Respiration

1
Respiration

• Starr/Taggarts
• Biology
• The Unity and Diversity of Life, 9e
• Chapter 41

2
Key Concepts

• Multicelled animals require the most energy to
  drive metabolic activities
• Aerobic respiration produces the most ATP
• Respiration provides oxygen and moves out carbon
  dioxide from the internal environment

3
Key Concepts

• Oxygen diffuses into the body due to pressure
  gradients
• Carbon dioxide diffuses from cells to air down a
  gradient
• Gas exchange occurs in a respiratory membrane and
  at the cellular/tissue level
• When air flow and rate of blood flow match, gas
  exchange is most efficient

4
Basis of Gas Exchange

• Concentration gradient
• Pressure gradient
• Atmospheric pressure
• 78 Nitrogen
• 21 Oxygen
• 0.04 CO2
• 0.96 gases

• Partial pressure of a gas
• Ficks Law

5
Factors Influencing Gas Exchange

• Surface-to-volume ratio
• Ventilation
• Gills in fish
• Circulatory system in vertebrates
• Transport pigments
• Hemoglobin (Hb)

6
Invertebrate Respiration

• Integumentary exchange
• Diffusion across body surface
• Gills
• Aquatic organisms
• Increased surface area
• Tracheal respiration
• Internal tubes and spiracles
• Insects

7
Gills and Tracheal Systems
8
Gills - Fishes and Amphibians

• Countercurrent flow
• Gill filaments
• Vascularized
• Gas exchange

9
Lungs

• Paired sacs
• Lung Fish
• Frogs
• Lungs and Integumentary exchange

10
Bird Respiratory System

• Air sacs attached to each of 2 lungs
• Supports high metabolic rates

11
Sound

• Produced as air is forced out
• Vocal cords
• Vibrations
• Amplitude
• Glottis
• Paired lungs are means of respiration in
  reptiles, birds, and mammals

12
Human Respiratory System
13
Human Respiration

• Alveolus
• Air sacs
• Vascularized
• Functions
• pH balance
• Gas exchange
• Diffusion

14
glottis (open)
VOCAL CORDS
glottis (closed)
epiglottis
cartilage
base of tongue
15
Sites of Gas Exchange in the Lungs

• Lungs in rib cage
• Diaphragm
• Contractions
• Increase/decrease in volume
• Pleural membrane
• Lines lungs and thorax
• Bronchial tree
• Bronchioles, respiratory bronchioles, alveoli

16
The Respiratory Cycle

• Inhalation
• Active
• Contraction of diaphragm
• Pressure gradient
• Increase in volume, decrease in pressure
• Negative intrapleural pressure
• Exhalation
• Diaphragm relaxes
• Volume decreases, pressure increases

17
INWARD BULK FLOW OF AIR
OUTWARD BULK FLOW OF AIR
18
The Respiratory Cycle and Pressure Changes
19
Lung Volumes

• 5.7 L in males
• 4.2 L in females
• Vital capacity
• Tidal volume
• Normal breath
• 500 ml
• Residual volume
• Forced volumes

20
Gas Exchange and Transport

• Respiratory surface
• Epithelium of alveoli
• Endothelium of capillary
• 98.5 of oxygen bound to hemoglobin
• Oxyhemoglobin
• Binding and release of oxygen
• Temperature
• pH
• Partial pressures

21
Carbon Dioxide Transport

• 10 dissolved in blood
• 30 bound to Hb
• Carbaminohemoglobin
• 60 as bicarbonate HCO3-
• In red blood cells (Buffer)

Carbonic anhydrase
CO2 H2O H2CO3
HCO3- H
22
Air Flow and Blood Flow

• Medulla oblongata
• Rhythmic breathing
• Pons
• Apneustic center
• Prolongs inhalation
• Pneumotaxic center
• Curtails inhalation

23
Control of Breathing

• H concentration
• CO2 levels - most critical
• Chemoreceptors
• CSF
• Aortic bodies
• Carotid bodies

24
foreign mass lodged in trachea
base of rib cage
fist of rescuer
navel
25
Diseases and Conditions

• Bronchitis
• Pneumonia
• Emphysema
• Alveoli break down
• Cigarettes, marijuana
• Second-hand smoke

• Lung cancer
• Cystic fibrosis
• Carbon Monoxide poisoning
• Nitrogen narcosis
• Decompression sickness

26
Normal Lungs
Lungs with Emphysema
27
Breathing at High Altitudes

• Hypoxia
• Acclimatization
• Breathing and cardiac output changes
• Erythropoietin
• Stimulates erythrocyte production

28
Respiration in Diving Mammals

• Hb and Myoglobin
• Short dives
• Aerobic respiration
• Long dives
• Heart and CNS get most of blood
• Respiratory adaptations
• Valves, storage, plexuses of blood vessels

29
In Conclusion

• Aerobic respiration provides the most energy for
  active animals
• Respiration is the process by which oxygen is
  acquired and carbon dioxide is disposed of
• Air is a mixture of gases each exerting a partial
  pressure

30
In Conclusion

• O2 and CO2 diffuse across a respiratory surface
• Modes of respiration differ among animal groups
• Some animals use integumentary exchange, gills or
  lungs for respiration
• Breathing ventilates the lungs

31
In Conclusion

• The respiratory cycle entails inhalation and
  exhalation
• Gas exchange takes place at the alveoli
• Partial pressure gradients drive the diffusion of
  gases
• Hb is the main carrier for Oxygen whereby most of
  the CO2 is carried as bicarbonate
• developed by M. Roig