Term 3: Oxygenation

Question 1

What impact does respiratory rate have on body fluid?

Answer 1

With increased respiration there can be as much as 20% fluid loss therefore dehydration can occur which will cause a decrease in blood volume.

Question 2

In the respiratory system, what does the conducting zone consist of and what is it for?

Answer 2

Nose and nasal cavity, sinuses, pharynx, larynx, trachea, bronchi, lungs. These make up the passageway where the air travels.

Question 3

What does the respiratory zone consist of? What is the function?

Answer 3

Bronchiole and alveoli. This is where gas exchange occurs.

Question 4

What is found in the lining of the conducting cell and what is it’s function?

Answer 4

Epithelium tissue and goblet cells produce mucous and form a membrane along the passageway. Cilia is also located here. These form a protective function by trapping particles and mucous and moving them towards the throat where they can be spat out or swallowed.

Question 5

What is the function of the nasal cavity during respiration?

Answer 5

Air is inhaled, warmed up, passes olfactory receptors and in to sinuses. Hollow sinuses assist with speech, warming air and adding moisture to incoming air.

Question 6

What is the function of the pharynx?

Answer 6

It’s a muscular organ that contributes to food and fluid movement

Question 7

What is the function of the larynx?

Answer 7

Channels air to lungs, channels food via epiglottis, produces sound and speech (voice box)

Question 8

What is the function of the trachea?

Answer 8

Rings of hyaline cartilage maintain passageway to the lungs. Often called windpipe.

Question 9

What are bronchi?

Answer 9

Branching out from the trachea is a network of vessels in to right and left branches called a bronchial tree. A structure of smooth muscle that contracts and relaxes making the diameter of the bronchi changeable during times of need.

Question 10

Which branch of the bronchi is larger/wider and why?

Answer 10

The right bronchus. This is to allow room for the heart.

Question 11

What is pleura and what does it do?

Answer 11

A membrane covering the lungs, chest wall and superior surface of diaphragm. Pleura produces pleural fluid allowing the lungs to move freely across each other during breathing.

Question 12

What are the two types of pleura?

Answer 12

Visceral pleura covering lungs Parietal pleura covering the chest wall and superior surface of diaphragm

Question 13

An elevated respiration rate can be a good indicator of infection. Why?

Answer 13

With infection there is an increase in white blood cells. This increases a person’s bmr which can increase heart rate which can increase a resp rate by up to 5 breaths per minute.

Question 14

What happens to volume and pressure in the lungs when breathing in?

Answer 14

When you breathe in the volume in the lungs increases to accommodate the air, but the pressure decreases because of the extended space within the lungs.

Question 15

What happens to volume and pressure in the lungs when breathing out?

Answer 15

The volume in the lungs decreases as space decreases and pressure increases – forcing air out of the lungs.

Question 16

What is happening in the respiratory system as a person breathes in?

Answer 16

The diaphragm and intercostal muscles contract, causing the thoracic cavity to increase in size. The volume within the lungs (the intrapulmonary volume) increases to accommodate the air entering the lungs. As the air moves into the lungs the pressure decreases.

Question 17

What is happening in the respiratory system as a person breathes out?

Answer 17

The diaphragm and intercostal muscles relax, the lungs recoil, and intrapulmonary volume decreases. As this volume decreases, pressure increases as it forces the air out.

Question 18

What is “inspiration”?

Answer 18

Breathing in.

Question 19

What is “expiration”?

Answer 19

Breathing out.

Question 20

What is asthma?

Answer 20

Irritants cause the bronchioles to become inflamed. Inflammation causes an over production of mucous and constriction.

Question 21

What are some common triggers of asthma?

Answer 21

Mould, cockroaches, pet hair, stress, illness, dust mites, pollen, cigarette smoke, medication, pollutants, car exhaust, fly spray, perfumes, paint, temperature and weather changes, food such as milk, wheat, seafood, soy and peanuts.

Question 22

What is “TV”?

Answer 22

Tidal volume. The lung volume in normal breathing in and out without any extra effort applied.

Question 23

What is IRV?

Answer 23

Inspiratory reserve volume. The maximum volume of air that can be inhaled after a normal inspiration.

Question 24

What is ERV?

Answer 24

Expiratory reserve volume. The maximum volume of air that can be expelled from the lungs after a normal expiration.

Question 25

What is RV?

Answer 25

Residual volume. The amount of air left in the lungs after a forced exhalation.

Question 26

What is VC?

Answer 26

Vital capacity. Total air exchange. The volume of air breathed out after the deepest inhalation.

Question 27

What are some common symptoms of asthma?

Answer 27

Wheezing, breathlessness, coughing, tight chest, hypoxia (decreased oxygen supplies)

Question 28

How is asthma diagnosed?

