Anatomy and Physiology of the Respiratory System

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Questions and Answers

What is the main purpose of tracheostomy?

To visualize the bronchial tree

To treat asthma attacks

To re-establish airflow past an airway obstruction (correct)

To remove a foreign object from the trachea

What is the function of the tertiary bronchi?

Supplying each bronchopulmonary segment (correct)

Supplying each lobe of the lungs

Forming the bronchial tree

Supplying each lung

What is the epithelial lining of the bronchial tree in the deeper parts of the lungs?

Non-ciliated simple cuboidal (correct)

Stratified squamous

Pseudostratified ciliated columnar

Transitional epithelium

What is the primary function of the tubes in the respiratory system?

To transport air into the alveoli for gas exchange Signup and view all the answers

What is the effect of epinephrine on the smooth muscle in the bronchioles?

It relaxes the smooth muscle Signup and view all the answers

Which of the following organs is NOT part of the upper respiratory tract?

Lungs Signup and view all the answers

What is the term for the narrow superior tip of the lung?

Apex Signup and view all the answers

Where are infections typically located in the lower respiratory tract?

Below the vocal cords Signup and view all the answers

What is the function of the pleural cavity?

To contain a lubricating fluid that reduces friction between the lungs and the thoracic wall Signup and view all the answers

What is the branch of medicine that deals with the diagnosis and treatment of diseases of the ear, nose, and throat?

Otorhinolaryngology Signup and view all the answers

What is the term for the segments of lung tissue supplied by the tertiary bronchi?

Bronchopulmonary segments Signup and view all the answers

Which of the following is a part of the lower respiratory tract?

Trachea Signup and view all the answers

How many lobes does the right lung have?

3 Signup and view all the answers

What is the term for the indentation in the lung that contains the pulmonary and systemic blood vessels?

Hilus Signup and view all the answers

What is the main function of the alveoli in the respiratory system?

To exchange gases Signup and view all the answers

What is the purpose of nebulization therapy?

To relax the smooth muscle in the bronchioles and reduce the thickness of mucus Signup and view all the answers

What is the primary function of pulmonary ventilation?

Exchange of gases between the atmosphere and lung alveoli Signup and view all the answers

What is the name of the muscle sheet located between the thoracic and abdominal cavities that plays a crucial role in breathing?

Diaphragm Signup and view all the answers

What is the pressure exerted by the air surrounding the body?

Atmospheric pressure Signup and view all the answers

What happens to intrapulmonary pressure during the phases of breathing?

It always eventually equalizes itself with atmospheric pressure Signup and view all the answers

What is the relationship between intrapleural pressure and intrapulmonary pressure?

Intrapleural pressure is always less than intrapulmonary pressure Signup and view all the answers

What is the name of the law that states that the volume of a gas varies inversely with pressure?

Boyle's law Signup and view all the answers

What is the primary mechanism that drives the flow of gases during breathing?

Volume changes leading to pressure changes Signup and view all the answers

What is the term for the process of exchanging gases between the bloodstream and tissue cells in systemic capillaries?

Internal respiration Signup and view all the answers

What is the term for normal quiet breathing?

Eupnea Signup and view all the answers

Which type of breathing involves the descent of the diaphragm, causing the stomach to bulge during inspiration?

Diaphragmatic breathing Signup and view all the answers

What is the term for the amount of air that enters or leaves the lungs during one respiratory cycle?

Tidal Volume Signup and view all the answers

What is the purpose of coughing?

To clear respiratory passages Signup and view all the answers

What is the term for the maximum volume of air that can be forcefully expelled from the lungs following a maximal inspiration?

Vital Capacity Signup and view all the answers

What is the amount of air that stays trapped in the alveoli?

Residual Volume Signup and view all the answers

What is the term for the volume of air contained in the lungs at the end of a maximal inspiration?

Total Lung Capacity Signup and view all the answers

What is the device used to measure air volumes exchanged during breathing and rate of ventilation?

Respirometer Signup and view all the answers

What is the result of injuries to the chest wall that let air enter the intrapleural space?

The lung on the same side as the injury collapses Signup and view all the answers

What is compliance of the lungs?

The measure of the change in lung volume that occurs with a given change in transpulmonary pressure Signup and view all the answers

What is one of the main factors that determines lung compliance?

The surface tension of the alveoli Signup and view all the answers

What can reduce lung compliance?

Blockage of the smaller respiratory passages with mucus or fluid Signup and view all the answers

What is the effect of emphysema on lung compliance?

Lungs become more compliant Signup and view all the answers

What is the effect of pulmonary fibrosis on lung compliance?

Lungs become less compliant Signup and view all the answers

What is the effect of kyphoscoliosis on chest wall compliance?

Chest wall becomes less compliant Signup and view all the answers

What is the effect of pregnancy on chest wall compliance?

