1. CHAPTER 40 INTRODUCTION TO ANIMAL FORM AND FUNCTION
Prepared by
Brenda Leady, University of Toledo
Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. All animal cells share similarities in the ways in which they
Exchange materials with their surroundings
Obtain energy from organic nutrients
Synthesize complex molecules
Duplicate themselves
Detect and respond to signals in their immediate environment

4. Tissues Specialized cells of a given types cluster together
4 categories
Muscle
Nervous
Epithelial
Connective

5. Muscle tissue Cells specialized to contract 3 types
Skeletal – attached to bone or exoskeleton for locomotion, voluntary control
Smooth – surrounds hollow tubes and cavities for propulsion of contents, involuntary control
Cardiac – only in the heart, involuntary control

7. Nervous tissue
Initiate and conduct electrical signals from one part of the animal’s body to another
Electrical signals produced in one nerve cell may stimulate or inhibit other nerve cells to
Initiate new electrical signals
Stimulate muscle to contract
Stimulate glands to release chemicals

9. Epithelial tissues Sheets of densely packed cells that
Cover the body or individual organs
Line the walls of body cavities
Specialized to protect and secrete or absorb
Rest on basal lamina or basement membrane
Can function as selective barriers

11. Connective tissues Connect, anchor, and support
Includes blood, adipose, bone, cartilage, loose and dense connective tissue
Form an extracellular matrix around cells
Provides scaffold for attachment
Protects and cushions
Mechanical strength
Transmit information

13. Creature Feature

14. Organs Composed of 2 or more kinds of tissues
Organ system – different organs work together to perform an overall function
Organ systems frequently work together – nervous and endocrine system
Spatial arrangement of organs into organ systems part of overall body plan
Body plan controlled by highly conserved family of genes with homologs in all animals

16. Organ Development and Function Are Controlled by Homeotic Genes
Homeotic genes – family of ancient highly conserved genes found in all animals
Determine timing and spatial patterning of the anteroposterior body axis during development
In vertebrates known as Hox genes
Important role in determining where organs form
Hox genes also important for growth, development and function of organs in adults

17. Body fluids 2 main compartments
Intracellular fluid – inside cells
Extracellular fluid – outside cells
Plasma – fluid portion of blood
Interstitial fluid – fluid between cells
Separate in closed systems
Hemolymph intermingles to fluids in many inverts
Intracellular and extracellular fluid can be very different in solute composition

19. Movement of water
Plasma membranes tend to be highly permeable to water and
Fluid moves readily between compartments
Osmosis
Swollen or shrunken cells do not operate well
Can happen when cells exposed to more dilute (hypoosmotic) or more concentrated (hyperosmotic) extracellular fluids

21. Movement of solutes Passive diffusion Transport proteins used in
Movement of a solute down its concentration gradient
No carrier or ATP required
Only lipid soluble molecules
Transport proteins used in
Facilitated diffusion – passive
Active transport

22. Fick diffusion equation:
Movement of solutes
What variables influence the rate of diffusion?
Fick diffusion equation:
J = KA (C1 - C2)

23. Structure and function
Key theme is structure determines function
Compare respiratory systems of insect and mammal
Structural similarities suggest similar function
Tubes connect with the outside environment terminating in 1 cell thick structures
Tubes serve as air conduits
Thin cells with high surface area for diffusion of gases

25. Increased space requirements avoided by shape changes
All organs that mediate diffusion or absorption have an extensive surface area
Increased space requirements avoided by shape changes
Folding for example
SA/V – surface area to volume ratio

27. Surface area to volume ratio
In groups of 3 discuss and come up with 3 specific examples of species/organs we studied that have important roles of increasing surface area

28. Homeo-stasis
Process of adjusting to the external environment and maintaining a stable internal environment
Conformers – maintain same fluid composition as environment – cheaper
Regulators – internal composition of fluids different from environment – more expensive
Animal can be both with respect to different variables

29. No physiological function is constant for very long, which is why we call them “variables”
Normally, blood sugar (glucose) remains at fairly steady and predictable levels in any healthy individual
After a meal the level of glucose in your blood can increase quickly
If you skip a meal, your blood sugar level may drop slightly
Homeostatic mechanisms restore blood glucose to normal levels in the blood

31. Homeostatic control systems
Sensor – monitors particular variable
Integrator – compares signals from the sensor to a baseline set point
Effector – compensates for deviations between actual value and set point
Example – body temperature in mammals

33. Feedback Fundamental feature of homeostasis
Major way disturbances are minimized
Negative feedback
Positive feedback

34. Feedback
Discuss with your neighbor a variable in the human body, the sensor, integrator and effector in the feedback system

35. Negative feedback
Variable being regulated brings about responses that move the variable in the opposite direction
Decrease in body temperature leads to responses that increase body temperature
May occur at organ, cellular or molecular level

37. Positive feedback Far less common Accelerates a process
Reinforces the direction of the change
Birth in mammals

39. Feedforward regulation
Animal’s body begins preparing for a change in some variable before it occurs
Anticipatory
Speeds up homeostatic responses and minimizes deviations from the set point
Many result from or are modified by learning

41. Pavlov Demonstrated the Relationship Between Learning and Feedforward Processes
Demonstrated that feedforward processes associated with digestion could be conditioned to an irrelevant stimulus
Used ticking metronome (not ringing bell)
Conditioned stimulus by itself can elicit increased salivation
Other sounds and stimuli also worked
Conditioned response not permanent

43. Local homeostatic responses
Some homeostatic responses may be highly localized
Paracrine signaling – molecules released into interstitial fluid to act on nearby cells
Neurotransmitters released from one nerve cell travel to an adjacent nerve cell
In contrast, hormones are chemical messengers produced in a gland, secreted into the blood, and act on distant cells