ch. 21

Question 1

Role of Respiratory system

Answer 1

-provide O2 and remove CO2 which are produced during cellular respiration (the burning or oxidation of glucose to produce ATP).

Question 2

Conducting zone vs. respiratory zone

Answer 2

Respiratory- actual site of gas exchange
- composed of the respiratory bronchioles, alveolar ducts, and alveoli (all microscopic structures)

Conducting- includes all other respiratory passageways, which provide fairly rigid conduits for all air to reach gas exchange sites.
-organs cleanse, humidify, and warm incoming air(so air reaching lungs has fewer irritants)

Question 3

Nose and nasal cavity

Answer 3

-nose consists of external nose and nasal cavity which is internal;
-floor of the cavity is the hard and soft palate. -Hairs in nasal vestibule, presence of mucous and serous glands, secretion of lysozyme and mucus, cleanse and humidify the air.
-Role of cilia.
Presence of an abundant blood supply: warming the air.
-Posterior nasal apertures open to the pharynx.

Question 4

Pharynx

description, function?

Answer 4

• passageway connecting nasal cavity to larynx and oral cavity to esophagus.
• passageway for air and food

Question 5

3 subdivisions of Pharynx and their locations

Answer 5

• Nasopharynx(region posterior to the nasal cavity,from internal choanae to soft palate)
• oropharynx (region posterior to root of tongue)
• laryngopharynx ( region posterior to behind larynx, from epiglottis to cricoid cartilage)

Question 6

nasopharynx

Answer 6

air only in this region, soft palate and uvula closing off the nasopharynx when swallowing, floor is hard palate and part of soft palate, adenoids (pharyngeal tonsil)

Question 7

oropharynx

Answer 7

palatine and lingual tonsils, air /food possible

Question 8

laryngopharynx

Answer 8

air/food possible..

Question 9

Larynx “voice box” (Description)

Answer 9

• made of 9 cartilages

- 3 main ones to know- thyroid, cricoid, epiglottis

Question 10

functions of epiglottis when swallowing

Answer 10

• larynz is pulled to superiorly and the epiglottis tips to cover laryngeal inlet (this keeps food out of lower respiratory passages)
• “guardian of the airways”

Question 11

voice..

Answer 11

-Voice production by the lower set of (true) vocal cords (vocal folds). Exhaled air passes through the glottis and causes the vocal cords to vibrate. Tense, thin, shorter cords vibrate faster and produce higher sounds

Question 12

Anatomy/functions of Trachea “windpipe”

-tracheal cartilage

Answer 12

• pseudostratified ciliated epithelium
• C shaped cartilage rings with trachealis muscle at the posterior where the esophagus is(allows it to bulge into the trachea during swallowing.)
• Contraction of trachealis muscle increases pressure of a cough.
• Carina, sensitive area.

Question 13

Bronchial tree

Answer 13

Right and left main (primary) bronchi, lobar (secondary) bronchi, segmental (tertiary) bronchi→bronchioles, terminal bronchioles (last conducting zone passageway). Cartilage replaced by smooth muscle.

Question 14

start of respiratory zone:

Answer 14

respiratory bronchioles → alveolar ducts→ alveoli. Alveolar sac =bunch of “grapes,” each alveolus is a “grape.”

Question 15

respiratory membrane

Answer 15

simple squamous epithelium of alveolus (type I cell) + fused basement membranes + simple squamous epithelium of capillary.

Question 16

Type II cells and surfactant (Role?)

Answer 16

-role in reducing surface tension so alveoli can expand easier

Question 17

Infant respiratory distress syndrome

Answer 17

-breathing disorder more common in premature babies
-develops within first 24 hours of birth
-cause is lack of surfactant in the lungs. (Surfactant is a liquid that coats the inside of the lungs.)
-The substance coats the insides of the air sacs in the lungs. This helps keep the lungs open so breathing can occur after birth.
Without enough surfactant, the lungs will likely collapse when the infant exhales (breathes out).

Question 18

Alveolar macrophages (dust cells)

Answer 18

• they are a significant feature of the alveoli

- Crawl freely along the internal alveolar surfaces

Question 19

Lungs and pleural coverings

Answer 19

• Root
• apex
• base
• lobes: 3 and 2, each lobe getting a lobar bronchus
• bronchopulmonary segments, usually 10 and 8, each getting a segmental bronchus.
• Parietal pleura on the thoracic wall and diaphragm
• visceral pleura on the lung surface.

Question 20

pleural fluid in pleural cavity?

Answer 20

-results in the lungs clinging to the thorax walls.

Question 21

Mechanics of breathing

Answer 21

**Gases move along pressure gradients

Question 22

Inspiration

Answer 22

To get air in the lungs, decrease the pressure in the lungs

Question 23

Boyle’s Law: pressure of a gas varies inversely with volume. To decrease the pressure, increase the volume.

Answer 23

p1v1=p2v2 where p is pressure of gas and V is its volume

Question 24

role of the diaphragm and the external intercostals in quiet inspiration

Answer 24

• diaphragm descends about 1 cm

- they both contract

Question 25

Use of sternocleidomastoid in forced inspiration

Answer 25

-flexes the neck, raises the sternum and assists in forced inspiration. Acting alone, tilts head to its own side and rotates it so the face is turned towards the opposite side.

Question 26

Expiration

Answer 26

-Quiet expiration is due to elastic recoil. -Forced expiration aided by abdominals.

Question 27

Respiratory volumes—

Answer 27

-Spirometer- to measure various volumes.

Question 28

TV (definition & approximate normal values)

Answer 28

(tidal volume)–amount of air moving into and out of the lungs
-about 500 ml

Question 29

IRV “ “

Answer 29

(inspiratory reserve volume)- amount of air that can be inspired forcibly beyond tidal volume
-2100-3200 ml

Question 30

ERV “ “

Answer 30

(expiratory reserve volume)- amount of air that can be evacuated from the lungs after a tidal expiration.
-1000-1200 ml

Question 31

VC “ “

Answer 31

(vital capacity)- total amount of exchangeable air.

-the sum of TV,IRV and ERV (4800 in healthy young males)

Question 32

Obstructive disease vs. restrictive disease

FVC (forced vital capacity)
FEV (forced expiratory capacity)

FVC is low for restrictive disease and FEV1 is low in obstructive disease.

Answer 32

obstructive- increased airway resistance(exhale way less than 80% of FVC or more within 1 second)
restrictive- involves reduction in total lung capacity( able to exhale 80% or more of FVC in 1 second)

-normal healthy lungs-can exhale about 80% of FVC in 1 second.