Respiratory physiology

Question 1

7 functions of the respiratory system

Answer 1

1. provides for gas exchange
2. filtration of inspired air
3. regulation of blood pH
4. metabolism of copmounds
5. detection of odours
6. vocalisation
7. immune function

Question 2

the process of respiration (5)

Answer 2

1. breathing/ventilation
2. gas exchange between air in lungs and blood
3. gas transport around body
4. gas exchange between blood and body cells
5. cellular metabolism

Question 3

wat is the compliance of the lung?

Answer 3

the measure of the lung’s ability to expand and contract (elasticity)

Question 4

Asthma triggers (2)

Answer 4

• can vary from person to person
• commonly consists of changes in airway structure

Question 5

what are Serca pumps essentially? (2)

Answer 5

• pumps that pump Ca2+ out of the muscle cell
• after contraction

Question 6

what is emphysema? (2)

Answer 6

• a lung condition wherby the alveoli in the lungs are damaged
• causing shortness of breath

Question 7

how slowed diffusion of gases can occur (1), and the causes of it (4)

Answer 7

pulmonary hypertension:
* cardiac insufficiency
* infection/ inflammation
* pulmonary embolism
* environmental hypoxia

Question 8

what is more effective in changing alveolar ventilation rate, tidal volume or respiratory frequency?

Answer 8

• tidal volume

Question 9

what is exercise hyperpnoea? (2)

Answer 9

• the increase in rate and depth of breathing that occurs during physical activity
• ensures adequate oxygen supply to body’s tissues & waste removal

Question 10

how is the Bohr effect mediated? (3)

Answer 10

local chemical changes in exercising muscles due to:
* more CO2 produced
* higher blood acidity
* increase in temperature

Question 11

does PO2 change with elevation, and if so how (2)

Answer 11

• PO2 stays the same no matter elevation above sea level
• always about 21%

Question 12

what is oedema?

Answer 12

a build up of fluid in the body, causing affected tissue to become swollen

Question 13

how do peripheral chemoreceptors monitor arterial blood chemistry? (4)

Answer 13

• aortic bodies send signals
• through carotid bodies
• to carotid sinus nerve and vagus nerve
• which transmit signal to brainstem respiratory area

Question 14

what is polycythaemia?

Answer 14

an increased total blood cell count in the body

Question 15

what is respiratory alkalosis? (2)

Answer 15

• an elevated pH (alkaline) and decreased level of CO2
• due to excessive removal of carbon dioxide by respiratory system

Question 16

what happens to PCo2 levels during hyperventilation & why?

Answer 16

• PCO2 falls
• becuases CO2 is exhaled at greater rate than production

Question 17

when does hyperventilation occur?

Answer 17

anytime ventilation is in excess of metabolic needs
* altitude
* astham attack
* under conditions of stress

Question 18

what is apnoea? (2)

Answer 18

• a temperary cessation in breathing when underwater
• characterised by the suspension of airflow into and out of the lungs

Question 19

what is splanchnic contraction?

Answer 19

the contraction of blood vessels in splanchnic circualtion, including the abdominal organs

Question 20

what is an embolus? (3)

Answer 20

• a mass such as a blood clot
• that is moving through the blood stream
• before lodging in a blood vessel

Question 21

what is an embolism? (1)

Answer 21

an embolus that has lodged in a blood vessel

Question 22

what can embolisms lead to? (2)

Answer 22

ischemia - lack of blood supply
infarction - tissue death

Question 23

examples of an embolus (6)

Answer 23

1. thombus (blood clot)
2. fat
3. septic (white blood cell clot)
4. tumour
5. foreign material
6. gas

Question 24

what is blood perfusion? (1)

Answer 24

blood flow through the tissues and organs of the body

Question 25

what do pulmonary embolisms cause within the respiratory system? (2)

Answer 25

* increased physiological dead space * increased minute ventilation

Question 26

what do measurements of systemic arterial blood give us an indicator of?

Answer 26

efficiency of gas exchange in the body

Question 27

two main features of foetal lungs

Answer 27

* hypoxic - as they do not participate in gas exchange * contains special fluid that helps develop structure of lungs

Question 28

how long after birth does the first breath usually occur?

Answer 28

20 seconds

Question 29

how long after birth is a rhythmic breathing pattern established?

Answer 29

90 seconds

Question 30

what is COPD? (3)

Answer 30

* a progressive respiratory condition * characterised by persistant airflow limitation * limitation typically associated with chronic inflamation of airways and lung tissue

Question 31

how many different cell types do humans have inside their genome?

Answer 31

about 250

Question 32

what makes each cell different from each other?

Answer 32

their epigenome

Question 33

what is the epigenome? (2)

Answer 33

* the collection of chemical compounds and modifications that can mark and modify DNA ans associated proteins * influences gene expression without altering underlying DNA sequence

Question 34

what are the key components of the epigenome? (4)

Answer 34

* DNA methylation * Histone modification * Non-coding RNA molecules * Chromatin structure

Question 35

can epigenomes be modified by toxins in daily life, and if so how?

Answer 35

yes - by pollutants such as smoking

Question 36

why is modification of the epigenome by toxins bad? (3)

Answer 36

* controls cell fate and differentation * cellular memory of past exposures occurs * epigenetic alteration is a key driver of many diseases

Question 37

function of fibroblasts (3)

Answer 37

* lung structure support & repair * cross-talk to epithelial cells

Question 38

relevance of fibroblasts in COPD:

Answer 38

* reduced repair capacity * premature aging * small airway fibrosis

Question 39

what is fibrosis of airways? (3)

Answer 39

* thickening of the area around airways * due to extracellualr matrix production * making the airway rigid

Question 40

how to diagnosis for COPD?

Answer 40

* Use spirometer * measures forced vital capacity in 1 second of exhalation

Question 41

what does DMR stand for?

Answer 41

**D**ifferentiated **M**ethylated **R**egion Multiple Sites