Download Gill arch O 2

Circulatory and Respiratory
Systems
Comparison of Gas Exchange
Systems
6 mechanisms for gas exchange
pg 916-918
1. Diffusion through cell membrane
– Ex: Single Cell
2. Diffusion through skin
– Ex: Earthworm
3. Tracheal system
– Ex: Insects
5. Gills
– Ex: Fish, sea star
5. Alveoli of Lungs
– Ex: Mammals
Figure 42.22
Gills are Shown In Pink
Coelom
Gills
Parapodium
(functions as gill)
(a) Marine worm
Gills
Tube foot
(b) Crayfish
(c) Sea star
Tracheoles Mitochondria
Muscle fiber
2.5 m
Figure 42.24
Tracheae
Air sacs
Body
cell
Air
sac
Tracheole
Trachea
External opening
Air
Comparison of Circulatory
Systems
What is transported in blood?
• Oxygen-carried on hemoglobin
• CO2 – carried in plasma and in rbc
• Nutrients (glucose, proteins, nucleic acids,
vitamins)
• Ions and minerals (calcium, Na, K, Fe, etc)
• Hormones
• Non- nutrient proteins (albumin for
osmoregulation, remember osmolarity?)
Page 900-902
and crocodile (not alligator)
Draw simple representations of these systems.
Comparison of Vertebrate Hearts
Read Captions on Page 901
• Fish has only 1 circuit
• Amphibian has 2 circuits, but only 1 ventricle. There
is some mixing of oxygenated and deoxygenated
blood (3 chambers)
• Reptiles generally have partially divided ventricle (3 +
chambers)
• Mammals, birds and crocodiles have fully divided
ventricle (4 chambers)
Oxygen Delivery Activity
• Need participants to be blood. (5- in a class of 25)
• The rest of the class are cells from various body
tissues (leg muscle, brain, stomach, heart, etc)
• Must have oxygen to function.
• Blood will deliver oxygen (beans) to hungry cells.
• Tissue cells will place one oxygen into the waste
cup every 30 seconds as they metabolize. (This
will change as different tissue becomes active).
• Each blood cell will circulate, delivering O2.
Set Up
• HEMOGLOBIN EGG CARTON
– 1 BLOOD CELL/ EVERY 5 STUDENTS
• 1 WASTE CUP PER STUDENT
• 2 BEANS PER STUDENT TO START WITH
• LARGE CONTAINER OF BEANS IS FOR LUNG
Tips for O2 Delivery Activity
• Give groups of students tissue assignments:
– Skeletal muscle, digestive system, brain
• As a certain tissue become more active, use
beans at a rate of every 15 seconds.
• Clear the aisles
• (Use clock- 30 seconds is every time second
hand reaches 12 and 6; for 15 seconds its
every 3,6,9 and 12).
Questions
• How many oxygen (beans) can be in each
blood cell (red cup)?
• How could we simulate exercise?
• How can we simulate that some tissues are
working harder than others at various times?
• How could we simulate pregnancy?
• How does blood flow change when the tissues
are more active?
Respiratory System
Organs of the Respiratory system
 Nose
 Pharynx
 Larynx
 Trachea
 Bronchi
 Lungs –
alveoli
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 13.1
Slide 13.1
Composition of Air
• Nitrogen- ~79%
• Oxygen- ~21%
• Carbon Dioxide- 0.03%
• At sea level, air has a pressure of 760 mmHg:
– PN2- 760 mmHg x 79%= ~ 600 mmHg
– PO2- 760 mmHg x 21%~ 160 mmHg
– PCO2- 760 mmHg x 0.03%~ 0.2 mmHg
What happens to the air pressure,
and thus the O2 available, as one
climbs a mountain?
See Figure 44.2
What is the pO2 at the peak of
Mount Whitney? Mt Everest?
Gas and Temperature Exchange
Counter Current Exchange/ Concurrent
Exchange
Let’s find out which is more efficient…
(see page 917)
• Ventilation moves the respiratory medium over
the respiratory surface
• Aquatic animals move through water or move
water over their gills for ventilation
• Fish gills use a countercurrent exchange
system, where blood flows in the opposite
direction to water passing over the gills; blood is
always less saturated with O2 than the water it
meets
© 2011 Pearson Education, Inc.
Figure 42.23
O2-poor blood
Gill
arch
O2-rich blood
Lamella
Blood
vessels
Gill arch
Water
flow
Operculum
Water flow
Blood flow
Countercurrent exchange
PO (mm Hg) in water
2
150 120 90 60 30
Gill filaments
Net diffusion of O2
140 110 80 50 20
PO (mm Hg)
2
in blood
Concurrent Exchange
Figure 42.23
O2-poor blood
Gill
arch
O2-rich blood
Lamella
Blood
vessels
Gill arch
Water
flow
Operculum
Water flow
Blood flow
Countercurrent exchange
PO (mm Hg) in water
2
150 120 90 60 30
Gill filaments
Net diffusion of O2
140 110 80 50 20
PO (mm Hg)
2
in blood
Which system is more efficient?
