Transcript 41.1: Diet Provides- 1)Chemical Energy 2)Organic Molecules 3

41.1: Diet Provides-
1)Chemical Energy
2)Organic Molecules
3)Essential Nutrients
Essential Nutrients
• Amino Acids
• Fatty Acids
• Vitamins (organic)
• Minerals (inorganic)
Dietary Deficiencies
• Undernutrition
• Lack essential nutrients
Figure 41.4
RESULTS
Number of
infants/fetuses
studied
Infants/fetuses
with a neural
tube defect
Vitamin supplements
(experimental group)
141
1 (0.7%)
No vitamin supplements
(control group)
204
12 (5.9%)
Group
41.2: Food Processing
4 Main Animal Feeding Mechanisms
Intracellular Digestion
• Food Vacuoles
• Avoid selfdigestion
Extracellular Digestion
• Compartments continuous w/ outside
CONCEPT 41.3
ORGANS SPECIALIZED FOR SEQUENTIAL STAGES OF FOOD
PROCESSING FORM THE MAMMALIAN DIGESTIVE SYSTEM
•Chapter 40
•Grace Cunnie
THE HUMAN DIGESTIVE SYSTEM
-
Mammalian digestive
system
- Alimentary canal
- Accessory glands
- Salivary glands
- Pancreas
- Liver
- Gallbladder
Figure 41.9: The human digestive system
1
1
TRAVELING DOWN THE ALIMENTARY
CANAL
Food is pushed along canal by peristalsis
Alternating waves of contraction and relaxation in
the smooth muscles lining the canal
Can be helped along by sphincters
Ring-like valves that form at some of the junctions
between specialized compartments
THE ORAL CAVITY, PHARYNX, AND
ESOPHAGUS
- As saliva is
released
- Amylase
helps break
down starch
- Mucus is
produced
DIGESTION IN THE STOMACH
DIGESTION IN THE SMALL INTESTINE
-
-
-
-
Duodenum
First 25 cm
Chyme from
stomach mixes with
digestive juices
Pancreas
Aids in digestion,
produces alkaline
solution rich with
bicarbonate, several
enzymes
Liver
Produces bile
Gallbladder
Stores bile
ABSORPTION IN THE SMALL INTESTINE
ABSORPTION IN THE LARGE INTESTINE
41.4- EVOLUTIONARY
ADAPTATIONS OF
VERTEBRATE
DIGESTIVE SYSTEMS
CORRELATE WITH DIET
Xia Whitaker
Mr. Reis
AP Biology
13 March
2013
DENTAL ADAPTATIONS

Dentition- an animals’ assortment of teeth

Structural variation reflects diet

Nonmammalian vertebrates generally have less
specialized dentition
STOMACH AND INTESTINAL
ADAPTATIONS
 Length of digestive system is correlated to diet

Carnivores= expandable, large stomachs

Herbivores & Omnivores longer alimentary
canals

Longer track= absorb more nutrients and more
time
MUTUALISTIC
ADAPTATIONS
 Mutualistic microbes break down cellulose
depending on the type of herbivore

Ruminants- animal with more complex
adaptations

Stomach has four chambers
41.5- FEEDBACK CIRCUITS
REGULATE DIGESTION,
ENERGY STORAGE, AND
APPETITE
REGULATION OF DIGESTION

Nutrition is regulated at different levels

Food in the alimentary canal triggers
nervous/hormonal responses

The responses control secretion of digestive
juices/promote movement of ingest material
REGULATION OF ENERGY
STORAGE
 When an animal takes in more energy-rich
molecules than needed, it stores excess energy

Vertebrates store excess calories is glycogen
(liver/muscle cells) and fat (adipose cells)

Glucose Homeostasis

Insulin and glucagon maintain glucose homeostasis

Insulin levels rise= glucose enters liver to synthesize
glycogen

Lower glucose level= glucagon stimulates liver to
breakdown glycogen (releases glycogen into
blood)
REGULATION OF APPETITE
AND
 SeveralCONSUMPTION
homeostatic mechanism regulate body
weight

Leptin and insulin regulate appetite by affecting
the brain

Control storage and metabolism of fat

Neurons transmit signals from digestive system,
regulating hormone release
OBESITY AND EVOLUTION

