Transcript Structure & Function Animals

Structure & Function
Animals
Overview: Diverse Forms, Common Challenges
• Anatomy is the study of
the biological form of an
organism
• Physiology is the study
of the biological
functions an organism
performs
• The comparative study
of animals reveals that
form and function are
closely correlated
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-3
Mouth
Gastrovascular
cavity
Exchange
Exchange
Exchange
0.15 mm
1.5 mm
(a) Single cell
(b) Two layers of cells
Fig. 40-4
External environment
CO2
Food
O2
Mouth
Respiratory
system
0.5 cm
50 µm
Animal
body
Lung tissue
Nutrients
Heart
Cells
Circulatory
system
10 µm
Interstitial
fluid
Digestive
system
Excretory
system
Lining of small intestine
Kidney tubules
Anus
Unabsorbed
matter (feces)
Metabolic waste products
(nitrogenous waste)
Tissue Structure and Function
• Different tissues have different structures that
are suited to their functions
• Tissues are classified into four main
categories:
– Epithelial
– Connective
– Muscle
– nervous
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 40-5a
Epithelial Tissue
Cuboidal
epithelium
Simple
columnar
epithelium
Pseudostratified
ciliated
columnar
epithelium
Stratified
squamous
epithelium
Simple
squamous
epithelium
Fig. 40-5c
Connective Tissue
Loose
connective
tissue
Chondrocytes
Cartilage
Elastic fiber
Chondroitin
sulfate
Nuclei
Fat droplets
Adipose
tissue
Osteon
150 µm
Fibrous
connective
tissue
30 µm
100 µm
120 µm
Collagenous fiber
White blood cells
Blood
55 µm
700 µm
Bone
Central canal
Plasma
Red blood
cells
Fig. 40-5j
Muscle Tissue
Multiple
nuclei
Muscle fiber
Sarcomere
Skeletal
muscle
Nucleus
100 µm
Intercalated
disk
50 µm
Cardiac muscle
Nucleus
Smooth
muscle
Muscle
fibers
25 µm
Fig. 40-5n
Nervous Tissue
40 µm
Dendrites
Cell body
Glial cells
Axon
Neuron
Axons
Blood vessel
15 µm
11 Body Systems
1. Nervous
2. Integumentary
3. Skeletal
4. Muscular
5. Circulatory
6. Respiratory
7. Digestive
8. Reproductive
9. Excretory
10. Endocrine
11. Immune & Lymphatic
Table 40-1
Stimulus
• Control and
coordination
within a body
depend on
the
endocrine
system and
the nervous
system
Stimulus
Endocrine
cell
Neuron
Axon
Signal
Hormone
Signal travels
along axon to
a specific
location.
Signal travels
everywhere
via the
bloodstream.
Blood
vessel
Signal
Axons
Response
(a) Signaling by hormones
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Response
(b) Signaling by neurons
Regulating and Conforming
40
• A regulator
uses internal
control
mechanisms
to moderate
internal
change in the
face of
external,
environmental
fluctuation
• A conformer
allows its
internal
condition to
vary with
certain
external
changes
Body temperature (°C)
River otter (temperature regulator)
30
20
Largemouth bass
(temperature conformer)
10
0
10
20
30
40
Ambient (environmental) temperature (ºC)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Homeostasis
• “Steady Internal
State”
Response:
Heater
turned
off
Room
temperature
decreases
Stimulus:
Control center
(thermostat)
reads too hot
• In humans,
Set
point:
20ºC
– body
temperature
– blood pH
– glucose
concentration
Stimulus:
Control center
(thermostat)
reads too cold
Room
temperature
increases
Response:
Heater
turned
on
• Endothermic
animals generate
heat by metabolism;
birds and mammals
are endotherms
(a) A walrus, an endotherm
• Ectothermic animals
gain heat from
external sources;
ectotherms include
most invertebrates,
fishes, amphibians,
