WEEK 4 Flashcards by Marija C

What is Boyle’s Law, and how does it relate to breathing?

Boyle’s Law states that in a closed system, air pressure and volume are inversely proportional (P1 × V1 = P2 × V2). When lung volume increases, internal air pressure decreases, causing inhalation.

How well did you know this?

Not at all

Perfectly

What is the principle of pressure equalization in breathing?

Air moves from a region of higher pressure to lower pressure:

Inhalation: Lung volume ↑ → Pressure ↓ → Air flows in
Exhalation: Lung volume ↓ → Pressure ↑ → Air expelled

How well did you know this?

Not at all

Perfectly

How does negative-pressure breathing work?

The thoracic muscles increase and decrease lung volume, allowing air to move in and out due to pressure differences.

How well did you know this?

Not at all

Perfectly

What is Tidal Volume (TV)?

The volume of air exchanged during relaxed breathing (~0.5L in males, ~0.4L in females).

How well did you know this?

Not at all

Perfectly

What is Vital Capacity (VC)?

The maximum volume of air exchanged in breathing:
VC = ERV + TV + IRV

Males: 4-5L
Females: 3-4L

How well did you know this?

Not at all

Perfectly

What is Inspiratory Reserve Volume (IRV)?

The maximum air inhaled after a normal tidal inspiration.
IRV = IC - TV

50% - 100% of lung capacity
Males: ~3L
Females: ~2L

How well did you know this?

Not at all

Perfectly

What is Expiratory Reserve Volume (ERV)?

The maximum air expelled after a normal exhalation.
ERV = FRC - RV

20% - 40% of lung capacity
Males: >1L
Females: <1L

How well did you know this?

Not at all

Perfectly

What is Functional Residual Capacity (FRC)?

The volume of air remaining in the lungs after a normal exhalation.
FRC = ERV + RV

0% - 40% of lung capacity
Males: >2L
Females: <2L

How well did you know this?

Not at all

Perfectly

What is Total Lung Capacity (TLC)?

The total volume of air the lungs can hold.
TLC = VC + RV

Males: 5-6L
Females: 4-5L

How well did you know this?

Not at all

Perfectly

What is Residual Volume (RV)?

The air that remains in the lungs even after maximum exhalation (~0% - 20% of lung capacity).

How well did you know this?

Not at all

Perfectly

How does speech breathing differ from tidal breathing?

Speech breathing: Uses 25%-70% of VC, with shorter inspiration and longer expiration for sustained airflow during speech.
Tidal breathing: Uses 50% of lung capacity, with an equal rhythmic pattern.

How well did you know this?

Not at all

Perfectly

Suppose a person’s lungs contain 500 mL (0.5L) of air at 1 atm before inhalation. If their lung volume increases to 700 mL (0.7L), what is the new pressure inside the lungs?

Using Boyle’s Law (P1 × V1 = P2 × V2):
1 atm × 0.5L = P2 × 0.7L
P2 = 0.714 atm

How well did you know this?

Not at all

Perfectly

Which of the following best defines Inspiratory Reserve Volume (IRV)?

A) The maximum volume of air inhaled after a normal inhalation
B) The maximum volume of air exhaled after a normal exhalation (ERV)
C) The total volume of air that can be exhaled after maximum inhalation (VC)
D) The volume of air remaining in the lungs after a maximal exhalation (RV)

A) The maximum volume of air inhaled after a normal inhalation

How well did you know this?

Not at all

Perfectly

What are the primary functions of the lungs?

The lungs are the primary organs of respiration, responsible for gas exchange. They contain alveoli, which facilitate oxygen-carbon dioxide exchange with the blood.

How well did you know this?

Not at all

Perfectly

How do the right and left lungs differ?

Right lung: 3 lobes (superior, middle, inferior)
Left lung: 2 lobes (superior, inferior); smaller due to heart placement

How well did you know this?

Not at all

Perfectly

What is the function of the pleura?

The pleura is a double-layered membrane surrounding the lungs:

Visceral pleura: Adheres to the lungs
Parietal pleura: Lines the chest wall
Pleural space: Contains pleural fluid, reducing friction for smooth movement

How well did you know this?

Not at all

Perfectly

What is the hierarchical structure of the airway leading to the lungs?

A) The trachea divides into bronchioles, which lead to the alveolar ducts and eventually the alveoli
B) The bronchi branch into the trachea, which further divides into alveoli
C) The bronchi branch directly into alveolar sacs, bypassing the bronchioles and alveolar ducts
D) The trachea bifurcates into bronchi, which divide into bronchioles, leading to alveolar ducts and alveoli

D) The trachea bifurcates into bronchi, which divide into bronchioles, leading to alveolar ducts and alveoli

How well did you know this?