Answer 28

Use of peak flow meter (best of three), diary, physical assesment and patient history.

Question 29

William Kirby is a 52 year old diabetic who has chronic renal failure. He is also anaemic. Explain the physiological connection between chronic renal failure and anaemia

Answer 29

Erythopoeitin stimulates erythropoiesis (erythrocyctes produced by the bone marrow). Erythropoetin is a protein hormone produces by the kidneys, production is based on availability of oxygen, it increases in response to hypoxia (low O2 levels) and decreases as O2 levels rise. Patients with chronic kidney disease do not produce enough erythropoietin, so therefore the person becomes anaemic. There are EPO injections to treat this.

Question 30

William Kirby is a 52 year old diabetic who has chronic renal failure. He is also anaemic. Explain why Mr Kirby might have an elevated pulse and resp rate.

Answer 30

He is anaemic so there is less O2 circulating in his blood due to a reduction in RBC and therefore haemoglobin. So therefore the heart needs to pump faster in order to supply O2 to the tissues.

He has lower o2 levels so needs to breathe faster to get the O2 he needs

Question 31

The runners in the Olympic marathon run just over 42 kilometres in about 2 hours 20 minutes. The place getters run even faster. During the race the participants access drink stations for fluids but seldom if ever stop to urinate. Explain the physiological basis for the low urine output

Answer 31

The body is losing fluid through the lungs because of an increased respiratory rate, to conserve blood volume the kidneys decrease GFR which decreases urine production

Question 32

As people age the pump action of their heart may start to deteriorate. This reduction in pump function may be accompanied by shortness of breath especially on exertion. What is the physiological basis for this?

Answer 32

When a person is moving or being more active they need more O2 going to the muscles and tissues. Under normal circumstances the heart will beat faster to provide a greater O2 demand. As people age their lungs are less elastic and chest wall is more rigid, so their vital capacity decreases by approx. 1/3. This together with the heart that does not function as well means that the person needs to compensate for this. Therefore the lungs needs to compensate for the increased O2 demand by increasing breathing and the respiratory rate.

Question 33

When a person drinks large amounts of alcohol they may pass out and become comatose. Their breathing can be affected and they may actually stop breathing. Can you provide a physiological explanation for this occurrence?

Answer 33

Alcohol acts as a depressant on the respiratory centre in the medulla (lower brain). This can slow or stop breathing.

Question 34

Annabel is a six month old baby with an ear infection and a temperature of 38.9 C. She has a respiratory rate of 44 breaths per minute. Her lung function is normal. Is there a physiological connection between fever and an elevated respiratory rate?

Answer 34

Fever stimulates respiration. White Blood cell increases, which increases Basal metabolic Rate. Oxygen need increases and so subsequently heart rate will increase (20% - up to 20 bpm). Because of the greater need for oxygen, respirations will increase (20% - up to 5 resp minute).

Question 35

Tommy aged 4 years has been admitted to the ward for a minor operation. He is prone to have temper tantrums when he doesn’t get his own way. When he is really angry he holds his breath until he goes grey and then faints. The nurses need to reassure his parents that Tommy will be ok and not die from this event. Explain the physiological basis for this situation.

Answer 35

Elevated blood carbon dioxide levels stimulate breathing. When the CO2 levels in Tommy’s brain reach a certain level then the mechanism of breathing is triggered, even though Tommy may not be conscious.

Question 36

What is the name for “normal” breathing?

Answer 36

Eupnea

Question 37

What is anatomical dead space?

Answer 37

Approx 500ml of air moves in/out of the lungs during breathing - this is called the tidal volume (TV). Of that, only 70% is involved in gas exchange. The other 30% remains in the conducting zone, this is called anatomical dead space and is not involved in gas exchange.

Question 38

What does a spirometer messure?

Answer 38

Diagnose how efficient the lungs are working during forced inspiration and expiration. Volume and rate of airflow.

Question 39

What are some factors that impact normal breathing?

Answer 39

• Anything that impacts on the intercostals, abdominal, neck muscles - the muscles of the torso & diaphragm.
• These respond to change in volume & pressure within the lungs
• Lungs ability to expand & recoil
• Airways must be capable of accommodating incoming / outgoing air

Question 40

Movement of gases is determined by partial pressure gradient, true or false?

Answer 40

True.

žMovement of gases (O2 / CO2) is either between lungs & blood OR blood & tissues
žIndividual gases move independently of each other
žMovement depends upon concentration (%) and solubility in a fluid
žTherefore movement is based on partial pressure gradient

Question 41

What can impact the movement of gases in the respiratory system?

Answer 41

• When O2 need increases (like during exercise) gases move faster between alveoli and blood
• žDiseases can impact on the distance between alveoli & blood, making exchange of O2 & CO2 more difficult therefore decreasing valuable gas exchange

Question 42

There are more O2 molecules in the alveoli compared to blood capillaries. True or false? Why/why not?

