Biology Chapter: Surfactant and Lung Volumes

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Questions and Answers

What causes the alveoli to expand during ventilation?

Increased lung compliance

Increased carbon dioxide levels

Decreased pleural pressure (correct)

Decreased oxygen availability

Which factor is NOT a reason for decreased lung elasticity?

Emphysema

Normal aging

Chronic infection

Healthy lung tissue (correct)

What happens to the pleural pressure during inspiration?

It increases

It remains constant

It fluctuates wildly

It decreases (correct)

What is the primary function of the respiratory membrane?

To facilitate gas exchange Signup and view all the answers

Which condition would likely increase respiratory passageway resistance?

Asthma attack Signup and view all the answers

How does oxygen diffuse from capillaries into interstitial fluid?

Due to lower Po2 in capillaries Signup and view all the answers

What is the average normal respiration rate for adults?

12-20 breaths per minute Signup and view all the answers

What is referred to as 'dead space' in the respiratory system?

Parts of the respiratory passages without gas exchange Signup and view all the answers

What is the primary function of surfactant in the lungs?

To reduce surface tension of the fluid lining the alveoli Signup and view all the answers

Which muscle is primarily responsible for elevating the first two ribs during inspiration?

Scalene Muscle Signup and view all the answers

What causes air to flow out of the alveoli during expiration?

Higher alveolar pressure compared to atmospheric pressure Signup and view all the answers

What is the primary function of the nasal sinuses?

To humidify, warm, and filter inspired air Signup and view all the answers

What volume of air can be forcefully expired after a normal expiration known as?

Expiratory Reserve Volume Signup and view all the answers

What structure is commonly referred to as the voice box?

Larynx Signup and view all the answers

Which of the following best describes Functional Residual Capacity?

Amount of air remaining in the lungs at the end of a normal expiration Signup and view all the answers

During inspiration, what happens to the diaphragm?

It descends into the abdominal cavity Signup and view all the answers

What is the relationship between Inspiratory Capacity and Total Lung Capacity?

IC is part of TLC, calculated as TV+IRV Signup and view all the answers

What is the glottis?

The area between the true vocal cords Signup and view all the answers

What mechanism helps prevent the lungs from collapsing?

Surfactant and pleural pressure Signup and view all the answers

How does oxygen diffusion occur in the lungs?

From higher to lower concentration Signup and view all the answers

During which process does air flow into the alveoli?

Inspiration Signup and view all the answers

Which nerve is NOT mentioned as innovating the upper respiratory airway?

Median Nerve Signup and view all the answers

What is the maximum volume of air that a person can expel from the respiratory tract after maximum inspiration known as?

Vital Capacity Signup and view all the answers

Which muscle is responsible for raising the sternum during breathing?

Sternocleidomastoid Signup and view all the answers

What is the process called that measures the volumes of air moving in and out of the respiratory system?

Spirometry Signup and view all the answers

What happens to gas exchange when the thickness of the respiratory membrane increases?

Gas exchange decreases Signup and view all the answers

What is the Tidal Volume at rest during quiet breathing?

500 mL Signup and view all the answers

What are respiratory capacities defined as?

Sums of two or more respiratory volumes Signup and view all the answers

What happens to gas exchange when the surface area of the respiratory membrane decreases significantly?

It is restricted under resting conditions Signup and view all the answers

What is the Inspiratory Reserve Volume?

Air that can be forcefully inspired beyond Tidal Volume Signup and view all the answers

What is partial pressure in the context of gas exchange?

It is the pressure exerted by a specific gas in a mixture Signup and view all the answers

What role do Higher Brain Centers play in respiration?

They enable voluntary control of breathing Signup and view all the answers

What are the structures found in the pancreas?

Acini and islets of Langerhans Signup and view all the answers

Which of these sounds are associated with lung assessment?

Rhonci and crackles Signup and view all the answers

What is the normal rate of breathing in adults?

12-20 cpm Signup and view all the answers

Which of the following structures is associated with bone?

Osteons Signup and view all the answers

Study Notes

Surfactant and Lung Function

Surfactant is a lipid molecule that reduces surface tension in the alveoli, preventing lung collapse.
Alveolar pressure is lower than atmospheric pressure during inspiration, allowing air to flow into the lungs.
During expiration, alveolar pressure exceeds atmospheric pressure, pushing air out of the lungs.

Lung Volumes and Capacities

Expiratory Reserve Volume (ERV): 1100 mL of air that can be forcefully expelled.
Residual Volume (RV): 1200 mL of air remaining in the lungs after maximum expiration.
Functional Residual Capacity (FRC): ERV + RV, amount of air left in lungs after normal expiration (2300 mL).
Inspiratory Capacity (IC): TV + Inspiratory Reserve Volume (IRV), amount of air that can be inhaled after a normal expiration (3500 mL).
Vital Capacity (VC): IRV + TV + ERV, maximum air expelled after full inspiration (4600 mL).
Total Lung Capacity (TLC): IRV + ERV + TV + RV, total lung space (5800 mL).

Factors Influencing Pulmonary Ventilation

Lung elasticity is critical for recoil; conditions like emphysema decrease elasticity.
Lung compliance is affected by thoracic cavity expansion; rib cage damage can hinder compliance.
Respiratory resistance increases during asthma attacks or due to tumors.

Changes in Alveolar Volume

Increasing thoracic volume lowers pleural pressure and increases alveolar volume, facilitating inspiration.
Decreasing thoracic volume raises pleural pressure, reduces alveolar volume, and promotes expiration.

Measurement of Respiratory Volumes

Spirometry measures respiratory volumes, including tidal volume (TV), which is typically 500 mL for quiet breathing.
Other measured volumes include Inspiratory Reserve Volume (3000 mL) and ERV (1100 mL).

Respiratory Mechanics

Gas exchange occurs at the respiratory membrane, where oxygen diffuses from alveoli to pulmonary capillaries.
Dead space refers to areas of the respiratory tract where no gas exchange occurs.

Control of Ventilation

Normal adult respiration rate is 12-20 breaths per minute, regulated by medulla oblongata neurons.
Breathing can be voluntarily controlled by higher brain centers.

Surface Area and Gas Exchange

Decreased surface area negatively impacts gas exchange; significant reductions can severely restrict this process during resting conditions.

Upper Respiratory Tract Functions

Nasal passages heat, humidify, and filter inhaled air.
Nasal sinuses contribute to resonance during speech.

Respiratory Structure Overview

Larynx serves as the voice box; glottis allows airflow and aids in coughing, a primary lung defense mechanism.

Lung Assessment

Normal respiratory rate is 12-20 breaths per minute (eupnea); rates outside this range indicate potential issues.
Abnormal lung sounds can indicate various conditions:
- Rhonchi: low-pitched snoring sounds.
- Crackles: fine or coarse crackling sounds.
- Rales: rattling sounds.

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Description

This quiz covers the concepts related to surfactant function in the lungs and the various lung volumes, including Inspiratory Reserve Volume, Expiratory Reserve Volume, and Residual Volume. Test your knowledge on how air flows and the role of pressure in respiration.