Human Respiratory Tract Flashcards
What are the two main parts of the respiratory tract?
the upper respiratory tract and the lower respiratory tract
What are the parts of the upper respiratory tract?
- nasal/oral cavity
- pharynx
- larynx
- trachea
What are the parts of the lower respiratory tract?
- bronchi
- bronchioles
- alveoli
What are the 3 main characteristics of the respiratory tract?
- it is wet with mucus
- it is hairy -> lined with cilia
- it is supported by cartilage
What is the purpose of mucus in the respiratory tract?
to trap foreign particles
What is the purpose of the cilia in the respiratory tract?
to move foreign particles out of the tract
What are the purposes of the the cartilage in the respiratory tract?
- they provide structure
- they are strong , and flexible connective tissues
- they prevent the tract from collapsing
What is the form of cartilage in the respiratory tract?
They are in the form of a ring
What are the main functions of the nasal cavity?
- cleans the air
- warms the air
- moistens the air
How does the nasal cavity clean the air?
The nostrils contain tiny hairs that clean the air
How does the nasal cavity warm the air?
epithelial cells and trubinate bones are lined with capilaries that warm the air
What are turbinate bones?
thin bony structures inside the nose, covered by soft tissue (mucosa)
- increases surface area
How does the nasal cavity moisten the air?
turbinate bones are lined with a thin membrane that secretes mucus to moisten the air
What does the increased surface area in the nose turbinate allow?
it allows air to reach more wamed, moist, surfaces which results in cleaner, warmer air reaching lungs
What part of the body houses the vocal cords?
the Larynx or voice box
How is sound produced?
via the passage of air through the cords, which causes them to vibrate producing sound
How is pitch controlled?
length of cords:
shortened cords = higher pitch
longer cords = lower pitch
Male vocal cords grow during puberty causing the voice to deepen
What is laryngitis
inflammation of vocal cords
What can laryngitis be caused by?
- infection (usually viral)
- smoking
- regurgitation of stomach acid during vomiting
- overuse
What are vocal cord nodules?
growth on the vocal cords
What are vocal cord nodules caused by?
constant straining of voice
How does the trachea main its rigidity?
the cartilage rings
what two types of cells make of the trachea lining?
- goblet cells
- epithelial cells
what do the goblet cells in the trachea do?
- produces mucus that traps foreign particles
what do the epithelial in the trachea cells do?
they are ciliated (have a bunch of small hairs) that brush mucus containing foreign particles upwards through the tract
What do sneezing and coughing do?
they help expel mucus as well as other inhaled particles
What is the structure of the trachea, and bronchi?
the traches branches into two bronchi, each one leads to a different lung
What is the beginning of the lower respiratory tract?
the bronchi
Bronchi are reinforced with cartilage
What is the structure of the general lungs
they are divided into lobes
What is the structure or the lobes in the right lung
there are 3 lobes
What is the structure of the lobes in the left lung
there are 2 lobes to accomodate the heart
What is the pleura?
flexible membrane that protects the lung.
What do the pleura do?
it allows the lung to expand and contract during breathing
What is the structure of the bronchi and bronchiole?
Bronchi branch into smaller tubes known as bronchioles
What are alveolus/alveoli
spherical hollow cavities (air sacs)
what is the purpose of the the alveoli?
to create a larger surface area for gas exchange
The alveoli are surounded by capillaries. The alveoli and capillaries have walls that are only a single cell layer think. Why?
this allows for rapid diffusion of gases
what does the lung surfactant do?
it helps lower surface tension in the airways keeping the alveoli open, it also defends against bacteria, viruses and other infectious agents with immune proteins
Where are the oxygen and carbon dioxide exchanged?
at the surface of the alveoli in the lungs and body cells
How are gases exchanged?
by diffusion along a concentration gradient
What is gas exchange in the lungs?
- carbon dioxide -
leaves the blood vessel into the alveolus - oxygen -
goes from alveolus into the blood vessel
What is external respiration?
The exchange of gasses between air and blood
Where does external respiration occur?
inside the lungs
What is internal respiration?
exchange of gasses between blood and the cells of the surrounding tissue
Where does internal respiration occur?
in the body tissues
What is the gas exchange in the internal respiration?
