Respiratory system Flashcards
End of semester exam
What are the four processes that make up respiration
- Pulmonary ventilation
- External respiration
- Respiratory gas transport
- Internal respiration
Important functions of the respiratory system
- Acid balance
- filters and protects respiratory surfaces from pathogens and dehydration
- Vocalization
- Olfaction
Anatomical divison - upper respiratory tract
transports air through common structures: nose, nasal cavity, pharynx and larynx
Anatomical division - lower respiratory tract
transports and carries out gas exchange: trachea, bronchial tree, lungs (alveoli)
Functional division: conducting zone
passageways that carry air to the site of gas exchange (filter, humidify, warm air)
Functional division: respiratory zone
the site of gas exchange in the lungs
List the functions of the nose
- Airway for respiration
- moistens and warms entering air
- filters
- resonance chamber for speech
- home to the olfactory receptors
List the two divisions of the nose and what comprises them
- External nose: bones and hyaline cartlidge
- Internal nose: nasal cavity
Describe the structure of the nasal cavity
- Air enters through external nares
- Nasal septum divides into right and left halves
- Posteriorly, continuous with the nasopharynx
- Roof formed by ethmoid and sphenoid bones
- Floor formed by the palate
- Surrounded by paranasal sinuses - filter air
What are the two types of mucosa membranes that line the nasal cavity
- olfactory mucosa: receptors for smell
- Respiratory muscosa: epithelium with goblet cells, function to trap inhaled debris and moisten
Describe the structure of the conchae
- bony plates found on the lateral walls of the nasal cavity that increase the surface area of the mucous membrane
- Groove inferior to each concha is a meatus
Describe how the conchae effect inhalation and exhalation
Inhalation: filter, heat and moisten air
Exhalation: cool conchae, take out moisture
Describe the structure and function of the pharynx
- common passageway for both food and air
- funnel-shaped passageway that connect the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly
- walls lined with mucosa and skeletal muscle
Describe the nasopharynx
only air, uvula closes entrance to prevent food from entering nasal cavity, pseudostratified ciliated columnar epithelium
Describe the oropharynx
food and air, stratified squamous epithelium
Describe the laryngopharynx
food and air, stratified squamous epithelium.
List what the larynx connects and its three main functions
connects the laryngopharynx to the trachea.
- produces vocalization
- provides and open airway
- routing air and food into proper channels (swallowing = closed, breathing = open)
Describe the 3 structures of the larynx
- vestibular folds: false vocal cords
- vocal folds: true vocal cords
- Laryngeal vestibule - above vocal cords; larngeal ventricle - between vestibular and vocal cords
What is the rima glottis
the opening between vocal folds
List the 9 cartlidges and what they look like/function
- Thyroid cartilage (adam’s apple - laryngeal prominence)
- Cricoid cartilage (complete ring)
- Arytenoid cartilage - 2 (pyramid shape - anchor vocal chords)
- Corniculate catrilage -2
- Cuneiform cartilage - 2
- Epiglottis (elastic, keeps food out of respiratory tubes)
Name the function of the trachea
- filter, warm, humidify air
- Connects larynx into mediastinum, divides into two primary bronchi at T4-T7
Describe the structure of the trachea
- 16-20 c-shaped rings of hyaline cartilage joined by connective tissue
- Trachealis muscle - contraction decreases trachea diameter
- Carina - cough reflex
- Annular ligaments connect cartilage rings
- Pseudostratified ciliated columnar epithelium.
List what the bronchial tree is made of
- cartilage and smooth muscle
- primary bronchi enter the hilium of each lung with pulmonary and lymphatic vessels and nerves.
What changes occur in the bronchial tree as the conducting tubes get smaller?
- Cartilage is replaced with smooth muscle and elastic connective tissue
- Epithelium transition to simple columnar and then to simple cuboidal (for gas exchange)
- No mucous or cilia in small bronchioles
What 2 types of cells do all alveolus have?
- single layer of type 1 alveolar cells, basal lamina and network of capillaries
- Type 2 alveolar cells produce surfactant
What is surfactant?
Detergent-like substance that reduces the surface tension within the alveoli
What would happen without surfactant?
- The inner walls of the alveoli would stick together during exhalation
Which body cavity are the paired lungs and pleural sacs located?
The thoracic cavity
What shape do the lungs have?
- conical
- concave base
- blunt apex
How are the lobes of the lungs divided?
fissures
Where is hilum found?
found on medial surface - indentation where vessels enter/exit lung
name the lobes and fissures of the left lung
Lobes: superior and inferior
separated by oblique fissure
Name the lobes and fissures of the right lung
Lobes: superior, middle and inferior
separated by oblique and horizontal fissures
What are the three surfaces of the lungs?
- Mediastinal (medial, hilum)
- Diaphragmatic (base)
- Costal
What are the three borders of the lungs
- anterior
- posterior
- inferior
List the three openings in the diaphragm
Oesophageal hiatus - Surrounded by muscle so during the contraction of diaphragm it’s closed.
- Vena caval foramen and aortic hiatus - surrounded by tendons so blood can flow during contractions
what does the pulmonary circuit do
Conducts blood from the heart to and from the gas exchange surfaces of the lungs
Describe the flow of blood through the pulmonary circuit
PULMONARY ARTERIES: take O2 poor blood to the lungs
PULMONARY CAPILLARY NETWORKS: site of gas exchange, alveoli
PULMONARY VEINS: take O2 rich blood back to the heart
What does bronchial circulation do?
(systemic circulation) supply the bronchi and bronchioles of the lung
Describe the flow of blood through the bronchial circuit
- Bronchial arteries branch from the anterior wall of the descending thoracic aorta and supply structures in the bronchial tree
- Larger bronchial veins collect venous blood and drain into the azygos and hemiazygous systems of veins
What is the plurae?
serous membrane that covers outer lund surface and the thoracic wall
What is the outer layer of the plurae?
The parietal plurae - covers internal surface of thoracic wall, superior surface of diaphragm, lateral surfaces of mediastinum (sensitive to pain)
What is the inner layer of the plurae
- the visceral pleura: covers the external lung surface (insensitive to pain)
What does pleural fluid do?
a lubricant that ensures opposing pleural membrane surfaces slide by each other with minimal friction during breathing
Muscles involved in normal inspriation - diaphragmatic breathing
- diaphragm contracts and expands the thoracic cavity
Muscles involved in normal inspiration - costal breathing
- external intercostals (elevate the ribs and enlarge the thoracic cavity
Muscles involved in deep or forced inspiration
sternocleidomastoid, scalenes, pec minor, quadratus lumborum
Muscles involved in deep or forced expiration
- internal and external obliques, transversus abdominus (force diaphragm superiorly, depress rib cage)
- Internal intercostals and latissimus dorsi
Describe bronchial asthma
allergic inflammatory response causes bronchoconstriction
Describe cystic fibrosis
accumulation of mucous, clogs respiratory system and causes bacterial infections
Describe chronic bronchitis
inhaled irritants - leads to excess mucous, inflammation and fibrosis - impairing ventilation and gas exchange
Describe emphysema
Permanent enlargement of alveoli due to inc, lysosymes destroying alveolar walls; lungs becoming less elastic
