Respiratory System, Fluids, and Electrolytes Lecture Review

Flashcards covering the introduction to the respiratory system, its functions, histology, airflow pathways, specific organ functions like the larynx and alveoli, vocalization, and the mechanics of pulmonary ventilation (inhalation and exhalation) based on Boyle's Law.

What is the primary function of the respiratory system related to gas exchange?

Getting oxygen into the blood and cells, and removing carbon dioxide.

Why is oxygen essential for cells?

For cellular respiration to make ATP.

What waste product is always produced during ATP synthesis?

Carbon dioxide.

What is the only way to get rid of CO2 from the body?

Exhalation.

Besides gas exchange, what other function does the conducting zone of the respiratory system serve?

Air passageway.

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

Olfactory epithelium.

What is the primary function of the larynx?

Sound production (vocalization).

Which body system is responsible for transporting oxygen and carbon dioxide throughout the body?

Cardiovascular system (blood).

Where does the exchange of oxygen and carbon dioxide occur in the lungs?

Between the alveoli and blood vessels.

Which body system controls pulmonary ventilation?

The nervous system.

What causes the volume changes necessary for inhalation and exhalation?

Specific muscles contracting and relaxing.

What is the respiratory lining also known as?

Mucosa or mucous membrane.

What type of epithelium makes up most of the respiratory lining?

Pseudostratified ciliated columnar epithelium.

Where is the pseudostratified ciliated columnar epithelium primarily found?

From the nasal cavity down to the lobar bronchi.

What type of epithelium is found in the alveoli?

Simple squamous epithelium.

What is the function of the goblet cells in the pseudostratified ciliated columnar epithelium?

Secrete mucus.

What is the function of the cilia on the pseudostratified ciliated columnar epithelium?

To help catch debris and move mucus.

Where does the mucus generally get moved to after catching debris?

Down to the esophagus and stomach, where acid kills microorganisms.

Why is the tissue in the alveoli very thin and largely devoid of mucus?

To facilitate efficient gas exchange by minimizing barriers.

What protein is produced by goblet cells that becomes mucus when mixed with water?

Mucin.

How does mucin contribute to the function of mucus?

It increases viscosity, helping to catch pollen, allergens, microorganisms, dust, and debris.

What are some defense mechanisms found in the respiratory system mucus, acting as a first line of immune defense?

Lysozymes, defensins, and IgA (an antibody).

What is the correct order of airflow through the respiratory system, starting from the nose?

Nose -> Pharynx -> Larynx -> Trachea -> Main bronchi -> Lobar bronchi -> Segmental bronchi -> Bronchioles -> Terminal bronchioles -> Respiratory bronchioles -> Alveolar ducts -> Alveoli.

Which structure functions in air, food, and liquid passage and contains the palatine and lingual tonsils?

Oral pharynx.

What is the main site of gas exchange in the lungs, composed mainly of simple squamous epithelium?

Alveoli.

Which structure functions as an air passage and contains C-shaped cartilage rings?

Trachea.

Which structures are also known as secondary bronchi?

Lobar bronchi.

Which part of the pharynx is continuous with the larynx and esophagus and functions in air, food, and liquid passage?

Laryngopharynx.

Which structures are the last of the conducting pathways, function in air passage, and have smooth muscle instead of cartilage?

Terminal bronchioles.

Which structures mark the start of the respiratory zone, function in air passage, and facilitate gas exchange?

Respiratory bronchioles.

Which ducts give rise to the alveoli, with about 2 million in the lungs?

Alveolar ducts.

What are tertiary bronchi also known as?

Segmental bronchi.

Which part of the pharynx functions in air passage and has openings to the Eustachian tubes?

Nasopharynx.

What is the comprehensive function of the nasal cavity regarding the air we breathe?

To condition air by warming, cleansing, and humidifying it.

What effect does cold air have on the bronchi?

It stimulates bronchoconstriction.

How do the conchae (turbinate bones) help condition air?

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

What two components are responsible for 'cleaning' the air in the nasal cavity?

Mucus and cilia.

What is the term for the coordinated action of mucus and cilia in clearing debris?

Mucus escalator.

How is the air warmed in the nasal cavity?

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

How is air humidified in the nasal cavity?

The moist mucus helps humidify the air.

What happens when a respiratory infection travels to the sinuses?

Inflammation and trapped mucus clog the ducts, creating a breeding ground for bacteria, leading to a sinus infection.

What are the additional functions of the larynx, besides sound production?

Ensuring food and liquid go down the correct passageway, increasing pressure in the abdominal-pelvic cavity, and producing sneezing/coughing reflexes.

Which folds in the larynx are considered 'false vocal cords' and serve a protective function?

Vestibular folds.

What is the opening between the vocal folds called?

Rima glottidis.

How is sound produced in the larynx?

Exhaling air across the true vocal folds causes them to vibrate.

What is the epiglottis made of, and why is this significant?

Elastic cartilage, which allows it to bend and temporarily close the passageway to the trachea during swallowing.

What is the primary function of the epiglottis?

To prevent ingested materials from entering the respiratory tract.

What type of tissue covers the true vocal cords, and why?

Elastic tissue, because it vibrates readily to produce sound.

What causes males to develop a deeper voice during puberty?

Testosterone targets the thyroid cartilage, causing it to elongate, which lengthens the vocal cord ligaments.

What type of muscles move structures within the larynx to help with vocalization?

