week 3 Flashcards
what are the Functions of the Respiratory System?
- Warming, humidification and
filtration of air (nasal cavity) - Defence against airborne
pathogens (lymphoid tissue in
respiratory tract) - Phonation (larynx)
- Gaseous Exchange (lungs
and muscles of respiration) - Acid-Base Balance (lungs)
– covered in more detail in
Acid/Base balance lecture
what is Gas Exchange?
Respiratory System is designed for gas
exchange between air and blood
* During metabolism, all cells in the body require a
continuous supply of oxygen (O2)
* As the cells use O2 they give off carbon dioxide (CO2)
* Cardiovascular system transports blood gases from
the lungs tissues and from the tissues lungs
* The failure to supply O2 to cells leads to hypoxia (
cell death)
* General and local hypoxia can lead to many serious
conditions e.g. gangrene, brain ischemia (stroke) and
myocardial infarction, etc.
what are the 4 Respiration Processes?
Four processes:
1. Pulmonary ventilation
- movement of air into the lungs
- movement of air out of the lungs
2. External respiration
- movement of O2: lungs blood
- movement of CO2: blood lungs
1 and 2 occur in respiratory system
3. Transport of respiratory gases
- transport of O2: blood body tissues
- transport of CO2: body tissues blood
4. Internal respiration
- movement of O2: blood tissue cells
- movement of CO2: tissue cells blood
2 and 3 occur in cardiovascular system
Basic Anatomy of respiratory system. point out structures in diagram. *Nose
* Nasal cavity
* Paranasal
sinuses
* Pharynx
* Larynx
* Trachea
* Bronchial Tree
* Lungs, Alveoli
and Pleurae
what are the Respiratory system divisions according to structure:
- upper respiratory tract
– nasal cavity, paranasal sinuses, and pharynx - lower respiratory tract
– larynx, trachea, bronchi, and lungs
what are the Respiratory system divisions according to function:
- conducting zone
– conduct gas to exchange sites
– includes all macroscopic respiratory structures - respiratory zone
– site of gas exchange
– microscopic structures: respiratory bronchioles, alveolar ducts, and alveoli
what is the nasal cavity?
The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. Kind of like an external nose that provides protection
what are the 2 parts of nasal cavity?
-divided into 2 compartments/cavities (L & R) by the nasal septum, known as fossae. Each cavity is the continuation of one of the two nostrils.
Function of nasal septum and what does it consist of
nasal septum consists of the vomer bone, perpendicular plate of ethmoid bone and septal cartilage and The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils.
what is the anterior opening?
anterior opening = nasal vestibule (with coarse hairs and glands)
what is the post opening?
post opening = post nasal aperture
what bones form the roof and floor of nasal cavity/nose?
- ethmoid and sphenoid bones form the roof
- hard and soft palate forms the floor
what does the nasal cavity involve?
contains:
– mucosa (wall lining)
– sinuses (air-filled spaces in skull)
– conchae (bony shelves)
– meatuses (spaces underneath the
bony shelves)
– hairs (found in the nostrils)
– blood vessels
– nerves
what structures are on this diagram?
Nasal Cavity
what anatomical structures are responsible for sense of smell?
olfactory nerves (CN1) protrude through cribriform plate –> olfactory epithelium which are found on the roof of the nasal cavity
what is the conchae and its function?
The conchae are structures made of bone inside of your nose., on the lateral wall of the nasal cavity. They help control the airflow into your nose. They also clean and warm air that you’ve inhaled so that it’s ready to go to your lungs for respiration. It consists of superior, middle and inferior parts. ↑ Increases respiratory mucosal area and enhances air turbulence
what is Respiratory Mucosa and its function?
- lines most of the nasal cavity
- has sensory nerve endings to trigger sneezing
- ## has rich vasculature which warms air
what is pseudostratified ciliated columnar epithelium?
the type of respiratory epithelium found in the linings of the trachea as well as other respiratory tract, which allows filtering and humidification of incoming air. help trap and transport particles brought in through the nasal passages and lungs. containing mucus-producing
cells (i.e. goblet cells) and enzymesecreting cells (i.e. lysozyme, defensins)
* mucus moistens air and traps dust
* cilia move mucus towards pharynx
(clearance)
what are Paranasal Sinuses and function?