Chest wall becomes functionally less compliant Signup and view all the answers

Study Notes

The Respiratory System

Consists of tubes that filter incoming air and transport it into the microscopic alveoli where gases are exchanged.
Includes:
- Nose
- Pharynx (throat)
- Larynx (voicebox)
- Trachea (windpipe)
- Bronchi (airways)
- Lungs

Organs of the Respiratory System

Divided into two groups:
- Upper respiratory tract (nose, nasal cavity, sinuses, and pharynx)
- Lower respiratory tract (larynx, trachea, bronchial tree, and lungs)
Locations of infections:
- Upper respiratory tract: above vocal cords
- Lower respiratory tract: below vocal cords

Tracheostomy and Intubation

Re-establishing airflow past an airway obstruction:
- Crushing injury to larynx or chest
- Swelling that closes airway
- Vomit or foreign object
Tracheostomy: incision in trachea below cricoid cartilage if larynx is obstructed
Intubation: passing a tube from mouth or nose through larynx and trachea

Bronchi and Bronchioles

Primary bronchi: supply each lung
Secondary bronchi: supply each lobe of the lungs (3 right + 2 left)
Tertiary bronchi: supply each bronchopulmonary segment
Repeated branchings form a bronchial tree

Histology of Bronchial Tree

Epithelium changes from pseudostratified ciliated columnar to non-ciliated simple cuboidal as pass deeper into lungs
Incomplete rings of cartilage replaced by rings of smooth muscle and then connective tissue
Sympathetic nervous system and adrenal gland release epinephrine that relaxes smooth muscle and dilates airways
Asthma attack or allergic reactions constrict distal bronchiole smooth muscle

Lungs: Gross Anatomy

Lungs occupy all of the thoracic cavity except the mediastinum
Root: site of vascular and bronchial attachments
Costal surface: anterior, lateral, and posterior surfaces in contact with the ribs
Apex: narrow superior tip
Base: inferior surface that rests on the diaphragm
Hilus: indentation that contains pulmonary and systemic blood vessels

Gross Anatomy of Lungs

Cardiac notch: cavity that accommodates the heart
Left lung: separated into upper and lower lobes by the oblique fissure
Right lung: separated into three lobes by the oblique and horizontal fissures
Each lung has 10 bronchopulmonary segments

Pleurae

Thin, double-layered serosa
Parietal pleura: covers the thoracic wall and superior face of the diaphragm
Visceral, or pulmonary, pleura: covers the external lung surface and divides the thoracic cavity into three chambers

Pleural Membranes and Pleural Cavity

Visceral pleura covers lungs; parietal pleura lines ribcage and covers upper surface of diaphragm
Pleural cavity: potential space between ribs and lungs contains a lubricating fluid

Mechanics of Breathing

Pulmonary ventilation (breathing): process by which gases are exchanged between the atmosphere and lung alveoli
Consists of two phases:
- Inspiration: air flows into the lungs
- Expiration: gases exit the lungs
Breathing is an active process requiring the contraction of skeletal muscles
Primary muscles of respiration:
- External intercostal muscles (located between the ribs)
- Diaphragm (a sheet of muscle located between the thoracic and abdominal cavities)

Pressure Relationships in the Thoracic Cavity

Respiratory pressure is always described relative to atmospheric pressure
Atmospheric pressure (Patm): pressure exerted by the air surrounding the body
Intrapulmonary pressure (Palv): pressure within the alveoli
Intrapleural pressure (Pip): pressure within the pleural cavity
Intrapulmonary pressure and intrapleural pressure fluctuate with the phases of breathing

Pulmonary Ventilation

A mechanical process that depends on volume changes in the thoracic cavity
Volume changes lead to pressure changes, which lead to the flow of gases to equalize pressure

Inspiration

The movement of air into and out of the lungs depends on pressure changes governed in part by Boyle's law
Pleural cavities are sealed cavities not open to the outside

Compliance of the Lungs

Ease with which lungs and chest wall expand
Determined by two main factors:
- Distensibility (elasticity) of the lung tissue and surrounding thoracic cage
- Surface tension of the alveoli

Factors That Diminish Lung Compliance

Scar tissue or fibrosis that reduces the natural resilience of the lungs
Blockage of the smaller respiratory passages with mucus or fluid
Reduced production of surfactant
Decreased flexibility of the thoracic cage or its decreased ability to expand

Compliance Changes in Disease

Lungs become somewhat more compliant with natural aging and become markedly more compliant with emphysema
Lungs become less compliant (stiffer) with pulmonary fibrosis or during edema caused by rheumatic heart disease
Chest wall becomes less compliant (stiffer) in conditions where the chest wall is deformed (e.g. kyphoscoliosis)

Breathing Patterns

Eupnea: normal quiet breathing
Apnea: temporary cessation of breathing
Dyspnea: difficult or labored breathing
Tachypnea: rapid breathing
Diaphragmatic breathing: descent of diaphragm causes stomach to bulge during inspiration
Costal breathing: just rib activity involved

Modified Respiratory Movements (MRM)

Coughing: deep inspiration, closure of rima glottidis, and strong expiration blasts air out to clear respiratory passages
Hiccupping: spasmodic contraction of diaphragm and quick closure of rima glottidis produce sharp inspiratory sound

Lung Volume and Capacities

Air volumes exchanged during breathing and rate of ventilation are measured with a spirometer, or respirometer, and the record is called a spirogram
One inspiration followed by expiration is called a respiratory cycle
Tidal Volume (TV): amount of air that enters or leaves the lungs during one respiratory cycle (Normal: about 500 ml)
Inspiratory Reserve Volume (IRV): amount of air that can be forcibly inhaled over and above normal (approx. 2100-3200 ml)
Expiratory Reserve Volume (ERV): additional amount of air forcibly expired after tidal expiration (1000-1200 ml)
Residual Volume (RV): amount of air that stays trapped in the alveoli (about 1.2 liters)
Total Lung Capacity (TLC): volume of air contained in the lungs at the end of a maximal inspiration (approximately 6000 ml in males)
Vital Capacity (VC): maximum volume of air that can be forcefully expelled from the lungs following a maximal inspiration

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Description

Learn about the respiratory system, its components, and the process of gas exchange in the alveoli. This quiz covers the basics of the respiratory system, including the nose, pharynx, and lungs.