Chapter 33: The Animal Body: Reading Guide
Student Learning Outcomes:
By the end of this chapter students should be able to:
❖ Explain the difference between the different types of body symmetry.
❖ Describe the limits on animal size and shape.
❖ Describe the difference between ectotherms and endotherms.
❖ Explain the relationship between basal metabolic rate and body size.
❖ Describe the structure and function of the 4 tissues found in animals.
❖ Define homeostasis
❖ Describe the difference between positive and negative feedback mechanisms used in
homeostasis.
❖ Describe the thermoregulation of endothermic and ectothermic animals.
Terms you should know:
❖ Asymmetry: No symmetry. Ex: sponges
❖ Radial symmetry: If you cut the organism through a central axis, there will be two equal
halves. Ex. Jellyfish, corals
❖ Bilateral symmetry: Cut along one plane (forehead through nose) two equal halves. Ex.
Goats
❖ Ectotherm: Maintain body temperature through behavior
❖ Endotherm: Conserve and maintain a relatively constant body temperature
❖ Homeostasis: The ability to maintain a relatively constant internal environment
❖ Epithelial tissue: Form sheets that cover the inner and outer body surfaces
➢ Provides protection from mechanical injury, fluid loss, and pathogens (first line of
defense)
➢ Sensory functions, secretion
➢ Cells have a luminal side (finger like projections) and basolateral side (basement
membrane; cells in the membrane are anchored)
❖ Connective tissue: Hold organs in place
➢ Cells embedded in extensive extracellular matrix (proteins and carbohydrates)
➢ Properties are determined by the extracellular matrix
➢ These tissues have the most diversity**
❖ Nervous tissue: Involved in communication
➢ Two types of cells: neurons and glial cells
❖ Muscle tissue: Long, thin cells; Cells can contract
➢ 3 types: Skeletal (involved in movement; called “voluntary” muscle because we
have control over movement of these muscles), smooth (found in internal organs;
responsible for contraction and movement of those organs), and cardiac (found
only in the heart; responsible for heartbeat)
, ❖ Thermoregulation: The ability of an animal to modify its behavior of physiology in
order to maintain a range of body temperatures
❖ Acclimatization: Process in which an individual organism adjusts to a change in its
environment (such as a change in altitude, temperature, humidity, photoperiod, or pH),
allowing it to maintain performance across a range of environmental conditions.
❖ Basal metabolic rate: The rate at which the body uses energy while at rest to keep vital
functions going, such as breathing and keeping warm.
❖ Hibernation: state of inactivity and metabolic depression in endotherms. Hibernation
refers to a season of heterothermy characterized by low body temperature, slow breathing
and heart rate, and low metabolic rate.
❖ Estivation: Prolonged torpor or dormancy of an animal during a hot or dry period.
❖ Torpor: Dormancy or lethargy
❖ Negative feedback: Returns the system back to the set point
➢ Speeding on the highway, police officer is the negative feedback to move back to
the speed limit
❖ Positive feedback: Allows further deviation from the set point
➢ Speeding on the highway, there is no police officer which is positive feedback,
which makes you go faster
➢ Go into labor, start off with minimal contractions that get more intense and
frequent. Set point is pain threshold that does not change, but contractions
increase in frequency and painfulness
❖ Set point: The range of values at which a physical parameter must be maintained for
optimal function
❖ Sagittal Plane: The area where you can slice to bilateral symmetrical organisms in half
and get two equal halves
❖ Transverse plane: Horizontal
Questions to think about:
1. What are the functions of epithelial tissues?
a. Form sheets that cover the inner and outer body surfaces
b. Provides protection from mechanical injury, fluid loss, and pathogens (first line of
defense)
c. Sensory functions, secretion
d. Cells have a luminal side (finger like projections) and basolateral side (basement
membrane; cells in the membrane are anchored)
2. What makes one connective tissue different from another?
a. Cells embedded in extensive extracellular matrix (proteins and carbohydrates)
b. Properties are determined by the extracellular matrix
c. These tissues have the most diversity**
Student Learning Outcomes:
By the end of this chapter students should be able to:
❖ Explain the difference between the different types of body symmetry.