*air-filled cavities in cranial
bones (lighten the skull)
* found in frontal, ethmoid,
sphenoid and maxillary
bones
* lined with respiratory
mucosa (secrete mucus)
* drain into the nasal cavity
* act as resonance
chambers for speech
* susceptible to infections
- sinusitis = blocked sinus openings = fluid build up.
label diagram
Paranasal Sinuses
what is Pharynx and function?
- Connects nasal cavity –> larynx and oral cavity –> oesophagus
- passageway for air and food
- Acts as a resonating chamber for speech production
- 3 subdivisions: Nasopharynx, Oropharynx, Laryngopharynx
- Contain tonsils (immune function), pharyngeal (adenoids), tubal,
lingual and palatine
(Waldeyer’s ring).
label diagram
Pharynx
what is Nasopharynx and contents?
- post. nasal aperture to soft palate (lined with pseudostratified columnar epithelium)
contains:
-pharyngeal tonsils (adenoids) - opening for the pharyngotympanic tube (old name Eustation/Auditory tube) which links the nasopharynx to the middle ear (hence ‘tympanic’), pressure equalisation and mucus drainage
- tubal tonsils
enlargement of pharyngeal tonsils (adenoids) can lead to….
loud snoring or sleep disturbances
what is Oropharynx and contents?
- soft palate to epiglottis (lined with
stratified squamous epithelium)
contains: - palatine tonsils
- lingual tonsils
what is Laryngopharynx and contents?
epiglottis to cricoid cartilage of larynx and beginning of oesophagus (lined
with stratified squamous epithelium)
what is the larynx
A cartilaginous chamber that connects the laryngopharynx to
the trachea (wind pipe)
larynx functions
Three functions: passageway for air, involved in voice production and prevents food and fluids from entering the lower respiratory tract
what is the larynx composed of?
Composed of 9 cartilages connected by fibrous membranes and ligaments and 3 pairs of internal folds
label the diagram
larynx
label the diagram
larynx
label the diagram
larynx
what are the Cartilages in larynx?
-thyroid cartilage: forms prominence (Adam’s apple)
- epiglottic cartilage: leaf-shaped, bends to cover the opening of the
larynx as the larynx moves upward during swallowing
- cricoid cartilage: ring-shaped, attached to the top of the trachea
- arytenoid, cuneiform and corniculate cartilages (paired): form the lateral and posterior walls of the larynx. The most important of these are the arytenoid cartilages, which anchor the vocal folds
what are the ligaments in larynx?
- thyrohyoid membrane: between the thyroid cartilage and hyoid bone
- cricothyroid ligament: between the cricoid and thyroid cartilages
- cricotracheal ligament: between the cricoid and tracheal cartilages
what are the Folds of the larynx?
vocal cords (true vocal cords/folds) and vestibular folds (false vocal cords/folds)
what are the vocal cords (true vocal cords/folds)?
*contain elastic connective tissue
* attached to the arytenoid cartilages and the thyroid cartilages
* the opening between the folds is called the glottis
* folds vibrate to produce sound as air rushes up from the lungs
* controlled by small intrinsic muscles that pull on the arytenoid
cartilages causing them to pivot –> abduction and adduction of the
vocal folds changes the size of the glottis
what are the vestibular folds (false vocal cords/folds) ?
- superior to the vocal cords
- no part in sound production
- help to close the glottis during
swallowing and breath holding
label this diagram
larynx
how is speech produced
- The intrinsic muscles alter the cartilage positions relative
to each other (lat. and post. cricoarytenoid muscles). They are controlled by recurrent laryngeal nerve (br. of Vagus
n. = CN10) - speech = intermittent release of expired air while
opening and closing glottis - pitch is determined by length and tension of vocal folds
- loudness depends upon force of expired air
- nasal, sinus and pharyngeal chambers amplify and
enhance sound quality - sound is shaped into language by muscles of pharynx,
tongue, soft palate and lips
what is the Trachea
- tube running from larynx
to the mediastinum - conducts air to and from
lungs (no gas exchange) - 12 cm long and 2 cm in
diameter
what does the Trachea contain?
