Introduction to Respiration and Anatomy
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Questions and Answers

What is the first step in the respiration process within the human body?

  • Cellular respiration
  • External respiration
  • Pulmonary ventilation (correct)
  • Internal respiration

Which of the following is NOT a function of the respiratory system?

  • Regulates blood pH
  • Filters inhaled air
  • Produces hormones (correct)
  • Exchanges gases

What does the conducting zone of the respiratory system do?

  • Exchanges oxygen for carbon dioxide
  • Site of gas exchange
  • Filters and humidifies air (correct)
  • Traps pathogens

Where does external respiration occur?

<p>In the lungs (C)</p> Signup and view all the answers

What is included in the upper respiratory system?

<p>Nose and nasal cavity (D)</p> Signup and view all the answers

What is the primary role of internal respiration?

<p>Gas exchange between blood and body tissues (C)</p> Signup and view all the answers

How does the respiratory system help with senses?

<p>It assists in vocal sounds and sense of smell (D)</p> Signup and view all the answers

What structure divides the nasal cavity into left and right halves?

<p>Nasal septum (C)</p> Signup and view all the answers

Which part of the pharynx is lined with ciliated pseudostratified columnar epithelium?

<p>Nasopharynx (C)</p> Signup and view all the answers

What is the function of the tonsils?

<p>Trap pathogens (B)</p> Signup and view all the answers

Which cartilage forms the anterior surface of the larynx and is known as the Adam's apple?

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

What keeps the trachea open and unobstructed?

<p>Hyaline cartilage rings (B)</p> Signup and view all the answers

What type of epithelium lines the true vocal cords?

<p>Non-keratinized stratified squamous epithelium (D)</p> Signup and view all the answers

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

<p>Carina (D)</p> Signup and view all the answers

What is the main role of nasal conchae within the nasal cavity?

<p>Swirl inhaled air (B)</p> Signup and view all the answers

What structure is responsible for covering the entrance of the larynx during swallowing?

<p>Epiglottis (A)</p> Signup and view all the answers

What is the main outcome when there is increased partial pressure of oxygen (PO2) in the blood?

<p>Increased formation of Hb-O2 (D)</p> Signup and view all the answers

Which factor does not affect hemoglobin's affinity for oxygen?

<p>Partial pressure of water vapor (D)</p> Signup and view all the answers

What percentage of carbon dioxide is transported as bicarbonate in the blood?

<p>70% (B)</p> Signup and view all the answers

What is the role of the dorsal respiratory group (DRG) in the medullary respiratory center?

<p>Controlling normal breathing (B)</p> Signup and view all the answers

Which statement is true about fetal hemoglobin (Hb-F) compared to adult hemoglobin (Hb-A)?

<p>Hb-F can carry oxygen more efficiently than Hb-A (C)</p> Signup and view all the answers

What is the function of pleural fluid in the lungs?

<p>It reduces friction and provides surface tension. (D)</p> Signup and view all the answers

Which structure separates the left and right lungs?

<p>The mediastinum (B)</p> Signup and view all the answers

What is the primary role of Type II alveolar cells?

<p>Secreting surfactant (D)</p> Signup and view all the answers

What splits the superior and inferior lobes of the lungs?

<p>Oblique fissure (A)</p> Signup and view all the answers

What is the definition of 'patency' in the context of airways?

<p>The ability of a passageway to remain unobstructed (C)</p> Signup and view all the answers

Which arteries bring deoxygenated blood to the lungs?

<p>Pulmonary arteries (A)</p> Signup and view all the answers

What occurs during inhalation or inspiration?

<p>Pressure in the lungs is lowered. (A)</p> Signup and view all the answers

How does Boyle's Law relate to lung pressure and volume?

<p>Pressure increases as volume decreases. (B)</p> Signup and view all the answers

What do lobar bronchi branch into?

<p>Segmental bronchi (C)</p> Signup and view all the answers

What is the primary function of respiratory bronchioles?

<p>To branch into the alveolar sacs (D)</p> Signup and view all the answers

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

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

What role does intrapleural pressure play during inhalation?

<p>Ensures lung tissue expands (B)</p> Signup and view all the answers

What is compliance in relation to the lungs?

<p>The ease of inflating the lungs (B)</p> Signup and view all the answers

Which muscle assists in active exhalation during vigorous exercise?

<p>Internal intercostal muscles (B)</p> Signup and view all the answers

What is the primary difference in gas exchange during external respiration?

<p>Occurs between the alveoli and the blood (B)</p> Signup and view all the answers

Which factor increases the rate of passive diffusion in gas exchange?

