Respiratory System

Question 1

Upper respiratory system

Answer 1

Above larynx

Question 2

Lower respiratory system

Answer 2

Below the larynx (includes larynx)

Question 3

Conducting portion

Answer 3

Nasal cavity➡️terminal bronchioles

Question 4

Respiratory portion

Answer 4

Respiratory bronchioles➡️alveoli

Question 5

Alveoli

Answer 5

Air-filled pockets w/in lung
-where most gas exchange takes place

Question 6

Type 1 cells

Answer 6

large, thin, flat cells that cover the majority of the alveolar surface and are primarily responsible for gas exchange in the lungs by forming the air-blood barrier

Simple squamous

Question 7

Type 2 cells

Answer 7

cuboidal epithelial cells primarily responsible for producing and secreting pulmonary surfactant, a substance that prevents the alveoli from collapsing by reducing surface tension; they also act as progenitor cells for repairing damaged alveolar epithelium by differentiating into type 1 alveolar cells when needed

Question 8

The nose

Answer 8

Air enter respiratory system:
-through the nostrils (external nares)
-into nasal vestibule

Nasal hairs:
-in nasal vestibule
-first particle filtration system

Question 9

Pharynx

Answer 9

■ A chamber shared by digestive and respiratory systems
■ Extends from internal nares to entrances to larynx and esophagus

Question 10

Components of respiratory defense system

Answer 10

-goblet cells and mucosa cells:
-produce mucus that bathes exposed surfaces

-cilia
-sweep debris trapped in mucus toward pharynx
-results: moving carpet of mucus (mucus escalator)➡️particles removed

Question 11

3 cartilages of the larynx

Answer 11

1) thyroid
2) cricoid
3) epiglottis

Question 12

Thyroid cartilage

Answer 12

■ with laryngeal prominence (Adam’s apple)
■ Is a hyaline cartilage
■ Forms anterior and lateral walls of larynx
■ Ligaments attach to hyoid bone, epiglottis, and laryngeal cartilages

-Protects vocal cords
-help create sound

Question 13

Cricoid cartilage

Answer 13

■ Is a hyaline cartilage
■ Form posterior portion of larynx
■ Ligaments attach to first tracheal cartilage
■ Articulates with arytenoid cartilages

maintain the patency of the airway by providing a stable structure within the larynx, serving as an attachment point for muscles that control the opening and closing of the vocal cords

Question 14

Epiglottis

Answer 14

■ Composed of elastic cartilage
■ Ligaments attach to thyroid cartilage and hyoid bone
■ covered in taste bud-containing mucosa

Question 15

Trachea

Answer 15

■ Also called the windpipe
■ Extends from the cricoid cartilage into mediastinum
■ where it branches into right and left pulmonary bronchi

Question 16

Primary bronchi

Answer 16

■ Right and left primary bronchi:
■ separated by an (the carina)

Question 17

Branching bronchial tree

Answer 17

Trachea➡️ primary brochi➡️ secondary bronchi ➡️ tertiary bronchi ➡️ bronchioles ➡️terminal bronchioles

Question 18

Primary bronchi goes to

Answer 18

Lungs

Question 19

Secondary bronchioles goes to

Answer 19

Lobes

Question 20

3 parts of respiratory membrane

Answer 20

1. Squamous epithelial lining of alveolus (Type 1 cells)
2. Endothelial cells lining an adjacent capillary
3. Fused basal laminae between alveolar and endothelial cells

Question 21

Pulmonary ventilation

Answer 21

-physical movement of air in and out of respiratory tract
-provided alveolar ventilation
-boyles law: ⬆️volume of cavity➡️⬇️pressure➡️pulls air in from high pressure to low pressure
-contraction and ⬇️volume (size) of cavity➡️⬆️pressure➡️pushes air to area of lower pressure

Question 22

Boyles law

Answer 22

In contained gas
-external pressure forces molecules closer together
-movement of gas molecules exerts pressure on container

Question 23

Intrapulmonary pressure

Answer 23

■ Also called intra-alveolar pressure
■ Is relative to Patm
■ In relaxed breathing, the difference between Patm and intrapulmonary pressure is small:
■ about —1 mm Hg on inhalation or +1 mm Hg on expiration

Question 24

Maximum intrapulmonary pressure

Answer 24

■ Maximum straining by exhaling forcibly , a dangerous activity, can increase significantly:
■ from —30 mm Hg to +100 mm Hg
■ Straining by exhaling forcibly against a closed glottis (aka the Valsalva maneuver) - exhale while lifting)

Question 25

Intrapleural pressure

Answer 25

■ Pressure in space between parietal and visceral pleura (pleural cavity)
■ Averages —4 mm Hg
■ Maximum of —18 mm Hg
■ Remains below Patm (subatmospheric) throughout respiratory cycle
■ Fluid level must be minimal
■ Pumped out by lymphatics
■ If accumulates: positive Pip pressure ➡️ lung collapse
■ Lungs are held open (expanded) in the pleural cavity by the pleural fluid layer.
■ The elastic fibers in the lungs expand and create the negative pressure

Question 26

Respiratory muscles during inspiration

Answer 26

Diaphragm- contracts, it moves down and increases the volume of the thoracic cavity, which draws air into the lungs

