Medical Post Graduation | Physiology | Respiratory physiology

The lung alveoli

ক

Are connected to each other to equalize air pressure

খ

Need to reduce their surface tension to prevent collapse

গ

Are present throughout the respiratory part of the bronchial tree

ঘ

Are lined by larger number of type I pneumocytes than type II pneumocytes

ঙ

Have epithelium without basal lamina

Constriction of bronchial smooth muscle can result from

ক

Stimulation of vagus nerve

খ

Cold stimulus to bronchial mucosa

গ

A decrease in PC02 in bronchial air

ঘ

Irritation of bronchial mucosa

ঙ

Stimulation of local beta adrenoceptors

Biologically active substances metabolized by the lungs are

ক

Surfactant

খ

Serotonin

গ

Histamine

ঘ

Bradykinin

ঙ

VIP

During inspiration there is increase in

ক

Intra abdominal pressure

খ

Venous return to the heart

গ

Heart rate

ঘ

Intrapleural pressure

ঙ

Intra alveolar pressure

Respiratory dead space

ক

Saturates inspired air with water vapour

খ

Is 150 ml in a 70 kg adult

গ

Takes part in gaseous exchange

ঘ

Decreases during deep inspiration

ঙ

Is more in standing than in lying position

When a person performs deep expiration against a closed glottis there is an increase in

ক

Intrapleuralpressure

খ

Intra-alveolar pressure

গ

Alveolar PO2

ঘ

Stroke volume

ঙ

Blood volume in systemic circulation

At the end of normal quiet inspiration

ক

Heart rate increases

খ

Physiological splitting of 2nd heart sound is more prominent

গ

Intrapleural pressure is lowest

ঘ

Most of the tidal air enters into the upper part of the lungs

ঙ

Intra alveolar pressure is lowest

Effects of moving to high altitude include an increase in

ক

Alveolar ventilation

খ

Diffusing capacity of the lungs

গ

Erythropoietin level

ঘ

Blood HCO3- level

ঙ

Arterial PO2

Inspiration causes

ক

Fall in jugular venous pressure

খ

Fall in blood pressure

গ

Prolonged right ventricular ejection

ঘ

Decrease in heart rate

ঙ

Single 2nd heart sound

For achieving normal quiet inspiration

ক

The pressure inside the pleural cavity needs to be reduced

খ

The anterior ends of some ribs are raised to increase the transverse chest-diameter

গ

The anterior medullary respiratory centres are principally involved

ঘ

Contraction of the internal intercostal muscles are vital

ঙ

The muscles running from the chest wall to the humerus contribute significantly

During normal quiet inspiration there is

ক

More prominent physiological splitting of 2nd heart sound

খ

An increase in heart rate

গ

An increase in pulmonary vascular resistance

ঘ

An increase in elastic recoil tendency of the lung

ঙ

Greater stroke volume in left than right ventricle

Duration of inspiration is decreased and rate of ventilation is increased due to stimulation of

ক

Pneumotaxic center

খ

Apneustic center

গ

Vagus nerve

ঘ

Nucleus of tractus solitarius

ঙ

Ventral respiratory group

Hemodynamic effects of respiration are

ক

Raised jugular venous pressure during expiration

খ

Fall of blood pressure up to 10 mm during expiration

গ

Splitting of second heart sound during expiration

ঘ

Increased heart rate during expiration

ঙ

Increased ejection fraction during inspiration

During normal quiet breathing

ক

Intrapleural pressure is lowest at the apex of the lung

খ

Intra alveolar pressure is lowest at mid-inspiration

গ

Intrapleural pressure is lowest at the end of inspiration

ঘ

Most of the tidal air enters into the apex of the lungs

ঙ

Intra alveolar pressure is lowest at the end of inspiration

During normal quiet inspiration there is an increase in

ক

Intra-abdominal pressure

খ

Venous return to the heart

গ

PO2 in dead space

ঘ

Intra-pleural pressure

ঙ

Intra-alveolar pressure