Zone
(from outermost to innermost)
Respiratory Bronchioles
Alveolar Ducts
Alveoli
The Divisions of the Respiratory Tract (based on location)
Upper Respiratory Tract - organs in head and neck, through larynx
Lower Respiratory Tract - organs of the thorax, trachea through lungs
What is the function of the nose? And what are some of its structures?
- provides a respiratory airway
- moistens, warms and filters air
structures:
- external nares
- nasal septum
- internal nares (choanae)
- vibrissae
- vestibule
- olfactory receptors
2
superior nasal concha
3
middle nasal concha
4
inferior nasal concha
5-7
Superior, Middle and Inferior Nasal Meatus (respectively)
- narrow mucosa-lined passages beneath each concha
- narrowness and turbulence increases air contact with mucous
8
External Nares
- nostrils
- external openings to nasal cavity
1
Internal Nares
- posterior openins of nasal cavity into pharynx
- posterior ends of the nasal meatuses
area just inside #8
Vestibule
- anterior region of nasal cavity just inside the nostirls
entire open space composed of #2-7
nasal cavity
What is the function of the nasal conchae? And what are they?
- they create air turbulence and increase the amount of contact between the nasal mucosa and inhaled air
- medially-projecting scroll-like mucosal structures on the walls of the nasal cavity
Two Types of Nasal Mucosa
Olfactory Mucosa - small patch near roof of nasal cavity which houses olfactory receptors
Respiratory Mucosa - lines nasal cavity
Respiratory Mucosa
- composition?
- function?
Composition:
- pseudostratified ciliated columnar epithelium
- contains goblet cells
- underlying lamina propria with glands
Function:
- mucosa warms, moistens and filters air
- cilia move contaminated mucus posteriorly (to pharynx)
cavities shown here
- what are they?
- what lines them?
- what is their function?
paranasal sinuses
- air-filled cavities within bones surrounded nasal cavity
- lined by mucosa
- lighten the skull and produce mucous which drains into nasal cavity
What is the highlighted area?
Its parts?
Its function?
Pharynx
- three parts:
- nasopharynx
- oropharynx
- laryngopharynx
- functions to warm, moisten and filter air as it conducts it towards the lungs
- skeletal muscle to assist in swallowing
Area posterior to internal nares, superior to soft palate
Nasopharynx
- most superior division of the pharynx
- Eustachian tubes enter here
area posterior to oral cavity, superior to the epiglottis, inferior to palate
oropharynx
- where pharynx meets oral cavity at opening formed by posteroinferior tip of palate and superior tip of epiglottis
Area inferior to the epiglottis and superior to the esophagus
Laryngopharynx
- attached to larynx
- most inferior portion of pharynx
What is the opening near the pointer for the nasopharynx?
- the meeting of the Eustachian (auditory) tube with the pharynx
- AKA pharyngotympanic tube
What are the three tonsils? And in which portion of the pharynx is each?
- Pharyngeal tonsil (adenoids) in the nasopharynx
- Palatine tonsil in the oropharynx
- Lingual tonsils are at the base of the tongue (not in the pharynx)
What is this structure?
Where is it?
What other organs is it continuous with?
What is its composition and function?
Larynx
- anterior to the C4-C6 vertebrae
- superiorly continuous with laryngopharynx
- inferiorly continuous with trachea
- composed of 8 rigid hyaline cartilages and 1 elastic cartilage flap connected by membranes & ligaments
- AKA voice box, functions in speech and directing of food and air
green highlighted structure
- what is it?
- what is it attached to?
- what is its function?
epiglottis
- blade-shaped elastic cartilage flap
- attached to dorsal/superior surface of thyroid cartilage
- folds over entrance to larynx during swallowing
- the central opening and the ligaments surrounding it
- what is its name and function?
Glottis
- composed of Rima glottidis (opening) and vocal ligaments
- produces sound as air is forced through the opening, vibrating the vocal folds
the part of the larynx indicated by the arrow:
- its name
- its function
- its attachments
thyroid cartilage
- forms most of anterior and lateral surface of larynx
- protects glottis and tracheal entrance
- attaches to laryngeal muscles/ligaments
- anterior projection is called the Adam’s apple
blue highlighted structure:
Cricoid Cartilage
- ring-shaped hyaline cartilage inferior to thyroid cartilage
- connects to trachea inferiorly
5
- name
- attachments
arytenoid cartilages
- two 3-sided pyramidal cartilages
- on superoposterior border of cricoid cartilage
- corniculate cartilages sit atop it
- aid vocal cord movement
3
corniculate cartilages
- paired pieces of elastic cartilage on superior surface of arytenoid cartilages
- prolong the arytenoid cartilages
Cartilage which supports soft tissue between the arytenoid cartilages and epiglottis
Cuneiform Cartilage
How many cartilages are there in the larynx? What kinds of cartilage? And their names?