Fat hoarding was necessary to our
ancestors

Natural selection may have selected them
for their ability to store food
Circulation and Gas
Exchange
Chapters 42.1 and 42.2
Mike Tillman
Circulatory System
 Animals with simple body plans – gas exchange
via diffusion
 Diffusion efficient over small distances
 Cells exchange materials with surrounding medium
 Cells of most animals exchange materials with the
environment with a circulatory system
Closed Circulatory System
 Blood circulates in a closed network of vessels and
pumps
 Blood, blood vessels, 2-4 chambered heart
Open Circulatory System
 Circulatory fluid bathes organs directly
 Circulatory fluid called hemolymph
 Hemolymph pumped through circulatory vessels by heart
 Chemical exchange between hemolymph and body cells
Circulation
The Cardiac Cycle
 Sequence of heart pumping and filling
 Systole – contraction
 Relaxation – diastole
 Pulse/Cardiac output – measure of heart function
Heartbeat
 Originates at the sinoatrial (SA) node
 “pacemaker”
 Pacemaker ability influenced by
 Nervous system
 Hormones
 Body temperature
Figure 42.1
Blood fun facts
• It takes a drop of blood 20 to 60 seconds for one roundtrip from and to the heart.
• We have approximately 100,000 miles of blood vessels
• Two million red blood cells die every second.
• The kidneys filter over 400 gallons of blood each day.
• The average life span of a single red blood cell is 120
days.
• There are 150 billion red blood cells in one ounce of
blood
• Our hearts pump 48 million gallons of blood/year (in 10
oz. intervals)
• White blood cells only last 4-6 hours
42.3
Patterns of blood pressure and flow
reflect the structure and
arrangement of blood vessels
• Endothelium – single layer of flattened epithelial
cells
• Capillaries – provides blood to tissues and
interstitial fluid in-between artery and vein
• Venules – connects vein to capillary
• Arterioles – conects artery to capillary
• Smooth Muscle – receives hormones, regulates
artery size
• Artery – carries blood away from heart to organs
• Vein – carries blood back toward heart
Lumen
Blood Pressure
Capillary Function
Lymph Nodes
• Lymphatic system – lost fluid and proteins
return to blood system
• Lymph – fluid lost by capillaries
• Lymph nodes – filter the lymph, house
bacteria/virus fighting cells
Concept 42.4: Blood components
function in exchange, transport, and
defense
By Ryan Tudino
The composition of mammalian blood
Cellular elements 45%
Plasma 55%
Constituent
Water
Solvent for
carrying other
substances
Ions (blood
electrolytes)
Sodium
Potassium
Calcium
Magnesium
Chloride
Bicarbonate
Osmotic balance,
pH buffering,
and regulation
of membrane
permeability
Plasma proteins
Albumin
Leukocytes (white blood cells)
Separated
blood
elements
5,000–10,000
Functions
Defense and
immunity
Lymphocytes
Basophils
Eosinophils
Neutrophils
Osmotic balance,
pH buffering
Fibrinogen
Clotting
Immunoglobulins
(antibodies)
Defense
Substances transported by blood
Nutrients
Waste products
Respiratory gases
Hormones
Number per L
(mm3) of blood
Cell type
Major functions
Monocytes
Platelets
Erythrocytes (red blood cells)
250,000–400,000
5–6 million
Blood
clotting
Transport
of O2 and
some CO2
Cellular Elements
• Platelets
• Leukocytes (white blood cells)
• Erythrocytes (red blood cells)
Why is the occasional cut or scrap not
life-threatening?
Figure 42.18a
3
2
1
Collagen fibers
Platelet
plug
Platelet
Fibrin
clot
Clotting factors from:
Platelets
Damaged cells
Plasma (factors include calcium, vitamin K)
Enzymatic cascade
Prothrombin