<p>Increased partial pressure gradient (A)</p> Signup and view all the answers

Carbon dioxide is how many times more soluble in water than oxygen?

<p>24X (C)</p> Signup and view all the answers

What happens to the lung volume during exhalation?

<p>Decreases as respiratory muscles relax (B)</p> Signup and view all the answers

What condition may arise from insufficient surfactant in the lungs?

<p>Respiratory distress syndrome (A)</p> Signup and view all the answers

Where does carbon dioxide move during internal respiration?

<p>From the blood to the tissues (A)</p> Signup and view all the answers

Flashcards

Respiration definition

The process of acquiring oxygen and eliminating carbon dioxide.

Pulmonary ventilation

Gas exchange between the atmosphere and lung tissues.

External respiration

Gas exchange between lung tissues and blood.

Internal respiration

Gas exchange between blood and body tissues.

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Respiratory system function 1

Exchanges gases (O2 and CO2).

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Respiratory system function 2

Regulates blood pH (acidity).

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Upper respiratory system parts

Nose, nasal cavity, pharynx, and associated structures.

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Nasal Cavity

The interior and anterior space of the nose, bounded by the nasal bones and oral cavity. It's divided into halves by the nasal septum.

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Paranasal Sinuses

Air-filled spaces within the skull around the nasal cavity, lined with mucous membranes, and aiding in sound resonance.

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Nasal Conchae

Bony structures within the nasal cavity that swirl inhaled air to warm and humidify it.

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Olfactory Epithelium

Part of the nasal cavity containing sensory receptors for smell, but without goblet cells.

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Larynx

Tube comprised of nine cartilage rings that connects the pharynx to the trachea. Site of vocal cords.

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Vocal Folds

Elastic folds in the larynx that vibrate when air passes over them, creating sound.

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Trachea

A tube with cartilage rings that connects the larynx to the bronchi, keeping it open (patent).

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Bronchi

The two branches of the trachea that enter the lungs, the bronchi branch numerous times.

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Terminal Bronchioles

The smallest bronchi branches leading to the lung sacs/alveoli.

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Pleural membrane

A double-layered membrane surrounding the lungs, consisting of the visceral pleura (inner layer) and parietal pleura (outer layer).

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Pleural cavity

The space between the visceral and parietal pleurae, filled with pleural fluid that reduces friction and provides surface tension.

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Hilum

An indentation on the medial surface of each lung where bronchi, blood vessels, nerves, and lymphatic vessels enter and exit.

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Cardiac notch

An indentation on the left lung that accommodates the heart, causing the left lung to be smaller than the right.

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Fissures

Deep grooves that divide the lungs into lobes, separating lung tissue for efficient function.

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Lobar bronchi

Branches within the lungs that carry air to specific lobes, named after the lobes they serve (e.g., superior lobar bronchus).

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Bronchopulmonary segment

A portion of lung tissue supplied by a segmental bronchus, allowing surgeons to remove diseased segments without affecting surrounding tissue.

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Lobules

Small compartments within a bronchopulmonary segment, containing bronchioles, blood vessels, and lymphatic vessels, all wrapped in elastic connective tissue.

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Respiratory bronchioles

Microscopic branches of the bronchi lined with simple cuboidal epithelium, leading to alveolar ducts and sacs.

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Alveoli

Tiny air sacs where gas exchange (oxygen and carbon dioxide) occurs; made of thin-walled type I alveolar cells for efficient diffusion.

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Diaphragm's role in inhalation

The diaphragm contracts, flattening and moving downwards, expanding the thoracic cavity and decreasing pressure, allowing air to enter the lungs.

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Intercostal muscles in inhalation

The external intercostal muscles contract, pulling the ribs upwards and outwards, further increasing the volume of the thoracic cavity.

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Intrapleural pressure

The pressure within the pleural cavity, which is always lower than atmospheric pressure, maintaining a suction effect that keeps lungs attached to the thoracic wall.

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Exhalation: Active or passive?

Exhalation is primarily passive, driven by the elastic recoil of lung tissues and the decrease in thoracic cavity volume as respiratory muscles relax.

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Active exhalation

The abdominal and internal intercostal muscles contract, further decreasing thoracic cavity volume during forceful exhalation.

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Surfactant's role

Surfactant reduces surface tension in the alveoli, preventing their collapse and facilitating efficient gas exchange.

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Compliance in respiration

Compliance describes the ease with which lung tissues can be stretched and expanded. High compliance means less effort is needed to breathe, while low compliance means more effort is required.

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Airway resistance

The resistance to airflow through the respiratory system. It's determined by factors like airway diameter, smooth muscle contraction, and obstructions.

