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