Download video slide

Anatomy and Physiology of animals
Animal form and Function
Animal size and shape
Tissue structure and function
Thermoregulation- Ectotherms and Endotherms
Nutrition
Stages of food processing
Animal diversity
Invertebrates- Porifera (sponges)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Text devoted to animals
• Except for Chapter 8 Animal like protists
(Amoeba and Paramecium)
• The inclusion of protozoa is part of a tradition
• Once considered a phylum (Protozoa) in the
animal kingdom
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Pattern of Organization
• Symmetry
• Asymmetry
• Radial symmetry
• Bilateral symmetry
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.7 Asymmetry red
encrusting sponge
asymmetrical
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.8
Radial symmetry tube coral pulp
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Part 2
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Part 2
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Bilateral animals
• Bilateral symmetry = important evolutionary
advancement
– Important for active, directed movement
• Anterior, posterior ends
– One side of body kept up (dorsal) vs. down
(ventral)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Directed movement evolved with anterior sense
organs cephalization
Cephalization
– specialization of sense organs in head end of
animals
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Bilateral
Symmetry
• Divided along sagittal plane into two mirror
images
– sagittal= divides bilateral organisms into right
and left halves
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Anterior= head end
• Posterior= tail end
• Dorsal= back side
• Ventral= belly side
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Symmetry, fig. 7.9
– Median= sagittal
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Other Patterns of Organization may reflect
evolutionary trends
• Unicellular (cytoplasmic)- organisms consist of
single cells or cellular aggregates,
– provide functions of locomotion, food acquisition,
digestion, water and ion regulation, sensory
perception and reproduction in a single cell.
– Cellular aggregates consist of loose association,
cells that exhibit little interdependence,
cooperation, or coordination of function
– Some cells may be specialized for reproduction,
nutritive or structural function
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Diploblastic Organization
– Cells are organized into tissues in most animal
phyla
– Body parts are organized into layers derived
from two embryonic tissue layers.
– Ectoderm- Gr. ektos, outside + derm, skin
gives rise to the epidermis the outer layer of
the body wall
– Endoderm- Gr. Endo, within, gives rise to the
gastrodermis that lines the gut
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Mesoglea- between the ecto and endo and may
or may not contain cells
– Derived from ecto and/or endo
– Cells form middle layer (mesenchyme)
– Layers are functionally inderdependent, yet
cooperate showing tissue level organization
i.e. feeding movements of Hydra or swimming
movements of a jellyfish
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.10
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Triploblastic (treis, three +blaste, sprout)
• Animals described in chapters 10-22
• Tissues derived from three embryological
layers
• Ectoderm- outer layer
• Endoderm- lines the gut
• Mesoderm- meso, middle, Third layer between
Ecto and Endo
– Give rise to supportive cells
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.11
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Most have an organ system level of
organization
• Usually bilaterally symmetrical or evolved from
bilateral ancestors
• Organized into several groups based on the
presence or absence of body cavity and for
those that posses one, the kind of body cavity
present.
• Body cavity- fluid filled space in which the
internal organs can be suspended and
separated from the body wall
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Body cavities are advantageous
1. Provide more room for organ development
2. Provide more surface area for diffusion of
gases, nutrients, and waste into and out of
organs
3. Provide area for storage
4. Often act as hydrostatic skeletons (supportive
yet flexible)
5. Provide a vehicle for eliminating wastes and
reproductive products from the body
6. Facilitate increase in body size
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
What does acoelomate mean?
• No coelom
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Acoelomate a, without+ kilos, hollow
• Mesoderm relatively solid mass
• No cavity formed between ecto and endo
• These cells within mesoderm often called
parenchymal cells
• Parenchymal cells not speciallized for a
particular fnc.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
What’s a coelom?
• coelom=
– true body cavity
– Fluid-filled
– lined by mesoderm-derived epithelium
Earthworm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Acoelomates lack a true body cavity
– Solid body
– no cavity b/w the digestive tract and outer body
wall
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Do these questions now…
• Think about aceolomate bilateral animals:
– To what domain do they belong
– “
”
kingdom ” ”
”
– What phyla include these organisms
• What is bilateral symmetry, and why was it
an important evolutionary advantage
movie
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Acoelomate Bilateral Animals
• Consist of phyla:
– Phylum
Platyhelminthes
– Phylum Nemertea
– Others…
flatworm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Ribon worm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Acoelomate Bilateral Animals
1.
Simplest organisms to
have bilateral symmetry
2.
