Transcript Carbonic anhydrase

Respiratory System
Organs
Control of Respiration
Homeostasis
Path of Air through the Respiratory System
nasal cavity
pharynx
nose
mouth
larynx
trachea
glottis
bronchus
(pl: bronchi)
bronchiole
lung
Made of alveoli
(air sacs)
Functions of Respiratory Tract Organs
• Nasal Cavities: warm, moisten and filter air
• Larynx: vocal cords produce sound
• Trachea (windpipe): permits passage of air,
ciliated cells move mucus and debris
toward pharynx
• Bronchial Tree: bronchi and bronchioles
permit passage of air
vocal
cords
• Lungs: gas exchange
glottis
Applying Your Knowledge
1.
2.
3.
4.
5.
A.
B.
C.
D.
Pharynx
Lung
Larynx
Bronchus
Bronchiole
Where are the vocal cords located?
Which leads to an alveolus?
Where does gas exchange take place?
Which is shared between the respiratory and
digestive systems?
Gas Exchange in Lungs: External Respiration
Carries
deoxygenated
blood from heart
Returns
oxygenated
blood to heart
Sites of gas
exchange
Exchange occurs between air in the alveolus
and blood in the surrounding capillaries:
Oxygen from alveolus enters bloodstream,
Carbon dioxide from blood enters alveolus
Action of intercostal
muscles between ribs
Dome-shaped
muscle
below lungs
Ventilation: Inspiration and Expiration
Control of Ventilation
• Respiratory Center in Brain
stimulates rhythmic inspiration,
responding to levels of carbon
dioxide and hydrogen ions
• Chemoreceptors in arteries send
signals to respiratory center in
response to changing oxygen levels
Diffusion Controls Gas Exchanges in the Body
• External Respiration
– gas exchange between air in alveoli and blood
in pulmonary capillaries
– pO2 is higher in air, pCO2 is higher in blood
– O2 diffuses into blood, CO2 diffuses into lung air
• Internal Respiration
– gas exchange between blood in systemic
capillaries and tissue fluid
– pO2 is higher in blood, pCO2 is higher in tissues
– O2 diffuses into tissues, CO2 diffuses into blood
Specialized Components
• Carbonic Anhydrase: enzyme involved in release of
carbon dioxide
• Hemoglobin: oxygen-carrying molecule on surface
of red blood cells
• Surfactant: layer of lipoprotein that lowers surface
tension and prevents alveoli from closing
Tissue Structure
• Trachea:
pseudostratified
ciliated columnar
epithelium
• Alveoli: simple
squamous
epithelium
Homeostasis
• Gas Exchange
– oxygen is needed for energy release through
cellular respiration
• Regulation of Blood pH
– When CO2 is released by tissues, levels of H+
increase and pH is lowered
– When CO2 is released from lungs, H+ has
been used to produce water, increasing pH to
neutral level (7.4)
Carbonic anhydrase
hydrogen ion
water
carbon
dioxide
carbonic
acid
bicarbonate
ion
Bicarbonate Buffering System of Blood
Applying Your Knowledge
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5.
Tissue Fluid
Hemoglobin
Carbonic Anhydrase
Blood
Alveolus
1.
2.
3.
4.
5.
Surfactant
Diaphragm
Columnar Epithelium
Intercostal Muscle
Squamous Epithelium
A. Which enzyme assists in controlling blood
pH? (Choices on left)
B. For internal respiration, where is pCO2
greater? (Choices on left)
C. Which one represents a muscle located
below the lungs? (Choices on right)