W8- Lecture 41- Respiratory system

Question 1

describe the functions of the respiratory systems

Answer 1

Supplies the body with oxygen and removes carbon dioxide.

Filters inspired air.

Goblet cells and cilia of the trachea remove more foreign particles.

Question 2

normal adult averages respiratory rate

Answer 2

12 breathes per minute

Question 3

where in the brain can voluntary breathing come from ?

Answer 3

cerebral cortex.

Question 4

where is the respiratory control centre?

Answer 4

brainstem, within the reticular formation through both the medulla oblongata and the pons

Question 5

what respiratory group has the most important role in the control of respiration (inspiration/ exhalation).

Answer 5

inspiration- DRG dorsal respiratory group

exhalation- VRG ventral respiratory group

Question 6

what is the Hering-Breuer (Inflation reflex) reflex ?

Answer 6

Hering-Breuer Reflexes prevent over inflation or excessive deflation of the lungs.

When the lungs are inflated to their maximum during inspiration, pulmonary stretch receptors send an action potential to the medulla and pons in the brain through the vagus nerve.

The PRG sends signals to inhibit the inspiratory area.

Signals are sent to the diaphragm to stop.

Question 7

what is the Hering-Breuer (deflation reflex) reflex ?

Answer 7

As inspiration stops, expiration begins and lungs deflate.

As the lungs deflate the stretch receptors are deactivated and the compression proprioreceptors activated.

Inhibitory signals stop and inhalation can begin.

Question 8

describe the role of Proprioceptors in muscles ?

Answer 8

Proprioceptors present in muscle detect movement of the body. These receptors input into the respiratory centres and they play a role in stimulating the increase in ventilation that occurs during exercise.

Question 9

describe the role of baroreceptors in vessels

Answer 9

Baroreceptors detect changes in blood pressure. A sudden increase in blood pressure will lead to a decrease in respiration rate (and vice versa).

Question 10

what components make up the upper respiratory tract

Answer 10

The upper respiratory tract – consisting of the nose and nasal cavity, and the pharynx.

Question 11

what components make up the lower respiratory tract

Answer 11

The lower respiratory tract – consisting of the larynx, the trachea, the bronchi, and the lungs.

Question 12

how are the airways divided ?(zones)

Answer 12

The airways are divided into two functional zones with the first 16 generations of branches comprising the conducting zone and functioning to conduct air to the deeper parts of the lungs.

The last seven generations participate in gas exchange and comprise the respiratory zone.

Question 13

what is the purpose of the conducting zone in the respiratory tract

structures

Answer 13

carries air into and out of the site of gas exchange.
The conducting airways are lined with mucus-secreting and ciliated cells that function to remove inhaled particles.
Humidifies the inhaled air and removes particles

Structures:
Nose
Pharynx
Larynx
Trachea

Question 14

where does the trachea begin/ length

splitting at what point ?

Answer 14

Trachea is 11cm long and begins at c6.
T4/5: Trachea bifurcation
Trachea consists of c-shaped hyaline cartilage rings

Question 15

describe mucosa in the respiratory tract

Answer 15

A layer of pseudostratified ciliated columnar epithelial cells that secrete mucus.

Found in nose, sinuses, pharynx, larynx and trachea.

Mucus can trap contaminants.

Cilia move mucus up towards mouth.

Question 16

describe the structure of the lower conducting zone

anatomical differences left v right

segments

clinical references

Answer 16

The position of the heart means that the left bronchus branches off at an angle so that inhaled foreign bodies tend to go down the right bronchus.

A broncho-pulmonary segment is a discrete anatomical and functional unit of the lung that can be removed without disturbing the function of the other segments.

The right lung has 10 segments. The left lung has 9-10.

Clinical relevance:
bronchitis, infection of the bronchi.
bronchiectasis can occur following infection, such as pneumonia, when the bronchi widen, and excess mucus gathers

Question 17

what structures form the respiratory zone of the resp tract

Answer 17

Respiratory bronchioles

Alveolar sacs

Question 18

describe the purpose of alveoli

number
structure to increase exchange
debris movements/ what by
diameter

Answer 18

Purpose: site of gaseous exchange between alveoli and capillary blood

Each lung has 200 million alveoli.

Gaseous exchange between alveolar gas and pulmonary capillary blood can occur efficiently as alveolar walls are thin with large surface area.

Contain alveolar macrophages to carry debris to upper airway.

Diameter of 200-500 μm.

Question 19

how does age effects the number of alveoli / SA ?
birth
8y
adult

Answer 19

birth-low no- low SA
8y-high no- mid SA
adult-high no- high SA

Question 20

lobes of lungs
right
left

how are the lobes separated ?

what are lobes divided into ?

