Basic principles of animal form

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Basic principles of animal form function

• Chapter 40

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Problem Solving

• Animals must solve basic challenges of life
• Obtain oxygen
• Nourish themselves
• Excrete waste products
• Move
• These questions will be addressed throughout our
  next unit.
• Unifying themes that will be introduced here
• Form function are closely related

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Vocabulary

• Anatomy is the study of the structure of an
  organism
• Physiology is the study of the functions an
  organism performs
• Bioenergetics how organisms obtain, process,
  and use their energy resources.
• Homeostasis regulating internal temperature

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40.1

• Physical laws and the environment constrain
  animal size and shape.
• An animals size and shape (body plan or design)
  affect the way it interacts with its environment.

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Physical Laws

• Physical laws and the need to exchange materials
  with the environment place certain limits on the
  range of animals forms.
• Examples Aquatic animals (sleek streamlined body
  forms) and flying animals (bones that allow for
  the organism to generate enough lift to become
  air born)

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Exchange with the environment

• Living cells must be bathed in a aqueous medium
  to keep the plasma membrane intact
• Single celled organisms Surface-to-volume ratio
  Fig. 40.3a

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Multicellular organisms

• Composed of numerous
• cells which also must be in
• water
• Saclike body plan
• Hydra Fig. 40.3b
• Flat body plan
• tapeworm

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• Both of these put a large surface area in contact
  with the environment but do NOT allow for
  complexity in internal organization
• Complex body forms allow for outer coverings to
  protect against predators, large muscles for fast
  movement internal digestive organs to break down
  food gradually, maintaining relatively stable
  internal environment, and for living on land.

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40.2

• Animal form and function are correlated at all
  levels of organization.
• Tissues are classified into 4 main categories
  pg. 824-826

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Epithelial

• Sheets of tightly packed cells
• Where is it found? Epithelial tissue covers the
  outside of the body and lines organs and cavities
  within the body
• Form function? Closely joined (tight junctions
  between them) so epithelium functions as a
  barrier against mechanical injury, microbes, and
  fluid loss.

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• Types?
• Stratified columnar
• Simple columnar
• Pseudostratified ciliated columnar
• Stratified squamous
• Simple squamous
• Cuboidal
• All have slightly different volumes of cytoplasm
  which allow them to perform different functions.

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Connective Tissue

• Sparse population of cells scattered through an
  extracellular matrix.
• Where is it found? Everywhere
• Form function? Bind and support other tissues

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• Types?
• Loose connective tissue holds organs in place
• Fibrous connective tissue tendons ligaments
• Cartilage
• Bone mineralized connective tissue
• Blood
• Adipose tissue stores fat

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Muscles tissue

• Long cells called muscle fibers
• Where is it found? Everywhere!! Most abundant
  tissue in most animals
• Form function? Contraction brings about movement

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• Types?
• Skeletal attaches to bones voluntary
  movement
• Cardiac striated involuntary
• Smooth lacks striations - involuntary

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Nervous Tissue

• Nerve cells
• Organs organ systems see table 40.1 pg. 827

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40.3

• Animals use the chemical energy in food to
  sustain form and function
• Bioenergetics limits the animals behavior,
  growth, and reproduction and determines how much
  food it needs.

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• Fig. 40.7 After the energetic needs of staying
  alive are met any remaining molecules from food
  can be used in biosynthesis (body growth
  repair, storage material such as fat and
  production of gametes)

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• Metabolic rate the sum of all the
  energy-requiring biochemical reactions occurring
  over a given time interval.
• Energy measured in Calories (cal) or kilocalories
  (kcal)
• Unit Calorie with a capital C is actually a
  kilocalorie
• Energy appears as heat so metabolic rate can be
  determined by measuring heat.