Thrombin
Fibrinogen
Fibrin
Fibrin clot
formation
Figure 42.19
Stem cells
(in bone marrow)
Myeloid
stem cells
Lymphoid
stem cells
B cells
T cells
Erythrocytes
Lymphocytes
Monocytes
Neutrophils
Platelets
Basophils
Eosinophils
Cardiovascular Disease
• Low-density lipoprotein (LDL)
• High-density lipoprotein (HDL)
– Risk for heart disease increases with a high LDL to HDL
ratio
Figure 42.20
Lumen of artery
Endothelium
Smooth
muscle
1
LDL
Foam cell
Macrophage
Plaque rupture
Plaque
2
Extracellular
matrix
4
3
Fibrous cap
Cholesterol
Smooth
muscle
cell
T lymphocyte
Percent of individuals
RESULTS
30
20
10
0
Average  105 mg/dL
Percent of individuals
Figure 42.21
30
Average  63 mg/dL
20
10
0
50 100 150 200 250 300
0
50 100 150 200 250 300
Plasma LDL cholesterol (mg/dL)
Plasma LDL cholesterol (mg/dL)
Individuals with two functional copies of
Individuals with an inactivating mutation in
PCSK9 gene (control group)
one copy of PCSK9 gene
0
42.6
Bridget Peterson
42.6 How an Amphibian
Breathes
 Positive Pressure Breathing: inflation of the lungs
through forced air-flow
42.6 How a Bird Breathes
 Pass air over the gas exchange surface in only one
direction
 Incoming fresh air does not mix with air that has
already carried out gas exchange
 Air sacs: keep air flowing through lungs
 Tiny channels called parabronchi allow air to flow in
the same direction
42.6 How a Mammal
Breathes
 Negative pressure breathing: pulling, rather than
pushing, air into their lungs
42.6 How a Mammal
Breathes
 Inhalation requires work
 Change air pressure within lungs relative to pressure
of outside atmosphere
 Air rushes through the nostrils and mouth and down
the breathing tubes to the alveoli
42.6 How a Mammal
Breathes
 Exhalation is passive
 Muscles controlling the thoracic cavity relax and
volume of cavity is reduced
 Increased air pressure in alveoli forces air up
breathing tubes and out of the body
42.6 Control of Breathing
 Breathing is regulated to ensure that gas exchange is
coordinated with blood circulation and with
metabolic demand
 Neurons in the medulla oblongata: form a breathing
control center
 When you breath deeply a negative feedback
mechanism prevents the lungs from over expanding
Concept 42.7: Adaptations for gas exchange
include pigments that bind and transport
gases
• The metabolic demands of many organisms
require that the blood transport large quantities of
O2 and CO2
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Coordination of Circulation and Gas
Exchange
• Blood arriving in the lungs has a low partial
pressure of O2 and a high partial pressure of CO2
relative to air in the alveoli
• In the alveoli, O2 diffuses into the blood and CO2
diffuses into the air
• In tissue capillaries, partial pressure gradients
favor diffusion of O2 into the interstitial fluids and
CO2 into the blood
© 2011 Pearson Education, Inc.
Figure 42.30
Alveolar
epithelial
cells
2 Alveolar
spaces
CO2
O2
Alveolar
capillaries
7 Pulmonary
arteries
3 Pulmonary
veins
6 Systemic
veins
4 Systemic
arteries
Heart
CO2
Partial pressure (mm Hg)
1 Inhaled air
8 Exhaled air
160
O2
5 Body tissue
(a) The path of respiratory gases in the circulatory
system
2
Exhaled
air
120
80
40
0
1
Systemic
capillaries
PO
2
PCO
Inhaled
air
2
3
4
5
6
7
(b) Partial pressure of O2 and CO2 at different points in the
circulatory system numbered in (a)
8
Respiratory Pigments
• Respiratory pigments, proteins that transport
oxygen, greatly increase the amount of oxygen
that blood can carry
• Arthropods and many molluscs have hemocyanin
with copper as the oxygen-binding component
• Most vertebrates and some invertebrates use
hemoglobin
• In vertebrates, hemoglobin is contained within
erythrocytes
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Hemoglobin
• A single hemoglobin molecule can carry four
molecules of O2, one molecule for each ironcontaining heme group
• The hemoglobin dissociation curve shows that a
small change in the partial pressure of oxygen can
result in a large change in delivery of O2
• CO2 produced during cellular respiration lowers
blood pH and decreases the affinity of hemoglobin
for O2; this is called the Bohr shift
© 2011 Pearson Education, Inc.
Figure 42.UN01
Iron
Heme
Hemoglobin
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
Carbon Dioxide Transport
• Hemoglobin also helps transport CO2 and assists
in buffering the blood
• CO2 from respiring cells diffuses into the blood
and is transported in blood plasma, bound to
hemoglobin, or as bicarbonate ions (HCO3–)
Animation: O2 from Blood to Tissues
Animation: CO2 from Tissues to Blood
Animation: CO2 from Blood to Lungs
Animation: O2 from Lungs to Blood
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Animation: O2 from Blood to Tissues
Right-click slide / select “Play”
© 2011 Pearson Education, Inc.
Animation: CO2 from Tissues to Blood
Right-click slide / select “Play”
© 2011 Pearson Education, Inc.
Animation: CO2 from Blood to Lungs
Right-click slide / select “Play”
© 2011 Pearson Education, Inc.
Animation: O2 from Lungs to Blood
Right-click slide / select “Play”
© 2011 Pearson Education, Inc.
Figure 42.32
Body tissue
CO2 produced
CO2 transport
from tissues
Interstitial
CO2
fluid
Plasma
within capillary CO2
H2O
Red
blood
cell
Capillary
wall
CO2
H2CO3
Hb
Carbonic
acid
HCO3 
Bicarbonate
HCO3
H+
To lungs
CO2 transport
to lungs
HCO3
HCO3 
H2CO3
Hemoglobin (Hb)
picks up
CO2 and H+.
H+
Hb
Hemoglobin
releases
CO2 and H+.
H2O
CO2
CO2
CO2
CO2
Alveolar space in lung
Respiratory Adaptations of Diving Mammals
• Diving mammals have evolutionary adaptations
that allow them to perform extraordinary feats
– For example, Weddell seals in Antarctica can
remain underwater for 20 minutes to an hour
– For example, elephant seals can dive to 1,500 m
and remain underwater for 2 hours
• These animals have a high blood to body volume
ratio
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• Deep-diving air breathers stockpile O2 and deplete
it slowly
• Diving mammals can store oxygen in their
muscles in myoglobin proteins
• Diving mammals also conserve oxygen by
– Changing their buoyancy to glide passively
– Decreasing blood supply to muscles
– Deriving ATP in muscles from fermentation once
oxygen is depleted
© 2011 Pearson Education, Inc.