respiratory anatomy and physiology

Question 1

what is respiration?

Answer 1

the exchange of gases between the tissues of the body and the external environment
involves 2 gases: O2 (required to function), CO2 waste product produced during metabolism

Question 2

what is some other functions of the respiratory system?

Answer 2

• enables speech, singing etc (flow of air over larynx)
• route for water loss and heat elimination
• enhances venous return (getting blood back to right atrium)
• helps maintain normal acid-base balance (metabolic and respiratory acidosis and alkalosis)
• defends against inhaled foreign matter
• nose served as organ of smell (stimulated by GPCRS)

Question 3

how many lobes are on each lung?

Answer 3

2 on the left
3 on the right

Question 4

what separates the thoracic and abdominal cavity?

Answer 4

diaphragm

Question 5

why are small bronchioles in the conducting zone important ?

Answer 5

there is no cartilage to hold them open so can expand and contract to control the amount of air that is reaching the lungs controlled by the ANS

Question 6

What cells are present in the respiratory zones?

Answer 6

cilliated epithelium

Question 7

what are type 1 alveolar cells?

Answer 7

non-cilliated epithelium for gas exchange

Question 8

what are type 2 alveolar cells?

Answer 8

supply surfactant which reduces surface tension and keeps the alveoli compliant

Question 9

what are macrophages?

Answer 9

clear foreign particles

Question 10

what are columnar epithelial cells?

Answer 10

ciliated to trap dust and microparticles which can trap bacterial and remove them out of the lungs

Question 11

what are goblet cells?

Answer 11

mucous secreting - specialised cells which can trap bacteria and kill it as contains antibacterial substances

Question 12

what is mucocillary clearance?

Answer 12

combination of mucous working with cilia (keeping area infection free)

Question 13

how is respiration controlled by the PNS?

Answer 13

direct interactions of the smooth muscle of the bronchioles - acetylcholine acts on muscarinic M3 receptors
- CONTRACTION

Question 14

how is respiration controlled by the SNS

Answer 14

indirect innervatiom
- release NA onto the alpha 2 receptors on the pre-ganglion of nerves
- Adr release from adrenal medulla
- reduction of release of acetylcholine
RELAXATION

Question 15

where is the ganglia on the PNS?

Answer 15

usually very close to the target of the end point or in the organ itself
- doesn’t go directly to smooth muscles on bronchioles

Question 16

how is blood supplied in the lungs?

Answer 16

By tracheal arteries (from thyroid arteries and veins)

Pulmonary artery from heart - gets replenished with oxygen then pulmonary vein back to heart

Question 17

what are two interrelated concepts involved in pulmonary elasticity?

Answer 17

Compliance
Elastic recoil

Question 18

what is elastic recoil?

Answer 18

defined as the tendency of an elastic structure to oppose stretching or distortion
- lungs are held open by a positive trans pulmonary pressure (Ptp)

Question 19

why is moisture required in the lungs and what does it cause?

Answer 19

• required to dissolve gases prior to moving across type I cells
• causes surface tension resulting in an inward pressure
• alveoli are less able to expand during inspiration (less compliant)
  -causes alveoli to collapse

Question 20

what is surfactant?

Answer 20

A phospholipid that gets in between water molecules and reduces the attraction between them
- prevents lung from collapsing
- works better in small alveoli
- prevents too much expansion (molecules get pushed further apart)