Chapter 29: The Respiratory System

Question 1

Where gas exchanges take place between air and blood

Answer 1

Alveoli

Question 2

Type 1 Pneumocytes

Answer 2

gas exchange from alveoli in to the blood

Question 3

Type 2 Pneumocytes

Answer 3

produces surfactant

major factor in lung compliance

Question 4

Alveolar Macrophages

Type 3 Phagocytic Pneumocytes

Answer 4

responsible for the removal of offending substances

Question 5

Roles of Surfactant (3)

Answer 5

1) prevents alveolar collapse on expiration
2) keeps alveoli dry
3) opsonizes pathogens

Question 6

Lung Compliance

Answer 6

how easily lungs can be inflated and recoil

Question 7

______ occurs when the lungs have lost their elasticity (unable to recoil) causing the thorax to become distended.

Answer 7

Increased compliance

emphysema

Question 8

______ occurs when lungs are stiff and unable to stretch fully

Answer 8

Decreased Compliance

pneumothorax, pulmonary edema, atelectasis

Question 9

Ventilation

Answer 9

the act of breathing

movement of gases into and out of the lungs

Question 10

Perfusion

Answer 10

provides blood to the gas exchange portion of the lungs

Question 11

Diffusion

Answer 11

movement of gases across the alveolar-capillary membrane

Question 12

In the act of ventilation, _____ is active and ______ is passive

Answer 12

inspiration

expiration

Question 13

Ventilation is affected by gravity and _____ portions of the lungs are better ventilated depending on position

Answer 13

sitting/standing = apex
supine = posterior portions
lateral = dependent lung

Question 14

Body position affects perfusion

Answer 14

lung tissues most dependent have better perfusion
sitting/standing = base
supine = more uniform btwn apex and base - more blood flow posteriorly

Question 15

Normal Ventilation-Perfusion Ratio

Answer 15

air and blood must be direct to the same place at the same time
rate of vent may be slightly less than perfusion (V/Q ratio = 4:5)

Question 16

Adequate ventilation with impaired perfusion is ______

Answer 16

Dead Space

high V/Q ratio

Question 17

Dead air space results from ______

Answer 17

impairment of blood flow to a portion of the lung

PE, cardiogenic shock

Question 18

Anatomic Dead Space

Answer 18

contained in conducting airways (trachea, bronchi, bronchioles, terminal bronchioles)

Question 19

Alveolar Dead Space

Answer 19

contained in the respiratory portion of the lung

Question 20

Physiologic Dead Space

Answer 20

includes anatomic dead space + alveolar dead space

Question 21

Adequate perfusion with inadequate ventilation is _______

Answer 21

Shunting

low V/Q ratio

Question 22

Physiologic shunts are due to _______

Answer 22

airway obstruction due to:

atelectasis, tumor, mucus plug

Question 23

Anatomic Shunt

Answer 23

congenital heart defect

blood moves from the venous to arterial side of the circulation without moving through the lungs

Question 24

First Aggregate Neurons

Answer 24

concerned primarily with INSPIRATION

control the activity of the phrenic nerves that innervate the diaphragm

Question 25

Second Aggregate Neurons

Answer 25

concerned with BOTH inspiration and expiration

controls the motor neurons of the intercostal and abdominal muscles

Question 26

Central Chemoreceptors

Answer 26

highly sensitive to PaCO2 and hydrogen ion concentration (increase ventilation with a rise in H+ concentration)

Question 27

Peripheral Chemoreceptors

Answer 27

monitors PaO2 (hypoxic drive to breath)
exerts little control over ventilation until the PaO2 has dropped below 60 mmHg

Question 28

Lung stretch receptors respond to______

Answer 28

pressure changes in the walls of airways

adjust the respiratory rate and tidal volume

Question 29

Lung irritant receptors are stimulated by irritants and leads to __________

Answer 29

airway constriction and pattern of rapid, shallow breathing

also ensures uniform lung expansion (sighing, yawning)

Question 30

Lung juxtacapillary receptors (J receptors) sense ________

Answer 30

lung congestion

responsible for rapid shallow breathing that occurs with pulmonary edema, PE, and PNA

Question 31

Neural control of the airways is under the control of the ________ nervous system

Answer 31

Autonomic NS (PSNS and SNS)

Question 32

Parasympathetic Innervation (Cholinergic)

Answer 32

responds to acetylcholine
main receptor = muscarinic
causes bronchoconstriction and
increased secretion of mucous glands and goblet cells

Question 33

Sympathetic Innervation (Adrenergic)

Answer 33

responds to norepi and epinephrine
main receptors = beta-2 adrenergic
causes relaxation of the airways, blood vessel constriction, bronchodilation, and inhibition of glandular secretions

Question 34

You would use __________ to induce bronchodilation

Answer 34

Beta-2 agonists (Albuterol)