- contains 16 to 20
incomplete C-shaped
cartilage rings (closed by
trachealis muscle) - divides inferiorly into 2
main bronchi (to enter the
lungs) ~ carina - inside is lined columnar
epithelium with cilia and
goblet cells which prevents foreign bodies from entering lungs by moving mucus/trapped
particles upwards -“mucociliary escalator
Bronchial Tree full view
what does the Bronchial Tree consist of ?
Primary bronchi (main)(L & R)
– supply each lung (L & R)
* Secondary bronchi (lobar)
– supply each lobe of the lung (3 in
R lung and 2 in L lung)
* Tertiary bronchi (segmental)
– supply each bronchopulmonary
segment
* bronchi are lined by simple
columnar epithelium with cilia
and goblet cells for mucus
production
– “mucociliary escalator”
what are these 3 circles?
these are the structures that branch of bronchial tree and trachea.
in bronchial tree what Cartilage changes occur?
Cartilage changes
* cartilage rings to cartilage
plates to no cartilage
in bronchial tree what Epitheliel changes occur?
Epitheliel changes
* pseudostratified columnar to
simple columnar (cilia) to
cuboidal, and goblet cells
become sparse
in bronchial tree what muscular changes occur?
Muscular changes
* smooth muscle increases
Lungs location
*housed in the
thoracic
cavity
* protected by
the ribs
* right lung ~ 3
lobes (S, M, I)
* left lung ~ 2
lobes (S, I)
label diagram
what are Pleural Membranes?
- The pleurae form a thin, double layered serous epithelial membrane
what does the Pleural Membranes consist of?
- parietal layer: lines the inside of the thoracic cavity and upper surface of
the diaphragm (outer) - sensory innervation –> pain
- visceral layer: covers the
lungs on all sides (inner) - no sensory innervation
- small (potential) space
between them is called the
pleural cavity - filled with a small amount of
pleural fluid for lubrication
and friction reduction - visceral and parietal layers are
normally very close to each
other due to the intrapleural
pressure (pressure in pleural cavity) being
less than the intrapulmonary
pressure (pressure in lungs)
what is the Lung Lobule?
Lung compartment composed of a single arteriole, venule and a terminal bronchiole wrapped by elastic connective tissue
contents of lung lobule: what is the respiratory zone for gas exchange?
Bronchiole –> Terminal Bronchiole –> Respiratory Bronchioles –> Alveolar Ducts -which are surrounded by alveolar sacs (2+ alveoli sharing an alveolar duct)
= respiratory zone (for gas exchange) everything else is the conducting zone
what are Alveoli?
microscopic bubble-like air sac where gas exchange
takes place
how much alveoli does the lungs contain?
lungs contain ~300 million = total surface area >70m^2
what cells do alveolis contain?
- Alveolar epithelial cells:
(Type I cells) squamous cells
that line alveoli (1 layer),
through which gas exchange
occurs (the most numerous
cells) - Surfactant secreting cells:
(Type II cells) secrete alveolar
fluid containing surfactant that
assists with lung expansion
(less numerous) - Alveolar macrophages:
wandering scavenger cells
that remove inhaled particles
and other debris
inside alveolis
what is a Respiratory Membrane?
a thin membrane where the quick diffusion of gases
occur.
what is a Respiratory Membrane composed of?
composed of four layers
– alveolar epithelial cells
– basement membrane of alveolus
– basement membrane of capillary
both basements r generally fused.
– endothelial cells of capillary
label coloured structures
respiratory membrane layers
Blood Supply and Drainage lungs: deoxygenated blood
*Deoxygenated blood arrives through the pulmonary arteries
(<– from pulmonary trunk <– from the right ventricle)
– entering the lung at the hilum
* pulmonary arteries follow the bronchial tree all the way down to
the lobules and form rich capillary networks in alveolar walls
that participate in gas exchange
–> oxygenation of the blood and the removal of carbon dioxide
Blood Supply and Drainage lungs: oxygenated blood
Oxygenated blood is then drained by the pulmonary veins
(–> into the left atrium)
* Bronchial arteries (L & R) enter the hilum to supply the
bronchial tree down to the respiratory bronchioles, the
connective tissue of the lungs and the visceral pleura
– arise from the thoracic aorta
– the arteries anastomose with the pulmonary vessels
– drained mostly by the pulmonary vessels and less by the bronchial veins
nerve supply: what are the lungs innervated by and what does it consist of?
