RESUMÃO: ANATOMIA DO SISTEMA RESPIRATÓRIO. VIDEO AULA. @biologia_etc

Overview of the Respiratory System

Introduction to the Respiratory System

• The discussion begins with an overview of the respiratory system, focusing on its theoretical aspects and functionality in gas exchange.

• Emphasis is placed on how the respiratory system captures air and eliminates gases, particularly carbon dioxide, which is toxic to the body.

Functions of the Respiratory System

• The respiratory system facilitates simultaneous gas exchanges: capturing oxygen from the atmosphere while eliminating carbon dioxide.

• It plays a crucial role in maintaining thermal balance within the body and aids in water elimination through respiration. This process is often misunderstood as solely related to sweating during exercise.

Weight Loss Misconceptions

• A common misconception is that sweating leads to weight loss; however, significant weight loss occurs through respiration as water vapor is expelled in microparticles.

• Proper nutrition also contributes to effective weight management alongside respiratory functions.

pH Regulation and Gas Levels

• The respiratory system helps maintain blood pH levels by regulating carbon dioxide and oxygen concentrations, ensuring homeostasis within the body.

Anatomical Structures of the Respiratory System

Upper vs Lower Respiratory Tract

• The anatomy of the respiratory system is divided into two main parts:

• Upper Respiratory Tract: Includes structures like nasal cavity, paranasal sinuses, nasopharynx, oropharynx, and part of the trachea.

• Lower Respiratory Tract: Comprises structures below the trachea such as bronchi, bronchioles, alveoli, and lungs. These are essential for gas exchange processes like hematosis.

Hematosis Process

• In hematosis, red blood cells (hemocytes) exchange carbon dioxide for oxygen at alveolar sites; this oxygenated blood then returns to circulation via pulmonary veins into the left atrium of the heart.

Importance of Nasal Cavity

Filtration Mechanism

• The nasal cavity contains mucus and cilia that filter inhaled air to remove pathogens such as viruses and bacteria before they enter deeper into the respiratory tract. This filtration prevents potential infections throughout systemic circulation.

• Understanding this filtration process highlights why maintaining clean airways is vital for overall health and disease prevention within bodily systems.

Understanding Nasal Anatomy and Its Implications

Nasal Structures and Development

• The nasal cavity contains three structures resembling a labyrinth, known as nasal turbinates. These structures may not develop properly due to genetic factors affecting their embryological formation.

• Atrophy of the nasal turbinates can lead to nasal obstruction, commonly referred to as adenoids, which many people are familiar with.

Adenoids and Breathing Issues

• Adenoids are fleshy growths that obstruct the upper airway, forcing patients to breathe through their mouths. This can lead to various respiratory issues.

• Patients using orthodontic devices may still experience mouth breathing, which can negate the benefits of dental alignment treatments over time.

Respiratory Pathway Mechanics

• Mouth breathing predisposes teeth to revert to their original positions after orthodontic treatment due to improper airflow and heating in the oral cavity.

• Proper nasal breathing filters air through the mucosa and cilia before it enters the nasopharynx, directing it towards either the esophagus or trachea.

Trachea and Bronchial Structure

• The epiglottis plays a crucial role in directing air into the trachea; if closed, it diverts air towards the esophagus instead.

• The trachea consists of approximately 20 cartilaginous rings that maintain its structure while branching into right and left bronchi leading into each lung.

Lung Anatomy Overview

• Bronchi further divide into smaller branches called bronchioles, resembling plant roots, facilitating airflow into lung tissues.

• Alveoli are microscopic structures where gas exchange occurs; they interact closely with pulmonary walls for efficient oxygen transfer.

Diaphragm's Role in Respiration

• The diaphragm separates thoracic from abdominal viscera and supports lung positioning within the thoracic cavity during respiration.

Nose Structure and Functionality

• The nose is primarily cartilaginous rather than bony; its apex (tip of the nose) is supported by bone while other parts consist mainly of cartilage.

• Key functions of the nose include olfaction (sense of smell), filtering dust from inhaled air, humidifying incoming air, and expelling secretions during illness.

Septum's Importance

• The septum divides nasal passages; understanding its structure is essential for comprehending overall nasal function.

This structured overview provides insights into nasal anatomy's complexities and implications for respiratory health.

