16 Anatomy of the respiratory tract Flashcards
Functions of the respiratory tract: (6)
Provides o2 Removal of CO2 Regulates pH Defence against pathogens Produces sound Smell
Upper respiratory tract consists of:
- Nose
- Pharynx
- Larynx
- Paranasal sinuses
What are the functions of the upper respiratory tracts?
- Modifies sound
- Smell
- Warms, moistens and filters air
Functional adaptations of the nose:
Vibrissae Conchae Mucosa Rich capillary network Olfactory muscles Paranasal sinuses
What are vibrissae?
nose hairs - at the entrance trap dust particles
What are conchae?
Shelf like projections in the lateral wall, cause turbulent (slow) airflow which allows time to moisten and warm air
What are the functional adaptations of mucosa in the nose?
-pseudostratified columnar epithelium with goblet cells
What is the purpose of the rich capillary network in the nose?
To warm the air
Olfactory mucosa:
- located in the upper aspect of the nose
- contains receptors for smell
What are the paranasal sinuses?
Air filled spaces that drain into the nasal cavity
lighten the skull and resonate sound
also lined with pseudostratified columnar epithelium with goblet cells
What is the pharynx?
A communal passageway for food and air to enter the body
-Air enters the nasopharynx (posterior to the nose) and travels down the laryngopharynx (posterior to the larynx)
-Food enters the oropharynx (posterior to the mouth) and passes down into the oesophagus
N
O
L
How many muscles do you use to swallow food?
28
What is the structure of the larynx?
Made up of three different cartilages -Arytenoid -Cricoid -Thyroid Lined by membranes which form the edges of vocal chords Also includes the glottis
How do we vary the pitch of voice?
By moving the arytenoid cartilage to determine how much air gets into the larynx
What is the glottis
the space where air goes down. The epiglottis can close up the glottis if food passes o stop it entering
What does the lower respiratory tract consist of?
Trachea Primary bronchi Secondary bronchi Tertiary bronchi Primary bronchioles Secondary bronchioles Terminary bronchioles Respiratory bronchioles Alveolar ducts Alveolar sacs Alveoli
What does the conductive portion of the resp system consist of?
Trachea Primary bronchi Secondary bronchi Tertiary bronchi Primary bronchioles Secondary bronchioles Terminary bronchioles
What does the respiratory portion of the resp system consist of?
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli
Structure of the trachea:
- 4.5 cm long
- 2.5 cm diameter
- consists of C shaped rings of cartilage
- Can’t be collapsed
- Lined by pseudostratified ciliated columnar epithelium with goblet cells
Position of the trachea
- anterior to oesophagus
- extends from larynx to carina
What changes from the trachea to the bronchi?
- series of tubes that get smaller in diameter
- cartilage decreases
- smooth muscle increases
- epithelial cells become more cuboidal
Structure of primary bronchi:
- Supply each lung
- Right is wider and more vertical than left because L is avoiding heart
- 2-3cm long
- C shaped cartilage present
Structure of secondary bronchi:
- supply each lobe
- 3 on the right 2 on the left
- plates of smooth muscle with cartilage imbetween
Structure of tertiary bronchi:
- supply segments of the lungs
- contain plates of cartilage
Structure of bronchioles
Don’t contain cartilage
Mainly smooth muscles so can contract and dilate
How many terminal bronchioles come from each bronchiole?
50-80
Whats in the terminal bronchioles?
- simple columnar ciliated epithelium incase some mucus gets down there
- clara cells produce surfactant
Whats in the respiratory bronchioles?
- no cilia
- clara cells
- simple cuboidal epithelia
- occasional alveoli extend from lumen so gas exchange can take place here
What are the types of alveolar cells?
1 and 2
2 secretes surfactant
1 simple squamous epithelium forms wall
macrophages are present in alveoli to engulf pathogens and dust particles
Respiratory membrane in alveoli:
-the basement membrane and the epithelial cells of the alveoli fuse, as do the basement membrane and endothelium of capillary making a shorter distance for diffusion
What happens if blood pressure in the lungs gets too high?
If pressure in the lung capillaries gets too high fluid can be forced out into the interstitial fluid or alveoli, pushing apart the basement membranes and greatly slowing gas exchange
What is the function of the conducting portion of the respiratory tract?
Warming and moistening air and conducting it to the lungs
