Chapter 22: The Respiratory System Overview

Respiratory System Functions

Obtains O2, removes CO2, regulates blood pH.

Respiration Processes

Four distinct processes: ventilation, exchange, transport, tissue.

Pulmonary Ventilation

Air movement into and out of lungs.

External Pulmonary Exchange

Gas exchange between lungs and blood.

Transport

O2 and CO2 movement via blood.

Internal Tissue Exchange

Gas exchange between blood and tissues.

Nose

Primary air passageway; resonance chamber for speech.

Larynx

Voice box; sound production and airway protection.

Trachea

Windpipe; conducts air to bronchi.

Bronchial Tree

Branching airways from trachea to lungs.

Alveoli

Tiny air sacs for gas exchange.

Goblet Cells

Secrete mucus to trap foreign particles.

Ciliated Epithelium

Lines respiratory tract; moves impurities out.

Diaphragm

Muscle aiding in inhalation and exhalation.

Right Lung

Three lobes; larger than left lung.

Left Lung

Two lobes; accommodates heart's position.

Nasal Cavity

Warms and moistens air; contains turbinates.

External Nares

Nostrils; entry points for air.

Internal Nares

Connects nasal cavity to pharynx.

Pharynx

Passageway for air and food.

Sound Production

Generated by air passing through larynx.

Cellular Respiration

O2 usage and CO2 production by cells.

Regulation of Respiration

Controlled by various physiological factors.

External Nose

Leads posteriorly to the nasal cavity.

Hard Palate

Floor of the nasal cavity separating it from the mouth.

Paranasal Air Sinuses

Drain mucus into the nasal cavity.

Nasolacrimal Ducts

Drain tears into the nasal cavity.

Nasal Conchae

Three bony projections in the nasal cavity.

Mucous Membrane

Lining that secretes mucus and contains blood vessels.

Air Filtration

Dust and pathogens caught by nostril hairs.

Air Warming

Blood warms air in the vascularized mucous membrane.

Air Moistening

Liquid secretion moistens the inhaled air.

Air Turbulence

Movement between conchae increases air mixing.

Gas Exchange

Warm, moist air is essential for lung efficiency.

Uvula

Prevents food from entering nasopharynx during swallowing.

Epiglottis

Closes larynx to prevent food entering airway.

Laryngeal Prominence

Adam's apple, larger in men than women.

Thyroid Cartilage

Middle cartilage forming the larynx framework.

Cricoid Cartilage

Most inferior cartilage, ring-shaped in structure.

Vocal Cords

Ligaments in larynx responsible for sound production.

Glottis

Cavity of larynx between vocal cords.

Resonating Chambers

Mouth and sinuses amplify sound quality.

Right Bronchus

Shorter, wider bronchus, more foreign object prone.

Left Bronchus

Longer, narrower bronchus, less foreign object prone.

Tracheal Cartilages

C-shaped rings maintaining tracheal structure.

Trachealis Muscle

Smooth muscle allowing esophageal expansion.

Lumen of Trachea

Airway passage within the trachea.

Pseudostratified Columnar Epithelium

Ciliated epithelial tissue lining the trachea.

Hyaline Cartilage

Type of cartilage forming tracheal rings.

Pulmonary Artery

Carries deoxygenated blood to lungs.

Pulmonary Veins

Carry oxygenated blood from lungs to heart.

Bronchus

Main passageway into the lungs.

Pleural Membrane

Protective layer surrounding the lungs.

Apex of Lung

Superior tip of the lung.

Base of Lung

Inferior surface resting on diaphragm.

Hilum

Entry/exit point for vessels and bronchi.

Oblique Fissure

Divides left lung into superior and inferior lobes.

Horizontal Fissure

Divides right lung into middle and inferior lobes.

Cardiac Notch

Indentation in left lung for heart accommodation.

Bronchopulmonary Segments

Ten segments in each lung lobe.

Lung Shape

Conical structure facilitating gas exchange.

Primary Bronchi

First division of trachea into lungs.

Secondary Bronchi

Branches into lobes; 3 on right, 2 on left.

Tertiary Bronchi

Supply bronchopulmonary segments; 10 on each side.

Alveolar Duct

Ducts leading to clusters of alveoli.

Terminal Bronchioles

Smallest bronchioles leading to alveolar ducts.

Surfactant

Substance preventing alveolar collapse during respiration.

Type I Alveolar Cells

Simple squamous cells for gas exchange.

Type II Alveolar Cells

Secrete surfactant; reduce alveolar collapse.

Alveolar Macrophages

Cells that remove debris from alveoli.

Respiratory Membrane

Thin membrane for gas exchange in lungs.

Elastic Fibers

Allow lung expansion and return to shape.

NRDS

Newborn respiratory distress syndrome due to surfactant deficiency.

Capillaries

Blood vessels surrounding alveoli for gas exchange.

Inspiration

Drawing air into the lungs.

Expiration

Expulsion of air from the lungs.

Pressure-Volume Relationship

Pressure inversely proportional to volume in containers.

Atmospheric Pressure

Pressure exerted by the weight of air.

Intrapulmonary Pressure

Pressure inside the lungs during breathing.

Thoracic Cavity

Space containing the lungs and heart.

External Intercostal Muscles

Muscles elevating ribs during inhalation.

Internal Intercostal Muscles

Muscles lowering ribs during forced expiration.

Normal Breathing Rate

Typically 12-20 breaths per minute.

Forced Inspiration

Increased air intake using neck muscles.

Passive Expiration

Air expulsion without muscle contraction.

Elastic Lung Tissues

Tissues that help lungs return to size.

Intrathoracic Volume

Volume of the thoracic cavity during breathing.

Transverse Diameter

Width of the thoracic cavity.

Anteroposterior Diameter

Depth of the thoracic cavity.

Forced Expiration

Active process using abdominal and intercostal muscles.

Airflow Direction

Air moves from high to low pressure.

Volume Increase

Occurs during inhalation to lower pressure.

Volume Decrease

Occurs during exhalation to raise pressure.

Rib Elevation

Increases thoracic cavity space during inhalation.

Diaphragm Contraction

Increases vertical diameter of thoracic cavity.

External respiration

Gas exchange between alveoli and blood capillaries.

Internal respiration

Gas exchange between blood and tissue cells.

Oxygen transport

Oxygen carried primarily by hemoglobin in blood.

Oxy-hemoglobin

Hemoglobin combined with oxygen for transport.

Oxygen saturation

Percentage of hemoglobin bound with oxygen.