Chapter 23 - Respiratory System

Question 1

respiratory system

Answer 1

• exchange of gases

- moves air to and from exchange surfaces of lungs

Question 2

mucus

Answer 2

along respiratory tracts

Question 3

Respiratory defense system

Answer 3

nose removes large particles

Question 4

Mucous cells and mucous glands

Answer 4

produces mucous to cover exposed surfaces

Question 5

cilia

Answer 5

gather mucus, trapped debris, microorganisms toward pharynx to be swallowed

Question 6

Alveolar macrophages

Answer 6

eat small particles that reach lungs

Question 7

Bronchioles

Answer 7

– Bronchioles branch into terminal bronchioles
– Bronchioles have no cartilage
• Dominated by smooth muscle

Question 8

autonomic nervous system

Answer 8

– Controls bronchioles diameter by regulating smooth muscle

– Controls airflow in lungs

Question 9

bronchodilation

Answer 9

– Caused by sympathetic activation
– Enlarges diameter of airway
– Reduces resistance to airflow

Question 10

bronchoconstriction

Answer 10

• Parasympathetic activation
  – Reduces diameter of airway
• Histamine release (allergic reactions)

Question 11

Alveolar cell layer

Answer 11

pneumocytes type I 
-thin walls 
-site of gas exchange 
-monitored by macrophages
pneumocytes type II 
-produces surfactant

Question 12

surfactant

Answer 12

– Oily secretion
– phospholipids + proteins
– Coats alveolar surface and reduces surface tension

Question 13

respiratory distress syndrome

Answer 13

– Alveoli collapse after each exhalation

– Caused by inadequate amounts of surfactant due to injury or genetic abnormalities

Question 14

Pneumonia

Answer 14

– Inflammation of lung tissue
– Causes fluid to leak into alveoli
– Compromises function of blood air barrier

Question 15

Gas exchange across blood air barrier is quick and efficient

Answer 15

– Because distance for diffusion is short

– And O2 and CO2 are small and lipid soluble

Question 16

Blood pressure in pulmonary circuit

Answer 16

– Lower than that in systemic circuit

– Pulmonary vessels are blocked by blood clots, fat, or air bubbles

Question 17

pulmonary embolism

Answer 17

A blocked branch of pulmonary artery that stops

blood flow to lobules or alveoli

Question 18

external respiration

Answer 18

exchange of O2 and CO2 with external environment

Question 19

internal respiration

Answer 19

• Uptake of O2 and release of CO2 by cells

* Result of cellular respiration

Question 20

hypoxia

Answer 20

Low tissue oxygen levels

Question 21

anoxia

Answer 21

Complete lack of oxygen in tissues

Question 22

inhalation

Answer 22

inspiration

Question 23

exhalation

Answer 23

expiration

Question 24

the lower the pressure

Answer 24

the lower the diffusion

Question 25

resistance

Answer 25

bronchodilation and bronchoconstriction

Question 26

compliance factors that affect compliance?

Answer 26

– A measure of expandability – Lower compliance requires greater force to fill lungs – Factors that affect compliance • Connective tissue of lungs • Level of surfactant production • Mobility of thoracic cage

Question 27

at sea level the partial pressure is

Answer 27

760 mm Hg

Question 28

the other atoms (partial pressure)

Answer 28

N- 78% 0- 21% water vapor - 0.5% CO2- 0.04%

Question 29

solubility of gases in body fluid

Answer 29

– CO2 is highly soluble – O2 is somewhat less soluble – N2 has very limited solubility

Question 30

Partial pressures in plasma of pulmonary vein

Answer 30

– PCO2 =40mmHg – PO2 =100mmHg – PN2 =573mmHg

Question 31

Blood arriving in pulmonary arteries has

Answer 31

* Low PO2 | * High PCO2

Question 32

concentration gradient causes

Answer 32

* O2 to enter blood | * CO2 to leave blood

Question 33

internal respiration what happens?

Answer 33

– Oxygenated blood mixes with deoxygenated blood | – Lowers PO2 of blood entering systemic circuit to about 95 mm Hg

Question 34

interstitial fluid

Answer 34

• PO2 40mmHg,PCO2 45mmHg

Question 35

Concentration gradient in peripheral capillaries is opposite of lungs

Answer 35

• CO2 diffuses into blood, O2 diffuses out of blood

Question 36

red blood cells have a higher affinity for

Answer 36

O and CO2

Question 37

O2 binds to ??? in hemoglobin (Hb) molecules

Answer 37

iron ions • In a reversible reaction • Forming oxyhemoglobin (HbO2)

Question 38

1 RBC has | 1 Hb molecule binds

Answer 38

280 million Hb molecules | 4 oxygen molecules

Question 39

hemoglobin saturation

Answer 39

% heme units containing bound oxygen at any given moment

Question 40

factors affecting Hb saturation

Answer 40

– PO2 of blood – Blood pH – Temperature – Metabolic activity within RBCs

Question 41

When temperature increases, hemoglobin | When temperature decreases, hemoglobin

Answer 41

releases more oxygen | holds oxygen more tightly

Question 42

the more BPG released

Answer 42

more oxygen released | • Due to increase in pH or certain hormones

Question 43

fetal hemoglobin

Answer 43

higher affinity for hemoglobin | • binds more O2 than does adult Hb, takes O2 from maternal blood

Question 44

70% of co2 in solution transported as 23% is

Answer 44

bicarbonate ions (HCO3-) bound to protein portions of Hb molecules in RBCs • Forming carbaminohemoglobin

Question 45

baroreceptors

Answer 45

in aortic or carotid sinuses sensitive to changes in blood pressure

Question 46

aging

Answer 46

elastic tissue deteriorates in lungs

Question 47

Emphysema

Answer 47

- Affects individuals over age 50 | - exposure to respiratory irritants (cigarette smoke)