Respiratory System

Question 1

What are the functions of the respiratory system?

Answer 1

• air conduction/gas exchange
• phonation (talking)
• olfaction (smell)
• heat regulation
• air conditioning (temp and moisture)
• protection
• acid-base regulation
• hormone conversion

Question 2

Describe the functions and components of the Conductive system

Answer 2

• composed of nasal cavity, pharynx, larynx, trachea, and bronchi
• brings air to the respiratory portion
• cleanses, moistens, and warms incoming air
• hair and secretions in nasal cavity trap particulate matter

Question 3

Describe the functions and components of the Transitional system

Answer 3

• composed of terminal bronchioles lined by club cells, non-ciliated secretory cells, and a few ciliated cells
• a transition zone between the conducting and gas exchange areas

Question 4

Describe the function and components of the Gas Exchange system

Answer 4

• composed of respiratory bronchioles and alveoli
• alveoli lined by epithelial type 1 and type 2 pneumonocytes
• where gas exchange occurs

Question 5

What is the path of airflow?

Answer 5

nasal cavity > nasopharynx > larynx > trachea > bronchi > bronchioles > respiratory bronchioles > alveolar ducts > alveolar sacs > alveoli

Question 6

What are the specific and non-specific defense mechanisms?

Answer 6

Non-Specific: mucous trapping, mucocilliary clearance, phagocytosis, air turbulance
Specific: antibody production, cell-mediated immunity

Question 7

Explain the lining epithelium of the Conductive system

Answer 7

pseudostratified ciliated, columnar epithelium, with secretory goblet cells and submucosal cells

Question 8

What are the three regions of the nasal cavity?

Answer 8

• vestibular region
• respiratory region
• olfactory region

Question 9

Describe the vestibular region of the nasal cavity

Answer 9

• external part of the nasal cavity
• cutaneous mucous membrane, hair, and glands
• lined with stratified squamous keratinized epithelium

Question 10

Describe the respiratory region of the nasal cavity

Answer 10

• largest region
• lined with pseudostratified columnar ciliated epithelium with goblet cells
• contains mucocilliary apparatus and Chonchae turbinates

Question 11

What are the Conchae Turbinates?

Answer 11

projections from the lateral wall that narrow the lumen of the nasal cavity and increase the area of contact of inhaled air with mucous membrane

Question 12

Describe the Mucociliary Apparatus

Answer 12

• pseudostratified ciliated columnar epithelium with goblet cells
• movement of cilia removes mucus with trapped inhaled particles
• a cleaning apparatus

Question 13

Describe Goblets cells: locations, functions, and features

Answer 13

• present from nasal cavity to the level of large bronchioles
• all cells in contact with basement membrane
• secrete mucinogen that traps particulate matter
• hyperplasia and metaplasia (lose cilia) in smokers

Question 14

Describe the Olfactory epithelium

Answer 14

• much thicker than respiratory epithelium
• no goblet cells
• specialized sensory cells: olfactory neurons, sustentactular cells, stem/basal cells

Question 15

Describe the Olfactory region

Answer 15

• located in dorsal part of nasal cavity
• lamina propria contains serous olfactory glands and non-myelinated axons of olfactory neurons
• rich in venus plexuses (swell bodies)

Question 16

What is the functions of the Vomeronasal Organ?

Answer 16

• chemoreception, sexual behavior

- smelling pheromones

Question 17

Describe the Larynx

Answer 17

• includes cartilage, vocal folds, skeletal muscle
• initial part lined by stratified squamous epithelium
• after the vocal chords, lining changes to pseudostratified ciliated columnar epithelium

Question 18

Describe the Trachea

Answer 18

• lined by ciliated pseudostratified columnar epithelium
• serous glands in the lamina propria/submucosa
• rings of hyaline cartilage incomplete in mammals, complete in birds
• contain goblet cells

Question 19

Describe the Bronchi

Answer 19

• trachea bifurcates into two bronchi
• lined by ciliated pseudostratified columnar epithelium
• smooth muscle surrounds lamina propria, then connective tissue with mixed bronchial glands and plates of hyaline cartilage

Question 20

What are the general features of Bronchioles?

Answer 20

• lack cartilage and glands
• subdivided into terminal and respiratory bronchioles
• Clara/Club cells bulge into lumen

Question 21

Describe Terminal Bronchioles

Answer 21

• lined by ciliated cuboidal cells with few to no goblet cells
• muscularis mucosae present

Question 22

Describe Respiratory Bronchioles

Answer 22

• function is gas exchange and conduction
• lined by ciliated cuboidal epithelium which become flattened distally
• have incomplete muscularis muscosae
• subdivide into alveolar ducts

Question 23

What are the functions of Clara/Club cells?

Answer 23

• source of surfactant-like substance which aids in maintaining patency of airway
• metabolize airborne toxins, may have immune function

Question 24

Describe the Alveolar Ducts

Answer 24

• part of the exchange system
• empty into alveolar sacs and alveoli
• walls composed of alveoli lined with simple squamous epithelium
• edge surrounding each opening of alveoli contains smooth muscle

Question 25

Describe Alveolar Sacs

Answer 25

- site of gas exchange - no smooth muscle - lined by pneumocytes type 1 and 2

Question 26

Describe the Alveolar Septum + Interstitium

Answer 26

- contains fibroblasts and capillaries - dust cells = macrophages that migrate through pores - collagen type III present in alveolar wall - collagen type I present in conducting airways - elastic fibers present, allow lungs to stretch

Question 27

Describe Type 1 Pneumocytes

Answer 27

- forms walls of alveoli - 95% of alveolar surface area - gas permeability, prevent fluid passage - not mitotic

Question 28

Describe Type 2 Pneumocytes

Answer 28

- 5% of alveolar surface area - secretory cells: produce surfactant via lamellar bodies (granules) - can be mitotic: produces types 1 and 2

Question 29

What is Surfactant and what is its function?

Answer 29

- mono-molecular layer of phospholipoprotein - reduces surface tension: reduces effort needed to inflate alveoli, so prevents alveolar collapse - constantly produced by type II pneumocytes - cortisol stimulates production in fetus prior to parturition

Question 30

What are the components of the Air-Blood Barrier

Answer 30

- vascular epithelium - basement membrane of the endothelial cells - basement membrane of type I pneumocytes - cytoplasm of type I pneumocyte covered by surfactant

Question 31

What is the pathway of oxygen into the blood stream?

Answer 31

oxygen in alveolar air > surfactant and cytoplasm of type I alveolar cell > basal lamina of type I cell and basal lamina of endothelial cell > cytoplasm of endothelial cell > capillary RBCs

Question 32

Describe the Pleura of the Respiratory system

Answer 32

- composed of simple squamous epithelial cells (mesothelial cells) - visceral pleura covers the lungs and is continuous with the parietal pleura