and non-avian
reptiles
(b) A lizard, an ectotherm
•Five general adaptations help
animals thermoregulate:
–
Insulation
–
Circulatory adaptations
• Countercurrent
Exchange
• Vasodilation
• Vasoconstriction
–
Cooling by evaporative
heat loss
–
Behavioral responses
–
Adjusting metabolic heat
production (BMR)
Fig. 40-12
Canada goose
Bottlenose
dolphin
Blood flow
Artery Vein
Vein
Artery
35ºC
33º
30º
27º
20º
18º
10º
9º
Overview: The Need to Feed
• Food is taken in, taken apart, and taken up in
the process of animal nutrition
• In general, animals fall into three categories:
– Herbivores eat mainly autotrophs (plants and
algae)
– Carnivores eat other animals
– Omnivores regularly consume animals as well
as plants or algal matter
Digestive System
• Digestion is the process of
breaking food down into
molecules small enough to
absorb
–
In chemical digestion, the
process of enzymatic
hydrolysis splits bonds in
molecules with the addition
of water
• Absorption is uptake of
nutrients by body cells
• Elimination is the passage of
undigested material out of the
digestive compartment
Fig. 41-7
Small
molecules
Pieces
of food
Mechanical
digestion
Chemical digestion
Nutrient
(enzymatic hydrolysis) molecules
enter body
cells
Undigested
material
Food
1 Ingestion
2 Digestion
3 Absorption
4 Elimination
Tentacles
Extracellular
vs
Intracellular
Digestion
Mouth
Epidermis
Gastrodermis
Food Gastrovascular
cavity
Fig. 41-9a
Crop
Esophagus
Gizzard
Intestine
Pharynx
Formation of
Alimentary
Canal
Anus
Mouth
Typhlosole
Lumen of intestine
(a) Earthworm
Digestive System
• The digestive system includes
the
– Mouth
– Pharynx
– Esophagus
– Stomach
– small intestine
– Liver
– Gallbladder
– Pancreas
– large intestine
– Rectum
Mouth
• Mechanical Digestion
– Tongue and teeth work
together to break down
food mechanically
– Type of teeth reflect
dietary habits
• Chemical Digestion
– SalivaryAmylase enzyme in saliva that
breaks the carbohydrates
• chemical bonds
between the sugar
monomers in
starches
Esophagus, Pharynx, Epiglottis
• Esophagus
– No digestion
– Food is directed from mouth, to pharynx, to
esophagus.
• Epiglottis – flap of cartilage
– Ensures food travels to esophagus and not
wind pipe (larynx)
Stomach
•
Stomach - large muscular sac that continues the mechanical and chemical digestion of food
–
Acidic pH – 2-3 on the pH scale
–
(TOP) Cardiac sphincter – circular muscle that keeps materials down in the stomach.
Stops acid and food from reentering the esophagus
–
(Bottom) Pyloric Sphincter
–
Mechanical Digestion •
–
Peristalsis
Chemical Digestion – protein digestion begins here
•
HCL and Pepsin - The combination of pepsin (enzyme) and hydrochloric
acid begins the complex process of protein digestion. Pepsin breaks
proteins into smaller polypeptide fragments.
– HCL changes inactive enzyme, pepsinogen
 active pepsin
•
Rennin – enzyme that aids in the digestion of the protein in milk
•
Chyme - mixture of stomach fluids and food produced in the stomach by
Fig. 41-12
Esophagus
Sphincter
Stomach
5 µm
Sphincter
Interior surface
of stomach
Small
intestine
Folds of
epithelial
tissue
Epithelium
3
Pepsinogen
1 Pepsinogen and HCl
are secreted.
Pepsin
2
HCl
Gastric gland
2 HCl converts
pepsinogen to pepsin.
1
Mucus cells
Cl–
3 Pepsin activates
more pepsinogen.
H+
Chief cells
Chief cell
Parietal cells
Parietal cell
Ulcers – tissue erosion
• Can occur in
stomach, esophagus,
or the duodenum
(upper intestine.)
