respiratory system (282-286)
DESCRIPTION
Respiratory System (282-286). Process that provides oxygen to tissue cells and removes carbon dioxide from the body Two requirements for respiration Surface area must be large for quick exchange of O2 and CO2 to meet body’s need Moist environment because O2 and CO2 are dissolved in water. - PowerPoint PPT PresentationTRANSCRIPT
Respiratory System (282-286)Process that provides oxygen to tissue
cells and removes carbon dioxide from the body
Two requirements for respiration1. Surface area must be large for quick
exchange of O2 and CO2 to meet body’s need
2. Moist environment because O2 and CO2 are dissolved in water
Respiratory TractExtends from nose to lungsPassageway for air & site for gas exchangeLined with mucous producing and ciliated
cells to capture foreign particles 2 parts: 1. Upper Respiratory Tract2. Lower Respiratory Tract
Pathway of the Respiratory system
AIR TRAVELS on two way pathwayUpper
In mouth & nose where it’s humidified, warmed and large foreign particles removed
Passes pharynx and flap like structure epiglottis (intersection of digestive and respiratory)
Past the larynx (voice box) down cartilage lined trachea towards the lungs
Lower Into either lung through the bronchi Then into bronchioles (smaller branch) for gas
exchange in alveoli which inflate and deflate with air movement
Stages of Respiration
Breathing •air enters and leaves lungs
External respiration •in lungs•between air and blood
Cellular respiration •takes place in cells•production of ATP
Internal respiration•within body •between blood and tissue fluids
Principle StructuresAdd the structures of the respiratory
system to Human Systems Hal (pg 283)
Respiration: Let’s get specific
Outcome: Explain the exchange of matter between the body and environment in gas
exchange
Breathing movements (pg 285)
Note: - Lungs and chest cavity are attached to
each other but don’t rub because pleural membrane between surfaces
- AIR will always move HIGH to LOW pressure
- Smaller the container the more pressure, larger the container the less pressure
Breathing in /InhalationDiaphragm muscle told to contract by
brain (moves down)Intercostal muscles between the ribs told
to contract (move up and out)Opens up chest cavity and lungs
decreasing air pressure therefore sucking air in
Breathing in/InhalationAir moves into the lungs.
Intercostal muscles contract; rib cage moves upward.
Diaphragm contracts and moves downward.
Pressure in the chest cavity is lower than the atmospheric pressure, air moves into the lungs.
Breathing out /ExhalationDiaphragm muscle relax (back up) Intercostals muscles relax (back down and
in)Closes chest cavity and lungs increasing
air pressure therefore pushing air out
Breathing out/ExhalationAir moves out of the lungs.
Intercostal muscles relax; rib cage falls.
Diaphragm relaxes and moves upward.
Pressure in the chest cavity is higher than the atmospheric pressure, air moves out of the lungs.
Respiratory VolumeUnder normal circumstances regular
breathing doesn’t use full capacity of lungs
Spirometer/respirometer- tool used to measure lung capacity
Spirograph-visual representation
Respiratory VolumeTidal volume-volume of air that is inhaled &
exhaled in normal breathing movementInspiratory reserve volume-additional volume
of air that can be taken into lungs beyond tidal volume
Expiratory reserve volume-additional volume of air that is forced out of lungs beyond tidal volume
Vital capacity(Total lung volume)=total volume of gas that can be moved into or out of the lungs Vital Capacity= Tidal volume + Inspiratory volume + Expiratory volume
Gas Exchange (pg 288)Air diffuses from high to low pressureO2 moves from alveoli to cellsCO2 moves from cells to alveoli
Alveoli
Capillary/Blood
CO2
O2
Capillary/Blood
Cell
CO2
O2
Alveoli (pg283)0.1 and 0.2 um in diameter, Single layer of
cells thick 150 million alveoli in 1 lung (enough
surface area to cover half a tennis court)Surrounded by capillaries (thin walled
vessels connecting body systems to the circulation system)
Oxygen Exchange Diffuses from alveoli to blood to cell
Hemoglobin Red colored respiratory pigment in blood that assists in
carrying oxygen Each red blood cell contains 250 million hemoglobin
Oxygen concentration is low in cellsBlood oxygen levels are high (97%
saturated when leaving lungs)
Carbon Dioxide Exchange
Diffuses from cell to blood to alveoliCarbon dioxide concentration is high in
cellsBlood carbon dioxide levels are lowWater and carbon dioxide form
bicarbonate further decreasing amount of CO2 in blood
Regulation of Breathing Movements (292)
Breathing is involuntary action controlled by nerves of medulla oblongata in brain
Specialized nerve receptors sensitive to specific chemicals (Chemoreceptor) sense accumulation of CO2, acids and need for O2
Carbon Dioxide control
CO2 chemoreceptor most sensitive and main regulators of breathing
Acid builds up if there is an accumulation of CO2 in the blood (Bicarbonate ions and hydrogen ions form carbonic acid)
Receptors pick up on accumulation and send message to brain
Brain sends message to diaphragm and rib muscles to contract
Breathing will occur/increase If irregular breathing is occurring breathing will
increase until the CO2 levels fall
Carbon Dioxide control
Body cells use oxygen tobreak down organic molecules. CO2 levels rise in the cell and CO2 diffuses into the blood
Chemoreceptors in the medulla oblongata detect high levels of CO2. A nerve impulse is sent to the intercostal muscles and diaphragm to increase breathing movements.
CO2 is expelled faster when breathing movements increase.
negative feedback
Oxygen control O2 chemoreceptor less sensitive
considered "back up” receptors in carotid and aortic arteries of heart sense
low O2 levels in blood Send message to brain Brain sends message ribs and diaphragm they contract breathing will occur or increase Situations where there is low O2 in air (high altitudes)
or carbon monoxide poisoning
Respiratory Disorders
Decrease oxygen delivery to the tissuesUpper Respiratory Tract infections
Caused by virus or bacteria E.g. Tonsillitis, Laryngitis
Lower Respiratory Tract Disorders Caused by infections, obstructive pulmonary
disorder (OPD), lung cancer E.g. Bronchitis, Pneumonia, Pleurisy, Emphysema,
lung cancer