Respiratory functional histology

Question 1

list main differences between true cord and false cord (2-3)

Answer 1

True cord:

1. vocalis muscle (skeletal) and vocalis ligament (within lamina propria) found
2. true focal fold is covered by STRATIFIED SQUAMOUS (NON-KERATINISED) epithelium = wear and tear during phonation
3. area between true fold: GLOTTIS

False cord:

• no vocalis muscle and ligament = cant make noise
• covered by RESPIRATORY EPITHELIUM
• lymphoid tissues, and glands (seromucus) present

Question 2

describe the process role of the epiglottis (larynx) and that of phonation

Answer 2

Fully closed epiglottis: protection of lower AW
Fully opened: allows the conduction of air into lower airway

Partialy opened: PHONATION
- allows the passage of air into the layrnx, where it will vibrate the structures within the true vocal folds created sounds

Question 3

list the structures of the upper airway and describe them

Answer 3

1. nasal cavity: open: external nares, end: internal nares, lined by vibrissae
2. paranasal sinus = continuous with nasal cavity
   - drained by osteomeatal complex
   - ethmoid, frontal, maxillary, sphenoid paranasal sinus
3. conchea (inferior, middle, superior)
   - are shelves of bones
   - creates meatus = air passage channel
   - increases SA for incoming air to contact the respiratory epithelim

Question 4

what is the component of respiratory epithelium?

It lines all the respiratory tract, apart from what and when does it change to simple columnar and simple cuboidal?

Answer 4

1. pseudostratified ciliated columnar cells, with goblet cells within the epithelium
2. lines the whole of the tract, APART FROM LARYNX
3. at the bronchioles it starts to change to simple epitheliem

Question 5

describe the bronchial tree and some important point

Answer 5

trachea

• bifurcation is called the carina, very sensitive to irritants
• hyaline, C shaped cartilage
• trachealis muscle link the open ends
• ligaments link the different levels

Primary, main, pulmonary bronchi
- right bronchi is wider and straighter than left = lodging of material

secondary, lobar bronchi
- supplies the lobes of lungs

tertiary, segmental bronchi
- supplies the bronchopulmonary segments

= THESE ARE ALL BRONCHI and penetrate deep into the actual lungs and the branches become narrower as they go down

Question 6

what is the 3 function of the respiratory epithelium in preparing incoming air?

Answer 6

1. humidify the air = water evaporates from airway secretions
2. to warm the air = abundant vascular supply in the submucosa (submucosa = below the lamina propria, which is a part of the mucosa)
3. filter the air = nasal hair, mucus trapping foreign material = beaten by ciliary hair

Question 7

describe the general changes in the airway structure as it approaches smaller airways

Answer 7

Trachea

• respiratory epithelium
• cartilage present (hyaline cartilage)
• glandular structures = serous and mucoserous secretion
• less smooth muscle

Bronchi

• respiratory epithelium
• cartilage still present
• glandular structures still present
• more smooth muscles

Bronchioles

• SIMPLE epithelium - columnar then cuboidal
• no glandular structures
• no cartilage, supported entirely by smooth muscles
• clara cells present = detoxification, secretion (mucin, surfactant, cytokines), immune defence