9 Larygneal Cartilages
- Epiglottis
- Thyroid
- Cricoid
- Arytenoid (2)
- Corniculate (2)
- Cuneiform (2)
All are hyaline, except epiglottis is elastic.
part A
vestibular folds (AKA false vocal cords)
- vestibular ligaments & mucosa
- protect true vocal cords
part C
Vocal Folds (aka vocal cords)
- produce sound via vibrating with expelled air
- vocal ligaments & mucosa
1
Trachea (aka windpipe)
- airway extending from larynx to primary bronchi
- tracheal cartilages support it, connected by fibroelastic CT for flexibility
3
what are these rings?
what is their function?
how many are there?
tracheal cartilage
- C-shaped cartilage rings
- stabilize and support tracheal structure
- 16-20 rings in human trachea
- indicated by red arrow:
- what is it?
- what is it made of?
- what’s its function?
trachealis muscle
- smooth muscle that coveriors posterior trachea where c-shaped tracheal cartilages end
- allows esophagus to expand when swallowing
Carina
- ridge on last tracheal cartilage
What is this entire structure?
Bronchial Tree
circled item:
Primary Bronchi
- first branch of bronchial tree off of trachea
- enter lungs at hilus
circled items
secondary bronchi (aka lobar bronchi)
- branches of primary bronchi
- one for each lobe: 3 on the right, 2 on the left
tertiary bronchi (AKA segmental bronchi)
- branches of secondary bronchi
- last branches of bronchial tree with cartilaginous support
What is this structure?
How can you determine that?
Bronchiole
- narrow bronchial branch without cartilage but with thicker smooth muscle layer
- lined with simple columnar or cuboidal cells
structure indicated by thin black arrow:
terminal bronchiole
- last bronchioles of the conducting zone of the bronchial tree
- last bronchioles without alveoli
structures indicated by thin black arrows:
respiratory bronchioles
- form first part of respiratory zone
- first part of bronchial tree lined with alveoli
central structure indicated by thin black arrow:
alveolar ducts
- thin airways of the respiratory zone lined with alveoli
- lined with simple squamous epithelium
- lead into terminal clusters (alveolar sacs) through openings called atria (sing. atrium)
entire yellow structure
alveolar sac
- dilated, distal terminal end of alveolar duct
- a cluster of alveoli (connected to alveolar duct via atrium)
- one single lobe on one of these clusters
alveolus (pl. alveoli)
- pockets at end of respiratory tree
- lined with simple squamous epithelium and surrounded by capillaries
- site of gas exchange between respiratory and cardiovascular systems
Green highlighted layer surrounding each lobe of each lung:
Visceral Pleura
- serous membrane that sits on lungs and maks up inner lining of pleural cavity
- How does this layer play an important role in inspiration?
Green highlighted layer that lines thoracic walls, superior surface of diaphragm, etc.:
Parietal Pleura
- serous membrane that makes up outer layer of pleural cavity
- it is attached to the diaphragm and pulls the visceral pleura down with it when the diaphragm contracts, expanding the lungs, lowering their internal pressure and drawing air inward
What is the serous cavity surrounding the lungs?
Pleural Cavity
How does the cartilage change along the pathway of the respiratory conducting zone?
Trachea - C-shaped rings support tracheal structure
Bronchi - irregular plates of cartilage
Bronchioles - no cartilage present
How does the epithelium change along the pathway from the nose into the lungs?
- the general trend is thinning of the epithelium towards the alveoli
Olfactory epithelium (in roof of nasal cavity for smell)
Pseudostratified ciliated columnar (in nasal cavity, nasopharynx, trachea, bronchi… AKA respiratory mucosa)
Stratified Squamous Epithelium (oropharynx, laryngopharynx to protect against abrasion from food)
Simple Columnar Epithelium (unciliated, in terminal bronchioles)
Simple Cuboidal Epithelium (unciliated, in respiratory bronchioles)
Simple Squamous Epithelium (unciliated, in alveolar ducts, sacs and alveoli for respiratory gas diffusion)
How does the smooth muscle change along the conducting pathway of the respiratory tract?
Trachea - trachealis muscle in posterior wall against esophagus
Bronchi & bronchioles: helical bands for flow regulation
Terminal Bronchioles: thin layer
Alveoli: absent (to avoid thickness & allow for diffusion)
- What is the network of vessels surrounding the alveoli here?
