Respiration 1 structure

Question 1

What is internal respiration and what is produced and consumed?

Answer 1

-within the cell
-CO2 produced in glycolysis + Krebs cycle
-O2 consumed in oxidative phosphorylation

Question 2

What is external respiration?

Answer 2

-ventilation
-exchange + transport of gases around the body

Question 3

What does respiration rely on?

Answer 3

-diffusion
-O2 diffuses in + CO2 out
-CO2 produced increases intracellular conc. creating a conc. grad
-movement of ventilation maintains diffusion gradients

Question 4

Describe the movement of gases from entering to leaving the lungs

Answer 4

-gases diffuse out of lungs into capillaries
-blood returns to left side of heart
-oxygenated blood pumped around body (O2 carried by haemoglobin)
-O2 rich blood is close to tissues so there’s a conc. grad
-O2 diffuses out of blood into cell + CO2 diffuses into blood
-CO2 carried in blood back to capillaries next to lung
-CO2 diffuses into lung down conc. grad

Question 5

What are the 2 zones in the lungs?

Answer 5

-conducting zone
-respiratory zone

Question 6

What does the conducting zone do?

Answer 6

-no gas exchange takes place
-mechanism to get gases to alveoli

Question 7

What does the respiratory zone do?

Answer 7

-where gas exchange takes place
-alveolie

Question 8

Describe the pathway that gases take after passing through the mouth

Answer 8

1. trachea
2. bronchi
3. bronchioles
4. alveoli
5. alveolar ducts
6. alveolar sacs

Question 9

What structures are in the conducting zone?

Answer 9

-nose
-nasopharynx
-oropharynx (mouth)
-pharynx
-larynx
-trachea
-bronchial tree

Question 10

What are the functions of the conducting zone?

Answer 10

-filters by removing the large particles
-warms it from atmospheric temp to body temp so gases are more soluble
-humidifies it by saturating it with water vapour so airway doesn’t dry out

Question 11

Describe the structure of the bronchial wall

Answer 11

-cartilage rings that prevent bronchial from collapsing
-smooth muscle to control airway diameter
-mucous glands produce mucus that traps and removes any stuck particles
-elastic tissue

Question 12

Describe the respiratory epithelium

Answer 12

-ciliated epithelium
-goblet cells that produce mucus
-sensory nerve endings that pick up chemicals that we breathe in e.g smoke

Question 13

Describe bronchioles

Answer 13

-less than 1mm diameter
-lack cartilage support so are more prone to collapsing
-lined by respiratory epithelium
-proportionately more smooth muscle compared to bronchi to control airway diameter

Question 14

Describe the alveoli

Answer 14

-large surface area for optimal gas exchange
-fed from terminal bronchiole
-thin wall for optimal gas exchange
-surrounded by many capillaries

Question 15

What is the air blood barrier?

Answer 15

-a ‘sandwich’ created by flattened cytoplasm of type I pneumocytes + the capillary wall
-multiple barriers have to be crossed for gas exchange (at least 5)
-membranes brought into very close contact to minimise diffusion distance
-provides a large SA for gas exchange

Question 16

What are the 2 processes of ventilation and what can they be?

Answer 16

-inspiration or expiration
-can be quiet (at rest) or forced (when active)

Question 17

During ventilation, how does the movement of air occur?

Answer 17

Down pressure gradients

Question 18

During inspiration, how is the pressure gradient created?

Answer 18

-atmospheric pressure > alveolar pressure
-air moves into lungs

Question 19

During expiration, how is the pressure gradient created?

Answer 19

-alveolar pressure > atmospheric pressure
-air moves out of lungs

Question 20

What muscles are involved in quiet inspiration?

Answer 20

-primary muscles of inspiration
-diaphragm
-external intercostal muscles

Question 21

What is the effect of muscles in quiet inspiration?

Answer 21

-increase thoracic + lung volume
-increase in volume = reduction in pressure
-air moves into lungs down pressure grad.
-this is Boyle’s law

Question 22

What muscles are used in forced inspiration?

Answer 22

-accessory (secondary) muscles
-scalenes, sternocleidomastoids, neck + back muscles
-upper respiratory tract muscles - increase airway diameter

Question 23

Is quiet expiration active or passive?

Answer 23

-passive
-uses elastic recoil
-no primary muscles of expiration

Question 24

How does quiet expiration occur?

Answer 24

-relaxation of external intercostal muscles
-recoil of lungs due to elastic forces
-diaphragm relaxes

Question 25

What muscles are used in forced expiration?

Answer 25

-accessory muscles
-internal intercostals
-abdominal muscles
-neck + back muscles

Question 26

Where are pleura membranes found?

Answer 26

-on outside of lung
-inside of chest wall

Question 27

What are pleural cavities filled with and where are they?

Answer 27

-in space between membranes
-filled with secretion

Question 28

What doe the pleural membranes do?

Answer 28

-prevents lungs from sticking to chest wall
-lungs can expand + collapse freely

Question 29

Why is it important that the elastic forces in lungs and chest are balanced?

Answer 29

-at rest, inward + outward forces balance
-results in pressure in intrapleural space < atmospheric pressure

Question 30

What is a pneumothorax and what happens as a result?

Answer 30

-collapsed lung
-air gets into intrapleural space due to puncture
-intrapleural space pressure = atmospheric pressure
-elastic nature of lungs takes over + they collapse