✅Lungs And Repiration System Flashcards
What are the functions of the respiratory system?
- Provides extensive gas exchange surface area between air and circulating blood
- Moves air to and from exchange surfaces of lungs
- Protects respiratory surfaces from outside environment
- Produces sounds
- Participates in olfactory sense
How does the respiratory system Moves the air to and from the exchange surface?
• Via nose, mouth, pharynx, larynx, trachea, bronchi to the lungs
• Moistens, warms and filters the air
How does the respiratory system Provide an extensive surface for gas exchange?
Alveoli or air sacs
How does the respiratory system Protect the respiratory surfaces at each stage from: dehydration, temperature changes, pathogens etc.
• Via vibrassae (nose hairs), mucosal membranes, surfactants and macrophages
• Reflexes such as coughing and sneezing
What does the respiratory tract consist of?
A conducting portion and a respiratory portion
Where is the conducting portion?
From nasal cavity to terminal bronchioles
Where is the respiratory portion?
The respiratory bronchioles and alveoli in the lungs
What are the components of the respiratory system?
The upper respiratory tract (above the larynx) and the lower respiratory tract (larynx and below).
What is the function of the respiratory system?
Exchange of carbon dioxide and oxygen is the primary function.
What is involved in the upper respiratory tract?
the nose, nasal cavity, paranasal sinuses and pharynx
What are the functions of the upper respiratory tract
• To purify, warm and humidify ambient air before it moves into the lower respiratory tract.
• Acts as a conduction pathway for the air to move into the lower respiratory tract.
How does air enter the respiratory system?
Through nostrils or external nares
Into nasal vestibule
What happens in the nasal cavity?
– The nasal septum
• Divides nasal cavity into left and right
– Superior portion of nasal cavity is the olfactory region
• Provides sense of smell
– Mucous secretions from paranasal sinus and tears
• Clean and moisten the nasal cavity
Describe Air flow in upper respiratory tract
From the vestibule to internal nares
• Through superior, middle, and inferior
meatuses
• Meatuses are constricted passageways that produce air turbulence
– Warm & humidify incoming air – Trap particless
Describe the hard palate
– Forms floor of nasal cavity
– Separates nasal and oral cavities
Describe the soft palate
– Extends posterior to hard palate
– Divides superior nasopharynx from lower pharynx
What does the respiratory mucosa consist of?
- An epithelial layer
- An areolar layer called the lamina
What foes respiratory mucosa do?
Line the conducting portion of respiratory system
What is the lamina propria?
Underlying layer of areolar tissue that supports the respiratory epithelium
What does the lamina propria do in the upper respiratory system, trachea and bronchi?
Contains mucous glands that secrete onto epithelial surface
What does the lamina propria do In the conducting portion of lower respiratory system
Contains smooth muscle cells that encircle lumen of bronchioles
What does the cilia from the epithelial cells form?
A dense layer
What does the movement of the cilia in the epithelial do?
propels mucus across the epithelial surface.
Describe the structure of the respiratory epithelium
– Pseudostratified ciliated columnar epithelium with numerous mucous cells
• Nasal cavity and superior portion of the pharynx
– Stratified squamous epithelium
• Inferior portions of the pharynx
– Pseudostratified ciliated columnar epithelium
• Superior portion of the lower respiratory system
– Cuboidal epithelium with scattered cilia
• Smaller bronchioles
What does the respiratory defence system consist of?
a series of filtration mechanisms
What does the respiratory defence system do?
It removes particles and pathogens
What are the components of the respiratory defence system
– Mucous cells and mucous glands
• Produce mucus that bathes exposed surfaces
– Cilia
• Sweep debris trapped in mucus toward the pharynx
(mucus escalator)
– Filtration in nasal cavity removes large particles
– Alveolar macrophages engulf small particles that reach lungs
What is the pharynx
A chamber shared by the digestive and respiratory systems
Where is the pharynx?
Extends from internal nares to entrances to larynx and oesophagus
What are the three parts of the pharynx
• The nasopharynx
• The oropharynx
• The laryngopharynx
Describe the nasopharynx
– Superior portion of pharynx
– Contains pharyngeal tonsils and openings to left and right auditory tubes
Describe the oropharynx
Middle portion of pharynx
Communicates with oral cavity
Describe the laryngopharynx
– Inferior portion of pharynx
– Extends from hyoid bone to entrance of larynx and esophagus
What is included in the lower respiratory tract?
Includes the larynx (voice box), trachea (windpipe), lungs, bronchi, bronchioles & alveoli
What are the components of the lower respiratory tract?
– Conducting zone
– Transitional zone
– Respiratoryzone
What are the functions of the lower respiratory tract
– Gas exchange
– Filtering of the venous blood before it enters the left ventricle of the heart
Describe the Tracheobronchial tree
» Trachea (cartilage rings + longitudinal muscle bundle) into L & R main bronchi
» 23 generations of branching / bifurcations
What are the two types of bronchioles
» terminal bronchioles
» respiratory bronchioles
Describe the alveoli
» approximately 300 million alveoli
» gas exchange surface (diffusion)
Describe the what is necessary for gasses to exchange efficiently
• Alveoli walls must be very thin (<1 μm)
• Surface area must be very great (about 35 times the surface area of the body)
Where does airflow from the pharynx enter?
