Transcript Respiratory System - Elmwood Park Memorial High School

Respiratory
System
Respiratory Function
• What do cells need to carry out their vital functions?
• Oxygen!
• As cells use oxygen they give off carbon dioxide as a
waste product.
• The respiratory system organs oversee the gas
exchanges that occur between the blood and the
external environment.
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Respiratory Organs
Nose
Pharynx
Larynx
Trachea
Bronchi
All serve as conducting passageways that allow air to
be purified, humidified, and warmed as the reach the
lungs
• The lungs contain tiny air sacs called alveoli where gas
exchanges with the blood occur.
Nose
• Also called nasal cavity
• Interior is lined with the respiratory mucosa and a
network of thin walled veins that warm the air as it flows
past.
• The sticky mucus also traps incoming bacteria and debris
and moistens the air.
• The ciliated cells of the mucosa move contaminated
mucus toward the throat for digestion.
Nose
• Conchae- located on lateral walls of nose
– Increase the surface area exposed to air
• The nasal cavity is separated from the oral
cavity by the hard and soft palates.
Pharynx
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Aka the throat
Muscular passageway
Food and air both pass through the pharynx.
Food is directed to the esophagus when the
epiglottis closes.
• Air is allowed through the epiglottis into the larynx.
Larynx
• Voicebox
• Formed by 8 rigid hyaline cartilages and the spoon
shaped flap of elastic cartilage called the epiglottis.
• Thyroid cartilage- largest- Adam’s apple
• When we swallow the larynx is pulled upward and
epiglottis tips, forming a lid over the larynx.
• Place your hand midway on the anterior
surface of your neck.
• Swallow.
• Can you feel the larynx rising as you swallow?
Trachea and Bronchi
• The trachea is also called the windpipe.
• It is lined with ciliated mucosa that beat
continuously in a direction opposite to the
incoming air.
• The right and left bronchi are formed by the
division of the trachea and enter the medial
depression of the lung.
Lungs
• The surface of each lung is covered with visceral
serosa called the pulmonary or visceral pleura.
• The thoracic cavity is lined with the parietal pleura
• These two layers cling tightly to one another while
still allowing smooth sliding of the lungs across the
thorax during breathing.
Lungs
• After the bronchi enter the lungs they subdivide
into smaller and smaller branches until they
become bronchioles.
• The terminal bronchioles lead to the respiratory
zone structures
• Respiratory zone structures eventually terminate
in the alveoli, or air sacs that serve as the site of
air exchange.
Respiratory Zone
Respiratory Membrane
• The external surfaces of the alveoli are
covered in a cobweb of pulmonary capillaries.
• Together these two structures make up the
respiratory membrane (air-blood barrier)
Respiratory Membrane
Tuesday 5/7/13
• Do Now:
• What is tidal lung volume?
• What is vital lung capacity?
Respiratory Physiology
• There are 4 distinct events collectively called
respiration.
1. Pulmonary Ventilation (breathing)- air must
move in and out of the lungs so that the gases in
the air sacs of the lungs are continuously
changed and refreshed.
Respiratory Physiology
2. External Respiration – gas exchange
between the pulmonary blood and
alveoli must take place
Respiratory Physiology
3. Respiratory Gas Exchange – oxygen
and carbon dioxide must be
transported to and from the lungs and
tissue cells of the body via the blood
stream.
Respiratory Physiology
4. Internal Gas Exchange – gas
exchange at the systemic capillaries
between the blood and tissue cells.
Mechanism of Breathing
• Volume changes lead to pressure changes
which lead to the flow of gases to equalize the
pressure.
• Inspiration: air flowing into the lungs
• Expiration: air leaving the lungs.
Mechanism of Breathing
• Atmospheric Pressure- pressure outside the
body
• Intrapulmonary Pressure – Pressure inside the
lungs
• Intrapleural Pressure – Pressure within the
Pleural space. (must always be less than the
atmospheric pressure or else the lungs will
collapse)
Gas Exchange
• always a higher concentration of oxygen in the
alveoli than in the blood
• oxygen moves from the alveoli, through the
respiratory membrane into the more oxygen
poor blood of the pulmonary capillaries.
