Respiratory System Flashcards
What are the main functions of the respiratory system?
Exchange of gases (oxygen and carbon dioxide) between lungs and blood.
What are the 2 subdivisions of the respiratory system? What do they consist of?
Upper respiratory system: nose nasal cavity, and pharynx Lower respiratory system: larynx, trachea, bronchial tree, and lungs
The respiratory system is lined with what? Describe the specific tissue types.
- Mucosa
- All have epithelial and CT
- Epithelial for most is ciliated pseudostratified columnar (with goblet cells)
- Cilia sweeps mucous to esophagus where swallowed - CT layer of all mucosa is lamina propria
What is the nose supported by?
Bone and hyaline cartilage
Nostrils = ?
Nares
What are the nasal cavities functions?
- Airway passage (heat +moisten air)
- Olfaction
- Speech (resonance chamber)
What is the nasal cavity divided by?
The nasal septum
What is the nasal septum made up of?
Anterior part: Hyaline cartilage
Posterior part: Vomer, ethmoid, maxillae, palatine bones
What are the 3 areas of the nasal cavity?
Vestibule, respiratory area, olfactory area
Describe the vestibule of the nasal cavity
- Anterior region of the nasal cavity
- Lined by skin with coarse hair
Describe the respiratory area of the nasal cavity
- posterior region of the nasal cavity
- mucosa = ciliated pseudostratified epithelium + CT
- conchae protrude from walls
- superior (ethmoid)
- middle (ethmoid)
- inferior - separate bone - inferior to chonchae = nasal meatuses (shallow groove)
- conchae + meatuses cause air turbulence to knock out dust
- lacrimal duct opens into cavity here (just below inferior nasal conchae)
- tears to nasal cavity
Describe the olfactory area of the nasal cavity
- sense of smell
- roof of nasal cavity
- neurons = olfactory receptors
What are the paranasal sinuses?
8 air filled spaces in the skull
- paired left and right spaces in: frontal, sphenoid, ethmoid, and maxillae
- open directly into nasal cavity
- function: warm, moisten air, lighten skull
- sinusitis = inflammation of mucous membrane
What are the 3 regions of the pharynx?
nasopharynx, oropharynx, and laryngopharynx
Describe the nasopharynx
- posterior to nasal cavity
- air passage only
- contains:
- pharyngeal tonsil
- openings:
- 2 posterior nasal apertures
- 2 pharyngotympanic tubes
Describe the oropharynx
- posterior to oral cavity
- air + food passage
- stratified squamous epithelium
- from soft palate to top of epiglottis
- contains: palatine tonsils, lingual tonsil
Describe the laryngopharynx
- air + food passage
- stratified squamous epithelium
- from epiglottis to opening of larynx
Describe the pharynx
- The throat
- made up of skeletal muscle lined by mucous membrane
Describe the larynx
- the voice-box
- made up of 9 cartilages (all hyaline cartilage, except epiglottis)
What are the unpaired cartilages of the larynx?
- thyroid: on anterior wall, Adam’s apple
- cricoid: forms complete ring
epiglottis: made of elastic cartilage, covers glottis during swallowing
What are the paired cartilages of the larynx?
- arytenoid: attaches the vocal cords (influence changes in position and tension of the vocal cords)
- don’t need to know the other 2
What are the vocal cords?
2 pairs of folds of mucosa membrane
- vestibular
- false vocal cords
- superior fold
- vocal fold
- true vocal cords
- inferior fold
- produce sound by vibration
What is the glottis?
- consists of true vocal cords + the space between them
- closes to prevent food and liquid from entering trachea
What is laryngitis?
inflammation of the larynx which can arise from infection or irritation
What is the trachea?
- connects the larynx to the main bronchi
- anterior to esophagus
- consists of 20 ‘C’ shaped pieces of hyaline cartilage (open part of ‘C’ faces the esophagus to allow expansion of the esophagus
What is the bronchial tree?
an extension of the trachea and serve as the central passageway into the lungs
What are the differences between the right and left lung?
The right lung has 3 lobes (superior, middle, and inferior) while the left lobes has 2 lobes (superior, and inferior) and a cardiac notch where the heart lies.
What separates the right and left lungs?
the mediastinum
What is the pleura?
the serous membrane of the lungs
- visceral layer: on the surface of the lungs
- parietal layer: on the thoracic wall, superior diaphragm, and the mediastinum
What is the pleura cavity?
Between the visceral and parietal layers of the pleura and is filled with serious fluid which:
- prevents friction when lungs move
- holds lungs to thoracic cavity wall
What is the respiratory zone?
- Where gas is exchanged between air and blood (oxygen gas enters blood, and carbon dioxide enters air, mainly alveoli)
- Consists of: respiratory bronchioles, alveolar ducts, and alveoli
What is the conduction zone?
- Filters, warms, and moistens air and conducts it into the lungs.
- Consists of: nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles
Which comes first, the respiratory zone or the conduction zone?
Conduction zone
What is the respiratory membrane?
A thin membrane made up of alveolar walls and surrounding capillaries (3 total layers)
What are the 3 layers of the respiratory membrane?
1) wall of alveolus:
- simple epithelium
- made up of 3 cell types
2) basement membrane of alveolus and capillary
3) wall of capillary
- simple squamous epithelium (=endothelial cell)
What are the 3 types of cells that the wall of the alveolus is made of? What are their functions?
1) Type 1 alveolar cells
- simple squamous
- allow gas diffusion
2) Type 2 alveolar cells
- simple cuboidal
- secrete surfactant (allows lungs to expand easily)
3) Macrophages
- free moving across surface of type 1 cells
- remove dust and debris
What are the 2 routes for blood supply to the lungs?
pulmonary circulation (blood to be oxygenated) and bronchial circulation (blood to nourish lung tissue)
Describe bronchial circulation
1) bronchial arteries (from aorta) carry oxygenated blood to lung tissues like bronchi where it becomes deoxygenated
2) blood returns to the heart in one of two ways
- bronchial vein: only a small amount of blood, feeds into superior vena cava, then right atrium
- pulmonary veins; most of the blood, feeds into left atrium where it is mixed with oxygenated blood
Explain ventilation
Muscles are all skeletal
1) Inspiration (intake of air)
- diaphragm and external intercostals contract
2) Expiration (air moves to atmosphere from lungs)
- diaphragm and external intercostals relax
- exhale is passive
