Cardio/ Resp

Question 1

Innervation of thoracic muscles

Answer 1

Nerves exit CNS at thoracic spinal level

Diaphragm enervated by phrenic(C3,4,5 root) nerve

Question 2

Main vagal afferents - respiratory system

Answer 2

Irritant receptors
J receptors - alveolar walls
Stretch receptors - smooth muscle of small airways

Question 3

Neurologic control of respiration

Answer 3

Medulla - Dorsal and Vent Resp group- Inspiratory centre/expiratory centre
Pons - Upper pons- Pneumotaxic centre limits inspiration
- Lower pons - apneustic centre - increases respiration

Question 4

Respiratory chemoreceptors

Answer 4

Central chemoreceptors located in the medulla respond to changes in H+in CSF
Peripheral chemoreceptors in aortic arch stimulated strongly by changes in PaO2 <60mmHg and weakly by PaCO2

Question 5

Normal PaO2 and SaO2

Answer 5

75-100 mmHg , 100%-95%

Question 6

Mild Hypoxemia

Answer 6

PaO2 60-75mmHg ; SaO2 90-95%

Question 7

Moderate Hypoxemia

Answer 7

PaO2 50-60mmHg ; SaO2 85%-90%

Question 8

Severe Hypoxemia

Answer 8

PaO2 <50mmHg; SaO2, 85%

Question 9

Normal ABG Lab values

Answer 9

pH 7.35-7.45
PaO2  75-100mmHg
PCO2  35-45mmHg
HCO3 22-26 mEq/L
BE(Base Excess) -4 to +2

Question 10

Adult tidal volume

Answer 10

500mL

Question 11

Inspiratory reserve volume (IRV)

Answer 11

3000mL

Question 12

Expiratory reserve volume (ERV)

Answer 12

1100mL

Question 13

Residual volume (RV)

Answer 13

1200mL

Question 14

Vital capacity (VC)

Answer 14

IRV +TV +ERV = VC 4600mL

Question 15

Treatable causes of Cardiac Arrest

Answer 15

Hypoxia
Hypovolemia
Hypothermia
H+
Hyper/Hypokalemia
Tension Pneumo
Tamponade
Thrombosis -PE
Thrombosis- coronary 
Toxin

Question 16

Causes of Bradycardia

Answer 16

PRIDE
Parasympathetic tone
Raised ICP
Ischemia
Depressant drugs 
Electrolytes - hypokalemia, hypocalcemia