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fig. 44.04(TE Art)
Core body
Temperature
36˚C
Warm blood
Veins
Artery
5˚C
Temperature
of environment
Artery
Capillary
bed
Cold
blood
Veins
Fick’s Law
• Pair and Share:
• List the factors that determine how much heat, gas or
molecules can diffuse into blood cells from the lungs (Can
you think of three things?)
• Distance for diffusion (d), Concentration Gradient (Δp) ,
Area over Which Diffusion Takes Place (A)
(and the Diffusion Constant)
Try to write an Equation for R- Rate of Diffusion
Fick’s Law
R= D A Δp
d
R= Rate of Diffusion
D= Diffusion Constant
A= Area
Δp= difference in concentration
d = distance across which diffusion takes place
Why do birds have unique
respiratory needs?
What did we learn in this
presentation?
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fig. 44.26(TE Art)
Parabronchi of lung
Anterior
air sacs
Trachea
Lung
Anterior
air sacs
Posterior
air sacs
Trachea
Inspiration
Cycle 1
Expiration
Inspiration
Cycle 2
Expiration
Posterior
air sacs
Describe hemoglobin
• 4 polypeptide chains
• Each chain has an iron containing heme group
that can bind to one oxygen molecule.
• Hemoglobin increases the carrying capacity of
blood from 3 mL/ L to 200mL/ L of blood
plasma.
• Found in: Annelids, mollusks, echinoderms,
flatworms, some protists. ALL VERTEBRATES
The brain regulates breathing rate
• What brain part regulates breathing?
• Medulla oblongata
• The chemoreceptors in the medulla detect
falling pH that corresponds to CO2
accumulation.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Choroid
plexus of
brain
CO
Fig. 44.29(TE
Art)
2
H2O + CO2
Capillary
blood
H2CO3
H+ + HCO3Cerebrospinal
fluid (CSF)
Chemo
sensitive
neuron
Medulla oblongata
Signal to
respiratory
system
Oxyhemoglobin Dissociation Curve
• As shown in our activity, hemoglobin needs to
release more oxygen in areas which are more
active.
• When leaving the lungs, hemoglobin holds
tightly to its oxygen. As it gets to active tissue,
it tends to release O2.
• This is shown on the oxyhemoglobin
dissociation curve.
100
O2 unloaded
to tissues
at rest
80
O2 unloaded
to tissues
during exercise
60
40
20
0
O2 saturation of hemoglobin (%)
O2 saturation of hemoglobin (%)
Figure 42.31
100
pH 7.4
80
pH 7.2
Hemoglobin
retains less
O2 at lower pH
(higher CO2
concentration)
60
40
20
0
0
20
40
60
Tissues during Tissues
at rest
exercise
PO2 (mm Hg)
80
100
Lungs
(a) PO2 and hemoglobin dissociation at pH 7.4
0
20
40
60
80
PO2 (mm Hg)
(b) pH and hemoglobin dissociation
100
O2 saturation of hemoglobin (%)
Figure 42.31b
100
Before pH 7.4
Exercise
80
pH 7.2
Exercise
Hemoglobin
retains less
O2 at lower pH
(higher CO2
concentration)
60
40
20
0
0
20
40
60
80
PO2 (mm Hg)
(b) pH and hemoglobin dissociation
100
The Oxygen Dissociation Curve
This curve shifts to the right in more active muscle
and in warmer muscle. The reverse is also true.
CO2 transport in blood
• Blood cells have no nucleus nor organelles to
maximize gas carrying capacity.
• 70 % of CO2 is buffered and becomes
bicarbonate in the plasma (blood buffering
system)
• 20 % is bound to Hb
• 8% is simply dissolved C02 in plasma
Hormones involved in Circulation
• Antidiuretic hormone- (ADH aka Vasopressin)
(anti pee hormone)
– Responds to dehydration
– Causes higher concentration of urine
– Causes thirst
– Raises Blood Pressure (BP)
• Aldosterone
– Responds to dehydration and low blood volume
– Retains Na+ and water, maintains blood
osmolarity
– Raises BP
…Hormones involved in Circulation
• Atrial natriuretic hormone (ANH)
– Na + secretion
– Increases urination
– Lowers BP
– Gets its name for its response to stretch in the atrium
• Nitric oxide (NO) gas
– Vasodilator- Dilates blood vessels
– Lowers BP