– Bacteria
Heliobacter
pylori  can lead
to ulcers, but can
be treated with
antibiotics
Small Intestine
•
Digestion is completed and nutrients are absorbed here.
–
pH – 8 and length of 6m
–
Digestion completed in Duodenum first 10 inches.
–
Digestion
•
•
–
Intestinal Enzymes – Lumen
–
Pancreatic amylases – starch
–
Peptidases (trypsin, chymotrypsin) – proteins  amino acids
–
Nucleases – nucleic acids  nucleotides
–
Lipases – break down fat
Epithelium of small intestine
–
Maltase
–
Lactase
Absorption – villi (villus-singular) – millions of fingerlike projections (latter portion of small intestine)
•
Increase surface area
•
Capillaries – absorb amino acids, vitamins, monosaccharides
•
Lacteal – absorbs fatty acid and glycerol  lymphatic system
•
Each villus contain microvilli
Villi and the Small Intestive
•Absorption – villi (villus-singular) – millions of fingerlike projections
(latter portion of small intestine)
•Increase surface area
•Capillaries – absorb amino acids, vitamins, monosaccharides
•Lacteal – absorbs fatty acid and glycerol  lymphatic system
•Each villus contain microvilli
Liver
•
Liver - large organ just above the stomach
that produces bile, a fluid loaded with lipids
and salts
–
Accessory gland
–
Produces bile that emulsifies fat
–
Bile mixed with Sodium Bicarbonate pH
11 (pancreas), neutralizes “chyme”
coming from the stomach
–
Sends bile to gallbladder for storage
–
Other functions
• Breaks down/recycles red blood
cells
• Detoxifies blood – removes alcohol
& drugs
• Produces cholesterol for cell
membranes
• Produces Urea (nitrogenous waste)
from protein metabolism
Gallbladder and Pancreas
•
Accessory glands
•
Gallbladder
–
Stores bile
–
Cholesterol
Deposits
(gallstones)
• We can
function
without it
•
Pancreas
–
Secretes enzymes
& bicarbonate
Large Intestine or Colon
•
large intestine
–
No digestion
–
3 major functions
•
Egestion – removal of
undigested waste
– Rectum – last
7-8inches
stores feces for
release
•
Vitamin Production
– B, K, folic acid
•
Reabsorption
– Constipation
– Diarrhea
Hormones that Regulate the Digestive System
Hormone
Site of Production
Effect
Gastrin
Stomach wall
Stimulate secretion of
gastric Juice
Secretin
Duodenum Wall
Stim. Pancreas to
release bicarbonate
Cholecystokinin
Duodenum Wall
Stim. Pancreas to
release enzymes and
gallbladder to release
bile
Fig. 41-18
Incisors
Canines
Premolars
(a) Carnivore
(b) Herbivore
(c) Omnivore
Molars
Fig. 41-19
Small intestine
Stomach
Small
intestine
Cecum
Colon
(large
intestine)
Carnivore
Herbivore
Fig. 41-13
Carbohydrate digestion
Oral cavity,
pharynx,
esophagus
Protein digestion
Nucleic acid digestion
Fat digestion
Polysaccharides Disaccharides
(starch, glycogen)
(sucrose, lactose)
Salivary amylase
Smaller polysaccharides,
maltose
Stomach
Proteins
Pepsin
Small polypeptides
Lumen of
small intestine
Polysaccharides
Pancreatic amylases
Polypeptides
Pancreatic trypsin and
chymotrypsin
DNA, RNA
Fat globules
Pancreatic
nucleases
Bile salts
Maltose and other
disaccharides
Nucleotides
Fat droplets
Smaller
polypeptides
Pancreatic lipase
Pancreatic carboxypeptidase
Glycerol, fatty
acids, monoglycerides
Amino acids
Epithelium
of small
intestine
(brush
border)
Small peptides
Disaccharidases
Monosaccharides
Nucleotidases
Nucleosides
Dipeptidases, carboxypeptidase,
and aminopeptidase
Amino acids
Nucleosidases
and
phosphatases
Nitrogenous bases,
sugars, phosphates