Subject Physiology

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Jun 07, 2018

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RESPIRATORY PHYSIOLOGY

1.       CO2 is primarily transported in arterial blood as: Bicarbonate

2.       During inspiration, intrapleural pressure becomes: More negative

3.       Total lung capacity: Volume of air contained in thelung at the end of maximal inspiration; 6 L (male); 4.7 L (female)

4.       Total lung capacity depends upon: Lung compliance

5.       Tidal volume: Amount of air breathed in or out during normal breathing; 500 ml (male); 390 ml (female)

6.       At the apex of lung: V (ventilation) > Q (perfusion)

7.       Volume of lung at the end of quite expiration, which can be expired with maximal effect: Expiratory reserve volume

8.       Minute alveolar ventilation is: 3.5 - 4.5 L

9.       Pulmonary surfactant is secreted by: Type II pneumocytes

10.   Surfactant is: Dipalmitoyl lecithin

11.   Surfactant production is accelerated by: Glucocorticoids

12.   Respiratory distress syndrome is due to: Deficiency of surfactant

14.   Respiratory distress syndrome is due to: Deficiencyof surfactant

15.   Chloride shift: Bicarbonate diffuses into plasma & same quantity of chloride diffuses into RBC in venous  circulation

17.   Pneumotaxic centre is present in: Pons (dorsal)

18.   Shape of oxygen hemoglobin dissociation curve: Sigmoid

19.   Decrease in temperature shifts the curve to: Left

20.   Increase in affinity of oxygen for hemoglobin shiftthe curve to: Left

21.   Increased pCO2 shift the curve to: Right

22.   Sickle cell hemoglobin presence shift the curve to:Right

23.   Respiratory distress syndrome shift the curve to: Right

24.   2,3 DPG (increased in anemia) shift the curve to: Right

25.   Most common  type of hypoxia: Hypoxic hypoxia

26.   Hypoxia means: Low pO2

27.   Response to high altitude:

·        - Increased ventilation (earliest),

·        - Increased response to carotid bodies,

·         -Respiratory alkalosis etc.

Surfactant is secreted by -  type II alveolar epithelial cells.

Cyanosis is - when arterial oxygen saturation falls below 75% corresponding to PO2 of 40 mmHg

  how many ml of oxygen  is transported to the tissues by 100 ml blood in every cycle - 5 ml

“Dust cells” - Pulmonary alveolar macrophages 

Total number of alveoli in man - 300 million

VOLUMES -

Tidal volume -  500 ml.

Inspiratory reserve volume - 3300 ml.

Expiratory reserve volume -  1000 ml.

Residual volume - 1200 ml.

Respiratory minute Volume in a normal person is 6.0 L/min.

Inspiratory capacity: 3800 ml.

Vital capacity : 4800 ml.

Total lung capacity: 6000 ml.

Functional residual capacity in a male is 2.2 liters.

Normal dead space air volume — 150 ml.

Muscles of Inspiration — Diaphragm and External Intercostals muscle (accessory  – Stcrnocleidomastoid, Serratus anterior).

Muscle of Expiration —Internal Intercostal muscle.

Respiratory centers:

• Inspiration – dorsal group of neurons near tractus solitarius nucleus.
• Expiration – ventral group situated in ventral part of medulla.

  Bohr’s effect -  decrease in 02 affinity of Hb when the pH of blood falls

Kausmaul breathing is found in -  diabetic ketoacidosis

Oxygen dissociation curve  -  ‘S’ shape or sigmoid shape

Peripheral chemoreceptors are found in -  carotid & aortic bodies. 

Most potent respiratory stimulant -  carbon dioxide.

Under resting conditions -

-  100 ml of blood transports 5 ml of O2 to tissues and carries 4 ml of CO2 from tissues to the lungs. 

Intra-pleural pressure which prevent collapse of the lung  is also k/s - (recoil pressure)