Introduction to Respiration and Anatomy
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Questions and Answers

What is the primary function of the respiratory system?

  • Regulation of body temperature
  • Exchange of gases (correct)
  • Production of hormones
  • Digestion of food

    • External respiration occurs between lung tissues and body tissues.

    False

    What is the term for the gas exchange that occurs between blood and the body's tissues?

    Internal respiration

    The __________ zone of the respiratory system filters, warms, and humidifies air.

    <p>conducting</p> Signup and view all the answers

    Match the following respiratory structures with their functions:

    <p>Nose = Entry point for air Larynx = Voice production Alveoli = Gas exchange Trachea = Air passage to lungs</p> Signup and view all the answers

    What is the function of the nasal conchae?

    <p>To filter and swirl inhaled air</p> Signup and view all the answers

    The olfactory epithelium in the nasal cavity contains goblet cells.

    <p>False</p> Signup and view all the answers

    What structure elevates to cover the entrance of the larynx during swallowing?

    <p>epiglottis</p> Signup and view all the answers

    The trachea is kept _________ by rings of hyaline cartilage.

    <p>patent</p> Signup and view all the answers

    Match the parts of the respiratory system with their characteristics:

    <p>Nasal cavity = Contains olfactory epithelium Larynx = Generates sound through vibrating vocal folds Trachea = Keeps airway patent with cartilage rings Bronchi = Branch point sensitivity triggers cough reflex</p> Signup and view all the answers

    Where does the trachea split into the left and right bronchi?

    <p>At the carina</p> Signup and view all the answers

    The true vocal cords are made of keratinized epithelium.

    <p>False</p> Signup and view all the answers

    What prevents the descent of food into the trachea during swallowing?

    <p>epiglottis</p> Signup and view all the answers

    The structure that serves as a common passage for air and food is the _________.

    <p>oropharynx</p> Signup and view all the answers

    Which cartilage of the larynx is commonly known as the Adam's apple?

    <p>Thyroid cartilage</p> Signup and view all the answers

    What is the likely condition of PCO2 in the blood when blood pH is low?

    <p>High</p> Signup and view all the answers

    Hypocapnia is a result of low levels of carbon dioxide in the blood.

    <p>True</p> Signup and view all the answers

    What physiological response increases the rate and depth of breathing?

    <p>Hyperventilation</p> Signup and view all the answers

    The condition that can result from hyperventilation is called __________.

    <p>hypocapnia</p> Signup and view all the answers

    Which of the following can cause fainting due to insufficient oxygen?

    <p>Hyperventilation</p> Signup and view all the answers

    Match the following effects to their corresponding terms related to breathing:

    <p>Pulmonary perfusion = Extent of blood flow to the lungs Limbic system = Affects breathing through emotions Ciliary function = Impaired by excess mucus Emphysema = Immune destruction of alveolar walls</p> Signup and view all the answers

    Increased blood pressure leads to an increased respiration rate.

    <p>False</p> Signup and view all the answers

    During rigorous exercise, __________ sense increased H+ and stimulate the DRG.

    <p>chemoreceptors</p> Signup and view all the answers

    What is the primary function of pleural fluid in the lungs?

    <p>To reduce friction and provide surface tension</p> Signup and view all the answers

    The right lung has one more lobe than the left lung due to the presence of the cardiac notch.

    <p>True</p> Signup and view all the answers

    What separates the left and right lungs?

    <p>mediastinum</p> Signup and view all the answers

    The inferior portion of the lungs is called the ________.

    <p>base</p> Signup and view all the answers

    Match the lung structures with their functions:

    <p>Alveoli = Site of gas exchange Bronchopulmonary segments = Segmented lung sections Lobar bronchi = First branches into lung lobes Pleural cavity = Space between lung membranes</p> Signup and view all the answers

    Which type of cells secretes surfactant in the alveoli?

    <p>Type II alveolar cells</p> Signup and view all the answers

    The respiratory membrane is made up of thick layers, making gas exchange inefficient.

    <p>False</p> Signup and view all the answers

    What is the primary role of pulmonary arteries?

    <p>To bring deoxygenated blood to the lungs</p> Signup and view all the answers

    The ___________ notch provides space for the heart within the left lung.

    <p>cardiac</p> Signup and view all the answers

    What occurs during inhalation?

