Respiratory System

Question 1

What does a failure of the respiratory or cardiovascular system lead to?

Answer 1

A disruption of homeostasis and rapid death of cells from oxygen starvation and accumulation of waste products

Question 2

What three functions are the interior structures of the nose specialised for?

Answer 2

1) Incoming air is warmed, moistened and filtered
2) Olfactory stimuli are received
3) Large, hollow resonating chambers modify speech sounds

Question 3

Where can the trachea be found?

Answer 3

from the larynx to the T5 vertebral area

Question 4

What is the hilum?

Answer 4

The region where the bronchus, blood vessels, nerves and lymphatics enter the pleural cavities and the lungs

Question 5

What cell types can be found in the alveolus?

Answer 5

1) Type 1 cells- form the continous lining of the alveolar wall and are the main site of gas exchange
2) Type II cells- produce the surfactant
3) Alveolar macrophages ( remove fine dust and other debris)

Question 6

What does surfactant do?

Answer 6

Helps lower the surface tension which helps keep the alveoli inflated. Also helps to keep the alveoli inflated.

Question 7

Where does the lower respiratory tract start?

Answer 7

From the trachea downwards

Question 8

What do the smallest bronchioles consist of?

Answer 8

A single layer of epithelial cells

Question 9

What can the lower respiratory tract be divided into/

Answer 9

Conducting and respiratory portions

Question 10

What happens in the respiratory portion?

Answer 10

Gas exchange- respiratory ( terminal) bronchioles, alveolar ducts and the alveolar sac containing many alveoli

Question 11

What are the main inspiratory muscles?

Answer 11

Diaphragm and intercostals

Question 12

What is pulmonary ventilation?

Answer 12

The movement of air between the atmosphere and lungs ( occurs because of the pressure gradient)

Question 13

Where is the diaphragm?

Answer 13

It separates the thoracic and abdominal cavities

Question 14

What is the p02 in alveolar air?

Answer 14

13.3 kPa.
The partial pressure of O2 in alveolar air is less than that of O2 in the atmosphere because O2 is continually moving out the alveoli into the pulmonary circulation

Question 15

How does the right primary bronchus differ to the left and what does this mean in practice?

Answer 15

Shorter, more vertial and wider than the left.

This means that fogein materials are more likely to get lodged here.

Question 16

How many lungs does the right lobe have?

Answer 16

Tri lobed

Question 17

What epithelium lines the bronchus?

Answer 17

Ciliated epitheilium ( columnar)

Question 18

What controls basic respiration rhythym?

Answer 18

Parts of the medulla oblongata and pons

Question 19

How does lung capacity change with age?

Answer 19

It decreases with age ( typically by 35% by the age of 70). This is due to airways and tissues loosing elasticity and becoming more rigid.

Question 20

What does a peak flow meter measure?

Answer 20

Measures Peak expiratory flow rate ( PEFR or PEF)

Question 21

What is an acceptable blood pH?

Answer 21

7.35-7.45

Question 22

What are the different types of hypoxia?

Answer 22

1) hypoxic hypoxia ( caused by low arterial p02)
2) anaemic hypoxia ( insufficient hb to carry o2)
3) stagnant hypoxia ( poor blood flow)
4) histotoxic hypoxia ( tissue has adequate oxygen supply but cannot use it, for example, cyanide poisoning)

Question 23

The posterior thoracic cage is composed of how many pairs of ribs?

Answer 23

12
Rib pairs 1-7 attach directly to the sternum ( true ribs), r
Ribs 8-10 attach to the cartilage of preceding ribs ( false ribs)
Ribs 11-12 do not attach to any part of anterior thoracic cage ( floating ribs) (false ribs)

Question 24

What are the specialist adaptions of alveoli for gas exchange?

