Respiratory system

Question 1

ventilation

Answer 1

air exchange between atmosphere and alveoli

Question 2

external respiration

Answer 2

gas exchange between alveoli and lung capillaries

Question 3

gas transport

Answer 3

movement of gases through pulmonary and systemic circulations
-to or from tissue cells

Question 4

Internal respiration

Answer 4

gas exchange between tissue capillaries and tissue cells

Question 5

cellular respiration

Answer 5

gases used and produced in cellular metabolic reactions

Question 6

inspiration

Answer 6

moving from atmospheric into alveoli (low pressure)

Question 7

expiration

Answer 7

moving from alveoli to atmospheric

Question 8

Air flow (F) is equal to what ?

Answer 8

proportional to pressure difference (delta P) between two points and inversely proportional to resistance (R)

F= Palv - Patm/ R

Palv= alveolar pressure

Patm= atmospheric pressure

R= resistance

Question 9

pressure at sea level

Answer 9

760 mmHg = 1 atmosphere

Question 10

boyles law

Answer 10

in a closed system, at constant temperature, pressure of a gas (P) and volume of its container (V) are inversely proportional

• *-increase volume decrease pressure**
• *-decrease volume increase pressure**

Question 11

during ventilation

Answer 11

• volume changes leads to pressure changes (create pressure gradient) and leads to air flow
• continues until pressures are equilibrated between areas (no pressure gradient

Question 12

hyperbaric environment

Answer 12

increased pressure environment

Question 13

transmural pressure

Answer 13

“across a wall”

pressure inside (P in) minus pressure outside (P out) a structure

Question 14

pleural surfaces seperated by?

Answer 14

extremely thin layer of intrapleural fluid in pleural cavity

Question 15

intrapleural fluid

Answer 15

lubricates layers, can slide over each other during breathing

-intrapleural fluid exerts hydrostatic pressure : intrapleural pressure (P ip)

Question 16

intrapleural space

Answer 16

subatmospheric , always less than atmospheric keeps lungs from collapsing

Question 17

transpulmonary pressure (P tp)

Answer 17

(lung wall/intrapleural fluid)

value at rest : 4

-opposes inward elastic recoil of lung

Question 18

chest wall pressure (P cw)

Answer 18

(between intrapleural fluid and atmospheric pressure P atm)

value at rest = -4

-opposes outward elastic recoil of chest wall

Question 19

normal quiet breathing (inspiration)

Answer 19

75% diaphragm

25 % external intercostals

Question 20

more forceful breathing (inspiration)

Answer 20

• diaphragm contracts stronger, more flattening
• external intercostals contract stronger
• recruit accessory muscles of inspiration (scalenes, SCM, Pec minor)
• thoracic cavity gets bigger

Question 21

normal quiet breathing (expiration)

Answer 21

elastic recoil of diaphragm and external intercostals

Question 22

more forceful breathing

Answer 22

• elastic recoil of diaphragm and external intercostals
• recruit accessory muscles of expiration (internal intercostals, abdominal muscles)

Question 23

pressure during expiration

Answer 23

alveolar pressure becomes greater than atmospheric pressure, leading to air flowing out of lungs

Question 24

Where is basic breathing rhythm set in

Answer 24

Medulla Oblongata

Question 25

Pre Botzinger complex

Answer 25

**pacemaker, sends signal to Dorsal Respiratory group**

Question 26

Dorsal respiratory group (DRG)

Answer 26

Carries **inspiratory** neurons (**active/inactive**) Controls **basic breathing cycle for normal, quiet breathing** **-gets infleunce from periphery (inputs) that help control and modify breathing**

Question 27

What drugs supress DRG inspiratory neurons

Answer 27

**Morphine, Barbiturates, fentanyl and heroin**. leads to overdose due to breathing stoppage

Question 28

describe dorsal respiratory group when active and also inactive

Answer 28

**ACTIVE** - 2 seconds - diaphragm contracts and external intercostals contract during most active phase - leads to _quiet inhalation_ **INACTIVE** - 3 seconds - diaphragm relaxes, external intercostals become less active and relax, followed by **elastic recoil of lungs** - leads to _normal quiet exhalation_ (not from DRG)

Question 29

Ventral respiratory Group (VRG)

Answer 29

- **inspiratory** and **expiratory** neurons recruited by DRG when need more than normal, quiet breathing - activate muscles of breathing for more forceful breathes **forceful Inhalation neurons** -→ activate accesory muscles of inhalation; _scalenes, SCM, and pec minor_ contract. **Along with DRG functions** of diaphagram and external intercostals contracting leads to _forceful inhalation_ **forceful exhalation neurons** -→ recuit accesory muscles of exhalation : **internal intercostals, external oblique, internal oblique, transversus abdominus and rectus abdominis** contract. leads to _forceful exhalation_