respiratory system Flashcards
What is respiration?
It refers to all parts of the process that supplies oxygen to body cells and rids the body of carbon dioxide.
The upper respiratory tract
This includes the: nasal/ oral passageway, pharynx, glottis, larynx, and trachea.
Nostrils or Mouth?
In the nostrils, bones called “turbinates” increase the surface area of air passing. The epithelial lining of the nasal chamber and the turbinate bones are well supplied with capillaries which serve to warm incoming air and increase its relative humidity. It is better to breathe through the nose because air is filtered from tiny hairs called “cilia” and it is also warmed.
Pharynx, glottis, epiglottis
P:alimentary canal that connects the mouth and nasal cavity to the larynx and esophagus.
G:the opening of the trachea which conducts air to the lungs.
E:a flap like structure that helps prevent food from entering the trachea thereby protecting the glottis.
The larynx
“voice box” – houses the two folded structure of the vocal cords which are held securely in place by cartilaginous material.
When breathing normally, there is a large gap between the two cords. When you prepare to speak, muscles around the larynx contract, bringing the cords closer together. The passage of air through this narrower space causes the cords to vibrate producing a sound. A long cord produces a low sound, while a shorter cord produces a higher sound. At puberty, the vocal cords of males grow quickly producing a “breaking” quality in the voice until the vocal cords finish growing.
Trachea
“windpipe”
*Supported by semicircular cartilage rings so there is no collapsing
or interference with the passage of food down the esophagus
(parallel structure carrying food into stomach).
The lower respiratory tract
This includes the bronchi, bronchioles and alveoli in the lungs
Bronchi, bronchioles, alveoli
Bronchi: Two smaller branches that come off of the trachea and enter
into the lungs (left and right).
They are lined with ciliated mucus membrane.
Bronchioles: A network of finer tubes that is subdivided from the bronchi
and that also have ciliated mucous membrane. They branch into
the alveoli.
Alveoli:Grape like cluster of tiny sacs which are always moist.
*The wall of the sac is one cell thick and is adjacent to a network
of tiny capillaries which are the site for the exchange of
oxygen and carbon dioxide.
The bronchioles and alveoli are kept together by elastic
connective tissue.
Mechanics of breathing
*Breathing relies on the principle of air flowing from a region
of higher pressure to a region of lower pressure.
Lobes, Pleura, Pleurisy
L:Each lung is divided into lobes (3 lobes on right side and 2 lobes on left
side – to accommodate space for the heart)
Pleura:Two layered membrane that protects and lubricates the lungs.
Pleurisy:When the pleura becomes inflamed, a secondary infection can happen
(i.e. pneumonia). It can be painful and require prompt medical attention.
Two muscles used to control air pressure inside your
lungs
1) Intercostal muscles (found between ribs)
2) Diaphragm
Air flow
Remember that air flows from a region of higher pressure to a region
of lower pressure.
pressure vs Volume In Inhalation
- Air pressure within lungs is lower than air pressure in external environment
- volume of air in lungs increases
Diaphragm
A strong wall of muscle that separates the chest cavity
from the abdominal cavity.
By the diaphragm moving downward, it contracts, and air
enters the lungs (inspiration).
If the diaphragm moves upwards, it relaxes, and air leaves
the lungs (expiration)
Spirometry
Is the most common type of pulmonary function or breathing test - this test measures how much air you can breathe in and out of your lungs as well as how easily and fast you can blow the air out of your lungs
Diffusion
Movemnt of air with concentration (high to low)
Differences of lung volumes amongst individuals
Men have larger
Women and children have smaller
Smoker has smaller vs non smoker
Athlete has more vs non athlete
Elders have smaller vs young adults
Autonomic Nervous System Sympathetic (Refer to picture)
Sympathetic
“fight or flight responses”
Increases speed heart rate, saliva flow, and perspiration
Speeds up
Autonomic Nervous System Parasympathetic (Refer to picture)
Parasympathetic
Counters the effects caused in moments of stress/stimulus
slows heart rate, dilates blood vessels, and relaxes involuntary smooth muscle fibres
Slows down
The Control of Breathing
- muscles need oxygen and the lack of oxygen will lead to an
increased breathing rate.
The presence of Carbon Dioxide plays
a main role in controlling the
breathing response.