Answer 42

There is more O2 in the lungs/alveoli and less in the blood therefore we can say the partial pressure of O2 is higher in the alveoli.

This difference in concentration moves O2 from the alveoli into the blood- into the pulmonary circulation. O2 doesn’t dissolve in water (less soluble in blood), therefore O2 relies on Hb to transport it., known as oxyhemoglobin.

Question 43

Are there more CO2 molecules in the pulmonary capillaries or alveoli? Why is this? ž

Answer 43

There are more CO2 molecules in the pulmonary capillaries than in the alveoli.

This difference in concentration is to ensure CO2 moves from the capillaries (blood) and in to the alveoli.

Question 44

As co2 travels from the capillaries, what happens to it?

Answer 44

Unlike O2 which relies on Hb to transport it, CO2 does dissolve in water (soluble in blood), therefore the majority is transported in blood / plasma as bicarbonate.

But CO2 in the blood is not good. When there are high levels of CO2, blood pH changes to become acidic. So to maintain pH of blood CO2 converts to HCO3 / bicarbonate.

Question 45

Is žpressure is greater in the blood capillaries than it is is in the alveoli? Why/why not?

Answer 45

Pressure is greater in the blood capillaries than it is is in the alveoli, therefore ensuring CO2 moves into the lungs to be breathed out

Question 46

Why might a person suffering from acidosis be hyperventilating?

Answer 46

If there are large changes in blood levels of CO2, acidosis can occur, respiratory rate increases (hyperventilation) in response to pH change - the body is trying to get rid of the large amount of CO2 in the blood by breathing it out

Question 47

What does the respiratory centre consist of?

Answer 47

pons, dorsal & ventral respiratory gp

Question 48

What part of the brain controls the respiratory system?

Answer 48

The brain stem.

Question 49

What happens to the neurons in the respiratory centre when breathing in?

Answer 49

They are stimulated

Question 50

What happens to the neurons in the respiratory centre when breathing out?

Answer 50

This occurs via reduced stimulation of neurons. Breathing out is also relient on the ability of the lungs to recoil.

Question 51

What stimulates breathing?

Answer 51

Breathing is stimulated by the body’s need to rid CO2, not to take in O2.

Stimuli for breathing is high blood CO2 (hypercapnia)
žWhen blood becomes high in CO2 pH becomes acidic
žReceptors in the medulla & aortic arch (aorta) respond to any change in CO2 levels to regulate rate & rhythm of breathing
žPerson will hyperventilate

Question 52

The body getting rid of CO2 is the stimuli for breathing. In which situations would it be that O2 becomes the stimuli for breathing?

Answer 52

It is only when oxygen levels are dangerously low such as in serious lung diseases and altitude changes that cause O2 to become the stimuli for breathing.

Question 53

What is it called when a person has low blood O2 levels?

Answer 53

Hypoxia. This refers to Impaired oxygen transport, or an inadequate supply of oxygen to the body’s tissues

Question 54

What are some signs of hypoxia?

Answer 54

If someone is hypoxic the nurse will notice impaired respiration & cyanosis: a bluish tinge to the skin and mucosa. In dark skinned people it is seen in the nails & mucosa.

Dysponea is also common.

Question 55

What is dyspnoea?

Answer 55

Dyspnoea – a clinical sign of hypoxia where the person will experience difficult or uncomfortable breathing

Question 56

How does smoking impact respiration?

Answer 56

Found in cigarettes are chemicals which:

• decrease cillary action resulting in excessive production of mucous, increasing the risk of pneumonia and other infections. Also ncreases the risk of cell mutations = increases the risk of cancer
• stimulates the inflammatory response: Inflammation brings an influx of WBC – because there is no infection, the cells still release enzymes which begin the destruction of bronchiole and the walls of the alveoli.
• the movement of gases is dependent upon the distance between the capillaries and alveoli, anything that disrupts that distance - gas exchange becomes impaired.

Question 57

How does the inflammatory response impact on gas exchange?

Answer 57

žDamaged alveoli walls means a reduced surface area & an increased diffusion distance, this reduces O2 partial pressure gradient & so less O2 moves into the blood

žIncoming air remains trapped in the anatomical dead space & as this volume increases gas exchange reduces

Question 58

What is surfactant in the lungs?

Answer 58

The main role of surfactant is to prevent collapse of the alveoli thereby reducing the effort needed to expand the lungs during inspiration (breathing in) and allow gas exchange to take place. Surfactant therefore helps breathing to be relatively effortless.

Question 59

What happens to breathing as the body ages?

Answer 59

As one ages, thorax becomes rigid, lungs loose their elasticity and protective mechanisms become less effective.

Resp rate also increases.