Human Physiology - Respiratory System Review Flashcards

Flashcards reviewing the key concepts of respiratory system mechanics.

What are the four main functions of the respiratory system?

1. Exchange of gases between the atmosphere and the blood, 2. Homeostatic regulation of blood pH, 3. Protection from inhaled pathogens and irritating substances, 4. Vocalization

What two systems coordinate the transfer of O2 and CO2 between the atmosphere and the cells?

The respiratory and circulatory systems

Name the components of the upper respiratory tract.

Mouth, nasal cavity, pharynx, larynx

Name the components of the lower respiratory tract.

Trachea, 2 primary bronchi, bronchioles, lungs

What is the primary function of alveoli?

Site of gas exchange

What structures surround the lungs?

Bones and muscles of the thorax

List the muscles involved in respiration.

Diaphragm, intercostal muscles, sternocleidomastoids, scalenes

What do pleural sacs do?

Each surround a lung

What are the functions of the airways?

1. Warming air to body temperature, 2. Humidifying, 3. Filtering out foreign material

What is the mucociliary escalator?

A mechanism involving mucus and cilia that filters out foreign material in the airways

How does pleural fluid contribute to breathing?

Lowers friction between membranes and holds lungs tight against the thoracic wall

What is found between the two sheets of epithelial tissue in the pleura membrane?

Pleural fluid

What is the role of elastic fibers surrounding alveoli?

Provide elasticity for recoil

What cells produce surfactants in the alveoli?

Type II alveolar cells

What is the function of macrophages in the alveoli?

Patrol alveoli, ingesting foreign material (phagocytotic leukocyte)

How does gas exchange occur in the respiratory membrane?

Diffusion of gases only

How are pressure and volume related?

Inversely proportional

What creates pressure gradients during ventilation?

A muscular pump (Thoracic cavity)

What primarily influences resistance to airflow?

Diameter of the tubes through which air is flowing

When does inspiration occur?

When alveolar pressure decreases

When does expiration occur?

When alveolar pressure increases

Is inspiration an active or passive process?

Active process

Is expiration an active or passive process?

Completely passive

What happens during pneumothorax?

Air flows into the pleural cavity, breaking the bond holding the lung to the chest wall, and the lung collapses.

What do chemoreceptors in the carotid and aorta detect?

Concentration of CO2 in blood

Increased CO2 in the blood leads to what?

More acidic (lower) blood pH

Lowered CO2 in the blood leads to what?

More alkaline (higher) blood pH

What is the effect of increased CO2 (paracrine) in expired air on bronchioles?

Bronchodilation

What is the effect of histamine (paracrine) on bronchioles?

Bronchoconstriction

What is the effect of parasympathetic responses on bronchioles?

Bronchoconstriction

What is the effect of sympathetic responses on bronchioles?

Bronchodilation via Epinephrine

How does the respiratory system regulate blood pH?

Via ventilation of CO2

What happens to blood pH if ventilation decreases (retain CO2)?

Blood pH decreases (acidic)

What happens to blood pH if ventilation increases (not enough CO2)?

Blood pH increases (alkaline)

Define compliance in the context of the lungs.

Ability to stretch

Define elasticity in the context of the lungs.

Ability to return to resting volume (snap back)

What occurs during emphysema?

Septum in alveoli degrades, decreasing surface area, and ciliated epithelia in airways are damaged.

What is the effect of elastase activation on the lungs?

Degrades elastic fibers, decreasing elasticity of lungs

Define Tidal Volume.

Amount of air in and out when resting

Define Inspiratory Reserve Volume (IRV).

Max air in

Define Expiratory Reserve Volume (ERV).

Max air out

Define Vital Capacity

Max air in and out (IRV + ERV)

Define Residual Volume.

Cannot be forced out of lungs