Respiratory System

Question 1

Pharynx v. Larynx

Answer 1

Pharynx allows food and air through.
Larynx allows only air through, blocks food from entering by using the epiglottis.

Question 2

Describe the structures of the lungs

Answer 2

Air comes in through the trachea where it reaches multiple bronchi. The bronchi leads to multiple bronchioles which terminate at alveoli which is where gas exchange occurs.

Question 3

Surfactant

Answer 3

Covers alveoli which prevents them from collapsing by lowering the surface tension.

Question 4

Pleurae

Answer 4

A sac that surrounds the lungs and allows them to expand.
- Visceral pleurae- attached to lungs themselves.
- Parietal pleurae - attaches to chest wall.

Inbetween these two pleurae layers is the interpleural space which contains fluid which lubricates layers and allow expansion of lungs into.

Question 5

Which muscles participate in breathing?

Answer 5

Intercostal muscles, diaphragm ( main muscle), and muscles of the chest wall/ neck/ back.

Question 6

Breathing is under what type of NS control?

Answer 6

The somatic NS system but breathing is the autonomic NS.

Question 7

Describe the process of inhalation?

Answer 7

Process of negative pressure breathing.

When we inhale our diaphragm contracts, pushing down, causing an increase in the volume of the interpleural space this results in decrease pressure in the space. The lungs which are greater in pressure then the space expands into the space allowing air to rush in to lungs.

Question 8

Describe the process of exhalation?

Answer 8

Our diaphragm relaxes ( goes back up) which causes a decrease in the volume and therefore an increase in pressure. Now the pressure of the space is greater than the lungs and the lungs removes out of the interpleural space and we exhale.

Question 9

Spirometer

Answer 9

Device used to measure lung capacities and volume.

Question 10

Total lung Capacity ( TLC)

Answer 10

Total volume of air the lungs hold when one inhales completely.

Question 11

Residual volume ( RV)

Answer 11

The volume of air remaining in the lungs when one exhales completely.

Question 12

Vital capacity ( VC)

Answer 12

TLC- RV

Question 13

Tidal volume

Answer 13

The volume of air in the lungs when one exhales completely

Question 14

Expiratory reserve volume ( ERV)

Answer 14

The amount of additional air that can be exhaled by the lungs when we exhale after a normal breath.

Question 15

Inspiratory reserve volume ( IRV)

Answer 15

The additional volume of air that can be inhaled when one inhales during a normal breath.

Question 16

How is our breathing controlled?

Answer 16

Through the ventilation system in the medulla oblongata. Regulates rhythmic breathing.

Question 17

Role of carbonic anhydrase?

Answer 17

Works to convert CO2 into bicarbonate ion so that it can be transported on hemoglobin in RBC ( some of the bicarbonate ion is dissolved in the plasma). In the lungs the reaction is reversed and CO2 is produced and exhaled.

Question 18

What other functions does the respiratory system carry out?

Answer 18

• Thermoregulation ( vasoconstriction/ vasodilation)
• gas exhange @ alveoli- CO2 and oxygen diffuse by the capillaries.
• immune function- muscous, vibrissae ( nasal hairs)
  
  • Muscociliary escalator- ciliary hairs move particulate matter towards oral cavity so it can be swallowed.
    -lungs has macrophages, musocal surfaces has Iga antibodies, lungs has mast cells.
• Control of pH via bicarbonate buffer system.

Question 19

Role of the bicarbonate buffer system?

Answer 19

Use to control body pH but using le chatliers principle to increase or decrease CO2 and O2 concentrations.