- the O2 diffuses from capillaries to tissue
- the CO2 diffuses from tissue to capillaries
Breathing definition
in inhalation and exhalation of air
What is inhalation/inspiration?
the act of taking air into the lungs
What is expiration or exhalation?
the act of removing air from the lungs
What are the two main muscles in the respiratory muscles?
the diaphagm and intercostal muscles
What is the diaphragm?
a dome shaped sheet of muscle that has separate and thoracic abdominal cavities
What are the intercostal muscles?
muscles of the ribcage.
What are the external intercostals and what do they do?
they are on the outer surface and they pull the ribs up
What are the internal intercostals and what do they do?
They are on the inner surface and pull ribs down
What are the mechanics of breathing in relation to the inhalation?
- diaphragm contracts and flattens downward
- external intercostals contract
- internal intercostals relax
- ribcage moves up and outward
- lung volume increases
inhalation/inspiration
What are the mecahnics of breathing in relation to the exhalation?
- diaphargm relaxes and returns to dome shape upward
- external intercostals relax
- internal intercostals contract
- ribcage moves downward
- lung volume decreases
- exhalation/expiration
How does the control of breathing work? (the brain)
- inspiration: respiratory center in brain stem sends signal that causes the diaphragm and intercostal muscles to contract
- feedback: stretch receptors in lungs send signals to brain indicating lungs have expanded
- expiration: brain stops signaling muscles causing them to relax
What kind of control is breathing under?
involuntary (autonomic). But signals can be overriden consiously to control breathing
What are examples of consiously holding breath?
- talking
- singing
- holding breath
What is the frequency of ventilation?
the number of breaths in a given amount of time
What is the normal number of breaths per minute?
16-20
An increase in cellular activity will….
increase cellular respiration, which leads to more CO2 being produced
- the CO2 forms carbonic acid in the blood -> lowers blood pH
- receptors in brain recognize pH decrease, which sends signals to diaphargm and intercostal muscles to contract more rapidly and forcefully and increases heartrate.
- results in increased breathing rate and volume of inhalation
Is the full lung capacity used up during normal breathing?
no
How can the volume of air in the lung be changed?
- yawning
- blowing out a candle
- exercising
What is a spirometer used for?
to measure the amount of air expired by the lungs
What is the tidal volume in lungs?
the volume of air inhaled and exhaled in a normal breath
What is the inspiratory reserve volume in lungs?
the additional volume of air that can be taken in, beyong a regular tidal inhalation.
inspiratory capacity = total volume of air that can be taken in
What is the expiratory reserve volume?
the additional volume of air that can be forced out of the lungs beyond a regular or tidal exhalation
What is the vital capacity in relation to lung capacities?
the total volume of gas that can be moved in or out of the lungs
What is the residual volume in relation to lung capacities
the amount of air that remains in the lungs and passageways of the respiratory tract even after full exhalation. This volume never leaces the lungs and prevents collapse of the respiratory tract
What is total lung capacity?
all the air that can exist in the lungs and respiratory tract
What are factors that affect the lung capacities?
- sex
- height
- smoking history
- fitness/athleticism
- altitude
Which has a smaller lung volume? people living at low altitudes or high altitudes
low altitudes
What is hypoxia?
altitude sickness
How does altitude sickness occur?
- air at higher altitudes has less pressure - less partial pressure of oxygen. The body is unable to adapt to the new conditions
What is an immediate short term adaptation to altitude sickness?
increased breathing and heart rate to increase oxygen intake and transport
What are long term adaptations to altitude sickness?
an increase in lung volume and red blood cell counts
What are the symptoms of altitude sickness?
headache, fatigue, dizziness, nausea, vomiting, shortness of breath
What is bends?
decompression sickness
What is decompression sickness?
when dissolved gases come out of solution in the body
What happens in the body during decompression sickness?
forms bubbles in tissue and bloodstream
what is the cause of decompression sickness?
rapid change in pressure from a higher pressure at deep underwater to lower pressure at the surface when a diver ascend too quickly
