M1_Respiratory System Anatomy and Physiology

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Questions and Answers

What is the primary function of the conducting zone?

To produce sound for vocal resonance

To filter out particles from inspired air

To transport gas in and out of the lungs (correct)

To facilitate gas exchange

What is the name of the structure that contains the vocal cords?

Trachea

Pharynx

Larynx (correct)

Bronchi

Why do physiotherapists encourage clients to breathe through their nose?

Because of its functions of filtering, warming, and humidifying the air (correct)

To reduce breathlessness

To improve vocal resonance

To facilitate gas exchange

What is the main purpose of the respiratory zone?

Gas exchange Signup and view all the answers

What is the name of the tube-like structure that connects the larynx to the bronchi?

Trachea Signup and view all the answers

What is the common passageway for both food and air?

Pharynx Signup and view all the answers

What is the angle of branching of the right main bronchus?

20-30 degrees Signup and view all the answers

What type of muscle is present in the bronchioles?

Smooth muscle Signup and view all the answers

What is the purpose of the cartilaginous rings in the trachea?

To provide structural support to keep the airway open Signup and view all the answers

What are the tiny sacs responsible for gas exchange between the lungs and the bloodstream?

Alveoli Signup and view all the answers

How many functional zones does the respiratory system have?

Two Signup and view all the answers

What is the name of the upper part of the respiratory system?

Upper respiratory tract Signup and view all the answers

What is the name of the process by which air enters the alveoli through pathways that bypass the normal airways?

Collateral ventilation Signup and view all the answers

What is the average number of pores of Kohn present in each adult alveolus?

5-20 Signup and view all the answers

What is the primary function of the alveolar ducts?

To transport air from the bronchioles to the alveoli Signup and view all the answers

What is the name of the membrane where perfusion occurs?

Alveolar membrane Signup and view all the answers

What is the branching pattern of a person's airway called?

The bronchial tree Signup and view all the answers

What is the purpose of collateral ventilation?

To preserve ventilation and gas exchange in distal parts of the lung beyond the point of obstruction Signup and view all the answers

At what age do Pores of Kohn typically develop?

Around 4 years of age Signup and view all the answers

What is the effect of age on the number of collateral channels in humans?

It decreases Signup and view all the answers

What is the approximate diameter of an alveolar sac?

0.3 mm Signup and view all the answers

What is the cross-sectional area of the lungs?

1,000,000 cm2 Signup and view all the answers

How many generations of airways are typically cleared when coughing?

6 Signup and view all the answers

What is the shape of the lungs?

Cone-shaped Signup and view all the answers

What holds the lungs in position?

Negative pressure between the pleural spaces Signup and view all the answers

How many lobes does the right lung have?

3 Signup and view all the answers

What is the purpose of the pleural cavity?

To create surface tension that pulls the pleura together Signup and view all the answers

Why is it important to understand the anatomy of the lungs?

To guide auscultation and clinical reasoning Signup and view all the answers

Which muscles are recruited to assist with inspiration during increased work of breathing?

Sternocleidomastoid and scalene muscles Signup and view all the answers

What is the result of quiet breathing during expiration?

Passive recoil of the lungs Signup and view all the answers

Which nerve innervates the diaphragm?

Phrenic nerve Signup and view all the answers

What is the spinal level that innervates the diaphragm?

C3, 4, 5 Signup and view all the answers

Which muscles contribute to expiration?

Internal intercostal muscles and abdominal muscles Signup and view all the answers

What is the purpose of the handy mnemonic 'C3, 4, 5, keeps the diaphragm alive'?

To remember the spinal level that innervates the diaphragm Signup and view all the answers

What is the result of a spinal cord injury at the level of C5?

Compromised innervation of the diaphragm Signup and view all the answers

What is true about inspiration?

It requires muscle contraction and is always active Signup and view all the answers

Which intercostal muscles contribute to inspiration?

External intercostal muscles Signup and view all the answers

What is the main muscle of respiration?

Diaphragm Signup and view all the answers

What is the role of the internal intercostal muscle during increased work of breathing?

To assist with active expiration Signup and view all the answers

What is the purpose of the pleural fluid in the pleural cavity?

To act as a lubricant and increase surface tension Signup and view all the answers

What is the pressure in the pleural cavity during normal breathing?

Negative pressure Signup and view all the answers

What is the role of the respiratory muscles in inspiration and expiration?

Involved in both inspiration and expiration Signup and view all the answers

What is the result of a weak respiratory muscle?

Increased work of breathing Signup and view all the answers

What is the purpose of inspiratory muscle training?

To strengthen the respiratory muscles Signup and view all the answers

What is the unit of respiration being referred to throughout this section?

One full breath in and one full breath out Signup and view all the answers

What is the lining of the rib cage?

Parietal pleura Signup and view all the answers

What is the direction of air movement during respiration?

From high pressure to low pressure Signup and view all the answers

What is the natural tendency of the chest wall and lungs?

