Lab 4

Question 1

Where are the lungs located?

Answer 1

Sit in thoracic cavity surrounding heart and above diaphragm

Question 2

What are the 3 structural features of the lungs?

Answer 2

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

Question 3

How many lobes does each lung have?

Answer 3

Right lung – 3 lobes.
Left lung – 2 lobes (no middle lobe)

Question 4

How many surfaces do both lungs have?

Answer 4

Costal surface – facing chest wall
Mediastinal surface – facing heart

Question 5

What is the hilum?

Answer 5

Hilum – area where airway and blood vessels go in and out of lung

Question 6

What are the 3 zones that form the passageway between the atmosphere and the lungs?

Answer 6

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.

Question 7

What part of the nasal cavity acts as the entrance and exit of the cavity?

Answer 7

Naris – entrance (external naris) and exit (internal naris) to nasal cavity.

Question 8

What are the turbinate?

Answer 8

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

Question 9

What are the 3 areas of the pharynx?

Answer 9

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.

Question 10

Where is the larynx located?

Answer 10

Starts below laryngeal pharynx.

Sound production / starts anterior passageway to lungs (esophagus forms posterior passageway to stomach; see with digestive system).

Question 11

What composes the larynx?

Answer 11

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

Question 12

What is the glottis?

Answer 12

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.

Question 13

Where does the trachea begin and what is a structural feature of this?

Answer 13

Starts below cricoid cartilage.
–> Series of cartilaginous rings until division into main bronchi.

Question 14

What are the subdivisions of the bronchi?

Answer 14

Bronchi (plural); bronchus (singular).
Main bronchi –> lobular bronchi –> segmental bronchi

Question 15

Where does the conducting zone start and end?

Answer 15

Trachea –> main bronchi –> lobular bronchi –> segmental bronchi –> ends with terminal bronchioles.

Question 16

Where does the respiratory zone start and end?

Answer 16

Continues as respiratory zone starting with next branch (respiratory bronchioles).

Respiratory bronchioles divide to form alveolar ducts leading into alveolar sacs.

Question 17

What is an alveolar sac?

Answer 17

An alveolar sac is like a cluster of grapes with individual grapes alveoli

Question 18

What does external respiration refer to?

Answer 18

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.

Question 19

What is the path deoxygenated blood follows during external respiration?

Answer 19

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.

Question 20

Why are the pulmonary vessels different from the rest?

Answer 20

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)

Question 21

What are the 2 types of pleura present in the lungs?

Answer 21

Additional tissue layers:
Visceral pleura – layer attached to lung costal surface.
Parietal pleura – layer attached to inner surface of chest wall.

Question 22

What is the intrapleural space?

Answer 22

Intrapleural space – between visceral and parietal pleura is a thin, fluid filled cavity (helps lubricate lung movement).