Lab 4 Flashcards
Where are the lungs located?
Sit in thoracic cavity surrounding heart and above diaphragm
What are the 3 structural features of the lungs?
Apex – top of lung
Base – bottom of lung
Cardiac notch – in left lung to help accommodate heart which is shifted slightly more left in thoracic cavity
How many lobes does each lung have?
Right lung – 3 lobes.
Left lung – 2 lobes (no middle lobe)
How many surfaces do both lungs have?
Costal surface – facing chest wall
Mediastinal surface – facing heart
What is the hilum?
Hilum – area where airway and blood vessels go in and out of lung
What are the 3 zones that form the passageway between the atmosphere and the lungs?
Upper airways – no gas exchange (alveoli absent)
Nasal cavity / pharynx / larynx
Conducting zone – no gas exchange (alveoli absent)
Trachea / bronchi* / bronchioles / terminal bronchioles
Respiratory zone – gas exchange (alveoli present)
Respiratory bronchioles / alveolar ducts / alveolar sacs / alveoli
Huge amount of branching starting from trachea.
What part of the nasal cavity acts as the entrance and exit of the cavity?
Naris – entrance (external naris) and exit (internal naris) to nasal cavity.
What are the turbinate?
Turbinate:
Bone (conchae) covered in a membrane.
Form shelves projecting into the nasal cavity.
Create a meatus (passageway) under each corresponding turbinate.
Combination of turbinates and meatuses direct air in nasal cavity to help with warming, filtering, and humidifying
What are the 3 areas of the pharynx?
Pharynx – “throat”; starts after internal naris.
1st area – nasal pharynx – end of internal naris to tip of uvula
Portion behind nasal cavity.
Within nasal pharynx: opening for auditory tube – connects to middle ear for equalizing middle ear pressure with atmospheric pressure; helps prevent rupturing tympanic membrane or ear drum.
2nd area – oral pharynx – tip of uvula to tip of epiglottis (flap of tissue that can block entrance to larynx).
Portion behind oral cavity.
3rd area – laryngeal pharynx – tip of epiglottis to start of larynx.
Portion above larynx.
Where is the larynx located?
Starts below laryngeal pharynx.
Sound production / starts anterior passageway to lungs (esophagus forms posterior passageway to stomach; see with digestive system).
What composes the larynx?
Composed of:
–>1 bone: Hyoid bone – horse-shoe shaped.
–> Ligaments/membranes.
Thyrohyoid membrane: between hyoid bone and thyroid cartilage.
Cricothyroid ligament: between thyroid cartilage and cricoid cartilage.
–> A series of cartilages
Anterior larynx
- Anterior of thyroid cartilage has a notch (thyroid notch) and a bump (laryngeal prominence; commonly “Adam’s apple”).
- Side view: cricoid cartilage is wider in posterior and narrower in anterior; cricoid cartilage is last part of larynx.
Posterior larynx
- Arytenoid cartilage: helps move vocal folds for sound production
- Corniculate cartilage
What is the glottis?
Glottis – part of passageway past vocal and vestibular folds (both for sound production).
Vocal folds – inferior, white / vibrate to produce sound.
Vestibular folds – superior, pink / modify air currents.
Where does the trachea begin and what is a structural feature of this?
Starts below cricoid cartilage.
–> Series of cartilaginous rings until division into main bronchi.
What are the subdivisions of the bronchi?
Bronchi (plural); bronchus (singular).
Main bronchi –> lobular bronchi –> segmental bronchi
Where does the conducting zone start and end?
Trachea –> main bronchi –> lobular bronchi –> segmental bronchi –> ends with terminal bronchioles.
Where does the respiratory zone start and end?
Continues as respiratory zone starting with next branch (respiratory bronchioles).
Respiratory bronchioles divide to form alveolar ducts leading into alveolar sacs.
What is an alveolar sac?
An alveolar sac is like a cluster of grapes with individual grapes alveoli
What does external respiration refer to?
External respiration – where airways and blood circulation meet for gas exchange.
Pulmonary circulation
After passing pulmonary valve enter pulmonary trunk which divides into pulmonary arteries.
Right ventricle – pulmonary trunk – pulmonary arteries – pulmonary arteriole – pulmonary capillaries – pulmonary venule – pulmonary veins – left atrium.
Pulmonary vessels are an exception to usual colour of artery – red and vein – blue.
Artery and arteriole: blue pulmonary vessels – towards pulmonary capillaries.
Venule and vein: red pulmonary vessels – away from pulmonary capillaries.
What is the path deoxygenated blood follows during external respiration?
Pulmonary circulation
After passing pulmonary valve enter pulmonary trunk which divides into pulmonary arteries.
Right atrium –> right ventricle –> pulmonary trunk (pulmonary valve) –> pulmonary arteries –-> pulmonary arteriole –-> pulmonary capillaries –-> pulmonary venule –-> pulmonary veins –-> left atrium.
Why are the pulmonary vessels different from the rest?
Artery and arteriole: blue pulmonary vessels – towards pulmonary capillaries. (carry deoxygenated blood)
Venule and vein: red pulmonary vessels – away from pulmonary capillaries. (carry oxygenated blood)
What are the 2 types of pleura present in the lungs?
Additional tissue layers:
Visceral pleura – layer attached to lung costal surface.
Parietal pleura – layer attached to inner surface of chest wall.
What is the intrapleural space?
Intrapleural space – between visceral and parietal pleura is a thin, fluid filled cavity (helps lubricate lung movement).
