1: Respiratory Histology

Question 1

Conducting vs respiratory portions of the respiratory system (specific organs)

Answer 1

Conducting: nasal cavity, paranasal sinuses, nasopharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
Respiratory: respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli

Question 2

Respiratory epithelium ***

Answer 2

Pseudostratified columnar ciliated epithelium

Question 3

Five cell types in the respiratory epithelium

Answer 3

1. Ciliated columnar cells (70%)
2. Goblet cells (15%)
3. Brush cells
4. Small granule cells
5. Basal cells

Question 4

Brush cells

Answer 4

Chemosensory cells with short microvilli -> connect to sensory nerve fibers

Question 5

Small granule cells

Answer 5

Have secretory granules for endocrine functions (part of the DNES)

Question 6

Basal cells

Answer 6

Non-ciliated stem cells on basement membrane of respiratory ep

Question 7

Larynx is between which two structures?

Answer 7

Pharynx and trachea

Question 8

Three parts of the larynx made of hyaline cartilage

Answer 8

Thyroid, cricoid, inferior aretenoid cartilages

Question 9

Four parts of the larynx made of elastic cartilage

Answer 9

Epiglottis, cuneiform, corniculate, superior arytenoid cartilages

Question 10

Core of epiglottis

Answer 10

Elastic cartilage

Question 11

Vestibular vs vocal folds

Answer 11

Vestibular: immovable pair of folds, superior
Vocal: movable for phonation and sound; inferior

Question 12

Vocal ligament

Answer 12

Dense CT bundle that supports free edge of each vocal fold

Question 13

Trachealis M

Answer 13

SM bundle that spans the open ends of cartilage rings posteriorly in the trachea

Question 14

Where primary bronchi enter

Answer 14

Lungs at the hilum, along with vessels and lymphatics

Question 15

Bronchi pathway

Answer 15

Primary bronchi -> secondary (lobar) -> tertiary (segmental) bronchi -> bronchioles

Question 16

Cartilage rings in bronchi as it moves downward

Answer 16

Primary bronchi have complete cartilage rings -> gradually replaced by plates of hyaline cartilage as lumen size decreases

Question 17

How many terminal bronchioles are formed from one tertiary bronchi

Answer 17

5-7

Question 18

Where are club cells found?

Answer 18

Terminal bronchioles

Question 19

Club cells

Answer 19

Non-ciliated, dome shaped apical ends contain secretory granules

Question 20

Three exocrine functions of the terminal bronchioles

Answer 20

1. Secrete surfactant and mucins onto epithelium
2. Detox inhaled xenobiotics by enzymes of SER
3. Secrete antimicrobial peptides and cytokines for local immune response

Question 21

First part of respiratory region of airways

Answer 21

Respiratory bronchioles

Question 22

Where are alveoli found?

Answer 22

Off respiratory bronchioles and respiratory ducts

Question 23

Path from respiratory bronchioles -> alveoli

Answer 23

Respiratory bronchioles -> alveolar ducts -> alveolar sacs -> alveoli

Question 24

What completely lines the alveolar ducts?

Answer 24

Openings of alveoli

Question 25

Alveolar sacs

Answer 25

Large clusters of 2+ alveoli forming the distal ends of alveolar ducts

Question 26

Alveolar pores

Answer 26

Small openings that permit movement of air between alveoli

Question 27

Interalveolar septa composition

Answer 27

Reticular fibers, elastic fibers, scattered fibroblasts, sparce ECM, richest capillary networks in the body

Question 28

Elastic fibers in interalveolar septa

Answer 28

Expand with inspiration, contract with expiration

Question 29

Reticular fibers in interalveolar septum

Answer 29

Prevent collapse and excess distention of alveoli

Question 30

Laryngitis

Answer 30

Inflammation of the larynx due to viral infection or allergies

Question 31

Mechanism of laryngitis

Answer 31

Edema of lamina propria -> changes shape of vocal folds -> hoarseness/loss of voice

Question 32

Croup

Answer 32

Viral laryngitis in young children with seal-like cough

Question 33

Asthma mechanisms

Answer 33

1. Bronchiole inflammation + SM contstriction -> bronchospasms 2. Infiltration of bronchiole walls by eosinophils, lymphocytes, and mast cells

Question 34

How are asthmatic bronchioles different than regular bronchioles

Answer 34

Thickened epithelium, increased goblet cells, thick basement membrane, hyperplastic smooth muscle cells

Question 35

Emphysema mechanism

Answer 35

Narrowing of bronchioles + destruction of alveolar walls -> chronic obstruction of airflow + significant loss of area for gas exchange + permanent enlargement of air spaces distal to terminal bronchiole

Question 36

Causes of emphysema

Answer 36

Cigs, chronic inhalation of particulate matter (coal dust, construction dust)

Question 37

Pneumonia mechanism

Answer 37

1. Air spaces fill with exudate: WBCs, RBCs, fibrin | 2. Capillaries enlarge and fill with RBCs

Question 38

Red hepatization stage in PNA

Answer 38

On gross exam, lungs appear red, firm, and heavy; due to lack of air spaces and exudate