Chapter 22

Question 1

inhaling

Answer 1

inspiration

Question 2

exhaling

Answer 2

expiration

Question 3

relaxed, unconscious, automatic breathing, the way one would breathe when reading a book or listening to lecture without thinking about breathing

Answer 3

quiet respiration

Question 4

deep or rapid breathing, as in a state of exercise or when singing

Answer 4

forced respiration

Question 5

what are lungs ventilated by?

Answer 5

pressure gradients by the muscle movements

Question 6

___ is the primary mover of breathing

Answer 6

diaphragm

Question 7

where is the ventral respiratory group located?

Answer 7

medulla oblongata

Question 8

ventilation of the lungs (breathing) or the use of oxygen in cellular metabolism

Answer 8

respiration

Question 9

breathing, or pulmonary ventilation, consists of repetitive cycle of ___ and ___

Answer 9

inspiration and expiration

Question 10

what are the principal muscles of respiration?

Answer 10

diaphragm and intercostal muscle

Question 11

the ___ is the prime mover of respiration; it alone produces about 2/3 of the pulmonary airflow.

Answer 11

diaphragm

Question 12

what muscles serve as synergist to aid the diaphragm?

Answer 12

internal and external intercostal muscles between the ribs

Question 13

the primary function of these muscles are to stiffen the thoracic cage during respiration and prevent it from caving inward when the diaphragm depends

Answer 13

internal and external intercostals

Question 14

other muscles of the chest and abdomen also aid in breathing, especially during forced respiration; thus they are considered ___ ___ of respiration

Answer 14

accessory muscles

Question 15

energy-saving passive process achieved by the elasticity of the lungs and thoracic cage

Answer 15

normal expiration

Question 16

Depression of the diaphragm raises abdominal pressure and helps to expel the contents of certain abdominal organs, thus aiding in childbirth, urination, defecation, and vomiting. During these actions, we often consciously or unconsciously employ the ___. This consists of taking a deep breath, holding it by closing the glottis and then contracting the abdominal muscles to raise abdominal pressure and push the organ contents out.

Answer 16

valsalva maneuver

Question 17

2 reasons for this dependence on the brain for breathing:

Answer 17

(1) skeletal muscles, unlike cardiac muscle cannot contracts without nervous stimulation
(2) breathing involves the well-orchestrated action of multiple muscles and thus requires a central coordinating mechanism

Question 18

breathing is controlled at 2 levels of the brain

Answer 18

1) cerebral and conscious; enabling us to inhale and exhale at will
2) unconscious and automatic

Question 19

the primary generator of the respiratory rhythm

Answer 19

ventral respiratory group (VRG)

Question 20

The ventral respiratory group (VRG) is an elongated neural network in the medulla with 2 commingled webs of neurons ____ and ____ - each forming a reverberating neural circuit

Answer 20

inspiratory (I) neurons & expiratory (E) neurons

Question 21

a web of neurons that extends for much of the length of the medulla between the VRG and the central canal of the brainstem

Answer 21

dorsal respiratory group (DRG)

Question 22

a web of neurons that extends for much of the length of the medulla between the VRG and the central canal of the brainstem

Answer 22

dorsal respiratory group (DRG)

Question 23

receives input from higher brain centers including the hypothalamus, limbic systems, and cerebral cortex, and issues output to both the DRG and VRG

Answer 23

pontine respiratory group (PRG)

Question 24

this respiratory group hastens or delays the transition from inspiration to expiration, making each breath shorter and shallower, or longer and deepens

Answer 24

pontine respiratory group (PRG)

Question 25

this respiratory group adapts breathing to special circumstances such as sleep, exercise, vocalization, and emotional responses

Answer 25

pontine respiratory group (PRG)

Question 26

brainstem neurons that respond especially to changes in the pH of the cerebrospinal fluid

Answer 26

central chemoreceptors

Question 27

these receptors are located in the carotid and aortic bodies of the larger arteries above the heart

Answer 27

peripheral chemoreceptors

Question 28

these receptors respond to O2 and CO2 content of the blood but most of all pH

Answer 28

peripheral chemoreceptors

Question 29

these receptors are found in the smooth muscle of the bronchi and bronchioles and in the visceral pleura

Answer 29

stretch receptors

Question 30

these receptors respond to inflation of the lungs and signal the DRG by way of the vagus nerves

Answer 30

stretch receptors

Question 31

excessive inflation triggers the ____, a protective somatic reflex that strongly inhibits the I neurons and stops inspiration

Answer 31

inflation (Hering-Breuer) reflex

Question 32

these receptors have nerve endings amid the epithelial cells of the airway

Answer 32

irritant receptors

Question 33

these receptors transmit signals by way of the vagus nerves to the DRG and the DRG returns signals to the respiratory and bronchial muscles, resulting in such protective reflexes as bronchocontriction, shallower breathing, breath-holding or coughing

Answer 33

irritant receptors

Question 34

the pressure that drives inspiration; the wi=eight of air above us

Answer 34

atmospheric (barometric) pressure

Question 35

at a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume.

Answer 35

Boyle’s law

Question 36

if the lungs contain a quantity of gas and lung volume increases, their internal pressure or their _____ falls. Conversely, if lung volume decreases, it also rises.

Answer 36

intrapulmonary pressure

Question 37

respiratory airflow is driven by a difference between what?

Answer 37

surrounding (ambient) atmospheric pressure and pressures in the chest

Question 38

what happens when the thoracic cage expands? why don’t the lungs remain the same size and simply occupy less space in the chest?

Answer 38

Consider the 2 layers of the pleura: the parietal pleura lining the rib cage and the visceral pleura on the lung surface

they are a