Pathophysiology of Breathing

Question 1

Define:

ventilation

Answer 1

The physical process of air moving in and out of the lungs.

Question 2

Fill in the blanks:

When you inhale, the diaphragm _______ and when you exhale, the diaphragm ______.

Answer 2

contracts, relaxes

Question 3

Define:

oxygenation

Answer 3

Process of loading hemoglobin with oxygen molecules.

Question 4

What type of muscle is the diaphragm?

Answer 4

Specialized skeletal muscle

The diaphragm is a specialized skeletal muscle with both voluntary and involuntary control.

Question 5

Define:

respiration

Answer 5

The exchange of O₂ and CO₂ through the alveoli and the body’s tissues

Question 6

Define:

accessory muscles

Answer 6

Secondary muscles of breathing that include sternocleidomastoid and trapezius muscles of the neck.

Question 7

What pressure do humans use to ventilate?

Answer 7

Negative-pressure ventilation

Question 8

Describe:

Negative-pressure ventilation

NPV

Answer 8

1. Inhalation causes the thoracic cage to expand.
2. Air pressure within the thorax decreases, creating a vacuum.
3. Air is pulled in through the trachea, filling the lungs.

Question 9

Define:

partial pressure

Answer 9

The amount of gas in the air or dissolved in a liquid.

The amount of oxygen dissolved in our blood is PaO².

Question 10

When more pressure is applied over a liquid, ____ gas can be dissolved into that liquid.

More or less?

Answer 10

more

Question 11

What is the normal tidal volume in an adult?

VT

Answer 11

5-7 mL/kg

Question 12

What is the normal tidal volume in infants and children?

VT

Answer 12

6-8 mL/kg

Question 13

Define:

dead space

Answer 13

The portion of inhaled volume that does not reach the alveoli.

Question 14

What is the formula to calculate minute volume?

VE

Answer 14

VT x RR

Tidal Volume x Respiratory Rate

Question 15

Define:

Functional Reserve Capacity

FRC

Answer 15

The volume of air remaining in the lungs after a normal exhalation.

Question 16

What type of process is inhalation and exhalation?

Answer 16

• inhalation: active
• exhalation: passive

Question 17

What is the feedback loop that prevents overexpansion of the lungs?

Answer 17

Hering-Breuer reflex

Question 18

What is the part of the brain that regulates the neural control of ventilation?

Answer 18

• Primary: Medulla oblongata
• Secondary: Pons

Question 19

Fill in the blanks:

The body regulates the depth and rate of ventilation by means of the ___ of the ___.

Answer 19

pH, CSF

Cerebrospinal fluid

Question 20

Location of the three sets of chemoreceptors that affect respiratory function.

Answer 20

• Carotid bodies
• Aortic arch
• Central chemoreceptors

Question 21

Chemoreceptors in the carotid bodies and aortic arch measure _____ _____ in the arterial blood.

Answer 21

carbon dioxide

Question 22

Define:

Hypoxic drive

Answer 22

Patients with COPD depend on lower oxygen levels to stimulate breathing through chemoreceptors.

Overoxygenation can negatively affect the body’s desire to breathe.

Question 23

Name the factors that affect the control of ventilation in the body.

Answer 23

• pH
• PaCO₂
• PaO₂
• temperature
• medications
• metabolic rate

Question 24

True or False.

At higher altitudes, there is less oxygen in the atmosphere.

Answer 24

False

The oxygen percentage remains ~21%, but the partial pressure is lower at higher altitudes.

Question 25

# Define: Fraction of Inspired Oxygen | FiO₂

Answer 25

The amount of **inhaled** oxygen in air. ## Footnote 21% of oxygen is in room air.

Question 26

What are the normal hemoglobin levels for **men and women**? | Hgb

Answer 26

* men: **14-16 g/dL** * women: **12-14 g/dL**

Question 27

How many oxygen molecules can bind to one hemoglobin?

Answer 27

four

Question 28

# Define: Oxyhemoglobin Dissociation Curve

Answer 28

The relationship between how **tightly** hemoglobin can hold on to oxygen molecules under certain conditions.

Question 29

# Fill in the blank: A shift to the **right** of the oxyhemoglobin dissociation curve causes hemoglobin to give up oxygen \_\_\_\_\_\.

Answer 29

faster ## Footnote _Causes:_ * Acidosis * Increased CO₂ * Hyperthermia

Question 30

# Fill in the blank: A shift to the **left** of the oxyhemoglobin dissociation curve causes hemoglobin to give up oxygen \_\_\_\_\_\_\.

Answer 30

slower ## Footnote _Causes:_ * Alkalosis * Decreased CO₂ * Hypothermia

Question 31

# Define: aerobic metabolism

Answer 31

The mitochondria of the cells **can** adequately convert glucose into energy in the **presence** of oxygen.

Question 32

What **elements** is the air composed of?

Answer 32

* **Nitrogen** 78% * **O₂** 21% * **CO₂** 0.3%

Question 33

# Define: anaerobic metabolism

Answer 33

The mitochondria of the cells are **not** able to adequately convert glucose into energy in the **absence** of oxygen.

Question 34

# Define: V/Q mismatch

Answer 34

**Ventilation** and **perfusion** do not adequately match.

Question 35

What causes **Respiratory Acidosis**? ## Footnote Hypoventilation

Answer 35

* respiratory distress/failure * trauma * damaged lungs * CNS depression * opiate OD * Bradypnea * CHF * head Injury * CO poisoning

Question 36

What causes **Respiratory Alkalosis**? ## Footnote Hyperventilation

Answer 36

Anxiety and panic attack.

Question 37

What causes **Metabolic Acidosis**?

Answer 37

* **Lactic Acidosis**: Anaerobic metabolism from hypoperfusion of tissues. * **Ketoacidosis**: Develops when cells are forced to switch to use fatty acids as energy. * **Acetylsalicylic OD**: Taking Aspirin between 10-30 g is overdose, stimulates brain to hyperventilate and renal compensatory. * **Alcohol**: Toxic alcohol ingestion (e.g., methanol, ethylene glycol, ethanol) ## Footnote _Signs/symptoms:_ * vasodilation * CNS depression * headaches * hot skin * tachypnea * nausea/vomiting

Question 38

What causes **Metabolic Alkalosis**?

Answer 38

* Excessive loss of acid: From increased urine output or decreased stomach acid. * Vomiting: Stomach loses acids through vomiting. * Water intoxication * Alkaline substances: Consumption of antacids. ## Footnote _Signs/symptoms:_ * confusion * tremors and cramps * bradypnea * hypotension

Question 39

What is the normal Respiratory Rate in an **adult**?

Answer 39

**12-20** breaths/min.