Name: how the brain regulates breathing
Uploaded: 2024-06-20T13:02:58.000Z
Duration: 1 min 23 s
Channel: JoVE

呼吸的生理控制起源于延髓和脑桥中的神经元。
延髓向参与呼吸的肌肉发出信号，而脑桥则控制呼吸频率。
这些呼吸中枢共同调节呼吸的非自主控制，而大脑皮层则实现对呼吸的自主控制。
最重要的呼吸兴奋剂是二氧化碳。它可引起呼吸深度和呼吸频率的增加。
化学感受器监测动脉血中pH值以及二氧化碳和氧气分压的变化，并向延髓传递信号，以向呼吸肌发送神经冲动。
脊髓发出的膈神经、迷走神经和后胸神经向上传导呼吸通路信号，以刺激膈肌和肋间肌。
这些肌肉的功能是通过引起呼吸系统内的体积和压力变化，从而促进通气。
因此，这种有意识的通气努力有助于清除体内多余的二氧化碳，同时提高氧气水平。

呼吸的生理控制

Physiological Control of Respiration

介绍

呼吸是一个看似被动的过程，由脑干呼吸中枢调节。该中心协调呼吸的非自愿控制，这意味着呼吸无需有意识的努力即可发生，从而确保平稳且不间断的模式。

通气量调节

身体通过监测动脉血中二氧化碳 (CO_2)、氧气 (O_2) 和氢离子浓度 (pH) 的水平来维持通气量。在这些因素中，二氧化碳水平在通气量控制中起着至关重要的作用。二氧化碳的增加会触发呼吸控制系统提高呼吸频率和深度，从而通过增加呼气促进去除多余的二氧化碳。

低氧血症和通气控制

患有慢性肺病的患者会经历持续的高碳酸血症。作为一种代偿机制，颈动脉和主动脉中的化学感受器对低氧血症变得敏感，表明动脉血氧水平较低。这些化学感受器是检测血液化学成分变化的特殊细胞。当动脉氧水平低于某个阈值时，这些受体会向大脑发出信号，要求增加通气速度和深度。由化学感受器介导的低氧血症和通气控制之间的相互作用有助于慢性肺病患者维持微妙的平衡。

补充低剂量氧气治疗

如果动脉血氧水平低于 88%，可能需要补充低剂量氧气。持续长期吸氧已被证明可以改善慢性阻塞性肺病（一种常见的慢性肺病）患者的生存率。研究表明，补充氧气在管理动脉氧水平、降低肺动脉高压等并发症的风险以及增强慢性阻塞性肺病患者的整体健康方面具有益处。

结论

呼吸的生理控制是一个多方面的过程，涉及复杂的机制以确保体内气体交换。了解 CO_2、O_2 和 pH 等因素之间的相互作用是理解通气调节的关键。此外，低氧血症的重要性以及补充低剂量氧疗在治疗慢性肺病中的作用也得到了强调。

引言  
呼吸看似是一个被动过程，实则由脑干中的呼吸中枢进行调控。该中枢协调着无意识的……

Education

教育

JoVE Core

Nursing

护理学

Unit 1

第一单元

Vital Signs: Respiration

生命体征：呼吸

KEY TERMS AND CONCEPTS

关键术语与概念

how the brain regulates breathing

How the brain regulates breathing is controlled by the respiratory center in the brainstem. This center manages involuntary breathing, so respirations continue without conscious effort and stay smooth and steady.

Ventilation is maintained by monitoring carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration, or pH, in arterial blood. CO2 is the most important signal in this control system. When CO2 rises, the respiratory control system increases the rate and depth of breathing so extra CO2 can be removed during exhalation.

In chronic lung disease, many patients develop ongoing hypercarbia, which means elevated carbon dioxide in the blood. In this setting, chemoreceptors in the carotid artery and aorta become more sensitive to hypoxemia, or low arterial oxygen. These specialized cells detect changes in blood chemistry and send signals to the brain when oxygen levels drop below a certain threshold.

That signal causes ventilation to increase in both rate and depth. This response helps support the balance of gases in patients with chronic lung disease. If arterial oxygen falls below 88%, supplemental low-dose oxygen may be needed. Long-term oxygen therapy has been shown to improve survival in people with COPD, reduce the risk of complications such as pulmonary hypertension, and improve overall well-being.