Alveolar capillaries
- form a mesh-like network around alveolus where O2 and CO2 exchange occurs
What is the 3 layered structure across which gas exchange occurs in the lungs, magnified in the picture here?
What are its 3 layers?
Respiratory Membrane
3 layers:
- alveolar epithelium
- capillary endothelium
- basal laminae of both alveolar and capillary epithelia
Indicated by black arrows:
Alveolar Pores
- pores between alveoli that provide alternate routes for air circulation
1
- what are they?
- what is their function?
- and how does their shape/type/structure help that function?
Type I Alveolar Cells
- make up most of the cells lining interior of alveoli
- are the squamous epithelial cells through which gas exchange occurs
- their organelles are collected around the nucleus, allowing for very thin extensions of plasma membrane away from nucleus for easier diffusion
2
- what is their general structure?
- what is their function?
Type II Alveolar Cells
- Scattered cuboidal secretory epithelial cells
- produce pulmonary surfactant to reduce surface tension, keeping alveoli from collapsing in on itself
What is the large, furry-looking central structure here?
Hint: It’s in an alveolus.
- what is its function?
Alveolar Macrophage (AKA dust cell)
- derived from monocytes
- on interior alveolar surface
- ingest bacteria and other inhaled particles
Apex of Lung
- deep to clavicle
- rounded superior tip
Green highlighted portion of lung:
Base of Lung
- wide, concave surface resting on diaphragm
What is the curving anterior, lateral and posterior portion of the lung?
the costal surface of the lung
What are the medial parts of the lungs called?
mediastinal surface of the lung
Hilum of lung
- the point where the bronchi, pulmonary vessels, lymphatic vessels and nerves enter lungs
What are the structures that attach the lung to the mediastinum known as collectively? And what are they?
the root of the lung
- pulmonary vessels, lymphatic vessels, bronchi and nerves
part C
Superior Lobe of Right Lung
part D
Middle Lobe of Right Lung
Part E
Inferior Lobe of Right Lung
Parts A and B, respectively
Superior and Inferior Lobes of Left Lung
line separating C and D
Horizontal Fissure
- separates superior and middle lobe of right lung
- line separating A and B as well as D and E
oblique fissure
- separates middle and inferior lobes of right lung, as well as superior and inferior lobes of left lung
Cardiac Notch
- deviation in left lung’s anterior border that accommodates the heart
a section of the lung that is served by a single tertiary bronchiole
bronchopulmonary segment
Blood supply in the lungs.
What are the arteries and where do they go?
What are the veins and where do they go?
Pulmonary Arteries: Branch with bronchial tree; lie posterior
Pulmonary Veins: carry oxygenated blood back to heart; anterior to bronchi
What is this entire structure?
How is that determined by the structures/cells seen here?
Bronchi
- incomplete rings of cartilage
- pseudostratified or regular ciliated columnar epithelium around lumen
- thin layer of smooth muscle between mucosa and cartilage
What is this entire structure?
- How can that be determined from what is seen here?
Bronchiole
- no cartilage
- thicker layer of smooth mucle than bronchi
- simple columnar or cuboidal epithelium
What structures are shown here?
How can you tell?
Alveoli
- simple squamous epithelium (as well as some cuboidal type II cells and alveolar macrophages)
- large central air spaces
- often seen bunched together like in the figure
How do you differentiate between types of blood vessels in lung histology?
Vein - smaller walls, larger lumen
Artery - thicker walls, smaller lumen
What is the structure on the left with the larger lumen?
How can you tell?
Trachea
- large cartilage ring surrounding side opposite esophagus
- trachealis muscle between trachea and esophagus
- pseudostratified ciliated epithelium w/ goblet cells
What kind of cells are these linging the tracheal lumen?
Pseudostratified Ciliated Epithelium
- with goblet cells
What is layer 2 here?
- How can you tell?
Hint: This is the trachea.
Submucosa
- deep to mucosal epithelium
- superficial to cartilagenous layer
- dense CT with seromucous glands
What are the groupings of cells in layer 2 here?
Seromucous Glands
- produce mucus within trachea
What is the bottom line indicating?
Tracheal Cartilage
What is the top horizontal line indicating?
Trachealis
- binds open ends of C-shaped tracheal cartilages
- sits between trachea and esophagus
This is the trachea. What is layer 4?
Adventitia
- most external tracheal layer
- dense irregular CT w/ blood vessels and adipocytes