Understanding the Nasal Structure and Function

The Role of the Nasal Septum

• The nasal septum (CTO nasal) separates the two nostrils, playing a crucial role in respiratory function throughout the day. There are cycles where one nostril is more dominant for breathing than the other.

Anatomy of Nasal Cavities

• The nasal cavity consists of two parallel cavities extending from the nostrils to the pharynx, featuring structures like paranasal sinuses and nasal turbinates (cornetos). These act as labyrinths for air filtration.

Importance of Turbinates

• There are three main turbinates in the nasal cavity, with the inferior turbinate being significantly larger and more robust than the others. This structure aids in air passage and filtration.

Mucosal Functionality

• The nasal cavity is lined with mucosa that helps filter pathogens from inhaled air, ensuring cleaner air reaches deeper into the respiratory system. This filtering process is vital for maintaining health.

Air Passage Through Pharynx

• After passing through the nasal cavity, air moves to the nasopharynx and oropharynx before reaching the trachea via an open epiglottis. Proper functioning prevents food from entering the airway during swallowing.

The Mechanics of Swallowing and Breathing

Epiglottis Functionality

• During swallowing, the epiglottis closes momentarily to prevent food from entering the trachea; this brief pause in breathing can lead to coughing if food accidentally enters. Understanding this mechanism is essential for safe eating practices.

Structural Overview of Nasal Cavity

• The nasal cavity has a ceiling (roof), floor (assoalho), and surrounding walls that contribute to its overall structure, which plays a significant role in both respiration and olfaction (sense of smell).

Vascularization and Innervation of Nasal Region

Arterial Supply

• Blood supply to this region comes from several arteries including branches from ophthalmic artery (anterior/posterior ethmoidal arteries) and maxillary artery (greater palatine artery), highlighting complex vascular networks supporting nasal functions.

Nerve Functions

• Sensory nerves such as nasopalatine nerve provide sensory perception within this area but do not control movement; they play a critical role in detecting stimuli related to smell and irritation within the nasal passages.

Overview of Laryngeal Anatomy

Description of Larynx

• The larynx connects with both pharynx and trachea, consisting mainly of cartilage structures located at cervical vertebrae levels 4 through 6; it plays an essential role in voice production due to its vocal folds' functionality.

Vocal Fold Health

• Healthy vocal folds appear smooth while lesions indicate potential carcinomas; understanding these changes is crucial for diagnosing laryngeal health issues effectively during examinations or assessments.

Understanding Vocal Cord Health and Cancer Risks

The Impact of Lifestyle on Vocal Cord Health

• Carcinomas can develop in individuals with unhealthy habits, particularly those who frequently use their vocal cords, such as teachers or singers.

• Constant shouting or loud speaking increases the risk of cancerous processes and other lesions that may alter voice quality.

• Vocal cords vibrate to facilitate sound production while allowing air passage; if they were closed, airflow would be obstructed.

Predisposition to Vocal Cord Lesions

• Individuals in vocations that heavily rely on voice usage are more susceptible to vocal cord injuries, which may not always lead to cancer but can still cause significant damage.

• Genetic predisposition plays a crucial role in developing cancer; those with harmful long-term habits are at higher risk.

Anatomy of the Larynx and Vocal Cords

• The larynx houses the vocal apparatus; during breathing, vocal cords remain open for airflow but vibrate during phonation.

• The thyroid cartilage forms part of the trachea's structure and is more prominent in males due to hormonal influences during puberty.

Cartilages Involved in Voice Production

• The epiglottic cartilage seals off the trachea during swallowing to prevent food from entering the airway.

• Arytenoid cartilages influence vocal cord tension and position, essential for sound modulation.

Functionality of Vocal Cords

• Vocal cords consist of uniform cartilage and are critical for sound production; each cord contains a vocal ligament and muscle covered by mucosa.

• Vestibular folds contain ligaments that assist in phonation; vascularization comes from branches of the thyroid artery supplying blood to the larynx.

Nerve Supply and Tracheal Structure

• Innervation is provided by the vagus nerve, which also affects heart function through electrical impulses.

• The internal laryngeal nerve is a major branch that penetrates into the laryngeal region from above.

Trachea Characteristics

• The trachea measures approximately 10–12 cm in length with a diameter of about 2.5 cm; it features incomplete cartilaginous rings anteriorly only.

