The Respiratory System 1 Flashcards
What are the five main functions of the respiratory system?
Pulmonary ventilation
Gas exchange
Protection of respiratory surfaces
Production of sound
Smell
What is pulmonary ventilation?
Moving air from the exchange surface of the lungs
Where does gas exchange happen?
In the alveoli (acinar tissue of the lung)
Why do respiratory surfaces need to be protected?
To prevent infection
How is sound produced?
Movement of air across larynx during breathing produces sound
What is the scientific name for smell?
Olfaction
What two parts is the respiratory system organised into?
Upper respiratory system
Lower respiratory system
What makes up the upper respiratory system?
4
Nose
Nasal cavity
Sinuses
Pharynx (back of the mouth)
What makes up the lower respiratory system?
5
Larynx
Trachea
Bronchi
Bronchioles
alveoli
What are the two zones of the respiratory system?
Conducting zone
Respiratory zone
What is the conducting zone of the respiratory system?
Where gases are transported
What is the respiratory zone of the respiratory system?
Where gases are exchanged
What structures make up the conducting zone?
8
Nose and nasal cavity
Nasopharynx
Oropharynx
Laryngopharynx
Larynx
Trachea
Bronchi
All bronchioles except respiratory bronchioles
What are the functions of the conducting zone?
4
Transport
Filtering
Humidifying
Warming
What makes up the upper respiratory passages?
2
Nose
Pharynx
What does the upper respiratory passages do?
They filter and humidify incoming air
What make up the conducting passageways?
3
Trachea
Bronchi
Large bronchioles
What are the functions of the conducting passageways?
They carry air to and from the alveoli
What make up the lower passageways?
2
Small bronchioles
Alveoli
What are the main characteristics of the lower passageways?
They have delicate passages and surfaces
What is the respiratory mucosa?
Respiratory epithelium and underlying connective tissue
What happens to the respiratory mucosa as you move along the tract?
The mucosa changes
Where is respiratory mucosa found?
It lines the conducting portion of the respiratory tract
What protects the respiratory mucosa?
A respiratory defence system
How is the respiratory mucosa protected?
3
It produces mucus (Goblet cells)
Macrophages patrol the epithelium
Cilia move mucous up and out of the respiratory tract
What type of epithelium is found in the trachea?
Ciliated pseudostratified columnar epithelium with goblet cells
What type of epithelium is found in the large bronchi?
Ciliated pseudostratified columnar epithelium with goblet cells
What type of epithelium is found in the bronchioles?
Simple cuboidal epithelium
What three things does the nose do to the air?
Filters air
Warms air
Provides moisture to air
What is the main function of the mucous in the trachea?
2
It captures things in air like dust and microorganisms
This is swept out by cilia and passed up and into digestive system
Why can you not see goblet cells on a slide?
Goblet cells contain lipids which melt when paraffin embedding tissues in the lab
What is the end of the trachea called?
The carina
From where does the trachea extend?
From the sixth cervical vertebra to the fifth thoracic vertebra
What is the trachea?
A tough, flexible tube running from the larynx to the bronchi
Where is the carina located?
In the mediastinum
What holds open the trachea?
C shaped tracheal cartilage found in the submucosa
What type of muscle is found in trachea?
Trachealis muscle which is smooth muscle
What separates the lobes of the lungs?
Fissures
How many lobes does the right lung have?
Three lobes
How many lobes does the left lung have?
Two lobes
Name the two bronchi
Right and left primary bronchi
Where do the bronchi enter the lung?
They enter at the hilum of the lung
What is the hilum of the lung?
Area of lung where all blood vessels, nerves and the bronchi enter/leave the lung
List the five parts of the bronchus.
Lumen
Epithelium
Smooth muscle layer
Submucosal glands
Cartilage
What is the function of a bronchus’ lumen?
Air flows through here
What is the function of the bronchus’ smooth muscle layer?
Broncho-dilation and broncho-constriction (controls how much air flows through lumen)
What is the function of the bronchus’ submucosal glands?
Produce secretions
What is the function of the bronchus’ cartilage?
Protects the bronchus and helps keep it open
What is the bronchial tree?
A system of tubes formed from the primary bronchi and their branches
What does the primary bronchi branch into?
The secondary bronchus
What do the secondary bronchi branch into?
Tertiary bronchi
What do the secondary bronchi supple air to?
Each lobe of the lungs
What do the tertiary bronchi supply air to?
A single broncho-pulmonary segment
What are the three types of bronchioles?
Small bronchioles
Terminal bronchioles
Respiratory bronchioles
What are terminal bronchioles?
The last airways without alveoli
What are respiratory bronchioles?
The first airways with alveoli (part of respiratory zone)
Do bronchioles have cartilage?
No
Do bronchioles have muscle?
Yes, smooth muscle
What type of epithelia do small bronchioles have?
Short columnar/tall cuboidal epithelium usually ciliated
What is found around the edge of a small bronchiole?
Some supporting connective tissue
What two things make up the exchange zone?
Respiratory bronchioles
Alveolar ducts
Write a note on respiratory bronchioles.
3
Mark beginning of exchange zone
Have alveoli interspersed amongst simple cuboidal epithelium
Give rise to alveolar ducts
Write a note on alveolar ducts.
2
Tubes consisting of side-by-side alveoli
Give rise to alveolar sacs
What are two other names for the alveolar region?
Acinar region
Parenchymal region
What is the main role of the alveolar region?
Gas exchange
What is the secondary role of the alveolar region?
Supporting other structures such as airways in the lungs
What is the role of parenchymal tissue in any organ?
Support
What are alveolar ducts?
Tube-like structures that end in alveolar sacs
What do alveoli consist of?
2
Alveolar wall
Alveolar airspace
What are alveolar walls also called?
Respiratory exchange surfaces
What are the alveolar walls connected to?
2
Circulatory system via pulmonary circuit
pulmonary capillaries inside the wall
What are the alveolar walls made of?
3
Simple squamous epithelium
Endothelial cells
A fused basal laminae between alveoli (common walls for efficient gas diffusion)
Septal cells
Alveolar macrophages
Give three different names for the epithelia of alveolar walls.
Type 1 alveolar cell
Type 1 septal cell
Type 1 pneumocyte
What is the function of the alveoli epithelia?
Provides structure to the wall
Where are the endothelial cells of alveoli found?
Found lining the capillaries
Why do alveoli have common walls?
For efficient gas diffsusion
What are two other names for septal cells?
Type 2 pneumocyte
Type 2 alveolar cell
Type 2 septal cell
How does the appearance of a type 2 cell differ from a type 1?
Type 2 is more rounded than 1
Type 2 is also twice as abundant
What is the main function of type 2 cells?
They produce surfactant which keeps the alveoli open during breathing and reduces surface tension (stops sticking)
What is the secondary function of type 2 cells?
They can replace type 1 cells when they die
What are alveolar macrophages also called?
Dust cells
What do dust cells do?
Patrol epithelium and engulf foreign particles
How is blood supplied to the conducting portions?
2
Receive blood from the systemic circuit through arteries
Blood returns mostly though the bronchial veins
How is blood supplied to the respiratory exchange surfaces?
Receive blood from the arteries of the pulmonary circuit
Pulmonary veins return blood to the left atrium of the heart
What is each lung covered by?
A pleura
What is a pleura?
2
A serous membrane which lines the pleural cavity (Visceral = inner, Parietal = outer)
Pleural fluid fills and lubricates space between pleura and lungs