Triploblastic
3.
Lack a coelom
4.
Organ-system level of
organization
5.
Cephalization
6.
Elongated, without
appendages
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Reproductive and
osmoregulatory systems
Acoelomate Bilateral Animals
1.
Simplest organisms to
have bilateral symmetry
2.
Triploblastic
3.
Lack a coelom
4.
Organ-system level of
organization
5.
Cephalization
6.
Elongated, without
appendages
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Reproductive and
osmoregulatory systems
Triploblastic Pseudocoelomate pseudes, false
• Body cavity not entirely lined by mesoderm
• No muscle or connective tissue associated with
gut
• No mesodermal
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Triploblastic Coelomate Pattern
• Coelom is a body cavity completely surrounded
by mesoderm
• Peritoneum- mesodermal sheet that lines the
inner body wall and serosa (outer covering of
visceral organs)
• Having mesodermally derived tissue (muscle,
connective tissue) enhances the function of all
internal body systems.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.12
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.3
Groups traced to separate ancestors
All descendants of a single ancestor
Includes some but not all of a members of a lineage
Fig 7.3 Evolutionary groups
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Fig 7.4 Vertebrate
Phylogenetic tree depicts
the degree of divergence
from a common ancestor
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.5
Fig 7.5 Interpreting Cladograms
Five taxa (1-5) and characteristics (A-H)
Symplesiomorphies- common characters in a group
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.6
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• The comparative study of animals
– Reveals that form and function are closely
correlated
Figure 40.1
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Physical laws and the environment constrain
animal size and shape
• Physical laws and the need to exchange
materials with the environment
– Place certain limits on the range of animal
forms
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Physical Laws and Animal Form
• Evolutionary convergence
– Reflects different species’ independent
adaptation to a similar environmental challenge
(a) Tuna
(b) Shark
(c) Penguin
(d) Dolphin
(e) Seal
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Exchange with the Environment
• An animal’s size and shape
– Have a direct effect on how the animal
exchanges energy and materials with its
surroundings
• Exchange with the environment occurs as
substances dissolved in the aqueous medium
– Diffuse and are transported across the cells’
plasma membranes
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• A single-celled protist living in water
– Has a sufficient surface area of plasma
membrane to service its entire volume of
cytoplasm
Diffusion
(a) Single cell
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Multicellular organisms with a sac body plan
– Have body walls that are only two cells thick,
facilitating diffusion of materials
Mouth
Gastrovascular
cavity
Diffusion
Diffusion
(b) Two cell layers
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Organisms with more complex body plans
Have highly folded internal surfaces specialized for exchanging materials
External environment
Mouth
Food
CO2
O2
Respiratory
system
0.5 cm
Cells
Heart
Nutrients
Circulatory
system
50 µm
Animal
body
A microscopic view of the lung reveals
that it is much more spongelike than
balloonlike. This construction provides
an expansive wet surface for gas
exchange with the environment (SEM).
10 µm
Interstitial
fluid
Digestive
system
Excretory
system
The lining of the small intestine, a digestive organ, is elaborated with fingerlike
projections that expand the surface area
for nutrient absorption (cross-section, SEM).
Anus
Unabsorbed
matter (feces)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Metabolic waste
products (urine)
Inside a kidney is a mass of microscopic
tubules that exhange chemicals with
blood flowing through a web of tiny
vessels called capillaries (SEM).
• Animal form and function are correlated at all
levels of organization
• Animals are composed of cells
• Groups of cells with a common structure and
function
– Make up tissues
• Different tissues make up organs
– Which together make up organ systems
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Tissue Structure and Function
• Different types of tissues
– Have different structures that are suited to their
functions
• Tissues are classified into four main categories
– Epithelial, connective, muscle, and nervous
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Epithelial Tissue
• Epithelial tissue
– Covers the outside of the body and lines
organs and cavities within the body
– Contains cells that are closely joined
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Epithelial tissue
EPITHELIAL TISSUE
Columnar epithelia, which have cells with relatively large cytoplasmic volumes, are often
located where secretion or active absorption of substances is an important function.