Answer 20

right - 3 lobes superior, middle and inferior.

left - 2 lobes superior and inferior.

by connective tissue

lobes into lobules the right lung consists of 10 lobules whilst the left lung consists of 9 lobules.

Question 21

each lung is contained in a separate cavity, what is this called ?

Answer 21

the pleural cavity

Question 22

The pleural cavities

• formed from
• 2 membranes make
• pleural fluid + functions

Answer 22

The pleural cavities are formed from 2 pleural serous membranes. Known as the parietal pleura, which covers the inner thoracic wall, the diaphragm, and the mediastinum. And the visceral pleura, which covers the surface of the lung.

Between these 2 membranes exists the pleural fluid.

The pleural fluid has 2 functions:
1- To lubricate the movement during breathing of the pleural membranes past one another
2- Holds the pleural membranes together, which in turn insures they can slide easily over one another, whilst making them hard to separate.

Question 23

what are the two lung pleura?

+ cavity between pleura

Answer 23

Parietal: lines the chest cavity and contains the lungs.
Visceral: lines the lung surface.

Cavity between the pleura is called the pleural space.

Question 24

how are both the pleura innervated ?

+ location of pain

Answer 24

Parietal pleura- somatic fibers from intercostal nerves and phrenic nerves; somatic pain will be localised to the intercostal spaces and/or referred to the neck and shoulder areas.

Visceral pleura- innervated by fibers from the cervical and thoracic sympathetic chain and parasympathetic fibers from the vagus nerve; visceral pain is typically vague and poorly localised.

Question 25

Pneumothorax(Entry of air into the pleural cavity )

• reason
• cause

Answer 25

resulting from a penetrating wound of the parietal pleura results in collapse of the lung.
Air sucked into the pleural cavity because of the negative pressure.

Surface tension adhering visceral to parietal pleura will be broken and the lung will collapse.

Question 26

which 2 routes are the respiratory system supplied by ?

Answer 26

Pulmonary circulation

Bronchial circulation

Question 27

which 3 spinal segments help the diaphragm move/ alive ?

Answer 27

c3, 4, 5

Question 28

when are expiratory muscled used for expiration ?

Answer 28

During exercise or disease, expiratory muscles involved.

Question 29

what is boyles law ?

Answer 29

Gases move from regions of high pressure to low pressure.

Boyle’s law states that if the volume increases (inspiration), then the pressure must decrease (and vice versa).

Question 30

name the muscled used for changing the intrathroracic pressure

Answer 30

main-Diaphragm

Sternocleidomastoid
Trapezius
Scalenes
Pectoralis minor
External intercostals

Question 31

which muscled are used for inhalation ?

Answer 31

Diaphragm
Sternocleidomastoid
Scalenes
Pectoralis minor
serratus anterior 
External intercostals

Question 32

which muscled are used for exhilation ?

Answer 32

transversus thoracis
internal intercoastal
diaphragm
rectus abdominis + abdominal muscles

Question 33

how many resp cycles do you expect in a minute ?

fresh air ventilation per min
change for heavy exercise ?

Answer 33

1 resp cycle =1 inspiration followed by 1 expiration

10-15 respiratory cycles per minute

Normal adult at rest approx 4L fresh air enters lungs/min

During heavy exercise
Airflow can increase x20

Question 34

define Tidal volume

Answer 34

Volume inspired and expired with each normal breath

Question 35

define Inspiratory reserve volume

Answer 35

Maximum volume that can be inspired over the inspiration of a tidal volume.

Question 36

define Expiratory reserve volume

Answer 36

Maximal volume that can be expired after the expiration of a tidal volume

Question 37

define Residual volume

Answer 37

Volume that remains in the lungs after a maximal expiration.

Question 38

define inspiratory capacity

Answer 38

Volume of maximal inspiration

Question 39

define Functional residual capacity

Answer 39

Volume of gas remaining in lung after normal expiration

Question 40

define Vital capacity

Answer 40

Volume of maximal inspiration and expiration

Question 41

define Total lung capacity

Answer 41

The volume of the lung after maximal inspiration

Question 42

what is covid 19

Clinical presentation

Answer 42

potentially severe acute respiratory infection caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

a symptom severity ranging from a mild common cold-like illness, to a severe viral pneumonia leading to acute respiratory distress syndrome that is potentially fatal.
Characteristic symptoms include fever, cough, and dyspnoea.
Complications of severe disease include, but are not limited to, multi-organ failure, septic shock, and venous thromboembolism.

Question 43

please review Symbols used in respiratory physiology

Answer 43

there are approx 50 listed

GlHf