Physiology

Question 1

Partial pressure of oxygen (Pa O2) in normal arterial blood

Answer 1

100 mm Hg

Question 2

Partial pressure of oxygen in mitochondrion

Answer 2

4-22 mmHg

Question 3

Delivery of O2 (DO2)

Answer 3

DO2=CaO2*Q
CaO2 arterial blood content
Q- blood flow (cardiac output)

Question 4

Arterial blood content (Ca O2)

Answer 4

CaO2=1,34HbSaO2+0.003*PaO2

Question 5

causes of hypoxemia

Answer 5

1) alveolar hypoventilation
2) diffusion impairment
3) ventilation -perfusion mismatch
4) right -to-left shunt

Question 6

Cardiovascular system and magnesium

Answer 6

1)Direct depressant effect on myocardial and vascular smooth muscle.
2) Inhibits the release of catecholamines from the adrenal medulla, peripheral adrenergic terminals and directly blocks catecholamine receptors.
3) As a result, cardiac output and vascular tone are reduced resulting in hypotension and decreased pulmonary vascular resistance.
4) Anti-arrhythmic: slows the rate of impulse formation at the SA node and prolongs SA conduction, the PR interval and the AV node refractory period

Question 7

Nervous system and magnesium

Answer 7

1) Reduces the release of acetylcholine at the neuromuscular junction by antagonising calcium ions at the presynaptic junction.
2) Causes reduced excitability of nerves
3) Anticonvulsant.
4) Reverses cerebral vasospasm

Question 8

Musculusaletal system and magnesium

Answer 8

1) Involved in terminating contraction, initiating relaxation in skeletal muscles
2) In combination with the effects above excessive plasma concentrations can cause muscle weakness

Question 9

Respyratory system and magnesium

Answer 9

1) Magnesium is an effective bronchodilator but does not affect respiratory drive.
2) Respiratory failure may occur as a result of excessive muscle weakness

Question 10

Geniito_urinary system and magnesium

Answer 10

1) Powerful tocolytic, decreasing uterine tone and contractility
2) Mild diuretic properties.

Question 11

Heamatalogical system and magnesium

Answer 11

Platelet activity is reduced resulting in prolonged bleeding time.

Question 12

Global CBF

Answer 12

45-55 ml/100 g/min

Question 13

Cortical CBF

Answer 13

75-80 ml/100g/min

Question 14

Muscles for inspiration

Answer 14

1) normal inspiration: diaphragm+external intercostal
2) forced inspiration:
Sternocleidomastoid+ serratus anterior+scalene muscles

Question 15

Muscles for expiration

Answer 15

1) normal: passive -elastic recoil
2) forced expiration: internal intercostal+abdominal muscles+triangularis sterni

Question 16

Tidal volume

Answer 16

Alveolar ventilation+dead space

Question 17

Alveolar ventilation

Answer 17

5 l/min

Question 18

Anatomic dead space

Answer 18

100-150 ml

Question 19

Alveolar O2 tension

Answer 19

Inspired O2 tension- alveolar CO2 tension/expiratory exchange range

Question 20

Pulmonary vascular resistance

Answer 20

1) (mean pulmonary pressure - left atrial pressure)/ cardiac output
2) 0.25-1.6 mmHg*min/L

Question 21

The major stimulus for HYPOXIC PULMONARY VASOCONSTRICTION

Answer 21

low alveolar oxygen tension (PAO2)

Question 22

Fick’s low

Answer 22

Vx=DADelta P/Delta X
Vx volume of gadgets transfer from membrane
D- coefficient
A -square
Delta P- partial pressure difference of gas across the membrane and
Delta X is the membrane thickness

Question 23

Vascular resistance

Answer 23

(Mean arterial pressure-venous pressure )/ cardiac output

Question 24

Norma of pulmonary vascular resistance

Answer 24

< 1.5 wood unit( WU)
PVR> 2WU-indicated of pulmonary vascular disease

Question 25

Norma of middle pulmonary artery pressure

Answer 25

10-20 mmHg

Question 27

Effects of GA on V/Q relationship

Answer 27

1) muscle relaxation => lost tonic activity => decrease FRC 10-30%=> Closing capacity >FRC =>atelectasis => areas perfused, not ventilated 2)GA=> low CO and pulmonary hypertension =>reduced perusing in non dependent region

Question 28

Dorsal respiratory group of respiratory center

Answer 28

1) close to the nucleus tractus solitarius 2) mainly inspiratory neurons 3) responsible for timing of the respiratory cycle

Question 29

Ventral respiratory group of respiratory center

Answer 29

1) caudal group: 1. Inspiratory +expiratory neurons 2. Controlling the force of contraction of the contralateral Inspiratory muscles 2) rostal group nucleus ambiguous 1. Controlling airway dilatation, function of the larynx, pharynx, tongue 3) pre-Botzinger complex 1. Central pattern generation

Question 30

Neurotransmitters for central pattern generation

Answer 30

1) expiratory: glutamate (NMDA+nNDMa) 2) inhibitory: glycine +GABA

Question 32

Alveoli

Answer 32

300 mln in adults lungs, 0,3 mm in diameter at FRC, the wall of alveoli 0,5 mcm

Question 33

Ventilation/perfusion ratio (V/Q)

Answer 33

0.8

Question 35

The Paintal juxtapulmonary capillary receptor (J receptor)

Answer 35

1) type of sensory receptor in the alveolar, specifically within the pulmonary capillaries and interstitial tissues. 2) sensitive to changes in increases in interstitial fluid volume, pulmonary capillary pressure, and the presence of certain chemical stimuli. 3) stimulated-can induce rapid shallow breathing, apnea, or a combination of both, depending on the intensity and nature of the stimulus.

Question 36

Chemical+irritant receptors in the nasopharyngeal, larynx, trachea

Answer 36

1) stimul: smoke, gastric acid 2) reflex: coughing, laryngeal closure, apnea, bronchoconstriction

Question 37

Pulmonary stretch receptors

Answer 37

1) slowly adapting stretch receptors: 1. In bronchial smooth muscle 2. Stimul: lung inflation 3. Volume sensor 2) rapidly adapting stretch receptors 1. Superficial mucosal layer 2. Stimul: change TV, RR, lung compliance 3. Inhibition of inspiration in response to lung distention+ reduce RR by increasing expiratory time

Question 39

Residual volume

Answer 39

20 ml/kg

Question 40

Expiratory reserve volume

Answer 40

15 ml/kg

Question 41

Inspiratory reserve volume

Answer 41

45 mlkg

Question 42

Dead space ventilation with facemask

Answer 42

+32-42% of physiological dead space

Question 44

P transpulmonary

Answer 44

P airway-P pleuraly

Question 45

Compliance of respiratory system

Answer 45

Delta V/Delta P

Question 46

Compliance normal level

Answer 46

0.2-0.30 l/cmH2O