A simple
columnar
epithelium
A stratified columnar
epithelium
A pseudostratified
ciliated columnar
epithelium
Stratified squamous epithelia
Cuboidal epithelia
Simple squamous epithelia
Basement membrane
40 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Connective Tissue
• Connective tissue
– Functions mainly to bind and support other
tissues
– Contains sparsely packed cells scattered
throughout an extracellular matrix
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
CONNECTIVE TISSUE
• Connective tissue
100 µm
Chondrocytes
Chondroitin
sulfate
100 µm
Collagenous
fiber
Elastic
fiber
Cartilage
Loose connective tissue
Adipose tissue
Fibrous connective tissue
Fat droplets
150 µm
Nuclei
30 µm
Blood
Bone
Central
canal
Red blood cells
White blood cell
Osteon
700 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Plasma
55 µm
Muscle Tissue
• Muscle tissue
– Is composed of long cells called muscle fibers
capable of contracting in response to nerve
signals
– Is divided in the vertebrate body into three
types: skeletal, cardiac, and smooth
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Nervous Tissue
• Nervous tissue
– Senses stimuli and transmits signals
throughout the animal
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Muscle and nervous tissue
MUSCLE TISSUE
100 µm
Skeletal muscle
Multiple
nuclei
Muscle fiber
Sarcomere
Cardiac muscle
Nucleus Intercalated
disk
Smooth muscle
50 µm
Nucleus
Muscle
fibers
25 µm
NERVOUS TISSUE
Process
Neurons
Cell body
Nucleus
50 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Organs and Organ Systems
• In all but the simplest animals
– Different tissues are organized into organs
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• In some organs
– The tissues are arranged in layers
Lumen of
stomach
Mucosa. The mucosa is an
epithelial layer that lines
the lumen.
Submucosa. The submucosa is
a matrix of connective tissue
that contains blood vessels
and nerves.
Muscularis. The muscularis consists
mainly of smooth muscle tissue.
Serosa. External to the muscularis is the serosa,
a thin layer of connective and epithelial tissue.
0.2 mm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Representing a level of organization higher
than organs
– Organ systems carry out the major body
functions of most animals
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Organ systems in mammals
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• After the energetic needs of staying alive are met
– Any remaining molecules from food can be used
in biosynthesis
Organic molecules
in food
External
environment
Animal
body
Digestion and
absorption
Heat
Nutrient molecules
in body cells
Carbon
skeletons
Cellular
respiration
Energy
lost in
feces
Energy
lost in
urine
Heat
ATP
Biosynthesis:
growth,
storage, and
reproduction
Heat
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Cellular
work
Heat
• Birds and mammals are mainly endothermic,
meaning that
– Their bodies are warmed mostly by heat
generated by metabolism
– They typically have higher metabolic rates
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Amphibians and reptiles other than birds are
ectothermic, meaning that
– They gain their heat mostly from external
sources
– They have lower metabolic rates
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Size and Metabolic Rate
• Metabolic rate per gram
– Is inversely related to body size among similar
animals
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Energy Budgets
• An animal’s use of energy
– Is partitioned to BMR (or SMR), activity,
homeostasis, growth, and reproduction
Annual energy expenditure (kcal/yr)
Endotherms
Activity 340,000
costs
8,000
4,000
60-kg female human
from temperate climate
(a) Total annual energy expenditures
Energy expenditure per unit mass
(kcal/kg•day)
Ectotherm
800,000 BasalReproduction Temperature
regulation costs
metabolic
rate
Growth
4-kg male Adélie penguin
from Antarctica (brooding)
0.025-kg female deer mouse 4-kg female python
from temperate
from Australia
North America
438
Human
233
Deer mouse
(b) Energy expenditures per unit mass (kcal/kg•day)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Python
Adélie penguin
36.5
5.5
Mechanisms of Homeostasis
• Mechanisms of homeostasis
– Moderate changes in the internal environment
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• A homeostatic control system has three
functional components
– A receptor, a control center, and an effector
Response
No heat
produced
Heater
turned
off
Room
temperature
decreases
Too
hot
Set
point
Too
cold
Set
point
Set point
Control center:
thermostat
Room
temperature
increases
Heater
turned
on
Response
Heat
produced
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Most homeostatic control systems function by
negative feedback
– Where buildup of the end product of the
system shuts the system off
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• A second type of homeostatic control system is
positive feedback
– Which involves a change in some variable that
triggers mechanisms that amplify the change
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Thermoregulation contributes to homeostasis
and involves anatomy, physiology, and
behavior
• Thermoregulation
– Is the process by which animals maintain an
internal temperature within a tolerable range
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Ectotherms and Endotherms
• Ectotherms