Answer 24

1) Only one cell thick- very short diffusion distance ( Fick)
2) Bathed in surfactant- moisture aids diffusion of gases
3) Surrounded by a vast capillary network ( provides good blood supply to move gases around) ( concentration gradient- Fick)

Question 25

The wandering phagocytes found in the alveoli are called?

Answer 25

Alveolar macrophages. They remove dust and other debris from the alveoli by phagocytosis. Some particles ( for example, asbestos, silica) cannot be engulfed and digested by alveolar macrophages, resulting in irreversible respiratory disease through an accumulation of these materials within lung tissue

Question 26

Carbon dioxide is carried from body tissues in what form?

Answer 26

HCO3- ( Bicarbonate ions

Question 27

Is HCO3- an acid or base? what role does it play?

Answer 27

It is an alkaline and has an important role in maintaining acid- base homeostasis within the body.

Question 28

Where is acid base homeostasis particularly important?

Answer 28

In the CNS tissues, where pH deviation too far beyond the normal range can be life threatening.

Question 29

Lung volumes exchanged during breathing are measured using a....?

Answer 29

spirometer

Question 30

How many respirations does a healthy adult have per minute?

Answer 30

Average of 12

Question 31

How many litres of air does a healthy adult move in and out of lungs when resting per minute?

Answer 31

6L

Question 32

What is the total lung capacity in a healthy male ( approx?)

Answer 32

6000mL ( 6L)

Question 33

What are lung volumes?

Answer 33

1) Inspiratory capacity ( the total inspiratory ability of lungs). Is the sum of the tidal volume plus inspiratory reserve volume 2) Functional residual capacity ( the sum of residual volume plus expiratory reserve volume) 3) Vital capacity ( sum of inspiratory reserve volume, tidal volume and expiratory reserve volume).

Question 34

What is total lung capacity?

Answer 34

The sum of all volumes

Question 35

Is the blood in the pulmonary artery truly deoxygenated?

Answer 35

No. It is low in oxygen (5.3 kPa) in comparison to the blood in the highly oxygenated pulmonary vein ( 13.3 kPa)

Question 36

How is most of the oxygen in blood transported?

Answer 36

98.5 % of oxygen within the blood is carried as oxyhaemoglobin. The remainder is dissolved in plasma

Question 37

What are the three forms CO2 is carried in the blood?

Answer 37

1) bicarbonate ions ( approx 70%) 2) carbaminohaemoglobin ( approx 23%) 3) dissolved CO2 ( approx 7%)

Question 38

What forms the walls of the larynx?

Answer 38

Muscle and cartilage

Question 39

What is external respiration

Answer 39

The exchange of gases between alveoli and their surrounding capillaries

Question 40

What is internal respiration?

Answer 40

Exchange of gases between the circulating blood and body tissues

Question 41

How many breaths per minute do healthy adults take?

Answer 41

12

Question 42

What affects the rate of breathing?

Answer 42

Age, exercise, fever, illness etc

Question 43

Is breathing exhalation passive or active?

Answer 43

During normal quiet breathing we exhale passively through lung recoil and muscle relaxation. For rapid and deep breathing the expiratory centre in the brain becomes active and sends impulses to the muscles to force exhalations.

Question 44

What can be consciously controlled?

Answer 44

The rate and depth of breathing

Question 45

What is compliance?

Answer 45

Ability of the lungs to stretch during a change in volume relative to a change in pressure.

Question 46

What can affect compliance?

Answer 46

Certain pulmonary diseases. Fibrosis of the lungs- makes lungs become stiffer and therefore decreases compliance. In emphysema- only a small pressure difference is necessary to maintain a large volume resulting in an increase in compliance.

Question 47

Where is the respiratory centre and what does it consist of?

Answer 47

The area which sends nerve impulses to respiratory muscles is located in the medulla oblongata and pons of the brain stem.

Question 48

What are the three neurones of the respiratory centre?

Answer 48

1) medullary rhythmicity centre in the medulla oblongata 2) pneumotaxic area in the pons 3) apneustic area ( also in the pons)