AP Biology 2008-2009

Respiratory System

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Respiration vs. Cellular Respiration

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Science in the News http://www.youtube.com/watch?v=cYAY

wujKvH4

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Respiration Review

What do we already know about respiration?

Cellular Respiration: the process by which an organism obtains energy by reacting oxygen with glucose to give water, carbon dioxide and ATP (energy)

Types of respiration: aerobic and anaerobic

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Aerobic Cellular Respiration

Reactants Products C6H12O6 + 6O2 6CO2 + 6H2O + 36ATP Oxygen goes in, Carbon dioxide comes out –

how? Gas exchange: process by which gases diffuse

between an organism and the external environment

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Why do we need a respiratory system? Gas Exchange: Need O2 in

for cellular respiration

Need CO2 and water out waste product

O2

food

ATP

CO2

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The Respiratory Surface The surface in which gas exchange

takes place Thin-walled Moist In contact with surrounding oxygen In contact with a transport system Based on diffusion Large surface area

O2

O2

O2 O2

O2

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Simple Organisms: Gas Exchange

Protists and Cnidarians: Gases diffuse through cell membranes

Annelida: Skin kept moist by mucous to facilitate gas diffusion into and out of blood

Grasshoppers: Gas enters spiracles in the abdomen and contacts body cells through branching tubes called tracheae

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Gills: getting O2 from water Gills are gas exchange

membranes outside of the body thin tissue

high surface area must stay wet

lots of blood vessels gas exchange

O2 into blood

CO2 out to water

gills

water

Just keepswimming…

http://www.youtube.com/watch?v=XEIRlw5rCUk

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Human Respiratory System

A system of passageways that connects the lungs to the outside air.

Permits air to permeate the lungs and waste gases to leave

Function: A moist internal membrane maintained for the exchange of gases between the body and the external environment

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Lungs gas exchange organ

trachea bronchi bronchiole tubes bronchioles alveoli

enclosed in pleura Layered membrane with lubricating fluid

Separated from abdominal cavity by diaphragm Muscle on at bottom of chest cavity

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Pathway of Air Inhalation

Nasal passages Hairs filter the air Mucus moistens the air Capillaries warm the air

Pharynx (throat) Back of oral cavity where it

joins nasal cavity Air passes to go to trachea Epiglottis covers opening to

trachea Larynx

Voice box made of cartilage Vocal chords produce sound

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Pathway of Air Trachea (windpipe)

tube made of ring shaped cartilage

Connects pharynx with bronchi cilia and mucus trap particles

http://www.youtube.com/watch?v=sU_8juD3YzQ&feature=player_embedded#!

Bronchi (right and left) Two cartilage ribbed tubes Enter each lung Lined with cilia Branch further into bronchial

tubes & bronchioles Highly branched microscopic

tubules (no cartilage)

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Pathway of Air Alveoli

Tiny air chambers at end of each bronchiole

Respiratory surface 1 cell thick Thin Moist Many capillaries High surface area

About 300 million alveoli in

your lungs!

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Moving gases into bloodstream

Inhale O2 diffuses from

alveoli to blood

Exhale CO2 and water

diffuses from blood to alveoli

capillaries(circulatory system)

http://www.youtube.com/watch?v=DoSTehS7iq8&feature=player_embedded#

!

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Gas exchange: Diffusion of gases Gases move by diffusion from high to low

concentration capillaries are thin-walled tubes of circulatory

system alveoli are thin-walled sacs of respiratory

system

blood lungs

CO2

O2

CO2

O2

blood body

CO2

O2

CO2

O2

capillaries in lungs capillaries in muscle

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Respiratory System

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What is breathing? Breathing: the act of inhalation and

exhalation, during which gas exchange occurs

Requires the movement of the ribcage and the diaphragm

Diaphragm: muscular layer separating the chest cavity and the abdominal cavity

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Negative pressure breathing

Air moves from high low pressure Diaphragm muscle that moves down & expands

chest cavity pulls air into lungs

inhale exhale

http://www.youtube.com/watch?v=hp-gCvW8PRY

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Automatic Brain Control You don’t have to think to breathe! Brain coordinates

breathing Measure CO2

CO2 = increase breathing

coordinate breathing, heart rate & body’s need for energy

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Breathing and Homeostasis Homeostasis

keeping the internal environment of the body balanced

need to balance O2 in and CO2 out need to balance energy (ATP) production

Exercise breathe faster

need more ATP bring in more O2 & remove more CO2

Disease poor lung or heart function = breathe faster

need to work harder to bring in O2 & remove CO2

O2

ATP

CO2

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Asthma Airways narrow, swell and produce extra

mucus Difficulty breathing, shortness of breath, coughing Environmental & genetic Triggered by exercise, allergens, cold, pollutants

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Lung Cancer Deadliest type of cancer Abnormal growth of cells in lungs

Leading cause: Cigarette smoke Chest pain, blood, coughing, wheezing

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Bronchitis Inflamed bronchial

passages Coughing, phlegm,

breathlessness Chronic or acute Viral or bacterial

Overtime alveoli become destroyed Less surface area Less oxygen

delivered Smoking

Emphysema

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Respiration & Homeostasis How does your respiratory system maintain

homeostasis when there is less O2 available? Exercise, high altitudes, disease

http://www.youtube.com/watch?v=YC9sBo1WHXA

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Gas Exchange in Plants

Plants exchange gases through stomates on the surface of the leaf

Open stomates permit the transport of oxygen and water vapor out of the plant

Lenticels on stems permit gas exchange