How the Brain Regulates Breathing

respiration

Respiratory System and Gas Exchange

The respiratory system supports energy production by bringing oxygen into the body and removing carbon dioxide. In human cells, oxidation uses food molecules and oxygen to produce carbon dioxide and water. This process helps sustain life and depends on the respiratory system. Air moves through a pathway that includes the nose, oropharynx, larynx, trachea, bronchi, bronchioles, and lungs. Air enters through the nose and mouth, passes through the pharynx, and then moves through the larynx, which...

physiological control of respiration

How the brain regulates breathing is controlled by the respiratory center in the brainstem. This center manages involuntary breathing, so respirations continue without conscious effort and stay smooth and steady. Ventilation is maintained by monitoring carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration, or pH, in arterial blood. CO2 is the most important signal in this control system. When CO2 rises, the respiratory control system increases the rate and depth of breathing so...

respiration and gaseous exchange

How Heart and Lungs Exchange Gases

Heart and lung function work together to move oxygen and carbon dioxide through the body. This gas exchange depends on the cardiovascular system, which includes the heart and blood vessels, and on the respiratory system, which brings air to the alveoli and removes waste gases. The heart is a cone-shaped muscular pump at the center of this system. It has four chambers: two atria on top and two ventricles below. The atria receive blood from veins, including the superior and inferior vena cava...

mechanism of breathing i: inspiration

How Air Moves Into the Lungs

Air enters the lungs through a coordinated breathing process called inspiration, or inhalation. This is the first phase of the respiratory cycle. The respiratory system includes the conducting zone and the respiratory zone, and both help move air toward the place where gas exchange occurs. During inspiration, air comes in through the nose or mouth and passes through the conducting zone. This pathway includes the nasal cavity, trachea, and bronchi. These structures filter, warm, and humidify...

mechanism of breathing ii: expiration

How the Body Pushes Air Out

Expiration is the process of pushing air out of the lungs. It begins when the inspiratory muscles relax. That relaxation starts a chain of changes in the chest and lungs. As the diaphragm relaxes, it moves upward. This lowers the volume of the thoracic cavity, or chest space. The pleural cavity also contracts and presses on the lungs. The intercostal muscles, which sit between the ribs, help during this phase too. They pull the ribs downward and inward. This makes the chest cavity even...

mechanism of breathing iii: the accessory muscles

mechanism-of-breathing-iii-the-accessory-muscles

Accessory Muscles That Support Breathing

Accessory muscles help the respiratory system expand the chest and move air when breathing needs extra effort. The diaphragm is still the main breathing muscle, but other muscles can assist during inhalation and exhalation. This support becomes important during deep breathing or when the body faces breathing challenges. Several accessory muscles help with inhalation. The sternocleidomastoid, which is in the neck, lifts the sternum and helps the chest cavity expand. The scalene muscles also sit...

factors affecting respiration

How Breathing Changes in Different Conditions

Respiration changes with age, activity, health, and the environment. It is the process of exchanging oxygen (O2) and carbon dioxide (CO2) between the body and the surroundings. Many factors can alter how fast and how deeply a person breathes. Newborns usually breathe faster than older children and adults. Their respiratory rate can range from thirty to sixty breaths per minute because their metabolic needs are higher. As people age, metabolic rate often decreases, and breathing tends to slow. <br...

respiratory assessment: purpose and indications

respiratory-assessment-purpose-and-indications

Breathing Checks in Patient Monitoring

Respiratory assessment is a key part of patient monitoring in nursing. It helps detect early signs of clinical deterioration. Breathing changes often appear before other signs of worsening health, so nurses watch respiratory rate, breathing pattern, and breath sounds closely. A complete respiratory assessment goes beyond counting breaths. It includes inspection, which means looking at chest symmetry, effort, and use of accessory muscles. It also includes palpation, or feeling for tenderness,...

assessment of airway, skin color, and use of accessory muscles

assessment-of-airway-skin-color-and-use-of-accessory-muscles

Respiratory Signs to Check During Breathing

Respiratory assessment starts with checking the airway, skin color, and use of accessory muscles during breathing. These signs give quick clues about respiratory status and possible complications. A clear airway, normal skin color, and no accessory muscle use usually point to effective oxygenation and perfusion. Airway assessment is an important first step in any health check. Clinicians look for anything that could block breathing, such as vomit, a foreign object, or the tongue. In a...

assessment of ventilation i: respiratory rate

assessment-of-ventilation-i-respiratory-rate

Checking Breathing Patterns and Respiratory Rate

Ventilation assessment helps monitor a patient’s health status by checking breathing patterns and respiratory rate. Respiration is one of the easiest vital signs to observe. It can also show problems in several body systems, including serious issues such as brainstem injury after head trauma. Accurate assessment depends on unobtrusive observation. The patient should not know they are being watched, because awareness can change breathing patterns. A full evaluation also considers the patient’s...