Intrinsic laryngeal muscles.

What effect do extrinsic laryngeal muscles have on the larynx and vocalization?

They move the larynx up and down, which can contribute to a deeper voice when the larynx drops.

What primarily determines the range of a person's voice (e.g., bass to soprano)?

The length of the vocal folds.

What determines the pitch of the voice?

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

How is the loudness of the voice regulated?

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

What is the difference between sound production and vocalization?

Vocalization is sound production combined with articulation (involving lips, cheeks, and tongue).

What is laryngitis?

Inflammation of the vocal folds, which prevents them from vibrating properly.

What are common causes of laryngitis?

Bacterial or viral infection, or overuse (like yelling).

What is epiglottitis and why is it dangerous?

Inflammation of the epiglottis, which can be lethal if it obstructs the airway.

What are the key differences between bronchi and bronchioles?

Bronchioles have a smaller diameter, no cartilage (replaced by smooth muscle), allowing for bronchoconstriction and bronchodilation.

Why is it important for bronchioles to have smooth muscle instead of cartilage?

Smooth muscle allows for changes in diameter (bronchoconstriction/bronchodilation) to regulate airflow.

Which part of the respiratory system is the main focus for gas exchange?

The alveoli.

What structures surround the alveoli to ensure efficient gas exchange?

Pulmonary capillaries.

What are alveolar pores, and what is their function?

They are holes allowing for collateral ventilation, ensuring proper airflow within the alveoli.

What two epithelial layers make up the respiratory membrane?

The alveolar epithelium and the capillary epithelium (both simple squamous).

Why must the respiratory membrane be as thin as possible?

For adequate and efficient gas exchange.

What natural phenomenon occurs in the alveoli due to hydrogen bonds between water molecules?

Surface tension, which creates an attractive force that can cause the alveoli to collapse.

What substance prevents the collapse of alveoli by breaking up hydrogen bonds and reducing surface tension?

Surfactant.

When does surfactant production begin in fetal development?

Around fetal month seven.

Why do premature babies often experience respiratory distress?

They may be born before surfactant production is adequate, leading to collapsing alveoli and difficulty breathing.

What type of tissue is abundant in the lungs and why is it important?

Elastic tissue, which allows the lungs to expand and recoil back to their original shape, aiding ventilation.

What is the very first step of respiration?

Pulmonary ventilation.

What are the four subsequent steps of respiration?

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

What term describes normal inhalation and exhalation at rest?

Eupnea.

What is 'forced breathing'?

Taking a deep breath in or forcing all air out of the lungs, which can be voluntary (e.g., yoga) or automatic (e.g., exercise).

What is the first step in pulmonary ventilation?

Nervous system stimulation.

What happens to skeletal muscles during inhalation versus exhalation?

They contract during inhalation and relax during exhalation.

What physical change occurs in the thoracic cavity due to muscle movement?

A change in its volume.

What law describes the inverse relationship between volume and pressure, which drives pulmonary ventilation?

Boyle's law.

Why is a pressure gradient necessary for breathing?

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

What are the primary muscles involved in quiet breathing?

Diaphragm and external intercostals.

What additional muscles are used during forced inhalation?

Neck muscles, some chest muscles, and some back muscles.

What muscles are primarily used during forced exhalation?

Abdominal muscles (abs).

How does the diaphragm change the volume of the thoracic cavity?

It changes it vertically; it flattens (moves inferiorly) when contracted and curves (moves superiorly) when relaxed.

What happens to atmospheric pressure and intrapulmonary pressure when the body is at rest and no gas is moving?

Atmospheric pressure is equal to intrapulmonary pressure (e.g., 760 mmHg).

What happens to the diaphragm and external intercostals during nervous system stimulation for inhalation?

They contract.

When the diaphragm contracts, which way does it move?

Inferiorly (down).

What happens to the volume of the thoracic cavity when the diaphragm and external intercostals contract?

It increases.

According to Boyle's Law, what happens to intrapulmonary pressure when thoracic cavity volume increases?

It decreases (e.g., to ~758 mmHg).

During inhalation, how is a pressure gradient created?

Atmospheric pressure becomes higher than intrapulmonary pressure.

In which direction does air move during inhalation due to the pressure gradient?

From the atmosphere (high pressure) into the lungs (low pressure).

Does exhalation during eupnea involve muscle contraction?

No, it's primarily passive, involving relaxation of muscles and elastic recoil of the lungs.

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

It decreases.

According to Boyle's Law, what happens to intrapulmonary pressure when thoracic cavity volume decreases?

It increases (e.g., to ~762 mmHg).

During exhalation, how is a pressure gradient created?

Intrapulmonary pressure becomes higher than atmospheric pressure.

In which direction does air move during exhalation due to the pressure gradient?

From the lungs (high pressure) to the atmosphere (low pressure).

Under normal conditions, does atmospheric pressure frequently change?

No, unless there's a change in altitude.

What is a common misconception about pulmonary ventilation steps?

That air inhaling causes the volume change, rather than muscle movement causing volume change, which then causes air movement.

What is the required relationship between intrapleural pressure and intrapulmonary pressure?

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

What can happen if intrapleural pressure is not sufficiently lower than intrapulmonary pressure?

A collapsed lung (atelectasis).

What can cause intrapleural pressure to change, potentially leading to a collapsed lung?

A puncture in the chest cavity.