– Include most invertebrates, fishes, amphibians,
and non-bird reptiles
• Endotherms
– Include birds and mammals
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• In general, ectotherms
– Tolerate greater variation in internal temperature
than endotherms
40
Body temperature (°C)
River otter (endotherm)
30
20
Largemouth bass (ectotherm)
10
0
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
10
20
30
40
Ambient (environmental) temperature (°C)
• Endothermy is more energetically expensive
than ectothermy
– But buffers animals’ internal temperatures
against external fluctuations
– And enables the animals to maintain a high
level of aerobic metabolism
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Nutrition
• Overview: The Need to Feed
• Every mealtime is a reminder that we are
heterotrophs
– Dependent on a regular supply of food
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• In general, animals fall into one of three dietary
categories
– Herbivores eat mainly autotrophs (plants and
algae)
– Carnivores eat other animals
– Omnivores regularly consume animals as well
as plants or algal matter
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Regardless of what an animal eats, an
adequate diet must satisfy three nutritional
needs
– Fuel for all cellular work
– The organic raw materials for biosynthesis
– Essential nutrients, substances such as
vitamins that the animal cannot make for itself
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Animals feed by four main mechanisms
SUSPENSION FEEDERS
SUBSTRATE FEEDERS
Feces
Baleen
Caterpillar
FLUID FEEDERS
BULK FEEDERS
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Homeostatic mechanisms manage an animal’s
energy budget
• Nearly all of an animal’s ATP generation
– Is based on the oxidation of energy-rich
molecules: carbohydrates, proteins, and fats
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Glucose Regulation as an Example of Homeostasis
• Animals store excess calories
– As glycogen in the liver and muscles and as fat
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• The main stages of food processing are
ingestion, digestion, absorption, and
elimination
• Ingestion, the act of eating
– Is the first stage of food processing
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Digestion, the second stage of food processing
– Is the process of breaking food down into
molecules small enough to absorb
– Involves enzymatic hydrolysis of polymers into
their monomers
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Absorption, the third stage of food processing
– Is the uptake of nutrients by body cells
• Elimination, the fourth stage of food processing
– Occurs as undigested material passes out of
the digestive compartment
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• The four stages of food processing
Small
molecules
Pieces
of food
Mechanical
digestion
Chemical digestion
(enzymatic hydrolysis)
Nutrient
molecules
enter body
cells
Undigested
material
Food
1 INGESTION
2 DIGESTION
3 ABSORPTION
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
4
ELIMINATION
Intracellular Digestion
• In intracellular digestion
– Food particles are engulfed by endocytosis
and digested within food vacuoles
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Extracellular Digestion
• Extracellular digestion
– Is the breakdown of food particles outside cells
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Animals with simple body plans
– Have a gastrovascular cavity that functions in
both digestion and distribution of nutrients
Tentacles
Mouth
Food
Gastrovascular
cavity
Epidermis
Mesenchyme
Gastrodermis
Nutritive
muscular
cells
Flagella
Gland cells
Food vacuoles
Mesenchyme
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Animals with a more complex body plan
– Have a digestive tube with two openings, a
mouth and an anus
• This digestive tube
– Is called a complete digestive tract or an
alimentary canal
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• The digestive tube can be organized into
specialized regions
– That carry out digestion and nutrient
absorption in a stepwise fashion
(a)
(b)
Earthworm. The digestive tract of
an earthworm includes a muscular
pharynx that sucks food in through the
mouth. Food passes through the
esophagus and is stored and moistened
in the crop. The muscular gizzard, which
contains small bits of sand and gravel,
pulverizes the food. Digestion and
absorption occur in the intestine,
which has a dorsal fold, the typhlosole,
that increases the surface area for
nutrient absorption.
Grasshopper. A grasshopper has several
digestive chambers grouped into three
main regions: a foregut, with an esophagus
and crop; a midgut; and a hindgut. Food is
moistened and stored in the crop, but most
digestion occurs in the midgut. Gastric ceca,
pouches extending from the midgut,
absorb nutrients.
Esophagus Crop
Gizzard
Intestine
Pharynx
Anus
Mouth
Typhlosole
Lumen of intestine
Foregut
Midgut
Hindgut
Esophagus
Rectum
Anus
Mouth
Crop
Gastric ceca
Esophagus
(c)
Bird. Many birds have three separate chambers—
the crop, stomach, and gizzard—where food is
pulverized and churned before passing into the
intestine. A bird’s crop and gizzard function very
much like those of an earthworm. In most birds,
chemical digestion and absorption of nutrients
occur in the intestine.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Gizzard
Mouth
Intestine
Crop
Stomach
Anus