Respiratory System

Question 1

What are the functions of the respiratory system?

Answer 1

Gas exchange, olfaction, acid-base balance, blood pressure regulation. blood and lymph flow, platelet production, blood filtration, expulsion of abdominal content

Question 2

What are the principal organs of the respiratory system?

Answer 2

Nose, pharynx, larynx, trachea, bronchi, lungs.

Question 3

What is the conducting zone of the respiratory system?

Answer 3

Include passages that serve only for airflow; nostrils through major bronchioles.

Question 4

What is the respiratory zone of the respiratory system?

Answer 4

Consists of alveoli and other gas exchange regions.

Question 5

What is the path of airflow?

Answer 5

nasal cavity → pharynx → trachea → main bronchus → lobar bronchus → segmental bronchus → bronchiole → terminal bronchiole → respiratory bronchiole → alveolar duct → atrium → alveolus

Question 6

Describe the trachea.

Answer 6

Anterior to the esophagus; Supported by hyaline cartilage; Lines by pseudostratified columnar epithelium; Mucous-secreting goblet cells.

Question 7

Describe the bronchi.

Answer 7

Lined by pseudostratified columnar epithelium; Mucous-secreting; smooth muscle layer to constrict or dilate the airway.

Question 8

Describe bronchioles.

Answer 8

Ciliates cuboidal epithelium; smooth muscle

Question 9

Describe the structure of pulmonary alveoli.

Answer 9

Squamous alveolar covers 95% of alveolar surface area; Great (type ll) alveolar cells cover 5% of alveolar surface area - secrete surfactant; Alveolar macrophages (dust cells) are most numerous in lungs. The thin epithelium allows for rapid gas diffusion between air and blood?

Question 10

Why is it important there is no fluid in the lungs? How do they stay dry?

Answer 10

Gasses would diffuse too slowly to aerate blood. To prevent fluid accumulation, alveoli are kept dry by low pressure in arteriole end capillaries - 10 mm Hg

Question 11

Describe lung drainage.

Answer 11

Lungs have more extensive lymphatic drainage than any other organ in the body.

Question 12

Describe the respiratory membrane.

Answer 12

The barrier between the alveolar air and blood, consists only of the squamous alveolar cell, the squamous endothelial cell of the capillary, and their shared basement membrane. These have a total thickness of only 0.5 um, just 1/15 the diameter of a single erythrocyte.

Question 13

What is the pleura?

Answer 13

A serous membrane that lines the thoracic wall and forms the surface of the lung.

Question 14

Describe the layers of the pleura.

Answer 14

The visceral layers form the surface of the lungs and extend into the fissures between the lobes. The parietal pleura adheres to the mediastinum, the inner surface of the rib cage, and the superior surface of the diaphragm.

Question 15

What is the pleural cavity?

Answer 15

The space between the parietal and visceral pleurae. The pleural cavity contains nothing but a thin film of lubricating pleural fluid; the cavity is only a potential space, meaning there is normally no room between the membranes.

Question 16

Describe pulmonary ventilation.

Answer 16

Repetitive cycle: inspiration (inhaling) & expiration (exhaling); Quiet respiration: At rest, automatic; Forces respiration: Deep, rapid breathing.

Question 17

What are the principal muscles of respiration?

Answer 17

The diaphragm and intercostal muscles.

Question 18

What do the intercostal muscles do?

Answer 18

Their primary function is to stiffen the thoracic cage during respiration and prevent it from collapsing when the diaphragm descends. However, they also contribute to enlargement and contraction of the thoracic cage and add about one-third of the air that ventilates the lungs.

Question 19

What is the Valsalva maneuver?

Answer 19

Breathing technique used to help expel contents of certain abdominal organs.

Question 20

Ventral respiratory group (VRG)

Answer 20

Primary generator of the respiratory rhythm; produces a respiratory rhythm of 12 breathers per minute

Question 21

Dorsal respiratory group (DRG)

Answer 21

Modifies the rate and depth of breathing; receives influences from external sources

Question 22

Pons respiratory group (PRG)

Answer 22

Modifies rhythm; adapts to sleep, emotion, and exercise.

Question 23

How do different receptors contribute to respiratory control?

Answer 23

Peripheral chemoreceptors respond to O2 and CO2 content of blood. Stretch receptors in the smooth muscles of bronchi and bronchioles and in visceral pleura that respond to inflation of the lungs. Irritant receptors nerve endings amid epithelial cells in the airway.

Question 24

What is hyperventilation?

Answer 24

Anxiety-triggered state in which breathing is so rapid that expels CO2 from the body faster than it is produced.Reduces cerebral perfusion which may cause dizziness or fainting.

Question 25

Describe voluntary control of breathing.

Answer 25

Originates into the motor cortex of the frontal lobe of the cerebrum. Sends impulses down corticospinal tracts to respiratory neurons in the spinal cord.

Question 26

What is the breaking point? (voluntary breathing)

Answer 26

When CO2 levels rise to a point where automatic controls override one’s will.