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67 terms

Chapter 25, Respiratory system

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Functions of the respiratory system
-Allows for the exchange of gases (especially O2 and CO2) between the atmosphere and the blood.
Functions of the respiratory system
-Immune functions
Functions of the respiratory system
-Sound production (speech, singing, etc)
Functions of the respiratory system
-Sensation of olfactory stimuli (smell)
Upper respiratory tract epithelia
Mostly lined by pseudostratified, columnar, ciliated epithelia
Upper respiratory tract structures
Nose
Nasal cavity
Sinuses
Pharynx
Lower respiratory tract epithelia
-Lined by various kinds of epithelia.
-The trachea, bronchi, and larger bronchioles contain mucus-producing goblet cells.
Lower respiratory tract structures
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
Nose
-Structurally supported by nasal bones and cartilage
-Two nostrils are the entrances to the nasal cavity
Nasal cavity
Lateral walls
Roof
Nasal septum
Floor
Lateral walls of nasal cavity
-superior, middle, and inferior nasal conchae
-walls beneath each concha is a meatus, or air passageway. (Superior, middle, and inferior meatus).
Roof of nasal cavity
Cribriform plate of ethmoid bone
Nasal septum
-separates the two portions of the nasal cavity
Nasal septum
-Ethmoid and vomer form the posterior part of the septum
Nasal septum
-Septal cartilage forms the anterior part
Floor of nasal cavity
hard palate
Sinuses
-Continuous with the nasal cavity, via ducts.
Sinuses
-Help condition (warm and humidify) inhaled air.
Sinuses
-Give resonance to voice.
Sinuses epithelia
-Lined with pseudostratified, columnar, ciliated epithelia.
Pharynx
-Includes the common passageway for food, drinks and air (what we call the throat).
Pharynx
Tonsils are found in several parts of the pharynx
Pharynx
-Soft palate normally elevates during swallowing, to ensure substances enter pharynx, and prevent substances
from entering nasal cavity.
Pharynx
Pharyngeal wall contains pharyngeal constrictors, the skeletal muscles involved in swallowing
Tonsils
large clusters of lymphatic cells (including lymphocytes).
Tonsils
trap invading organisms, and lymphocytes coordinate immune responses.
Tonsils
therefore help fight upper respiratory infections
Lower respiratory tract structures
Larynx
Trachea
Bronchial tree
Larynx
Cylindrical airway (for air only)
Thyroid cartilage
Largest of nine pieces
V-shaped notch (easily palpated) is above the laryngeal prominence (or adam's apple) of the thyroid cartilage.
Epiglottis
Elastic cartilage flap
Moves inferiorly and posteriorly, to block entrance to trachea, during swallowing
Larynx
aka- voice box
voice box
Vibration of vocal folds produces sound
vocal cords
two ligaments, covered with epithelial tissue, that stretch from anterior to posterior across the
larynx.
vocal cords
They are at the level of the thyroid cartilage.
vocal cords
They are open during breathing, closed when holding one's
breath, and they vibrate during speech.
Trachea
Also called windpipe (air only)
Trachea
Anterior to esophagus
Trachea
Extends from larynx (superiorly) to the bronchial branch point (inferiorly, at the level of the sternal angle).
Trachea
Contains 15-20 C-shaped tracheal cartilages
Trachea epithelia
Lining of pseudostratified, columnar, ciliated epithelium, like upper respiratory tract
Tracheal cartilages
connected to each other by annular ligaments
Bronchial tree
Branch about 9 to 12 times in tota linto smaller bronchi
All bronchi have smooth muscle in walls, and cartilage to prevent collapse when pressure is low.
Primary bronchi
1 on left, and 1 on right
secondary bronchi
3 on right, 2 on left
tertiary bronchi
10 on right, 8 to 10 on left
bronchioles
smallest bronchi
less than 1mm in diameter
Bronchioles are small enough that they don't need cartilage to prevent collapse. They have smooth muscle for
regulation of the amount of airflow.
respiratory portion of the respiratory tract
Where gas exchange actually occurs
Respiratory bronchioles and alveoli
Alveoli
Small air-filled structures (about 0.3 mm in diameter)
Alveoli
surrounded by capillaries of the pulmonary circuit
Alveoli
350 million/person
Pleura
serous membranes of the lungs
Visceral pleura
The inner layer of the serous membrane
Tightly lines the outer surface of the lungs
Parietal pleura
The outer layer of the serous membrane
Lines the inside of the thoracic walls, the lateral surfaces of the mediastinum, and the superior surface of the
diaphragm
Pleura Reflection
The two layers of the serous membrane reflect on each other at the hilum (see below).
This arrangement is similar to the serous pericardium of the heart.
pleural cavity
the serous fluid-filled potential space between the two serous layers
Breathing
Inhalation
Exhalation
Inhalation
Muscles of inhalation enlarge the thoracic cavity.
Because the thoracic cavity is airtight, the lungs also are enlarged. This decreases the pressure inside the lungs,
especially in the alveoli.
This draws air into the alveoli, where gas exchange occurs.
Exhalation
When the muscles relax, the thoracic cavity returns to its resting size, and air is expelled.
In forced exhalation, muscle contraction (including the internal intercostal muscles) leads to a more forceful
decrease in lung volume.
right lung
has 3 lobes
left lung
has 2 lobes
lobes
are separted by fissures
Bronchopulmonary segments
10 in right lung
8-10 in left lung
Bronchopulmonary segments
Separate regions of a lung
Bronchopulmonary segments
Each has its own air supply (separate tertiary bronchi)
Each has its own blood supply
Left and right lungs
Left lung smaller, to accommodate larger left ventricle of heart
Note cardiac impression and notch
Hilum
Medial entrance point for bronchi, blood vessels, nerves, and lymph vessels