Transcript Chapter 22: Respiration: The Exchange of Gases

Chapter 22: Respiration: The Exchange of
Gases
NEW AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Fig. 22.1
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Fig. 22.1
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Fig. 22.1
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Fig. 22.1
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
- the site of gas diffusion (O2 in, CO2 out)
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface – 4 properties
1.Made of cells
2. thin
3. must be moist (wet)
4. large surface area
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
Fig. 22.2A
1. Entire outer skin (“skin-breathers”)
- Annelida
- What type of environment would
you expect to find them?
- Why must they be narrow and
long?
- How come all animals don’t
“skin-breathe”?
- What other organ system is a
must with this type of resp. sys?
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
2. Gills
- Aquatic animals
- Why are they able to be outside
the body?
- The shape?
Fig. 22.2B
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
2. Gills
- Aquatic animals
- Why are they able to be outside
the body?
- The shape?
- Ventilation
i. Energy Intensive – water is
denser than air
- Oxygen in water is 3-5% that of
air
i. Countercurrent flow (exchange)
Fig. 22.3
Fig. 22.4
- Circulatory system needed
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
2. Gills
- Aquatic animals
- Why are they able to be outside
the body?
- The shape?
- Ventilation
i. Energy Intensive – water is
denser than air
- Oxygen in water is 3-5% that of
air
i. Countercurrent flow (exchange)
Fig. 22.3
Fig. 22.4
- Circulatory system needed
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
2. Gills
Fig. 22.3
Fig. 22.4
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
Fig. 22.4C
3. Tracheal system
- Why is the system now within the body?
- Easier to breathe air than water.
- Insects (class of arthropoda)
i. Tracheal system
- tracheae
- tracheoles
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
Fig. 22.5C
3. Tracheal system
- Why are they now within the body?
(spiracles)
Fig. 22.5A
- Easier to breathe air than water.
- Insects (class of arthropoda)
i. Tracheal system
- tracheae
- tracheoles
- air sacs
ii. Circulatory system?
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
Fig. 22.5B
3. Tracheal system
- Why are they now within the body?
(spiracles)
Fig. 22.5A
- Easier to breathe air than water.
- Insects (class of arthropoda)
i. Tracheal system
- tracheae
- tracheoles
- air sacs
ii. Circulatory system NOT involved
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
4. Lungs
- Terrestrial Vertebrates
- Restricted to one part of body
i. What other system do we need?
Fig. 22.2D
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
4. Lungs
- Terrestrial Vertebrates
- Restricted to one part of body
i. What other system do we need?
- Special Case
i. Amphibians
a. Small lungs
b. Also uses body surfaces
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface
Four types of resp. organs in animals
4. Lungs
Which type of organisms would you predict to have a greater lung
surface area, endotherms or ectotherms? Explain.
Endotherms (warm-blooded) need to maintain their body temperatures
and therefore will need to perform a greater number of chemical
reactions to generate heat = more oxygen needed and more CO2
generated.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Respiratory surface of single celled organisms?
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
Fig. 22.6A
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
Fig. 22.6A
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
Air is:
a. Filtered by hairs/mucus/cilia
b. Warmed or cooled to 1 degree within body
temp. as to not disrupt fluidity of membranes
of epithelial cells of lungs (alveoli).
c. Humidified to keep respiratory
surface (alveoli) from drying out.