❖ Describe the limits on animal size and shape.
❖ Describe the difference between ectotherms and endotherms.
❖ Explain the relationship between basal metabolic rate and body size.
❖ Describe the structure and function of the 4 tissues found in animals.
❖ Define homeostasis
❖ Describe the difference between positive and negative feedback mechanisms used in
homeostasis.
❖ Describe the thermoregulation of endothermic and ectothermic animals.
Terms you should know:
❖ Asymmetry: No symmetry. Ex: sponges
❖ Radial symmetry: If you cut the organism through a central axis, there will be two equal
halves. Ex. Jellyfish, corals
❖ Bilateral symmetry: Cut along one plane (forehead through nose) two equal halves. Ex.
Goats
❖ Ectotherm: Maintain body temperature through behavior
❖ Endotherm: Conserve and maintain a relatively constant body temperature
❖ Homeostasis: The ability to maintain a relatively constant internal environment
❖ Epithelial tissue: Form sheets that cover the inner and outer body surfaces
➢ Provides protection from mechanical injury, fluid loss, and pathogens (first line of
defense)
➢ Sensory functions, secretion
➢ Cells have a luminal side (finger like projections) and basolateral side (basement
membrane; cells in the membrane are anchored)
❖ Connective tissue: Hold organs in place
➢ Cells embedded in extensive extracellular matrix (proteins and carbohydrates)
➢ Properties are determined by the extracellular matrix
➢ These tissues have the most diversity**
❖ Nervous tissue: Involved in communication
➢ Two types of cells: neurons and glial cells
❖ Muscle tissue: Long, thin cells; Cells can contract
➢ 3 types: Skeletal (involved in movement; called “voluntary” muscle because we
have control over movement of these muscles), smooth (found in internal organs;
responsible for contraction and movement of those organs), and cardiac (found
only in the heart; responsible for heartbeat)
, ❖ Thermoregulation: The ability of an animal to modify its behavior of physiology in
order to maintain a range of body temperatures
❖ Acclimatization: Process in which an individual organism adjusts to a change in its
environment (such as a change in altitude, temperature, humidity, photoperiod, or pH),
allowing it to maintain performance across a range of environmental conditions.
❖ Basal metabolic rate: The rate at which the body uses energy while at rest to keep vital
functions going, such as breathing and keeping warm.
❖ Hibernation: state of inactivity and metabolic depression in endotherms. Hibernation
refers to a season of heterothermy characterized by low body temperature, slow breathing
and heart rate, and low metabolic rate.
❖ Estivation: Prolonged torpor or dormancy of an animal during a hot or dry period.
❖ Torpor: Dormancy or lethargy
❖ Negative feedback: Returns the system back to the set point
➢ Speeding on the highway, police officer is the negative feedback to move back to
the speed limit
❖ Positive feedback: Allows further deviation from the set point
➢ Speeding on the highway, there is no police officer which is positive feedback,
which makes you go faster
➢ Go into labor, start off with minimal contractions that get more intense and
frequent. Set point is pain threshold that does not change, but contractions
increase in frequency and painfulness
❖ Set point: The range of values at which a physical parameter must be maintained for
optimal function
❖ Sagittal Plane: The area where you can slice to bilateral symmetrical organisms in half
and get two equal halves
❖ Transverse plane: Horizontal
Questions to think about:
1. What are the functions of epithelial tissues?
a. Form sheets that cover the inner and outer body surfaces
b. Provides protection from mechanical injury, fluid loss, and pathogens (first line of
defense)
c. Sensory functions, secretion
d. Cells have a luminal side (finger like projections) and basolateral side (basement
membrane; cells in the membrane are anchored)
2. What makes one connective tissue different from another?
a. Cells embedded in extensive extracellular matrix (proteins and carbohydrates)
b. Properties are determined by the extracellular matrix
c. These tissues have the most diversity**