The lungs are innervated by the pulmonary plexus, which
consists of:
– parasympathetic motor fibres
* rest & digest
* from vagus nerve (CN10)
* cause the bronchial tree to constrict
* vasodilator to vessels
* secretomotor to glands
– sympathetic motor fibres
* fight or flight
* from sympathetic chain
* cause the bronchial tree to dilate
* vasoconstrictor to vessels
* inhibits alveolar glands
– visceral sensory fibres
* senses pain from lungs
The pulmonary plexus enters each lung at the hilum and runs
along the bronchial tree and accompanying blood vessels
Thoracic Cage Movements
Pump handle
– sternum moving upwards and
anteriorly
– changes the anterior/posterior
dimension of the thoracic cavity
Bucket handle
– ribs moving upwards and laterally
– changes the medial/lateral dimension
of the thoracic cavity
Calipers
– lower ribs moving anteriorly, laterally and posteriorly
– changes the anterior/posterior and the medial/lateral dimensions of the thoracic cavity
The movement of the
diaphragm (though not a
thoracic cage movement) – changes the superior/inferior
dimension of the thoracic cavity
what is Pulmonary Ventilation?
the process by which air moves into and out of the lungs
Basic principles of Pulmonary Ventilation?
- Movement of air is a result of air pressure differences between two points
- Air moves into lungs when pressure inside lungs (intrapulmonary) is lower than
atmospheric pressure* - Air moves out of the lungs when intrapulmonary pressure is greater than
atmospheric pressure* *Normal atmospheric pressure at sea level = 1 atm or 760mm Hg - Changes in intrapulmonary pressure is caused by the breathing phases
what is boyle’s law?
Pulmonary Ventilation
Boyle’s Law = the inverse relationship between the volume of a closed
container and pressure of the gas inside it
- as the size of the closed container decreases,
the pressure inside increases - this is because the gas molecules have less
surface area to push up against –> therefore
the pressure on a given surface area increases - as the size of the closed container increases,
the pressure inside decreases - this is because the gas molecules have more surface area to push up against –> therefore
the pressure on a given surface area decreases
Breathing can be affected by:
Lung disease/disorders
– Chronic Obstructive Pulmonary Diseases (COPD): e.g.
emphysema
* alveolar walls are destroyed –> less respiratory membrane surface area for
gas exchange
– Fibrosis
* alveolar walls thickened by immune system and fibrous tissue
– Asthma
* alveolar walls swollen by immune cells –> airways blocked by mucus
Infections
– Flu/colds
– Upper respiratory tract infections
* tonsillitis, viruses, pharyngitis, etc.
– Bronchitis
– Pneumonia
* fluid accumulates in alveoli
Which tonsils are
found in the
oropharynx?
Oropharynx: palatine
and lingual tonsils
Which tonsils are
found in the
nasopharynx?
Nasopharynx: tubal and
pharyngeal (adenoids)
What is the purpose
of nasal conchae?
To increase the surface
area of the nasal
mucosa
Name the arteries that
bring oxygenated
blood to the bronchial
tree and the lung
tissue itself. Do they
enter the lungs at the
hilum?
Bronchial arteries. Yes,
they enter at the hilum
Which muscles are
involved in quiet
expiration? And why?
None. Quiet expiration
results from the
passive recoil of the
lungs
The lungs are
innervated by the
____________ which
enters the lungs at
the ____________
Pulmonary plexus.
Hilum.
. Identify structure A
Middle lobe of the right
lung.
Identify muscle B, what does the contraction of B cause
(inspiration or expiration)?
The diaphragm.
Inspiration.
The respiratory mucosa of the nasal
cavity consists of what type of
epithelium?
Pseudostratified ciliated columnar
epithelium, containing mucusproducing cells (i.e. goblet cells) and
enzyme-secreting cells.
How are trapped foreign particles
removed from the nasal cavity?