External intercostals- help move the ribcage up and out, which increases the volume of the thoracic cavity

Question 27

Respiratory muscles during expiration

Answer 27

1. Internal intercostal and transversus thoracis muscles:
   o depress the ribs
2. Abdominal muscles:
   ■ compress the abdomen
   ■ force diaphragm upward

Question 28

Henry’s law

Answer 28

■ When gas under pressure comes in contact with liquid:
■ gas dissolves in liquid until equilibrium is reached
■ At a given temperature:
■ amount of a gas in solution is proportional to partial pressure of that gas
■ Increasing gas pressure increases the amount gas that can go into solution

Pressure in air ⬆️➡️goes to water

Question 29

O2Hb saturation curve

Answer 29

Saturation of Hb vs partial pressure of O2
-higher Po2➡️⬆️Hb saturation

Question 30

PO2

Answer 30

pressure exerted by oxygen gas alone within a mixture of gases

Question 31

pH effect on O2 Hb saturation curve

Answer 31

decrease in pH (more acidic) shifts the oxygen-hemoglobin saturation curve to the right, meaning hemoglobin has a lower affinity for oxygen and releases more oxygen to the tissues, while an increase in pH (more alkaline) shifts the curve to the left, increasing hemoglobin’s affinity for oxygen and making it hold onto oxygen more readily

⬇️pH➡️⬆️O2 release➡️⬇️PO2 and ⬇️Hb saturation

Question 32

Temp effect on O2Hb saturation curve

Answer 32

An increase in temperature causes the oxygen-hemoglobin saturation curve to shift to the right, indicating that hemoglobin has a decreased affinity for oxygen, meaning it releases oxygen more readily at higher temperatures; conversely, a decrease in temperature shifts the curve left, increasing hemoglobin’s affinity for oxygen and causing it to hold onto oxygen more tightly

When temp ⬆️➡️⬆️O2 release➡️⬇️PO2 and ⬇️Hb saturation

Question 33

Bohr effect

Answer 33

■ Is the effect of pH on hemoglobin saturation curve
■ When pH goes down, H+ ions bind to Hb and change its shape decreasing its affinity for O2 and vise versa
■ CO2 is not very soluble in blood
■ The change in pH is Caused by CO2:
■ CO2 diffuses into RBC
■ an enzyme, called carbonic anhydrase, catalyzes reaction with H2O
■ produces carbonic acid (H2CO3)
■ H2CO3 is very a soluble ionic compound
■ Carbonic acid (H2CO3):
■ dissociates into hydrogen ion (H+) and bicarbonate ion (HCO3—)
■ Hydrogen ions can diffuse out of RBC, lowering pH
■ Most H+ is removed by buffers, especially

Question 34

CO2 in the blood stream

Answer 34

-may be:
-converted to H2CO3
-70% transported as H2CO3
-bound to protein portion of Hb
-HCO3- goes into bloodstream
-23% is bound to amino groups of globular proteins in Hb molecule:
-forming carbaminohemoglobin
-H+ gets buffered by Hb
-dissolved in plasma
- 7% is transported as CO2 dissolved in plasma

Question 35

Respiratory centers of the brain

Answer 35

-both voluntary and involuntary
-main generator: medulla oblongata
-some in the pons

Question 36

Medullary respiratory centers

Answer 36

Inspiration neurons excite inspiratory muscles via phrenic (diaphragm) and intercostal nerves (external intercostals)

Expiratory neurons ➖ inspiratory neuron

Question 37

sensory modifiers of respiratory center activities

Answer 37

1) chemoreceptors are sensitive to:
-PCO2, PO2, or pH
-of blood or cerebrospinal fluid
2)baroreceptors of aortic or carotic sinuses
-sensitive to changes in BP
3)stretch receptors
-respond to changes in lung volume
4) irritating physical or chemical stimuli:
-in nasal cavity, larynx, or bronchial tree

Question 38

Chemical factors

Answer 38

■ Influence of Pco2 (normally most potent; normally most closely controlled)
■ If blood Pco2 levels rise (hypercapnia), CO2 accumulates in brain ➡️pH drops in brain
■ H+ stimulates central chemoreceptors of brain stem
■ Chemoreceptors synapse with respiratory regulatory centers à increased depth and rate of breathing à lower blood Pco2 à pH rises

Question 39

Baroreceptor reflex

Answer 39

■ Carotid and aortic baroreceptor stimulation:
■ affects blood pressure and respiratory centers
■ When blood pressure decreases :
■ respiration increases
■ When blood pressure increases:
■ respiration decreases

Question 40

Hypercapnia

Answer 40

⬆️PCO2(⬇️pH) (arterial)in CSF➡️ ➕chemoreceptors in medulla oblongata➡️ ⬆️ respiratory rate➡️⬆️elimination of CO2 in alveoli➡️⬇️ arterial PCO2➡️ hometostasis

Question 41

Hypoventilation

Answer 41

A common cause of hypercapnia
■ Abnormally low respiration rate:
■ allows CO2 build-up in arterial CSF at alveoli

Question 42

Hyperventilation

Answer 42

■ Excessive ventilation
■ Results in abnormally low PCO2 (hypocapnia)- ⬆️pH
■ Stimulates chemoreceptors to decrease respiratory rate