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Factors affecting respiration: Partial pressure gradient

The difference in partial pressure of a gas between the alveoli and the blood drives gas exchange. A steeper gradient leads to faster diffusion.

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Factors affecting respiration: Surface area

The larger the surface area of gas exchange, the more efficient the process. The alveoli have a massive surface area to maximize diffusion.

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Hemoglobin Saturation

The percentage of hemoglobin molecules carrying oxygen. It is influenced by factors like partial pressure of oxygen, acidity, temperature, and the type of hemoglobin.

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What causes decreased Hb affinity for oxygen?

Increased acidity (lower pH), higher partial pressure of CO2, elevated temperatures, and the presence of 2,3-bisphosphoglycerate (BPG) all decrease hemoglobin's affinity for oxygen.

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Chloride Shift

The exchange of bicarbonate ions (HCO3-) from the red blood cell into the blood plasma, accompanied by the movement of chloride ions (Cl-) into the red blood cell, to maintain electrical balance.

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Medullary Respiratory Center

A cluster of neurons in the medulla oblongata responsible for controlling the rhythm and depth of normal breathing.

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Chemoreceptors

Sensory receptors that detect changes in chemical composition of blood, specifically carbon dioxide (CO2) and hydrogen ions (H+).

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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, and excretes wastes during exhalation.
    • Oto(rhino)laryngology is the study of the respiratory system.
  • Cells need oxygen for aerobic cellular respiration.

Anatomy of the Respiratory System

  • Structurally, the respiratory system is divided into:
    • Upper respiratory system: Nose, nasal cavity, pharynx, and associated structures.
    • Lower respiratory system: Larynx, trachea, bronchi, and lungs.
  • Functionally, the system is divided into two zones:
    • Conducting zone: Directs air to the respiratory zone, filters, warms, and humidifies the air.
    • Respiratory zone: Site of gas exchange, includes respiratory bronchioles, alveolar ducts, alveolar sacs.
  • The nose: Made of bone, cartilage, and connective tissue; air enters through external nares (nostrils).
  • The nasal cavity: Interior space of the nose, bounded by the oral cavity and nasal bones. The nasal septum divides it, contains paranasal sinuses (lined with mucous membranes) and nasal conchae (swirls inhaled air), and olfactory epithelium (sensory receptors for smells).
  • The pharynx: Tube of skeletal muscle lined with mucous membrane, starts at internal nares and extends to the cricoid cartilage.
    • Nasopharynx (superior): Ciliated pseudostratified columnar epithelium, sweeps mucus into the pharynx.
    • Oropharynx (intermediate): Common passage for air and food, contains tonsils (trap pathogens).
    • Laryngopharynx (inferior): Similar to oropharynx.
  • The larynx: Tube with nine cartilages.
    • Thyroid cartilage: Forms the anterior surface (Adam's apple).
    • Epiglottis: Flap of cartilage that covers the entrance to the larynx during swallowing.
    • Cricoid cartilage: Inferior ring of cartilage, landmark for tracheotomies.
    • Vocal folds (true vocal cords): Made of stratified squamous epithelium, vibrate to produce sounds; tension on ligaments changes pitch.
    • Vestibular folds (false vocal cords): Protect the vocal cords.
  • The trachea: Tube with 16-20 C-shaped hyaline cartilages, keeps the trachea patent, anterior to the esophagus, lined with ciliated pseudostratified epithelium.
  • The bronchi: Trachea splits into right and left bronchi (carina = ridge, triggers cough reflex); branch into smaller tubes (bronchial tree) ending in terminal bronchioles. The mucous membrane changes along the bronchial tree.
  • The lungs: Wrapped in pleural membrane (2 serous membranes, pleural fluid reduces friction); separated by the mediastinum and its organs; extend from clavicles to diaphragm, rest on the costal surfaces (ribs).
    • Base: Inferior portion of the lung.
    • Apex: Superior portion of the lung.
    • Hilum: Permits passage of bronchi, blood vessels, nerves, and lymphatic vessels.
    • Cardiac notch: Space for the heart (decreases the size of the left lung).
    • Fissures: Divide the lungs into lobes.
      • Oblique fissure: Separates superior and inferior lobes.
      • Horizontal fissure: Borders the middle lobe of the right lung.
      • Lobar bronchi: Named for the lobes they branch into.
      • Segmental bronchi: Support a bronchopulmonary segment (13 in right lung, 8 in left).
      • Lobules: Small compartments containing a branch of a terminal bronchiole, arteriole, venule, lymphatic vessel, and elastic connective tissue.
    • Respiratory bronchioles: Microscopic branches of bronchi, lined with simple cuboidal epithelium, branch into alveolar ducts.
    • Alveoli: Air sacs where gas exchange occurs.
      • Type I alveolar cells: Simple squamous epithelium, facilitating gas diffusion.
      • Type II alveolar cells: Secrete surfactant (phospholipids + lipoproteins) preventing alveolar collapse.
      • Respiratory membrane: Alveoli and associated capillaries (0.5 µm thick).
  • Blood supply to the lungs:
    • Pulmonary arteries: Bring deoxygenated blood from right ventricle.
    • Bronchial arteries: From the aorta, deliver oxygenated blood to lung tissue.