assessment of ventilation ii: respiratory depth and rhythm

assessment-of-ventilation-ii-respiratory-depth-and-rhythm

Watching Breathing Depth and Rhythm

Breathing depth and rhythm help show how a person is ventilating. Respiratory depth is the amount of air inhaled or exhaled in one breath. It may be shallow or deep, and it usually stays steady when a person is resting or asleep. A deep sigh is an automatic deep breath that fills the lungs with more air than normal breathing. Respiratory depth is checked by watching chest excursion, or chest movement. Deep respiration shows full lung expansion and complete exhalation. Shallow respiration moves...

assessment of diffusion and perfusion

Gas Exchange Checks in Respiratory Care

Gas exchange checks in respiratory care focus on diffusion, perfusion, oxygen saturation, and capnography. These measures help show how well the lungs and blood vessels move oxygen in and remove carbon dioxide from the body. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. In the lungs, oxygen diffuses from the alveoli, the tiny air sacs, into the bloodstream. Carbon dioxide, which is made during cell metabolism, moves from the...

respiratory volumes and capacities i

Breathing Rates and Pattern Changes

Breathing rate and rhythm are important signs of respiratory health. A complete one-minute count helps show the patient’s breathing pattern. Even a small rise of three to five breaths per minute can be an early sign of respiratory distress. Patients with a rate above twenty-four breaths per minute need close monitoring for possible changes in body function. Normal and abnormal respirations have clear names. Eupnea means normal, gentle breathing with a regular rate and rhythm, usually twelve to...

alterations in respiration ii

Breathing Patterns and Their Clinical Meaning

Breathing patterns can be regular, deep, or shallow, and they can also become abnormal. These changes help explain how ventilation is affected in different conditions. Clinically, they are important because they can guide patient evaluation. Biot's breathing is irregular in both rate and depth. It alternates between deep gasping breaths and apnea, which is a pause in breathing. It may occur with increased intracranial pressure or damage to the brain's respiratory center, such as from stroke,...

respiratory volumes

Measuring Lung Air Volumes

Respiratory volumes measure how much air moves in and out of the lungs during breathing. These values help assess lung function, support diagnosis of respiratory conditions, and track overall respiratory health. Each measurement gives a different view of how the lungs work. Tidal volume (TV) is the air inhaled or exhaled in one normal breath. In adults, it is about 500 milliliters per breath. It serves as the baseline volume for resting breathing. Minute volume (MV) is the total air exchanged...

respiratory capacities

Lung Capacity Measures in Breathing

Lung capacity measures show how much air the respiratory system can move and hold during different parts of breathing. These measures help describe lung function in a more complete way. They are useful for understanding how the lungs work during inhaling and exhaling. Inspiratory capacity, or IC, is the maximum amount of air that can be inhaled with full effort. It is found by adding tidal volume and inspiratory reserve volume. IC usually ranges from 2.4 to 3.6 liters. Functional residual...

special considerations while measuring oxygen saturation

special-considerations-while-measuring-oxygen-saturation

Checking Breathing Rate and Oxygen Levels

Checking breathing rate and oxygen levels helps assess how well a patient is breathing. Respiratory rate is the number of breaths taken in one minute. Oxygen saturation shows how much oxygen is being delivered to the body’s tissues. Together, these signs give a fuller picture of respiratory function. The normal adult breathing rate is usually 12 to 20 breaths per minute. A lower rate may suggest respiratory depression or decreased oxygen levels. A rate above 20 breaths per minute may point to...

assessment of respiration

Respiratory Assessment Signs and Findings

Respiratory assessment looks at the signs and findings that show how well a person is breathing. It uses both subjective data and objective data to judge respiratory health. The respiratory system’s basic structures and main functions provide the basis for this check. Subjective assessment starts with an interview. Nurses ask about medical history, medicines, current symptoms, past respiratory problems like asthma or COPD, surgeries, and allergies. Family history also matters because it can...

key terms and concepts

Learn how the brainstem controls breathing by tracking CO2, O2, and pH. Explore hypoxemia, chemoreceptors, and low-dose oxygen therapy in COPD.

How the Brain Regulates Breathing | JoVE K12

JoVE Core Nursing offers concise animated lessons on nursing practices, covering health systems, nursing organizations, and health concepts. It includes practical communication, infection prevention, and nursing fundamentals, providing students with a clear understanding of nursing principles.

nursing

How the Brain Regulates Breathing

Description

Transcript