    <p>Air moves into the lungs due to a decrease in lung pressure</p> Signup and view all the answers

    Bronchial arteries supply deoxygenated blood to the lung tissues.

    <p>False</p> Signup and view all the answers

    What type of epithelium lines the respiratory bronchioles?

    <p>simple cuboidal epithelium</p> Signup and view all the answers

    The ________ in the lungs help to reduce surface tension and prevent collapse of alveolar walls.

    <p>surfactant</p> Signup and view all the answers

    Match the lung parts to their corresponding characteristics:

    <p>Apex = Superior portion of the lungs Base = Inferior portion resting on the diaphragm Hilum = Entry point for bronchi and blood vessels Lobules = Smaller compartments within a bronchopulmonary segment</p> Signup and view all the answers

    What percentage of inhaled air is due to depression of the diaphragm?

    <p>75%</p> Signup and view all the answers

    Exhalation is considered an active process.

    <p>False</p> Signup and view all the answers

    What is the term used to describe the distensibility of elastic tissues in the lungs?

    <p>compliance</p> Signup and view all the answers

    The diaphragm depresses by 1 cm during normal inhalation.

    <p>depresses</p> Signup and view all the answers

    Match the following factors affecting pulmonary ventilation with their definitions:

    <p>Compliance = Ease of lung expansion Resistance = Opposition to airflow Surface tension = Liquid's cohesive forces affecting alveoli Elastic recoil = Ability of lungs to return to resting state</p> Signup and view all the answers

    Which muscle assists the diaphragm during inhalation?

    <p>Intercostal</p> Signup and view all the answers

    Carbon dioxide is 24 times more soluble in water than oxygen.

    <p>True</p> Signup and view all the answers

    What is the primary mechanism for gas exchange in the body?

    <p>passive diffusion</p> Signup and view all the answers

    Insufficient surfactant can lead to _difficulty breathing.

    <p>difficulty breathing</p> Signup and view all the answers

    What happens to the pressure inside the lungs during exhalation?

    <p>It increases</p> Signup and view all the answers

    High compliance of lung tissues indicates a high effort required for breathing.

    <p>False</p> Signup and view all the answers

    What role does intrapleural pressure play during inhalation?

    <p>Ensures lung expansion</p> Signup and view all the answers

    The arterial end of capillaries has higher partial pressure of oxygen (PO2).

    <p>arterial</p> Signup and view all the answers

    What is the primary transport mechanism for oxygen in the blood?

    <p>On hemoglobin molecules</p> Signup and view all the answers

    What is the relationship between airway diameter and resistance?

    <p>Larger diameter leads to less resistance</p> Signup and view all the answers

    What percentage of oxygen saturation occurs in nearly full hemoglobin?

    <p>100%</p> Signup and view all the answers

    High acidity decreases the affinity of hemoglobin for oxygen.

    <p>True</p> Signup and view all the answers

    What is the main product of carbonic acid dissociation in blood?

    <p>bicarbonate</p> Signup and view all the answers

    Hemoglobin binds to carbon dioxide to form __________.

    <p>carbaminohemoglobin</p> Signup and view all the answers

    Match the factors affecting hemoglobin saturation with their effects:

    <p>Partial pressure of oxygen = Increases saturation with higher PO2 Blood acidity = Decreases affinity at low pH PCO2 = Decreases affinity with high levels Temperature = Increases release of O2 to tissues</p> Signup and view all the answers

    What is the role of chloride shift?

    <p>To maintain electrical balance in erythrocytes</p> Signup and view all the answers

    The fetal hemoglobin (Hb-F) has a higher affinity for oxygen than adult hemoglobin (Hb-A).

    <p>True</p> Signup and view all the answers

    What are the two main centers in the respiratory centre of the brain?

    <p>medulla oblongata and pons</p> Signup and view all the answers

    The average atmospheric pressure at sea level is approximately __________ mm Hg.

    <p>760</p> Signup and view all the answers

    During exercise, what happens to the partial pressure of oxygen in skeletal muscle?

    <p>It decreases</p> Signup and view all the answers

    Erythrocytes can perform glycolysis leading to the production of 2,3-bisphosphoglycerate (BPG).

    <p>True</p> Signup and view all the answers

    What chemical triggers the respiratory center to resume normal breathing after holding breath?

    <p>PCO2 and H+</p> Signup and view all the answers

    Hemoglobin structure changes due to high levels of __________ in blood.

