Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine 1.2 > Respiratory Physiology > Flashcards

Respiratory Physiology Flashcards

1
Q

What is the role of the lungs?

A
  • To bring in fresh air, rich in the O2 needed to fuel the body
  • To expel the waste gas (CO2) produced from cells in the body.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why do we breathe?

A

To maintain blood, gas homeostasis (O2, CO2 and pH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is partial pressure?

A

Sum of the partial pressures (mmHg) or tensions (torr) of a gas must be equal to total pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How can partial pressure of gas be calculated?

A

Pgas = fraction of a gas in gas mixture(Fgas) X barometric pressure
Pgas=Fgas X Pb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens in airwyas to air?

A

Air warmed and humidified (becomes saturated with water vapour)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the barometric pressure at sea level?

A

760mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the respiratory muscles?

A
  • Diaphragm major; inspiratory, dome-shaped skeletal muscle

- Other respiratory skeletal muscles activate during more strenous breathing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the mechanisms by which quiet breathing occurs?

A
  • Inspiration = active
  • Diaphragm contracts downwards pushing abdominal contents outwards.
  • External intercostals pull ribs outwards and upwards
  • Expiration = Passive
  • Elastic recoil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the mechanisms of strenous breathing?

A
  • Inspiration = active
  • Greater contraction of diaphragm and external intercostals.
  • Inspiratory accessory muscles active eg. sternocleid omastoid, alae nasi, gengiglossus
  • Expiration = Active
  • Abdominal muscles (rectusabdominus, internal oblique, external oblique and transversus abdominus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the components of the resp. system?

A
  • Nasal cavities, paranasal sinuses (filter, warm, air)
  • Pharynx, larynx
  • Bronchi
  • Alveoli
  • Trachea
  • Lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where and how does filtering of air happen?

A
  • Upper airways to bronchioles lined by pseudo stratified, ciliated, columnar epithelium.
  • Inhaled particles stick to mucous. Mucous moved towards mouth by beating cilia.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why do we have a cough refulx?

A

Protective reflux - rids airways of offending material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are RAR’S?

A

Rapidly adapting pulmonary stretch receptors are found in epithelium of resp. tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the role of RAR’s?

A

Activated by dust, smoke, ammonia, oedema etc.

RAR’s afferents of vagus nerve, which send signal to brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the process of the cough reflux?

A
  • Stimulation of RAR’s by irritant
  • Afferent info sent via vagus nerve, which send signal to brain
  • Brain sends info to diaphragm and external intercostals to induce strong contraction
  • Air rushes into lungs
  • Abdominal muscles contract to induce expiration
  • Glottis opens to forcefully release air and irritants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the process of respiration (in relation to pressure)?

A
  • Beginning of inspiration, no flow Pa=0, Pb=0
  • Inspiratory muscles contract-inc.thoracic volume
  • Pleural pressure becomes more negative
  • Increase in transpulmonary pressure
  • Lungs expand and alveolar volume increases
  • Pa becomes negative (below Pb)
  • Air flows into alveoli (from high to low pressure)
  • End inspiration; muscles stop contracting, thorax and alveoli stop expanding, Pa=Pb (no flow)
  • Begin expiration : thoracic volume decreases
  • Ppl and Pl return to pre-inspiration values
  • Thorax and lungs recoil (elastic recoil pressure)
  • Air in alveoli compressed
  • Pa becomes greter than Pb
  • Air flows out of lungs
17
Q

What is the respiratory tree formed of?

A

Airways branch into smaller, more numerous bronchioles until terminating in a group of alveoli.

18
Q

What happens in each division of the resp. tree?

A

Each division results in an increase in no., a decreased diameter and an increase in surface area.

19
Q

What is the role of conducting airways?

A
  • Conduct air to body
  • Bronchi containing cartilage and non respiratory bronchioles
  • Dont participate in gas exchange
  • 150 mls in volume, form anatomic dead space
20
Q

What is the role of respiratory airways?

A
  • Bronchioles with alveoli, where gas exchange occurs (from terminal bronchioles to alveoli)
  • Resp. unit is gas exchanging unit; consists of resp. bronchioles, alveolar ducts and alveoli.
  • 2500ml volume
  • 5mm long
21
Q

How many alveoli are there and what are they composed of?

A
  • In adult; 300-400 million alveolar sacs

- Composed of type 1 and 2 epithelial cells

22
Q

What is the role of alveoli?

A

Perfectly designed for gas exchange: - large SA

  • Very thin walls
  • Good diffusion characteristics
23
Q

What are type 1 and 2 epithelial cells?

A

Type 1 = Primary site of gas exchange 97% surface area of alveoli.
Type 2 = (septal cells) produce pulmonary surfactant (reduces surface tension)

24
Q

What are the blood supplies of the lungs?

A

It has 2 separate supplies:

  • Pulmonary; brings deoxygenated blood from heart to lung and oxygenated blood form lung to heart and then rest of body.
  • Bronchial; brings oxygenated blood to lung parenchyma
  • Also has lymphatic system
25
Q

What are arteries features like?

A

Thin walled, highly compliant, large diameter, low resistance (compared to systemic circulation)

26
Q

Why does blood supply increase during exercise?

A

Increases during exercise due to recruitment of new capillaries secondary to an increase in pressure and flow.

27
Q

What are the gas gradients in the pulmonary and systemic circulation?

A

-Pulmonary: O2 enters blood, CO2 leaves
-Systemic: O2 leaves blood, CO2 enters
Gases move down their pressure gradients
Similar volumes of CO2 and O2 move each minute.
Pressure gradient for O2 much biggr than for CO2.

28
Q

How does gas exchange occur?

A

Through dense mesh like network of capillaries and alveoli.
Type 1 epithelial cell, capillary endothelial cells and basement membrane involved.
RBC’s pass through capillaries in less than 1 sec, sufficient time for CO2 and O2 gas exchange.

29
Q

Where does CO2 and O2 move during gas exchange?

A

CO2 goes from capillary to alveoli and O2 moves from alveoli to capillary.

30
Q

Describe the basic breathing mechanism?

A
  • During breathing, the contraction and relaxation of muscles acts to change the volume of the thoracic cavity. As the thoracic cavity and lungs move together, this changes the volume of the lungs, in turn changing the pressure inside the lungs.
  • When the volume of the thoracic cavity increases- the volume of the lungs increases and the pressure within the lungs decreases.
  • Whene the volume of the thoracic cavity decreases- the volume of the lung decreases and pressure in the lung increases.
31
Q

Alveoli are sac-like structures where gas exchange occurs in the lungs. How do alveoli remain open (that is, do not collapse in on themselves)?

A

Production of surfactant

Medicine 1.2 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions