2008-2009
Respiratory System

• 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

• Reactants Products
• C
6
H
12
O
6
+ 6O
2

6CO
2
+ 6H
2
O + 36ATP
• Oxygen goes in, Carbon dioxide comes out – how?
• Gas exchange: process by which gases diffuse between an organism and the external environment

• Gas Exchange:
• Need O
2 in
– for cellular respiration
• Need CO
2 and water out
– waste product food
O
2
CO
2
ATP

• 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
O
2
O
2
– Large surface area
O
2
O
2
O
2

• 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

2
• Gills are gas exchange membranes outside of the body
– thin tissue water
• high surface area
• must stay wet
– lots of blood vessels
Just keep swimming…
– gas exchange
• O
2 into blood
• CO
2 out to water gills http://www.youtube.com/watch?v=XEIRlw5rCUk

• 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

 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

• 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

• Trachea (windpipe)
– tube made of ring shaped cartilage
– Connects pharynx with bronchi
– cilia and mucus trap particles

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) http://www.youtube.com/watch?v=sU_8juD3YzQ&feature=player_embedded# !

• 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 !

• Inhale
– O
2 diffuses from alveoli to blood
• Exhale
– CO
2 and water diffuses from blood to alveoli capillaries
(circulatory system) http://www.youtube.com/watch?v=DoSTehS7iq8&feature=player_emb edded# !

• 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

• Air moves from high  low pressure
• Diaphragm muscle that moves down & expands chest cavity pulls air into lungs http://www.youtube.com/watch?v=hp-gCvW8PRY inhale exhale

• You don’t have to think to breathe!
• Brain coordinates breathing
– Measure CO
2
• 
CO
2
= increase breathing
– coordinate breathing, heart rate & body’s need for energy

• Homeostasis
– keeping the internal environment of the body balanced
– need to balance O
2 in and CO
2 out
– need to balance energy (ATP) production
• Exercise
– breathe faster
• need more ATP
• bring in more O
2
• Disease
& remove more CO
2
O
– poor lung or heart function = breathe faster
• need to work harder to bring in O
2
& remove CO
2
2
ATP
CO
2


Airways narrow, swell and produce extra mucus

Difficulty breathing, shortness of breath, coughing

Environmental & genetic

Triggered by exercise, allergens, cold, pollutants


Deadliest type of cancer

Abnormal growth of cells in lungs

Leading cause: Cigarette smoke

Chest pain, blood, coughing, wheezing

• Inflamed bronchial passages
– Coughing, phlegm, breathlessness
– Chronic or acute
– Viral or bacterial
Emphysema

Overtime alveoli become destroyed

Less surface area

Less oxygen delivered

Smoking


How does your respiratory system maintain homeostasis when there is less O
2

Exercise, high altitudes, disease available?
http://www.youtube.com/watch?v=YC9sBo1W
HXA

• 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