    <p>H+</p> Signup and view all the answers

    Match the respiratory influences with their locations:

    <p>Central chemoreceptors = Near medulla oblongata Peripheral chemoreceptors = Aortic and carotid bodies</p> Signup and view all the answers

    Study Notes

    Introduction to Respiration

    • Respiration is the process of acquiring oxygen and eliminating carbon dioxide.
    • Three steps in the human body:
      • Pulmonary ventilation: Gas exchange between atmosphere and lung tissues.
      • External respiration: Gas exchange between lung tissues and blood.
      • Internal respiration: Gas exchange between blood and body tissues.
    • Functions of the respiratory system:
      • Exchanges gases.
      • Regulates blood pH.
      • Permits vocal sounds and the sense of smell; filters inhaled air; excretes wastes during exhalation.
      • Oto(rhino)laryngology is the medical study of the respiratory system.
    • Why do cells need oxygen?
      • Aerobic cellular respiration.

    Anatomy of the Respiratory System

    • Structurally, the respiratory system is divided into:
      • Upper respiratory system: Includes nose, nasal cavity, pharynx, and associated structures.
      • Lower respiratory system: Includes larynx, trachea, bronchi, and lungs.
    • Functionally, the respiratory system is divided into:
      • Conducting zone: Directs air to the respiratory zone; filters, warms, and humidifies air.
      • Respiratory zone: Site of gas exchange; includes respiratory bronchioles, alveolar ducts, alveolar sacs.

    Upper Respiratory System

    • Nose: Made of bone, cartilage, connective tissue. Air enters through external nares (nostrils).

    • Nasal Cavity: Interior space of the nose; bounded by oral cavity and nasal bones. Bone and cartilage prevent obstruction. Divided into left and right halves by nasal septum.

      • Nasal conchae: Swirls inhaled air. Lined with olfactory epithelium, which contains sensory receptors for smells.
      • Paranasal sinuses: Lined with mucous membranes; vibrate to permit singing and speech.
      • Pharynx: Tube of skeletal muscle, lined with mucous membrane. Three parts:
        • Nasopharynx: Superior part; lined with ciliated pseudostratified columnar epithelium that sweeps mucus into pharynx.
        • Oropharynx: Intermediate part; common passage for air and food. Lined with non-keratinized stratified squamous epithelium; contains tonsils.
        • Laryngopharynx: Inferior part; similar structure to oropharynx.

    • Larynx: Tube made of nine rings of cartilage:

      • Thyroid cartilage: Forms the anterior surface; larger in males.
      • Epiglottis: Flap of elastic cartilage; covers the larynx entrance during swallowing.
      • Cricoid cartilage: Ring of hyaline cartilage; landmark for tracheotomies.
      • Vocal Folds (true vocal cords): Made of non-keratinized stratified squamous epithelium and elastic ligaments; vibrate to produce sound. Skeletal muscles on cartilages alter tension on ligaments to change pitch.
      • Vestibular Folds (false vocal cords): Come together when holding breath.

    • Trachea: 2.5 cm wide x 12 cm long tube; 16-20 rings of hyaline cartilage connected by dense connective tissue. Keeps trachea patent (open); anterior to the esophagus; lined with ciliated pseudostratified epithelium.

    • Bronchi: Trachea splits into right and left bronchi, with the carina marking the branchpoint (sensitive mucous membrane). Branch into smaller tubes forming the bronchial tree. The mucous membrane of the bronchi changes throughout this tree. Supporting cartilage and proportion of smooth muscle also change.

    • Lungs:

      • Surrounded by pleural membrane (two serous membranes).
      • Pleural fluid reduces friction.
      • Extend from above clavicles to diaphragm.
      • Concave base conforms to diaphragm.
      • Superior apex.
      • Medial surfaces include:
        • Hilum: Permits passage of bronchi, blood vessels, nerves, lymphatic vessels.
        • Cardiac notch: Space for the heart; decreases size of left lung.
      • Fissures divide the lung into lobes:
        • Oblique fissure: Separates superior and inferior lobes.
        • Horizontal fissure: Separates superior and middle lobes (right lung only)
        • Lobar bronchi: Named after lobes; branch into segmental bronchi.
        • Bronchopulmonary segments: 13 in the right lung; 8 in the left; contain individualized bronchi. Can be surgically removed.
        • Lobules: Smaller compartments with terminal bronchiole, arteriole/venule, lymphatic vessel, and elastic connective tissue.
      • Respiratory bronchioles: Microscopic bronchial branches, lined with simple cuboidal epithelium, branch into alveolar ducts.
      • Alveoli: Air sacs; site of pulmonary and external respiration. Extensive surface area; made of simple squamous epithelium (Type I) and non-ciliated cuboidal epithelial cells (Type II) that secrete surfactant (to prevent sticking).
        • Respiratory membrane: Very thin structure (0.5 µm) composed of alveolar wall, epithelial basement membrane, capillary basement membrane, and capillary endothelium.

