Respiratory system (262-271) Flashcards Preview

BOARD: Biochemistry (Dental Decks) > Respiratory system (262-271) > Flashcards

Flashcards in Respiratory system (262-271) Deck (35):
1

Alveolar ventilation = ?

Respiratory rate x (tidal volume - dead space)

2

Alveolar ventilation is a good criterion to determine what?

Effectiveness of breathing

3

Where does the exchange of oxygen and carbon dioxide between the lungs and blood occur?

Inside alveoli

4

T or F, When the lungs are in the resting position, the pressure inside them is less than the atmospheric pressure

False, Equal to atmospheric pressure

5

T or F, under normal circumstances, intrapulmonary pressure is ALWAYS greater than intracellular pressure

True

6

Pulmonary ventilation is influenced by what three things?

Arterial PO2, arterial PCO2 and arterial pH

7

What are the receptors that influence pulmonary ventilation

1. Central (medullary) chemoreceptors - located in the medulla; stimuli that increase breathing rate are decrease pH and increase PCO2
2. Peripheral chemoreceptors - located in the carotid and aortic bodies; stimuli that increase breathing rate are PO2, increase in PCO2 and decrease in pH

8

If there is a very low PO2 in arterial blood what happens to the pulmonary ventilation

It increases

9

If there is elevated arterial PCO2, what happens to pulmonary ventilation?

It increases

10

If there is a high arterial pH, what happens to pulmonary ventilation?

It decreases

11

What is the major stimulus for the respiratory centers?

Arterial PCO2

12

What is the Hering-Breuer Reflex?

It prevents overinflation of the lungs. It is mainly a protective mechanism that prevents the lungs from overfilling during inspiration. It is initiated by distention in lung stretch receptors.

13

3 major types of sensory receptors located in the tracheobronchial tree that control breathing?

1. J receptors (juxta-alveolar)
2. Irritant receptors
3. Joint and muscle receptors

14

Where are the J receptors located and what do they do?

located in alveolar walls; when stimulated J receptors cause rapid, shallow breathing

15

Where are the irritant receptors located and what do they do?

Located between airway epithelial cells; are stimulated by noxious substances

16

What activates the joint and muscle receptors?

activated during exercise to stimulate breathing

17

An increased PCO2 does what to respiration by stimulating what receptors?

increases respiration
- by stimulating the central H+ chemoreceptors

18

What term is the greatest amount of air that one can exchange in a forced respiration?

Vital capacity (VC)
- VC = TV+IRV+ERV

19

What term is the amount of air inspired or expired with each breath?

Tidal volume (TV)
- normal RR is about 12 times per minutes

20

What term is the volume of air inspired in a full inhalation, after an normal expiration?

Inspiratory capacity
- IC = IRV + TV

21

What is the amount of air remaining in the lungs at the end of normal expiration?

Functional residual capacity (FRC)
- provides air to alveoli that will aerate the blood evenly between breaths
- FRC = ERV + RV

22

What is the extra volume of air that can be inspired over and above the normal tidal volume (by taking a deep breath)

Inspiratory Reserve (IRV)

23

What is the extra volume of air that could still be expired past the normal expiration of tidal volume

Expiratory Reserve (ERV)

24

What is the volume of air moved into the respiratory passageways in one minute?

Minute respiratory volume (MRV)
- MRV=TV x RR

25

What is the maximum volume that the lungs can be expanded with the greatest possible inspiratory effrot?

Total lung capacity

26

What is the volume of air remaining in the lungs at the end of a forced maximal expiration?

Residual volume (RV)

27

4 factors that will determine how fast gas will pass (Diffuse) through the respiratory membrane

1. Thickness of Membrane - rate is inversely proportional
2. Surface area of membrane - rate is directly proportional
3. Gas solubility and MW - increasing pressure, more molecule dissolve in liquid
4. Pressure difference between the two sides of the membrane - net diffusion from high to low pressure regions

28

What is Apnea

Transient cessation or absence of breathing

29

What is Hyperapnea

Abnormally deep and rapid breathing

30

What is Dyspnea

Unpleasant sensation of difficulty in breathing

31

What is Hypercapnea

Excess CO2 in arterial blood

32

What is Hypocapnea

Below normal CO2 in arterial blood

33

What is Respiratory arrest

permanent cessation of breathing

34

Most important test for hypoventilation

Arterial CO2 tension

35

Two situations that excite respiratory neurons and increase respiration are?

1. Increase in [H+] in the arterial blood
2. Increase in arterial blood PCO2