Repiratory Systems

Question 1

Primary function of the lung

Answer 1

Maintain tension of oxygen and carbon dioxide of the arterial blood in normal range,

Question 2

The fundamental mechanisms achieved in attaining respiration

Answer 2

Ventilation , diffusion , perfusion

Question 3

Pulmonary function tests are classified into

Answer 3

Tests that assess ventilation , tests that asssess gas exchange in lungs and tests that assess pulmonary circulation

Question 4

Process of ventilation is concerned with

Answer 4

movement of air in and out of the alveoli

Question 5

The most sensitive and non invasive test of lung function to differentiate obstructive from restrictive disease

Answer 5

FEV1

Question 6

Airflow of lungs can be broken down into three interconnected regions

Answer 6

Upper airway. , conducting airway and alveolar airway

Question 7

Alveolar airway is also known as

Answer 7

Lung parenchyma or acinar tissue

Question 8

Two crucial functions provided by nose and upper airway

Answer 8

(1) filtering out large particulates to prevent them from reaching the conducting and alveolar pathways
(2) serving to warm and humidify air as it enters body

In addition to olfaction

Question 9

Most of the 5-10 micrometer impact on the nasopharynx and race the rest of their path

Answer 9

Impact on the nasopharynx and do not enter conducting airway ,
Settle on mucous membranes in the nose and pharynx .
Because of momentum , do not follow airstream , curves downwards into lungs ,
Impact on or near tonsils and adenoids

Question 10

What are the collections of immunologically active lymphoid tissue in the back of the pharynx

Answer 10

Tonsils , adenoids

Question 11

What is the respiratory center composed of

Answer 11

Several groups of neurons located bilaterally in the medulla oblongata and pons of the brain stem

Question 12

Respiratory center is divided into three major collections of neurons

Answer 12

1.a dorsal respiratory group , mainly causes inspiration (dorsal medulla )
2. Ventral respiratory group , mainly causes expiration (ventral medulla )
3.The pneumotaxic center
Controls rate and depth of breathing (dorsally pons )

Question 13

Describe the Chemical control of respiration (long answer )

Question 14

The respiratory activity is highly responsive to changes in

Answer 14

O2 , CO2 , H+in tissues .
Goal of respiration is to maintain proper concentration of them

Question 15

The effect of oxygen in the chemical control of respiration

Answer 15

Acts almost entirely on peripheral chemo receptors located in carotid and aortic bodies . These receptors in turn transmit appropriate signals to reps center for real control

Question 16

The area sensitive to blood CO2 and H+ conc.

Answer 16

Chemosensitive area

Question 17

H+ concentration and respiratory stimulation

Answer 17

*likely the primary stimulus
*H+ ions do not easily cross the BBB, Hence changes in it have less effect than CO2 in blood
*tho CO2 is said to stimulate these neurons secondarily by changing H+ conc

Question 18

Timed vital capacity (FEV1)

Answer 18

Aka forced expiratory volume in 1 second (FEV1)
*Defined as the percentage of FVC expired in the specified time (in 1 sec =FEV1, in 2 sec =FEV2)
*measures FVC in relation to time ,
an index of air flow rate
*Normal conditions - 72 to 85% of FVC is expired in the first second ,
95% in 2 seconds
97% in 3 seconds
* generalised test to detect airway obstruction
*ratio of FEV1:FVC important than clinical measurements .
Normally 0.8

Question 19

Clinical importance of FEV1

Answer 19

*detect generalised airway obstruction
1. FEV1<72% , difficulty exhaling air due to ob,
Hallmark of obstructive lung disease like bronchial asthma
2. FEV1 FVC ratio normal in restrictive lung disease

Question 20

What is periodic breathing ?

Answer 20

Cyclical repetition of apnea and shallow breathing (like hyperpnea) in normal individuals.
* can occur in normal conditions and in CHEYNE-STOKES RESPIRATION (occurs in diseases and abnormal condition )

Question 21

Cheyne-Stokes Respiration seen in

Answer 21

• occurs in deep sleep of normal individuals
• more common in congestive cardiac failure , *uremia or Renal failure
  and brain diseases
• premature infants
  *unacclimatized persons at high altitude

Patients have increased sensitivity to CO2 due to disruptions of neural pathways .
Accumulation of CO2causes hyperventilation that lowers PCO2
Decreased co2 removes the co2 drive on ventilation and produces apnea which consequently increases pco2 again

Question 22

What is valsalva ratio

Answer 22

Measure of parasympathetic and sympathetic function .
Ratio of minimal heart rate in phase IV to max heart rate in phase II as depicted in terms of RR interval
= longest R-R interval during phase 4 / shortest R-R interval, during phase II

Question 23

Valsalva Maneuver

Answer 23

procedure is performed closing both nostrils and then blowing into a tube connected to sphyg- momanometer. By putting strain, blowing pressure is maintained at 40 mm Hg for 15 seconds.
Has 4 phases
1. Onset of strain , transient increase in blood pressure e