PERIODE 2.1
VOEDING EN ENERGIE
,Week 0: zelfstudie
Diverse forms, common challenges
• Anatomy is the biological form of an organism
• Physiology is the biological functions an organism performs
• The comparative study of animals reveals that form and function are closely
correlated
Evolution in animal size and shape
• Physical laws govern strength, diffusion, movement and heat exchange
• Properties of water limit possible shapes for fast swimming animals
• Convergent evolution often results in similar adaptations of diverse organisms
facing the same challenge
• As animals increase in size, thicker skeletons are required for support
Exchange with the environment
• Materials such as nutrients, waste products, and gases must be exchanges
across the cell membranes of animal cells
• Rate of exchange is proportional to a cell’s surface area, while amount of
exchange material is proportional to a cell’s volume
• A single-celled organism living in water has sufficient surface area to carry out all
necessary exchange (amoeba)
• Multicellular organisms with a saclike body plan have body walls that are only
two cells thick (hydra)
, • In animals, the space between cells is filled with interstitial fluid, which links
exchange surfaces to body cells
• A complex body plan helps an animal living in a carriable environment to
maintain a relatively stable internal environment
Hierarchical organization of body parts
• Most animals are composed of cells organized into tissues that have different
functions
• Tissues make up organs, which together make up organ systems
• Some organs such as the pancreas belong to more than 1 organ system
Coordination and control
• Control and coordination within a body depend on the
endocrine and nervous system
• The endocrine system releases hormones into the
bloodstream
• A hormone may affect one or more regions throughout the
body
• Hormones are relatively slow acting but can have long-
lasting effects
• The nervous system transmits information between
specific locations
• The information conveyed depends on a signal’s pathway
not the type of signal
• Nerve signal transmission is very fast
• The endocrine and nervous system often work in close coordination
, Feedback control maintains the internal environment in many animals
• Faced with environmental fluctuations
animals manage their internal
environment by either regulating or
conforming
o A regulator uses an internal
control mechanism to control
internal change in the face of
external fluctuation
o A conformer allows its internal
condition to vary with certain
external changes
• Animals may regulate some environmental variables while conforming to others
Homeostasis
• Organisms use homeostasis to maintain a steady state or internal balance
regardless of the external environment
• In humans, body temperature, blood pH and glucose concentration are each
maintained at a constant level
Mechanisms of homeostasis
• Mechanisms of homeostasis moderate changes in
the internal environment
• For a given variable, fluctuations above or below a set
point serve as a stimulus, these are detected by a
sensor
• A control center then generates output that triggers a
response
• The response returns the variable to the set point
Feedback control in homeostasis
• Homeostasis in animals relies largely on negative feedback, which helps to
return a variable to a normal range
• Positive feedback amplifies a stimulus and does not usually contribute to
homeostasis in animals
VOEDING EN ENERGIE
,Week 0: zelfstudie
Diverse forms, common challenges
• Anatomy is the biological form of an organism
• Physiology is the biological functions an organism performs
• The comparative study of animals reveals that form and function are closely
correlated
Evolution in animal size and shape
• Physical laws govern strength, diffusion, movement and heat exchange
• Properties of water limit possible shapes for fast swimming animals
• Convergent evolution often results in similar adaptations of diverse organisms
facing the same challenge
• As animals increase in size, thicker skeletons are required for support
Exchange with the environment
• Materials such as nutrients, waste products, and gases must be exchanges
across the cell membranes of animal cells
• Rate of exchange is proportional to a cell’s surface area, while amount of
exchange material is proportional to a cell’s volume
• A single-celled organism living in water has sufficient surface area to carry out all
necessary exchange (amoeba)
• Multicellular organisms with a saclike body plan have body walls that are only
two cells thick (hydra)
, • In animals, the space between cells is filled with interstitial fluid, which links
exchange surfaces to body cells
• A complex body plan helps an animal living in a carriable environment to
maintain a relatively stable internal environment
Hierarchical organization of body parts
• Most animals are composed of cells organized into tissues that have different
functions
• Tissues make up organs, which together make up organ systems
• Some organs such as the pancreas belong to more than 1 organ system
Coordination and control
• Control and coordination within a body depend on the
endocrine and nervous system
• The endocrine system releases hormones into the
bloodstream
• A hormone may affect one or more regions throughout the
body
• Hormones are relatively slow acting but can have long-
lasting effects
• The nervous system transmits information between
specific locations
• The information conveyed depends on a signal’s pathway
not the type of signal
• Nerve signal transmission is very fast
• The endocrine and nervous system often work in close coordination
, Feedback control maintains the internal environment in many animals
• Faced with environmental fluctuations
animals manage their internal
environment by either regulating or
conforming
o A regulator uses an internal
control mechanism to control
internal change in the face of
external fluctuation
o A conformer allows its internal
condition to vary with certain
external changes
• Animals may regulate some environmental variables while conforming to others
Homeostasis
• Organisms use homeostasis to maintain a steady state or internal balance
regardless of the external environment
• In humans, body temperature, blood pH and glucose concentration are each
maintained at a constant level
Mechanisms of homeostasis
• Mechanisms of homeostasis moderate changes in
the internal environment
• For a given variable, fluctuations above or below a set
point serve as a stimulus, these are detected by a
sensor
• A control center then generates output that triggers a
response
• The response returns the variable to the set point
Feedback control in homeostasis
• Homeostasis in animals relies largely on negative feedback, which helps to
return a variable to a normal range
• Positive feedback amplifies a stimulus and does not usually contribute to
homeostasis in animals