Trapped in mucus, moved by cilia
down to throat for clearance.
Name the two sinuses that are not
seen in a sagittal section of the head.
Ethmoidal and maxillary
What is sinusitis?
Inflammation of a sinus. This can be
due to an infection, blocked sinus
opening (excess fluid in sinuses).
What important openings are found in
some of the meatuses?
Openings for the sinuses
What is the function of the
pharyngotympanic tube? What tonsil
is located here?
Connects the
pharynx to the middle ear.
Function: mucus drainage and
pressure equalisation. Tubal
tonsil.
What prevents food and fluid from
entering the larynx?
Downward
movement of the epiglottis, which
covers the opening of the larynx
What is the significance of the fact that the
human trachea is reinforced with cartilaginous
rings?
Prevents the collapse of the airways
. What is the significance of the fact that the
rings are incomplete posteriorly?
Allows the airways to expand. Remember
oesophagus is posterior to trachea.
Which primary bronchus (Right or Left)
more often traps a foreign object that has
entered the respiratory passageways and
why?
Right, because it is more vertical
What are the anatomical differences
between a bronchus and a bronchiole?
Cartilage differences: cartilage rings vs
cartilage plates/limited cartilage.
Epithelial differences: Pseudostratified columnar vs cuboidal and cilia + goblet
cells become sparse. Muscle differences: less smooth muscle vs more smooth
muscle.
- In the wet specimens, dark spots are visible within the spongy lung tissue. What are
they? What types of cells would trap this material?
Environmental pollutants e.g. car
exhaust, smoke, etc. Alveolar macrophages.
What is the difference between the parietal and visceral pleura?
Parietal lines the thoracic
cavity, diaphragm and mediastinum, visceral lines the lungs.
Where is the pleural cavity? What is its content and function?
Pleural fluid. Allows
free, unhindered movement of the lungs. The pressures between the pleural cavity
and lungs maintain the joining of the two pleural membranes.
Which nerve supplies the diaphragm? Can you locate it in the thorax?
The phrenic nerve. Yes, you can see it lateral to the heart piercing the dome of the
diaphragm.
. Is it possible to collapse a lung on one side without collapsing the one on the opposite
site and why?
Yes, because each lung is in its own pleural compartment.
What are the three cell types found in the alveoli? What are their functions?
Alveolar epithelial cells: Type I cells: squamous cells that line alveoli (1 layer),
through which gas exchange occurs (the most numerous cells)
Surfactant secreting cells: Type II cells: secrete alveolar fluid containing
surfactant that assists with lung expansion (less numerous)
Alveolar macrophages: wandering scavenger cells that remove inhaled
particles and other debris
-
’
Trachea
’
\
The elastic cartilage that shields the opening to the larynx during swallowing is the:
The epiglottis
Which respiratory structure has the smallest diameter?
Bronchiole
A. Diaphragm
B. Visceral pleura
C. Pulmonary artery
D. Pulmonary vein
E. Secondary bronchus
F. Bronchiole
What is the name of the membrane that lines the inner surface of the thoracic cavity?
Parietal pleura
Which tonsils are located in the nasopharynx?
Tubal and pharyngeal tonsils
A. Right primary bronchus
B. Right pulmonary artery
C. Right pulmonary vein
D. Right oblique fissure
E. Right inferior lobe
A. Right horizontal fissure
B. Right inferior lobe
C. Cardiac notch
D. Left oblique fissure
E. Lingula
F. Diaphragm
A. Trachea
B. Carina
C. Right middle lobe
D. hyoid
E. Thyrohyoid membrane
F. Thyroid cartilage
G.cricoid cartilage
H. Thyroid gland
I. Left primary bronchus
What cell type that is NOT found in the alveoli
Goblet cells
This region filters, moistens and warms the air entering the lungs
Pharynx
Which layers make up the respiratory membrane?
Alveolar epithelial cells, alveolar basement membrane, capillary basement membrane and capillary endothelial cells
Where is the main site of gas exhange?
In the alveoli
Which of the following events is characteristic of the inspiratory phase during normal quiet respiration?
diaphragm flattens
What is NOT a function of the conducting zone?
Gas exchange