The chest wall pulls outwards and the lungs pull inwards Signup and view all the answers

What is the primary function of the costovertebral and costotransverse joints?

To allow for proper movement of the chest during breathing Signup and view all the answers

What is the term used to describe the movement of the ribs during inspiration?

Bucket handle movement Signup and view all the answers

Which of the following is NOT a condition that can impact involuntary breathing?

Pneumonia Signup and view all the answers

What is the principal muscle of inspiration?

External intercostals Signup and view all the answers

What is the stimulus for breathing in involuntary breathing?

Increased CO2 Signup and view all the answers

Which of the following is a type of voluntary breathing control?

Cortical control Signup and view all the answers

What is the purpose of the respiratory control centers in the brain?

To control the muscles responsible for breathing Signup and view all the answers

Which of the following muscles is responsible forexpiration?

Internal intercostals Signup and view all the answers

What is the term used to describe the movement of the sternum during inspiration?

Pump handle movement Signup and view all the answers

What is the primary function of the diaphragm?

To contribute to inspiration Signup and view all the answers

What is the main difference between lung volumes and lung capacities?

Lung volumes refer to specific amounts of air contained within different compartments, while lung capacities refer to the sum of two or more lung volumes. Signup and view all the answers

What is functional residual capacity (FRC) of the lungs?

The volume of air left in the lung at the end of normal quiet expiration. Signup and view all the answers

Which of the following factors affects lung volumes?

Body size, age, gender, muscle training, and respiratory disease. Signup and view all the answers

What is the purpose of understanding lung volumes and lung capacities in physiotherapy?

To track changes in lung function over time and design appropriate treatment plans. Signup and view all the answers

What is the outward spring of the rib cage responsible for?

Determining the functional residual capacity (FRC) of the lungs. Signup and view all the answers

What is the name of the graph that demonstrates different variables related to inspiration and expiration?

Figure 01-13. Signup and view all the answers

Why do people living at altitude have larger lung volumes?

To increase gas exchange where the partial pressure of oxygen is reduced. Signup and view all the answers

What is the effect of aging on lung volumes?

Lung volumes decrease due to reduced lung elasticity and reduced compliance of the thoracic cage. Signup and view all the answers

What is the difference between tidal volume and inspiratory reserve volume?

Tidal volume is the volume of air inspired during quiet breathing, while inspiratory reserve volume is the volume of air inspired from tidal volume to maximal inspiration. Signup and view all the answers

What is the relationship between lung volumes and surfactant?

Surfactant deficiency can lead to respiratory distress and other lung diseases, affecting lung function. Signup and view all the answers

What is the result of the diaphragm contracting during inspiration?

A negative intrapulmonary pressure Signup and view all the answers

What is the purpose of accessory muscles in pulmonary ventilation?

To increase thoracic volume Signup and view all the answers

What is airway compliance?

The ratio of change in volume to change in pressure Signup and view all the answers

What contributes to the elastic recoil of the lungs?

Both the elastin fibers and the surface tension of the alveoli Signup and view all the answers

What is the effect of surfactant on pulmonary compliance?

It increases pulmonary compliance Signup and view all the answers

What is hysteresis?

The energy applied to the lung during inspiration that is not recovered in expiration Signup and view all the answers

What is the purpose of the chest wall in pulmonary ventilation?

To push the lungs outward Signup and view all the answers

What happens to the intrapulmonary pressure at the end of inspiration?

It becomes equal to atmospheric pressure Signup and view all the answers

What is the result of the recoil of the lungs and chest wall at the end of inspiration?

The lungs recoil and exhalation occurs Signup and view all the answers

Why is pulmonary surfactant essential for efficient gas exchange in the lungs?

It reduces the surface tension of the alveoli Signup and view all the answers

Study Notes

The Respiratory System: Anatomy and Physiology

The respiratory system is divided into two functional zones: the conducting zone and the respiratory zone.

Conducting Zone

The conducting zone transports gas in and out of the lungs.
It consists of the nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles.
The nose:
- Filters, warms, and humidifies the air during inspiration.
- Has multiple functions, including olfaction and vocal resonance.
The pharynx:
- Is the common passageway for food and air.
- Connects the nasal cavity and mouth to the larynx.
The larynx:
- Contains the vocal cords.
- Is located between the pharynx and trachea.
The trachea:
- Is a tube-like structure that connects the larynx to the bronchi.
- Composed of cartilaginous rings that provide structural support.
The bronchial tree:
- Is the branching pattern of the airway.
- Has approximately 23 generations of branching.
- Features of note:
  - The right main bronchus is more vertical than the left.
  - Bronchioles lack cartilage but have smooth muscles.

Respiratory Zone

The respiratory zone is responsible for gas exchange.
It includes the respiratory bronchioles, alveolar ducts, and alveoli.
Alveoli:
- Are tiny sacs responsible for gas exchange between the lungs and bloodstream.
- Have a liquid membrane where perfusion occurs.
- Are bunched together, forming a "grape-like" structure.