• It bifurcates into bronchi within the thoracic cavity, with its last section known as "Carina," marking where it splits.

Understanding the Trachea and Bronchial Structure

Anatomy of the Trachea and Bronchi

• The trachea bifurcates into two bronchi, one for each lung, leading to approximately 20 bronchioles in total, with about 10 on each side.

• The trachea is lined with mucosa that contains glands and ciliated epithelium, aiding in the expulsion of mucus and foreign bodies. This serves as a secondary filtration system after the nose.

• Vascularization of the trachea occurs via the inferior thyroid artery, while it is innervated by sympathetic and parasympathetic fibers. During stress, there is an increased air intake due to adrenaline's effects.

• The vagus nerve plays a crucial role in innervating the trachea, facilitating airflow during respiratory processes. The bronchi serve as conduits between the trachea and lungs.

Pathological Conditions Affecting Bronchi

• Bronchial inflammation can lead to obstruction; when inflamed, bronchi swell and narrow, making breathing difficult for patients suffering from viral infections like bronchitis.

• Patients may experience normal air intake but struggle with efficient air passage to the lungs due to narrowed bronchial passages caused by inflammation.

Structure of Bronchioles and Alveoli

• The bronchioles branch out into smaller tubes resembling plant roots before reaching alveoli where gas exchange occurs (hematosis). These structures become microscopic near lung walls.

• Alveoli are also microscopic structures involved in gas exchange; they contain pneumocytes responsible for tissue repair following damage from factors such as smoking.

Immune Response in Alveoli

• Pneumocytes play a vital role in repairing alveolar tissue damaged by various conditions; macrophages present within alveoli act as defenders against pathogens through phagocytosis even after initial nasal filtration has occurred.

• Macrophages patrol alveolar spaces to eliminate pathogens that breach initial defenses, highlighting their importance in respiratory health alongside other immune cells like neutrophils and lymphocytes.

Pulmonary Anatomy and Function

Overview of the Lungs

• The speaker introduces the lungs, noting that there are two: the right lung, which is more complete, and the left lung, which is less so.

Lobes of the Lungs

• The right lung consists of three lobes (superior, middle, inferior), separated by horizontal and oblique fissures.

• In contrast, the left lung has only two lobes due to anatomical constraints; it features a single oblique fissure separating its superior and inferior lobes.

Anatomical Differences

• The left lung would typically have a third lobe called "língula," but it is atrophied because the heart's apex occupies space on the left side.

Lung Structure and Weight

• Adult lungs weigh approximately 700 grams to 1 kg and have a volume ranging from 4 to 6 liters. Their height is about 25 cm.

Hilar Structures

• The hilum of the lungs serves as an entry point for blood vessels, nerves, and lymphatics. It includes pulmonary arteries and veins.

Respiratory Pathway

Airflow Through Respiratory System

• Air enters through nasal or oral cavities; however, nasal breathing is preferred due to filtration benefits.

Passage Through Airways

• The air travels from nasal cavity to pharynx, then larynx, trachea (including carina), bronchi, bronchioles, and finally reaches alveoli where gas exchange occurs.

Vascularization and Innervation

Blood Supply to Lungs

• Pulmonary circulation involves both right and left pulmonary arteries supplying blood; bronchial arteries nourish lung tissue.

Nervous System Influence

• The vagus nerve plays a crucial role in innervating various structures including heart and lungs while contributing sympathetic and parasympathetic fibers.

Protective Structures of Lungs

Pleurae Functionality

• The pleurae consist of visceral and parietal layers that protect the lungs while allowing smooth movement during respiration. They also produce serous fluid to reduce friction during lung expansion/contraction.

Understanding the Pleura: Parietal vs. Visceral

Overview of the Pleura

• The pleura consists of two layers: the parietal pleura, which is more external and provides protection and coverage for surrounding structures, and the visceral pleura, which closely adheres to the lungs.

Functions of Each Layer

• The visceral pleura has a close contact with the lung surface and contains a serous fluid that reduces friction during respiratory movements, allowing smooth lung expansion and contraction.

Conclusion on Respiratory System

• Both layers of the pleura produce serous fluid; it is not limited to just one layer. This understanding wraps up the discussion on the respiratory system before transitioning to another platform for further interaction.