1 Respiratory System Anatomy
Click on prefixes, combining forms, and suffixes to reveal a list of word parts to memorize for the Respiratory System.
Introduction to the Respiratory System
How long you can hold your breath as you continue reading… How long can you do it? Chances are you are feeling uncomfortable already. Although oxygen is critical for cells, it is the accumulation of carbon dioxide that primarily drives your need to breathe.
The major structures of the respiratory system function primarily to provide oxygen to body tissues for cellular respiration, remove the waste product carbon dioxide, and help to maintain acid-base balance. Portions of the respiratory system are also used for non-vital functions, such as sensing odors, speech production, and for straining, such as coughing.
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Media 7.1. Respiratory System, Part 1: Crash Course A&P #31 [Online video]. Copyright 2015 by CrashCourse.
Respiratory System Medical Terms
Anatomy (Structures) of the Respiratory System
The Nose and its Adjacent Structures
The major entrance and exit for the respiratory system is through the nose. When discussing the nose, it is helpful to divide it into two major sections:
The nares open into the nasal cavity, which is separated into left and right sections by the nasal septum (Figure 7.2). The nasal septum is formed anteriorly by a portion of the septal cartilage and posteriorly by the perpendicular plate of the ethmoid bone and the thin vomer bones.
Each lateral wall of the nasal cavity has three bony projections the inferior conchae are separate bones and the superior and middle conchae are portions of the ethmoid bone. Conchae increase the surface area of the nasal cavity, disrupt the flow of air as it enters the nose, causing air to bounce along the epithelium, where it is cleaned and warmed. The conchae and meatuses trap water during exhalation preventing dehydration.
The floor of the nasal cavity is composed of the hard palate and the soft palate. Air exits the nasal cavities via the internal nares and moves into the pharynx.
Paranasal sinuses, serve to warm and humidify incoming air and are lined with a mucosa which produces mucus. Paranasal sinuses are named for their associated bone:
- frontal sinus
- maxillary sinus
- sphenoidal sinus
- ethmoidal sinus
The nares and anterior portion of the nasal cavities are lined with mucous membranes, containing sebaceous glands and hair follicles that serve to prevent the passage of large debris, such as dirt, through the nasal cavity. An olfactory epithelium used to detect odors is found deeper in the nasal cavity.
The conchae, meatuses, and paranasal sinuses are lined by respiratory epithelium composed of pseudostratified ciliated columnar epithelium (Figure 7.3). The epithelium contains specialized epithelial cells that produce mucus to trap debris. The cilia of the respiratory epithelium help to remove mucus and debris with a constant beating motion, sweeping materials towards the thr