d. Sampled for odors
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
i. Tonsils and Adenoids
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
b. Surrounded by cartilage
(adam’s apple)
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
4. Trachea
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
4. Trachea
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
4. Trachea
a. Enforced with rings of cartilage like a vacuum cleaner hose to prevent
collapse when breathing due to drop in pressure
b. Lined with ciliated cells and mucus producing goblet cells. Mucus
producing cells secrete mucus, which lines the trachea and traps
dust/bacteria/viruses/etc… and the ciliated cells use their cilia to push
the mucus up the trachea into the pharynx to be swallowed and
digested. This is always happening.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
4. Trachea
5. Bronchi
6. Bronchioles
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
4. Trachea
5. Bronchi
6. Bronchioles
7. Alveoli – dead end
- Site of diffusion
- millions per lung
- Simple squamos epithelium
- The respiratory surface
Fig. 22.6B
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Human respiration
- surface area = 100m2
- Respiratory Path
1. Nasal Cavity (nostril breathing)
2. Pharynx
3. larynx - voice box
a. Vocal cords
4. Trachea
5. Bronchi
6. Bronchioles
7. Alveoli
Fig. 22.6C
- site of diffusion
- millions per lung
- Simple squamos epithelium
- resp. surface
Alveoli in yellow interacting with capillaries in
red (notice the surface area)
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Smoking
- 43 carcinogens
- destroy cilia and
macrophages (type of WBC
that fights infection)
- coughing becomes last line
of defense
- 430,000 people die a year
(more than the sum of deaths caused by AIDS,
alcohol, drug abuse, traffic accidents and murders)
- lung cancer
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Smoking
- 43 carcinogens
- destroy cilia and macrophages
- coughing becomes last line
of defense
- 430,000 people die a year
(more than the sum of deaths caused by AIDS,
alcohol, drug abuse, traffic accidents and murders)
- lung cancer
- emphysema
i. Toxins trapped in lungs cause inflammation
ii. Inflammatory chemicals released by your own cells break down walls of alveoli leading to collapse
iii. Not getting enough oxygen into blood, leads to hyperventilation
iv. Blood vessels near damage constrict to divert blood to working regions of lungs
v. Heart needs to beat harder, gets thicker/larger and eventually fails
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Bronchitis
-itis:
Suffix denoting diseases
characterized by inflammation
itself often caused by an
infection.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Asthma
1. An immune response brought about by
white blood cells in the lungs reacting to
foreign although otherwise harmless
substances (allergens) or rapid-mouth
breathing during exercise (genetic and
environmental).
2. Breathing passages (bronchi) become
inflamed (swollen, red, warm) and smooth
muscle around bronchi constrict
(bronchospasm).
3. Symptoms include wheezing, coughing,
chest tightness and shortness of breathe.
4. In the end, the precise cause is not known
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Asthma Treatment
Β2-andrenergic agonists
Adrenaline (epinephrine)
albuterol
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Breathing
- Ventilates the lungs
i. Diaphragm and intercostal (between rib) muscles contract
- Negative pressure breathing
Fig. 22.8A
When the muscle contract
(diaphragm contracts downward
and the intercostals pull the ribs
toward each other), the volume
of the lungs increases, which
decreases the pressure inside
the lungs (fewer collisions of air
molecules with the walls of the
bronchi, alveoli, etc…) causing
higher pressure air to rush in.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is breathing controlled?
- Some conscious control
- Predominantly Involuntary
a. Breathing control centers
- coordinates respiratory and circulatory
system with metabolic needs of body
i. pons
ii. medulla
- monitors pH
- indirect measure of CO2
CO2 + H2O
H2CO3 (carbonic acid)
The more CO2 in the blood…
…the more acidic it is.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is breathing controlled?
- Some conscious control
- Predominantly Involuntary
a. Breathing control centers
- coordinates respiratory and circulatory
system with metabolic needs of body
i. pons
ii. medulla
- monitors pH
- indirect measure of CO2
As the blood gets more acidic (lower pH),
proteins on the surface of medulla cells change
shape and the cells will signal the diaphragm to
contract more frequenlty (breathe heavier).
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is breathing controlled?
- Some conscious control
- Predominantly Involuntary
a. Breathing control centers
- coordinates respiratory and circulatory
system with metabolic needs of body
i. pons
ii. medulla
- monitors pH
- indirect measure of CO2
increases
As pH decreases, breathing _________.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is breathing controlled?
