Unit 6.4 and D6 - Respiratory system

Question 1

Define ventilation, gas exchange, and respiration

Answer 1

Ventilation: the physical transport of air to and from the lungs.

Gas exchange: the net movement (diffusion) of carbon dioxide and oxygen to and from the alveoli and bloodstream

Respiration: the creation of ATP from a cellular perspective. (aerobic or anaerobic)

Question 2

Purpose of ventillation

Answer 2

To ensure that there is enough oxygen in the body to undergo anaerobic respiration (as energy is required for life) a high concentration gradient of oxygen must be maintained in the lungs through ventilation as to allow constant gas exchange to occur.

Question 3

Structure and function of both type 1 and type 2 pneumocytes

Answer 3

Type 1: Squamous and flat, to allow for the diffusion distance to be small as to allow for a faster diffusion rate. They are amitotic, meaning they cannot undergo mitosis / cell replication. They are connected by occluding junctions as to remove the leakage of tissue fluid into open space

Type 2: Cuboidal in shape, produce pulmonary surfactant which reduces surface tension in alveoli, this is useful as it ensures the shape of the alveoli are maintained.

Question 4

How is carbon dioxide transported in the body?

Answer 4

1) Dissolved in blood plasma
2) As carbonic acid
3) In the haemoglobin (carbaminohaemaglobin)

Question 5

Explain Bohr shift

Answer 5

Bohr shift is when the dissociation curve of % of haemoglobin binding sites for oxygen on partial pressure of oxygen shifts to the right as a cause of a lowered pH. This lowered pH is usually as a cause of increased cellular respiration as CO2 is released as a product and is acidic. So, haemoglobin is required in these cells to continue cellular respiration. Thus, oxygen needs to be expelled from the haemoglobin, so affinity is lowered.