Gas Exchange
• As tissue cells remove oxygen from the blood,
they release carbon dioxide into the blood.
• Because the concentration of carbon dioxide
is much higher in the pulmonary capillaries
than in the alveolar air, it will move from the
blood into the alveoli and be flushed out of
the lung on expiration.
Wednesday 5/8/13
• Do Now:
• Describe pulmonary ventilation
Objectives
• Control of Respiration
• Factors that influence the respiratory
system:
– Physical factors
– Volition (conscious control)
– Emotional Factors
– Chemical Factors
Neural Regulation: Setting the Basic
Rhythm
• Phrenic and intercostal nerves transmit impulses to
control the activity of respiratory muscles, diaphragm, and
external intercostals.
• Medulla- sets basic rhythm for breathing.
• Pons- smooth out the basic rhythm of inspiration and
expiration set by the medulla.
• Impulses going back and forth between the pons and
medulla maintain a rate of 12-15 respirations/minute.
– eupnea
Neural Regulation: Setting the Basic
Rhythm
• Bronchioles and alveoli have stretch receptors
that respond to extreme over inflation.
• Hyperpnea- more impulses sent to respiratory
muscles
Physical Factors
• Talking, coughing, exercising
• Increased body temperature causes an
increase in the rate of breathing.
Volition (Conscious Control)
• During singing and swallowing breath control is
important.
• Hold our breath to swim underwater.
• Voluntary control is limited
• Respiratory system will ignore messages from the
cortex(wishes) if pH is falling or oxygen supply in
blood is getting low.
Volition (Conscious Control)
• Try to run at your fastest speed and then hold
your breath- it is impossible
Emotional Factors
• Watching a horror movie and holding your
breath
• Watched a horror movie and got so scared
that you start panting
Chemical Factors
• ***most important*** levels of carbon
dioxide and oxygen in the blood
• Increased carbon dioxide or decreased blood
pH are the most important stimuli leading to
an increase in respiratory rate.
Chemical Factors
• Changes in carbon dioxide concentrations in the
blood act directly on the medulla centers.
• Changes in oxygen concentration detected by aorta
and carotid arteries
• Although oxygen is important- it is the body’s need
to rid itself of carbon dioxide
Thursday 5/9/13
• Do Now: How can emotional
factors affect respiratory rate
and depth?
Objectives
• Respiratory Disorders
–Chronic Obstructive Pulmonary Disease
(COPD)
• Emphysema
• Chronic bronchitis
• Lung cancer
Respiratory Disorders
• Respiratory system is vulnerable to infections
because it is open to airborne pathogens.
• COPD- Chronic Obstructive Pulmonary Disease
• Lung cancer
• Living proof of cigarette smoking’s devastating
effects on the body.
COPD
• Examples: chronic bronchitis and emphysema
• Major cause of death in the United States
• Common features (emphysema and chronic
bronchitis)
– 1. patients almost always have a history of
smoking
– 2. dyspnea- difficulty breathing- occurs and
becomes more progressively severe
– 3. coughing and frequent pulmonary infections
– 4. hypoxic, retain carbon dioxide, and have
respiratory acidosis
Emphysema
• Alveoli enlarge- walls of adjacent chambers
break through- chronic inflammation
promotes fibrosis of the lungs.
• Lungs become less elastic
• Airways collapse
Emphysema
• These patients use a lot of energy to exhale
and are always exhausted.
• Oxygen exchange is surprisingly efficient
because air is trapped in the lungs.
• People who suffer from the disease – “pink
puffers” - overinflation of the lungs leads to
an expanded barrel chest.
Chronic Bronchitis
• Mucosa of the lower respiratory passages
becomes severely inflamed and produces
excessive amounts of mucus.
• Mucus pulls and impairs ventilation and gas
exchange.
• “Blue bloaters”- hypoxia and carbon dioxide
retention occur early in the disease and cyanosis
is common