Lecture 5 Overview of Respiratory System

Question 1

What are the 2 sections of respiratory sections and how are they split?

Answer 1

upper and lower respiratory tract

upper respiratory tract:
-Nose, nasopharynx, pharynx, larynx

Lower respiratiry tract:
-Trachea, lungs, bronchi, alveoli

Question 2

What are the primary functions of the respiratory system?

Answer 2

-exchanging oxygen and carbon dioxide between blood and the atmosphere
-olfaction
-voice

Question 3

What are the secondary functions of the respiratory system?

Answer 3

-warming and humidifying incoming air
-maistening of cell lining
-keeping lining clean
-keeping airways open during pressure changes
-keeping alveoli open against surface tension

-(fun fact) humans exhale 400ml of water per day

Question 4

Regarding the nasal cavity, what are the key anatomical adaptations? Where is it?

Answer 4

blood supply and hairs

Question 5

Regarding the sinuses what are the key anatomical adaptations? Where is it?

Answer 5

Air cavities in the cranial bones

Question 6

Why is the larynx important? Where is it?

Answer 6

find larynx on a diagram
important for-
-speech- pitch and volume
-preventing material reaching the LRT
-stimulation of larynx by ingested matter produces strong cough reflex- vagal receptors

Question 7

What is the pleura and what does it do? What are the two pleuras?

Answer 7

each lung is surrounded by 2 membranes- this is the pleura
- outer pleura and inner pleura
-space between pleuras is filled with fluid and there is surface tension exists to reduce friction

Question 8

What happens in the trachea? Why is it important?

Answer 8

ends where it bifurcates into 2 main bonchi at the level of the sternal angle
- has horseshoe cartilaginous rings

Question 9

What happens at the main bronchi? Why is it important?

Answer 9

left main bronchus is longer than the right
-bronchi subdivides into lobar and segmental until terminal bronchioles reached

Question 10

What is the pulmonary airway tree made up of?

Answer 10

bronchi and bronchioles

Bronchi-
Segmental bronchus
-large segmental bronchus (about 5 generations)
-Small bronchi (about 15 generations)

Bronchioles-
terminal bronchioles, smooth and elastic fibre layers
-respitory bronchioles (with 3 orders)
- alveolar ducts and alveolar sacs make up the bottom end (contain pores of Kohn)

Question 11

What is the Acinus made up of?

Answer 11

the alveolar ducts and the alveolar sacs

Question 12

What are the differences between the bronchi and bronchioles?

Answer 12

bronchi- cartilage
bronchioles- no cartilage

Question 13

What does the terminal bronchiole do?

Answer 13

supplies the acinus

Question 14

How many alveoli do we have? How and why are they important?

Answer 14

each lung has about 300-350 million alveoli

0.1-0.2 microns in diameter and are a ines single layer of flattened epithelial cells

Question 15

What is the difference between type 1 and type 2 pneumocytes?

Answer 15

10% are type 2 epithelial cells
90% are type 1 epithelial cells and are important because they have direct contact with our pulmonary capillaries

-Type 2 develope after an infection and are important because they secrete surfactant- surfactant is important for surface tension

Question 16

What is cytology?

Answer 16

study of cells

Question 17

What is the nasal cavity lining made up of?

Answer 17

-hairs
-olfactory mucosa- a small area, roof of the nasal cavity, pseudostratified epithelium (respiratory epithelium), ciliated, olfactory cells

-Respiratory mucosa
- cilia, goblet cells, serous and mucous glands, venous plexus

Question 18

What is the olfactory mucosa made up of?

Answer 18

a small area, roof of the nasal cavity, pseudostratified epithelium (respiratory epithelium), ciliated, olfactory cells

Question 19

What is needed for clearance?

Answer 19

goblet cells- produce mucus

Question 20

What is the respiratory mucosa?

Question 21

What are the conducting airways cells?

Answer 21

pseudostratified cells

Question 22

What are the goblet cells structure?

Answer 22

simple cuboidal

Question 23

What are cilia covered with?

Answer 23

a thin layer of mucus

Question 24

What is the mucociliary escalator?

Answer 24

it is the coordinated wave of movment produced by the cilia

Question 25

What is surfactant? What does it contain? Where is it produced and what are the functions of surfactant?

Answer 25

contains- pospholipids, lipoproteins and essential ions

Produced-
it is produced by type 2 epithelial cells

Functions-
-aids expansion of alveoli
-transports solutes out of the alveolar space
it decreases the surface tension of the fluid so decreases the chance of alveolar collapse