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2 Bioenergetic Strategies

• Endothermic bodies are warmed mostly by heat
  generated by matabolism and body temperature is
  maintained within a relatively narrow range.
• Ectothermic meaning that they gain their heat
  mostly from external sources

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Endo or Ectothermic?
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Endo or Ectothermic?
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Endo or ectothermic?
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Influences on metabolic rate

• Size and metabolic rate amount of energy it
  takes to maintain each gram of body weight is
  inversely related to body size. (Example each
  gram of a mouse requires about 20 times more
  calories than a gram of an elephant)

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• Activity and metabolic rate every animal
  experiences a range of metabolic rates. Basal
  Metabolic rate (BMR) metabolic rate of a
  nongrowing endotherm that is at rest, has an
  empty stomach, and is not experiencing stress.
• 1,600-1,800 kcal per day for adult male
• 1,300-1,500 kcal per day for adult female

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• Standard Metabolic rate (SMR) metabolic rate of
  a resting, fasting, nonstressed ectotherm at a
  particular temperature.
• Maximum potential metabolic rates and ATP sources
  pg. 830 fig. 40.9

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• Energy budgets pg. 831 Fig. 40.10

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40.4

• Many animals regulate their internal environment
  within relatively narrow limits
• Interstitial fluid (Bernard more than a century
  ago) internal environment of vertebrates
  today homeostasis steady state

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Regulators vs. Conformers

• Regulators animal is a regulator for a
  particular environmental variable is it uses
  internal control mechanisms to moderate internal
  change in the face of external fluctuation

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• Conformer an animal is said to be a conformer
  for a particular environmental variable if it
  allows its internal condition to vary with
  certain external changes
• Regulators and conformers are extremes and no
  animal is a perfect regulator or conformer
• Some animals may regulate some internal
  conditions and conform to external conditions for
  others.

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Mechanisms of Homeostasis

• Negative feedback thermostat in your house pg.
  832 Fig. 40.1
• Positive feedback amplify rather than reverse
  the change (child birth)

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40.5

• Thermoregulation process by which animals
  maintain an internal temperature within a
  tolerable range. Critical because most
  biological processes work best at optimal
  conditions (plasma membrane)

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Ectotherms vs. Endotherms

• Ectotherms include invertebrates, fishes,
  amphibians, lizards, snakes, and turtles
• The amount of heat they generate has little
  effect on body temperature
• Bask in the sun to warm
• Seek shade to cool
• Can tolerate greater variation in internal
  temperature than endotherms
• Not cold-blooded

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• Endotherms include mammals, birds, some fish, and
  numerous insect species
• Can use metabolic heat to regulate body
  temperature
• Sweating to cool
• Not warm-blooded

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Advantages Disadvantages

• Advantages able to generate a large amount of
  heat metabolically can perform vigorous
  activity for much longer than is possible for
  most ectotherms, can tolerate extreme
  temperatures
• Disadvantages energetically expensive
  requires more food

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Modes of heat exchange

• Conduction
• Convection
• Radiation
• Evaporation

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Balancing heat loss gain

• Insulation
• Circulatory adaptations
• Cooling by evaporative heat loss
• Behavioral responses
• Adjusting metabolic heat production

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Insulation

• Skin, hair, nails, fur
• Skin houses nerves, sweat glands, blood vessels,
  and hair follicles

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Insulation
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Circulatory adaptations

• Vasodilation (warms skin) increases in diameter
  of superficial blood vessels
• Vasoconstriction (cools skin) reduces blood
  flow and heat transfer by decreasing the diameter
  of superficial blood vessels
• Countercurrent heat exchanger important for
  reducing heat loss in many endotherms

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Cooling by evaporative heat loss

• Water absorbs considerable heat when it
  evaporates
• Panting
• Sweat glands
• Spreading saliva on body surface

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Roxy panting!!
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Behavioral responses

• Both ecto and endotherms
• Hibernation
• Migration
• Huddling in cold weather

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Adjusting metabolic heat production

• Endotherms must counteract constant heat loss
• Heat production is increased by shivering
• NST nonshivering thermogenesis (produce heat
  instead of ATP)

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• Feedback mechanisms controlled by hypothalamus in
  the brain

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• Acclimatization both ectotherms and endotherms
  can adjust to new range of environmental
  temperatures.
• Shedding, growing a thicker coat
• Heat shock proteins help maintain integrity of
  cells proteins when exposed to extreme heat so
  they dont denature

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Torpor energy conservation

• Torpor a physiological state in which activity
  is low and metabolism decreases
• Hibernation long term torpor to winter cold and
  food scarcity
• Estivation summer torpor
• Daily torpor adapted to feeding patterns