The larynx
What is the larynx?
A cartilaginous structure that surrounds the glottis, which is a narrow opening
What are the three, unpaired cartilages from the larynx?
- Thyroid cartilage
- Cricoid cartilage
- Epiglottis
Describe the thyroid cartilage
-hyaline cartilage
– Forms anterior and lateral walls of larynx
– Anterior surface called laryngeal prominence (Adam’s apple)
– Ligaments attach to hyoid bone, epiglottis and laryngeal cartilages
describe the cricoid cartilage
– hyaline cartilage
– Forms posterior portion of larynx
– Ligaments attach to first tracheal cartilage
– Articulates with arytenoid cartilages
Describe the eppiglottis
– Composed of elastic cartilage
– Ligaments attach to thyroid cartilage and hyoid bone
What is the function of the the thyroid and circoid cartilages?
To support and protect the glottis and the entrance to the trachea
What is the function of the larynx during swallowing?
– The larynx is elevated
– The epiglottis folds back over glottis
• Prevent entry of food and liquids into respiratory tract
What are the 3 pairs of smaller hyaline cartilages?
- Arytenoid cartilages
- Corniculate cartilages
- Cuneiform cartilages
What do The arytenoid and corniculate cartilages function in?
– Opening and closing of glottis
– Production of sound
Describe the Vestibular ligaments and vocal ligaments
– Extend between thyroid cartilage and arytenoid
cartilages
– Are covered by folds of laryngeal epithelium that project into glottis
Where do the vestibular ligaments lie?
Within the vestibular folds (protecting delicate vocal folds).
How are sound waves produced?
Air passing through the glottis vibrates vocal folds
How is sound varied?
– Tension on vocal folds
• Vocal folds involved with sound are known as vocal cords
– Voluntary muscles (position arytenoid cartilage relative to thyroid cartilage)
How is speech produced?
- Phonation
• Sound production at the larynx
– Articulation
• Modification of sound by other structures
What does the trachea do?
Extends from the cricoid cartilage, then branches into right and left pulmonary bronchi
Where is the submucosa and what does it contain?
beneath mucosa of trachea contains mucous glands
How many tracheal cartilages are there?
15-20
What do the tracheal cartilages do?
– Strengthen and protect airway
– Discontinuous where trachea contacts oesophagus
How are the ends of each tracheal cartilage connected?
by an elastic ligament and trachealis muscle
How are the right and left primary bronchi separated?
by an internal ridge (the carina)
R primary bronchus is larger in diameter descends at a steeper angle than L primary bronchus
True or false?
True
Where are the left and right lungs?
In the left and right pleural cavities
What is the base of a lungs and where is it?
the inferior portion of each lung, resting on the superior surface of diaphragm
How are the lobes of the lungs separated?
By deep fissures
What are the three lobes of the right lung and how are they separated?
– Superior, middle, and inferior
– Separated by horizontal and oblique fissures
What are the two lobes of the left lung and how are they separated?
- superior and inferior
- separated by an oblique fissure
Describe the size of the right lung and its placing?
- wider
- displaced upwards by liver
Describe the size of the left lung and its placing?
Longer
Displaced leftward by the heart forming the cardiac notch
What is the hilum?
where the pulmonary nerves, blood vessels, lymphatics enter lung, anchored in a meshwork of connective tissue.
What is the root of the lung?
a complex of connective tissues, nerves, and vessels.
What are the two types of bronchial branches?
– Extrapulmonary Bronchi: the left and right bronchi branches outside the lungs
– Intrapulmonary Bronchi: branches within the lungs
a primary bronchus branches to from?
A secondary bronchi
One secondary bronchus goes to each what?
Lobe
A secondary bronchus branches to from what?
Tertiary bronchi (segmental bronchi)
Each segmental bronchus supplies air to what?
A single bronchopulmonary segment
How man bronchopulmonary segments are their in each lung?
10 in right, 8-9 in left
Describe why there is smooth muscle in the walls of primary, secondary and tertiary bronchi
– With each bifurcation in the bronchial tree, there is progressively less cartilage and more smooth muscle
– Increased smooth muscle tension affects airway constriction and resistance
Describe bronchioles
– Each tertiary bronchus branches into multiple bronchioles
– Bronchioles branch into terminal bronchioles (one tertiary bronchus forms about 6500 terminal bronchioles!)
– Have no cartilage and are dominated by smooth muscle
Each terminal bronchiole delivers air to what?
A single pulmonary lobule
Each pulmonary lobule is supplied by what?
Pulmonary arteries and veins
Each terminal bronchiole branches to form what?
Several respiratory bronchioles, where gas exchange takes place
How are respiratory bronchioles connected to alveoli?
Along alveolar ducts
Where to alveolar ducts end?
alveolar sacs, common chambers connected to many individual alveoli
Each alveolus has an extensive network of what?
capillaries, surrounded by elastic fibres
Describe Alveolar epithelium
• Very delicate, simple squamous epithelium
• Contains scattered and specialised cells
• Lines exchange surfaces of alveoli
What do Alveolar epithelium consist of?
– thin, delicate type I pneumocytes patrolled by alveolar macrophages (dust cells)
– type II pneumocytes (septal cells) that produce surfactant