Not at all

Perfectly

What is the primary muscle of inhalation, and how does it function?

The diaphragm is the primary muscle of inhalation. It contracts and flattens, increasing thoracic volume and decreasing lung pressure, allowing air to enter.

How well did you know this?

Not at all

Perfectly

What is the central tendon of the diaphragm, and what is its function?

A tough, flat sheet of tendon at the diaphragm’s core

Functions:
- Transmits force from muscle contractions
- Enables the diaphragm to flatten and move downward during inhalation

How well did you know this?

Not at all

Perfectly

What is the advantage of having a central tendon instead of all muscle?

Tendons are stronger and more cushiony than muscles, helping transfer energy efficiently to the lungs.

How well did you know this?

Not at all

Perfectly

What are the accessory muscles of inhalation, and what do they do?

External intercostal muscles: Elevate the ribs, expanding the chest wall
Sternocleidomastoid muscles: Raise the sternum, increasing thoracic volume

How well did you know this?

Not at all

Perfectly

What role does the central tendon play in the functioning of the diaphragm during inhalation?

A) It acts as a hinge point allowing the diaphragm to expand outward
B) It serves as the attachment site for the heart and lungs
C) It transmits the force generated by the diaphragm’s muscular contractions and enables the diaphragm to flatten and move downward
D) It prevents the diaphragm from over-contracting during inhalation

C) It transmits the force generated by the diaphragm’s muscular contractions and enables the diaphragm to flatten and move downward

How well did you know this?

Not at all

Perfectly

What is the difference between passive and active exhalation?

Passive exhalation: Relaxation of the diaphragm and elastic recoil of the lungs push air out.
Active exhalation: Requires abdominal and internal intercostal muscles to forcefully push air out.

How well did you know this?

Not at all

Perfectly

What muscles are involved in active exhalation?

Study These Flashcards

Abdominal muscles (rectus abdominis, obliques, transversus abdominis)
Internal intercostal muscles (pull ribs down to reduce thoracic volume)

What nerves innervate the muscles of exhalation?

- Abdominal muscles: T7-T12 (lower thoracic spinal nerves) - Internal intercostals: Intercostal nerves (branches of thoracic spinal nerves)

What is the difference between diaphragmatic and chest breathing?

- Diaphragmatic breathing: Deep breathing using the diaphragm; results in abdominal movement rather than chest expansion. - Chest breathing: Shallow breathing using chest muscles, characterized by upward and outward chest movement.

A patient with weakened abdominal muscles is likely to experience difficulty with which aspect of breathing? A) Passive inhalation during relaxed breathing B) Active exhalation during activities such as coughing or singing C) Elastic recoil of the lungs during quiet breathing D) Contraction of the diaphragm for inhalation

B) Active exhalation during activities such as coughing or singing

Where are the lungs located?

The lungs are located in the thoracic cavity, on either side of the heart, enclosed by the ribcage and protected by the pleura.

What is the structural composition of the lungs?

- Spongy tissue containing alveoli - Lobes and fissures divide the lungs - Bronchial tree transports air - Pleura protects and lubricates

How many lobes does the right lung have, and what are their names?

The right lung has three lobes: Superior lobe Middle lobe Inferior lobe It is divided by the horizontal and oblique fissures.

How many lobes does the left lung have, and what are their names?

The left lung has two lobes: Superior lobe Inferior lobe It is divided by the oblique fissure.

Why does the left lung have fewer lobes than the right lung?

The left lung is smaller because the heart is positioned on the left side of the chest, reducing space.

What is the function of the trachea?

The trachea (windpipe) is a cartilaginous tube that transports air from the throat to the lungs.

What are the bronchi, and what do they do?

- The right and left bronchi branch from the trachea into each lung. - They further divide into smaller bronchioles, leading to the alveoli.

What are alveoli, and why are they important?

Alveoli are tiny air sacs where gas exchange occurs between the lungs and the blood. The lungs contain about 300 million alveoli, increasing surface area for efficient oxygen-carbon dioxide exchange.

What happens during inhalation?

- Diaphragm contracts and flattens - Thoracic volume increases - Lung pressure decreases, drawing air in

What happens during exhalation?

- Diaphragm relaxes - Thoracic volume decreases - Lung pressure increases, forcing air out

What is the difference between negative-pressure breathing and positive-pressure breathing?

- Negative-pressure breathing: Normal breathing where air enters the lungs due to lower pressure inside. - Positive-pressure breathing: Artificial breathing (e.g., ventilators) where air is forced into the lungs.