- Some conscious control
- Predominantly Involuntary
a. Breathing control centers
- coordinates respiratory and circulatory
system with metabolic needs of body
Oxygen sensing by the aortic body
1. There are also a bunch of cells in the
aorta that sense O2 levels.
2. Blood in the aorta just came from the
lungs and should be fully oxygenated.
3. Neural signals sent to pons/medulla, which will send signal to diaphragm.
4. This signal is much less important than the pH signal.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is breathing controlled?
Story:
As you run, your muscle cells (majority of your cells)
are using a great deal of O2 and producing CO2.
The CO2 enters the blood and combines with H2O
to make H2CO3 catalyzed by carbonic anhydrase.
carbonic anhydrase
CO2 + H2O
H2CO3 (carbonic acid)
The H2CO3 will dissociate (fall apart) to H+ + HCO3resulting in a slight decrease in the pH of the blood.
The pons/medulla respiratory center cells senses this drop in pH by a change
in the shape of the proteins on their surface signally the cells to send a neural
signal to the diaphragm to increase the frequency of contractions.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is breathing controlled?
Story (continued):
At the same time, the aortic body senses a decrease
in oxygen and also sends a signal to the
pons/medulla with the same result as before. This
signal is not a strong/important as the drop in pH.
The exact opposite happens if you hyperventilate
(breathe in and out quickly). CO2 concentrations drop
, pH rises and pons/medulla does not send a signal
to breathe…can be very dangerous and deaths have
been known to be a result.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is oxygen transported?
X 50,000,000,000
per human
250,000,000 / RBC
1. Very little dissolved in blood
2. Carried by hemoglobin
- 4 subunits (polypeptides)
- 1 heme per subunit
- 1 O2 per heme
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
How is CO2 transported?
1. Dissolve in blood as gas
2. some binds to hemoglobin
Fig. 21.11
3. Remainder forms H2CO3 via carbonic anhydrase inside RBC’s
i. H2CO3 is a buffer and helps buffer blood at pH ~7.4
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Gas exchange in the fetus…
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Gas exchange in the fetus…
The placenta is the only human organ
made of tissue from two different
organisms…the mother and the child.
1. The fetus’ heart will pump blood
through the fetus and out to the placenta
via the umbilical cord.
2. In the placenta, the gas and nutrient
exchange will occur via diffusion (mom’s
and baby’s blood DO NOT MIX).
3. The blood then returns to the fetus. The
placenta acts like the “lungs” and “kidneys”.
4. The mother will then get rid of the CO2
via the lungs and nitrogenous waste (urea)
via the kidneys.
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Gas exchange in the fetus…
What about the fetus’ feces?
- There is no feces, did the fetus ever eat
anything?
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
1. Respiration
a. Respiratory surface
- moist, large surface area, thin, made of cells
b. Types of systems
- skin breathers
- gills
- tracheal system
- lungs
c. Human respiration
- nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles
- alveoli
- the resp. surface of lungs
d. smoking
- lung cancer and emphysema
e. breathing
- diaphragm, intercostal muscles, negative pressure breathing
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
f. Breathing control
- control centers - pons, medulla of brain stem
- medulla monitors pH
-Indirect measure of CO2
- sends neural signals to diaphragm and intercostals
- bromothymol blue
g. Transport of O2 and CO2
- RBC’s
- hemoglobin
- heme cofactor containing iron
- iron binds oxygen
h. Transport of CO2
- dissolved in blood, as carbonic acid, bound to hemoglobin (not
at the iron)
i. Fetal respiration
Chapter 22: Respiration: The Exchange of
Gases
AIM: How have different organisms evolved to perform gas
exchange (respiration)?
Watch tutorial under misc section of website
Chapter 21: Nutrition and Digestion
AIM: How do animals obtain nutrition?
Milestone Questions
1. Explain why when you exercise your breathing rate increases.
2. What are the four requirements of a respiratory surface?
3. How does negative pressure breathing work in humans?
4. How is CO2 carried in the blood?