Respiratory System and Fluids & Electrolytes

Flashcards covering the functions, anatomy, physiology, and processes of the respiratory system, including gas exchange, vocalization, and pulmonary ventilation mechanics.

What is the primary function of the respiratory system?

To get oxygen into the blood and cells and remove carbon dioxide.

Why do cells need oxygen?

To undergo cellular respiration and make ATP.

What waste product is produced when ATP is made during cellular respiration?

Carbon dioxide (CO2).

How does the body get rid of CO2?

Through exhalation.

What is another function of the respiratory system besides gas exchange?

Air passageway, detecting odors, vocalization.

Which part of the nasal cavity is responsible for detecting odors?

The olfactory epithelium.

Which structure is mainly responsible for sound production?

The larynx.

What other body systems aid the respiratory system in its function?

Cardiovascular (blood transport), nervous (control of ventilation), and muscular (volume changes).

What is the respiratory lining also known as?

The mucosa or mucous membrane.

What type of epithelium typically forms most of the respiratory lining from the nasal cavity down to the lobar bronchi?

Pseudostratified ciliated columnar epithelium.

What is the function of the pseudostratified ciliated columnar epithelium in the respiratory tract?

It contains goblet cells to secrete mucus and cilia to trap debris and move mucus.

Where does the mucus eventually go after trapping particles?

It is usually swallowed and killed by stomach acid.

What type of epithelium is found in the alveoli?

Simple squamous epithelium.

Why is the alveolar epithelium so thin (simple squamous)?

To facilitate efficient gas exchange.

What would a layer of mucus in the alveoli do to gas exchange?

It would create a barrier, hindering gas exchange.

What cells mainly produce mucus secretions?

Goblet cells.

What is mucin?

A protein that, when mixed with water, becomes mucus.

What is the purpose of mucus's increased viscosity?

To help catch pollen, allergens, microorganisms, dust, dirt, and debris.

How much mucus do we produce daily?

Anywhere between one and seven tablespoons daily.

What increases daily mucus production?

Sickness, allergic reactions, or active allergies.

What are some defense mechanisms found in mucus?

Lysozymes, defensins, and the IgA antibody.

What are the three main processes involved in conditioning air in the nasal cavity?

Warming, cleansing, and humidifying the air.

Why is it important for air to be warm, clean, and moist when it reaches the lungs?

Warm air prevents bronchoconstriction; clean air protects lungs; moist air helps with surface tension for gas exchange.

What are the turbinate bones also known as?

Concha.

How do the turbinate bones help condition the air?

They swirl the air, increasing surface area for cleaning, warming, and humidifying.

What specific structures clean the air in the nasal cavity?

Mucus and cilia (forming the mucus escalator).

How is the air warmed in the nasal cavity?

Superficial blood vessels underneath the epithelium warm the mucus, which then warms the air.

What happens when a respiratory infection travels to the sinuses?

It becomes a sinus infection due to inflammation, mucus trapping, and bacterial breeding.

What are the multiple functions of the larynx?

Sound production, ensuring food/liquid enter the correct passageway, increasing abdominal-pelvic pressure, and producing sneezing/coughing reflexes.

Which vocal folds are used for sound production?

True vocal cords (folds).

What is the opening between the vocal folds called?

The rima glottidis.

How is sound produced?

Exhaled air vibrating the vocal folds.

What is the function of the epiglottis?

It bends over to close the passageway to the trachea during swallowing, preventing food/liquid from entering the respiratory tract.

What type of cartilage makes up the epiglottis, and why is this important?

Elastic cartilage, which allows it to bend easily and pop back open.

How does puberty affect male voices?

Increased testosterone elongates the thyroid cartilage and vocal cords, leading to a deeper voice.

What determines the pitch of the voice?

The tension on the vocal cords; increased tension causes higher vibration and higher pitch.

What determines the loudness of the voice?

The amount of air forced over the vocal folds; more air equals louder sound.

What is laryngitis?

Inflammation of the vocal folds, which impairs their vibration.

What are common causes of laryngitis?

Overuse of the larynx (like yelling), bacterial, or viral infections.

What is the main difference between bronchi and bronchioles regarding their structure?

Bronchioles have no cartilage and more smooth muscle, while bronchi have cartilage.

Why do bronchioles have more smooth muscle and no cartilage?

To allow for bronchoconstriction and bronchodilation, changing airflow diameter.

Where does pulmonary gas exchange primarily occur?

In the alveoli.

What covers the alveoli to facilitate efficient gas exchange?

Pulmonary capillaries.

What is the respiratory membrane composed of?

Alveolar epithelium and capillary epithelium (both simple squamous).

What is surface tension in the alveoli?

The attractive force between water molecules lining the alveoli, tending to collapse them.

What is the function of surfactant in the alveoli?

It breaks up hydrogen bonds between water molecules, reducing surface tension and keeping the alveoli open.

Why do babies born prematurely (before fetal month seven) often suffer from respiratory distress?

They have insufficient surfactant, causing their alveoli to collapse.

What important tissue property do the lungs possess that aids ventilation?

Elastic tissue, allowing them to expand and recoil to their original shape.

What are the four subsequent steps of respiration?

Pulmonary ventilation, pulmonary gas exchange, gas transport, and tissue gas exchange.

What is eupnea?

Normal inhalation and exhalation that occurs at rest.

What distinguishes forced breathing from eupnea?

Forced breathing involves voluntary (yoga, meditation) or automatic (exercise) deep breaths or forced exhalations.

What is the very first step required for skeletal muscle movement in pulmonary ventilation?

Nervous system stimulation.

What happens to the volume of the thoracic cavity during inhalation?

It increases.

What happens to the pressure inside the lungs (intrapulmonary pressure) when the thoracic cavity volume increases?

It decreases (according to Boyle's Law).

What is Boyle's Law?

It describes the inverse relationship between volume and pressure: if volume increases, pressure decreases, and vice versa.

How does a pressure gradient drive airflow?

Air moves from an area of high pressure to an area of low pressure.

What are the primary muscles involved in quiet inhalation?

The diaphragm and external intercostals.

What happens to the diaphragm during contraction for inhalation?

It flattens and moves inferiorly (down).

What pressure relationship must always be maintained to prevent lung collapse?

Intrapleural pressure must always be below intrapulmonary pressure (typically 4 mmHg lower).

What does a collapsed lung (atelectasis) indicate about intrapleural pressure?

The intrapleural pressure has changed and is no longer significantly lower than intrapulmonary pressure, often due to a puncture.