A speech-language pathologist is working with a client who has chronic obstructive pulmonary disease (COPD). The client reports difficulty expelling air completely and experiences shortness of breath during speech. The pathologist aims to improve the client’s ability to control airflow and extend speech duration by focusing on the lung volume that remains in the lungs after normal expiration. Which lung volume is the pathologist most likely focusing on? Functional residual capacity Inspiratory reserve volume Residual volume Tidal volume

Functional residual capacity

A professional athlete is undergoing respiratory training to improve breath control and endurance. During a session, the coach instructs the athlete to take the deepest breath possible, filling the lungs completely, and then to exhale as much air as possible. This exercise is designed to maximize lung function by utilizing multiple lung volumes. Which lung volumes or capacities are primarily involved in this breathing exercise? Only the inspiratory reserve volume (IRV) Only the expiratory reserve volume (ERV) The inspiratory reserve volume (IRV), tidal volume (TV), and expiratory reserve volume (ERV) Both the inspiratory reserve volume (IRV) and the expiratory reserve volume (ERV)

The inspiratory reserve volume (IRV), tidal volume (TV), and expiratory reserve volume (ERV)

Which of the following statements about the location of abdominal muscles is false? The rectus abdominis muscle is superficial to the external oblique muscle. The transversus abdominis muscle is the deepest of the four abdominal muscles. The external oblique muscle is superficial to the internal oblique muscle. The internal oblique muscle is positioned between the external oblique and transversus abdominis muscles.

The rectus abdominis muscle is superficial to the external oblique muscle.

Which of the following statements about the diaphragm muscle is false? The diaphragm is the primary muscle of inspiration, contracting to increase thoracic volume. The diaphragm contracts and moves upward during inhalation, decreasing lung volume. The diaphragm is innervated by the phrenic nerve, which originates from cervical spinal nerves C3–C5. The central tendon of the diaphragm is a contractile structure that actively shortens during inspiration.

The diaphragm contracts and moves upward during inhalation, decreasing lung volume.

If a blockage were to occur in one of the bronchiole in the right lung, gas exchange in all the alveolar sacs would be restricted. true or false

false

The cervical vertebrae play a crucial role in respiration because they provide attachment points for the ribs and facilitate rib movement during breathing. true or false

false

A researcher is analyzing raw surface EMG signals from the masseter muscle during speech production. The recorded data shows both positive and negative voltage values in millivolts. The researcher concludes that this means some motor units are actively contracting while others are simultaneously inhibiting the muscle. Is this likely true or false?

false

A yoga instructor is leading a class in deep belly breathing exercises. One student, curious about the role of different muscles, states that the rectus abdominis plays a crucial role in belly breathing by actively expanding the abdomen during inhalation. Is this likely true or false?

false

What is Electromyography (EMG)?

EMG is a technique used to measure and analyze the electrical activity produced by skeletal muscles (myoelectric signals).

What type of muscle activity does EMG detect?

EMG detects electrical activity from multiple muscle fibers as they are activated by motor neurons.

Does EMG work for smooth muscles?

Not effectively. - Smooth muscles are controlled by the autonomic nervous system. - Their electrical activity is weaker and less synchronized than skeletal muscles. - Alternative techniques: EHG for uterine muscles EGG for gastric muscles

What is a Motor Unit Action Potential (MUAP)?

MUAP is the action potential generated by a motor unit (a motor neuron and the muscle fibers it controls).

How is MUAP different from neural activation potential?

- MUAP occurs in muscle fibers. - Neural activation potential happens in the axon of the neuron.

What are the two main types of EMG?

- Surface EMG (sEMG) – Uses electrodes on the skin surface (non-invasive). - Intramuscular EMG (Needle EMG) – Uses needle electrodes inside the muscle (invasive but detailed).

What are the advantages of Surface EMG (sEMG)?

- Non-invasive - Used in biomechanics, rehabilitation, and sports science - Measures summed electrical activity of multiple muscle fibers

What are the advantages of Intramuscular (Needle) EMG?

- Provides detailed muscle activity - Detects individual motor unit signals - Used in clinical diagnostics for neuromuscular disorders

What is the typical range of raw EMG signals?

Between ±5000 microvolts (for athletes), with frequencies ranging between 6–500 Hz.

Why does the raw EMG signal need to be rectified?

- EMG signals are bipolar (contain positive and negative values). - Rectification converts all values to positive, making the signal easier to analyze. - Helps in smoothing and integration of data.

Why is a rectified EMG signal smoothed?

- Removes high-frequency noise. - Reduces rapid fluctuations from motor unit firing. - Reveals trends in muscle activation. - Facilitates comparison across trials and subjects.

What is the best method to stabilize an EMG signal after rectification?

Apply a low-pass filter to remove high-frequency noise and improve interpretability.

Where should EMG electrodes be placed for best signal quality?

Electrodes should be placed on the muscle belly, between tendons, to capture maximum electrical activity.

WEEK 4 Flashcards

(59 cards)