    • Blood Supply to the Lungs:

      • Pulmonary arteries: Bring deoxygenated blood to be oxygenated. Constrict/dilate in response to hypoxia (ventilation-perfusion coupling).
      • Bronchial arteries: Branch from aorta & deliver oxygenated blood to the lungs' muscular tissue.

    Gas Exchange and Ventilation

    • Pulmonary ventilation: Inhalation and exhalation; regulated by pressure change in thoracic cavity; requires skeletal muscle.
    • Mechanics of inhalation:
      • Pressure drops below atmospheric pressure to draw air inward.
      • Driven by diaphragm contraction and external intercostal muscle contraction.
    • Mechanics of exhalation:
      • Passive process. Respiratory muscles relax; elastic recoil of lung tissues generates pressure and forces gases out. Active process facilitated by abdominal and internal intercostal muscles during vigorous activity.
    • Factors affecting pulmonary ventilation:
      • Surfactant: Prevents alveolar collapse and is essential to ventilation.
      • Compliance: Distensibility of lung tissues; high compliance is desirable.
      • Resistance: Determined by airway diameter.
    • Lung volumes/capacities: Measurements of air intake, exhalation, and storage; measured with a spirometer.

    Principles of Gas Exchange

    • External respiration: Gas exchange in alveoli and pulmonary capillaries, driven by partial pressure gradients. Pulmonary oxygen decreases to maximize oxygenation during exercise.
    • Internal respiration: Tissue cells produce CO2, leading to higher PCO2 outside systemic capillary. Oxygen diffuses from blood to tissues at the arterial end. Factors affecting rate: partial pressure gradient, surface area, diffusion distance.

    Oxygen Transport

    • Most O2 is transported bound to Hb in erythrocytes.
    • Hb binds O2 reversibly; increased PO2 favors O2 binding.
    • Factors affecting Hb saturation: PO2, blood pH (acidity), PCO2, temperature, intermediate glycolysis products (ex. 2,3-bisphosphoglycerate), and hemoglobin type. Fetal hemoglobin has higher affinity for oxygen than adult hemoglobin.

    Carbon Dioxide Transport

    • CO2 is transported: dissolved in plasma; bound to proteins (carbaminohemoglobin); or as bicarbonate.
    • Chloride shift maintains electrical balance in erythrocytes during CO2 transport.

    Regulation of Breathing

    • Respiratory center: Cluster of neurons in medulla oblongata and pons. -Medullary respiratory group: Further subdivided into dorsal and ventral respiratory groups.
    • Pontine respiratory group: Affects normal breathing, influencing the DRG.
    • Cortical influences: Voluntary control over breathing.
    • Chemoreceptors:
      • Central Chemoreceptors: Located near the medulla; sense changes in PCO2 and H+ in cerebrospinal fluid (CSF). -Peripheral Chemoreceptors: Located in aortic and carotid bodies; sense changes in blood PCO2, PO2, and H+.
    • Hyperventilation: Response to low blood pH/high PCO2; increased rate/depth of breathing leading to hypocapnia.
    • Inflation reflex: Prevents lung overinflation through stretch receptors in bronchi & bronchioles; sends signals to inhibit breathing.
    • Homeostatic imbalances: Ex: Tobacco smoking causes increased risk of COPD.

    Exercise and Respiratory System

    • Exercise increases pulmonary perfusion and ventilation; chemoreceptors sense increased H+, stimulating increased rate/depth of breathing.

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    Description

    This quiz covers key concepts of respiration, including the three essential steps involved in gas exchange within the human body. It also addresses the structure and function of the respiratory system, highlighting the roles of its upper and lower components. Test your understanding of the vital processes that sustain life through respiration.

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