Collateral Ventilation

Is the ventilation of alveolar structures via pathways that bypass the normal airways in the lungs.
Occurs when the airways are restricted or obstructed.
Enables the preservation of ventilation and gas exchange in distal parts of the lung.

The Lungs

Are cone-shaped and positioned vertically in the chest cage, around the heart.
Are held in position by negative pressure between the pleural spaces.
Have a membrane called the visceral pleura, which covers the surface of the lungs.

Clinical Note

Understanding the anatomy of the lungs is crucial for clinical reasoning and auscultation (listening to lung sounds with a stethoscope).

Respiratory Mechanics

The biomechanics of the respiratory system is essential for understanding respiration.
The morphology of the joints in the rib cage, the origin and insertions of muscles, and their planes of action contribute to understanding normal function.
The movement of the rib cage:
- Moves like a bucket handle during inspiration.
- Moves like a pump handle during inspiration.

Muscles of Respiration

The principal muscles of inspiration are the external intercostals, the interchondral part of the internal intercostals, and the diaphragm.
Accessory muscles that contribute to inspiration include the sternocleidomastoid and scalenes.
Muscles of expiration:
- Quiet breathing is a passive process, resulting from the recoil of the lungs.
- Active expiration occurs through the recruitment of internal intercostal muscles and abdominal muscles.

Innervation of the Diaphragm

The phrenic nerve innervates the diaphragm.
The phrenic nerve originates from the anterior rami of the C3-C5 roots.

Respiratory Pathways

The neural pathways to the respiratory muscles operate similarly to all other neural pathways.
Conditions that impact the neural pathways to respiratory muscle include:
- Guillain-Barré syndrome
- Spinal cord injury
- Poliomyelitis

Clinical Note

As a physiotherapist, consider the muscles of respiration as trainable muscles that can be strengthened.
Inspiratory muscle training can be used to improve respiratory function.### Pulmonary Ventilation
Three air pressures are involved in pulmonary ventilation: intrapulmonary pressure (within the lungs), intrapleural pressure (in the pleural cavity), and atmospheric pressure (surrounding air).
Air moves from high pressure to low pressure, and this pressure gradient drives air in and out of the lungs.
The chest wall and lungs have natural tendencies: the chest wall pulls outwards, and the lungs tend to pull inwards and collapse, resulting in a slightly negative pressure (-4cm of water) in the intra-pleural space.
At the beginning of inspiration, the intrapulmonary pressure is equal to atmospheric pressure (0).
When the diaphragm contracts, it creates a negative intrapulmonary pressure, allowing air to enter the lungs.
During inspiration, the intra-pleural pressure becomes more negative (-7), and the chest wall expands.
At the end of inspiration, the intrapulmonary pressure is higher than atmospheric pressure, and air moves out of the lungs.

Muscle Movement and Rib Expansion

Muscle movement and rib expansion change the pressures in the lungs during breathing.
Accessory muscles are used to increase thoracic volume.

Airway Compliance

Compliance refers to how easily air can move in and out of the lungs.
It is calculated as the change in volume over the change in pressure.
High compliance means a large change in volume for a small change in pressure; low compliance means a small change in volume for a large change in pressure.
Factors contributing to compliance include:
- Elastic recoil of the lungs (due to elastin fibers and surface tension)
- Recoil of the chest wall (pulling outwards)
A compliant lung is like inflating a thin balloon, whereas a poorly compliant lung is like inflating a thick balloon.

Surfactant

Surfactant is a surface-active lipoprotein complex that reduces the surface tension of alveoli.
It decreases elasticity and increases pulmonary compliance.
Surfactant is essential for efficient gas exchange in the lungs and is important for understanding lung function and respiratory diseases.

Hysteresis

Hysteresis is the energy applied to the lung during inspiration that is not recovered in expiration.
It is a phenomenon that occurs due to the surface tension that needs to be overcome during inspiration.
Hysteresis is calculated by plotting change in volume over change in pressure.

Lung Volumes and Capacities

Lung volumes refer to the amount of air contained within specific parts of the respiratory system.
Lung capacities refer to the sum of two or more lung volumes.
Important lung volumes and capacities include:
- Tidal volume (TV)
- Inspiratory reserve volume (IRV)
- Expiratory reserve volume (ERV)
- Residual volume (RV)
- Functional residual capacity (FRC)
- Vital capacity (VC)
- Total lung capacity (TLC)

Factors Affecting Lung Volumes

Body size: taller people tend to have larger lung volumes, while obese people have smaller lung volumes.
Age: lung tissue loses elasticity with age, leading to a reduction in lung volume.
Gender: men tend to have larger lung volumes due to their physical size.
Muscle training: inspiratory muscle training increases lung volumes.
Respiratory disease: may lead to an increase or decrease in lung volumes.
Altitude: people living at high altitude have larger lung volumes to increase gas exchange.

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Description

Revise the anatomy and physiology of the respiratory system from a physiotherapy perspective. This quiz covers the upper respiratory tract, including the sinuses, nasal cavity, pharynx, and glottis.