Gas Exchange and Ventilation

  • Pulmonary ventilation: Inhalation and exhalation; regulated by pressure changes within the thoracic cavity and respiratory muscle contractions.
  • Inhalation (inspiration):
    • Pressure in lungs must decrease below atmospheric pressure to draw air in.
    • Diaphragm contracts, increasing thoracic cavity volume. Intercostal muscles also elevate ribs.
    • Negative intrapleural pressure keeps the pleural membranes adhering to the thoracic cavity wall.
  • Exhalation: -Passive process; respiratory muscles relax, thoracic cavity volume decreases.
    • Elastic recoil of lung tissue generates pressure for exhalation.

Factors affecting pulmonary ventilation

  • Surfactant: Essential for preventing alveolar collapse.
  • Compliance: Distensibility of elastic tissues; high compliance = easier breathing. Low compliance is harder because much more effort is needed.
  • Resistance: Airway diameter and smooth muscle constriction affect resistance. Obstruction / collapse of airways increases resistance.

Lung volumes and capacities

  • Lung volumes are specific measures of air movement (inhaled, exhaled, or retained).
  • Lung capacities are sums of specific lung volumes.

Principles of Gas Exchange

  • Gases move from high to low partial pressure.
  • Solubility of gases affects rate; CO2 is more soluble than O2, elimination of CO2 is 20x faster than O2 acquisition.
  • External Respiration: Gas exchange between alveoli and blood.
  • Internal Respiration: Gas exchange between blood and body tissues.

Factors affecting respiration

  • Partial pressure gradient: Decreased atmospheric pressure affects O2 gradient, lowering the rate of respiration and oxygen availability.
  • Surface area: Large surface area of alveoli enhances gas exchange efficiency.
  • Diffusion distance: Thin alveolar walls facilitate efficient diffusion.
  • Molecular weight and solubility affect the rate of net elimination of CO2 (20x faster than net O2 acquisition).

Oxygen Transport

  • Hemoglobin (Hb) in erythrocytes transports 98.5% of oxygen.
  • Hb binds oxygen reversibly.
    • Increased PO2 favors Hb-O2 formation.
    • Factors affecting Hb saturation: partial pressure of oxygen, blood acidity, partial pressure of CO2, temperature, the type of hemoglobin, and intermediate products of glycolysis

Carbon Dioxide Transport

  • CO2 is transported as dissolved gas, bound to proteins, and as bicarbonate.
  • Chloride shift: maintains electrical balance during CO2 transport.

Regulation of Breathing

  • Respiratory center: Cluster of neurons in the medulla oblongata and pons that regulate respiratory muscles.
    • Medullar respiratory group: Dorsal respiratory group (normal breathing), ventral respiratory group (forceful breathing).
    • Pontine respiratory group: Influences normal breathing.
  • Cortical influences: Allows voluntary control over breathing.
  • Chemoreceptors: Sense changes in blood chemistry.
    • Central chemoreceptors: Located near medulla oblongata; sense PCO2 and H+.
    • Peripheral chemoreceptors: In aortic and carotid bodies; monitor PCO2, PO2, and blood pH.
  • Hyperventilation: High breathing rate and depth; response to low blood pH to increase O2 levels. Hypocapnia and hypoxia can result if sustained.
  • Inflation reflex: Prevents over-inflation of the lungs.

Other Influences on Breathing

  • Emotions, temperature, pain, airway irritation, blood pressure can all influence breathing rate.

Exercise and the Respiratory System

  • Exercise increases pulmonary perfusion and ventilation.

Homeostatic Imbalances

  • Tobacco smoking can lead to COPD (emphysema, increased mucus secretion) impairing ciliary function and decreasing alveolar surface area.

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Description

This quiz explores the fundamental processes of respiration, including gas exchange and the anatomical structures involved in the respiratory system. Understand the significance of pulmonary ventilation, external and internal respiration, and the overall functions of the respiratory system. Delve into the components that make up the upper and lower respiratory systems.

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