1. Animal Form & Function

2. I. Characteristics of Life
A. Livings things have to – obtain oxygen & nutrients, fight off infection, produce offspring
B. All living these face the challenges of their environment through many different adaptations all living things have found ways to increase fitness.
1. The form of any adaptation can give clues to the function of the anatomy of the organism or physiology.

3. II. Exchange with the Environment
A. All animals must exchange materials with the environment and this places limits on body plans.
1. Rate of exchange is proportional to membrane surface area and the amount of material that must be exchanged to sustain life is proportional to cell volume
a. some organisms need adaptations to deal with these limitations – interstitial fluid, membrane folding

5. III. Organization of the Body
A. Every cell in an animal body is both an independent unit & an interdependent part of an organism.
B. The levels of organization in a multicellular organism include: cells  tissues  organs  organ systems.

6. III. Organization of the Body
1. Cells – are the basic unit of structure & function in living things and can perform uniquely suited jobs.
2. Tissues – groups of cells that perform a single function
4 basic types of tissue include:
1. epithelial tissue – includes glands, covers interior & exterior surfaces (tight junctions)
2. connective tissue – provides strength & flexibility for the body (collagenous fibers) & connects parts (reticular fibers), and elasticity
3. nervous tissue – transmits nerve impulses throughout body
4. muscle tissue – enables body to move with proteins called actin and myosin (skeletal, smooth, and cardiac)

8. III. Organization of the Body
3. Organs – a group of different tissues that work together to perform a single function.
Example: eye
4. Organ systems – a group of organs that perform closely related functions.
Some organs are part of several systems
Example: pancrease – digestive & endocrine

9. IV. Coordination & Control
A. All tissues, organs, & systems must act in concert with one another. The body has 2 ways to coordinate the activity between the cells of your body.
B. Two signaling processes:
Endocrine system – use of hormones, broadcast across entire body slow acting but long lasting
Nervous system – use of neurons that carry a message to specific location quickly

11. V. Maintaining Homeostasis
A. An organism is a regulator for a particular environmental variable if it uses internal mechanism to control internal change due to external change but a conformer is it allows the internal condition to change with the external change.
B. Homeostasis is the process by which organisms keep internal conditions relatively constant despite changes in external environments.
1. pH blood 7.4, temp. 98.6C, blood sugar
Hypothalamus!!

13. VI. Forms of Feedback
A. Your body has a specific conditions called set points. Any variable that causes fluctuations from these conditions are called a stimulus that are going to trigger a response by the sensor to return the body to the set point.
B. Two ways to return to set point:
Negative feedback – reduces the stimulus (sweating)
Positive feedback – amplifies the stimulus (childbirth)

15. VII. Alternations of Homeostasis
A. Circadian rhythm – physiological changes to set points that occur roughly every 24 hours
1. melatonin levels
B. Acclimatization – gradual process by which an animal adjusts to changes in its external environment
1. sea level to mountains

16. IIX. Thermoregulation
A. Thermoregulation – process by which animals maintain their internal temperature controlled by the hypothalamus
1. every 10 degree changes how effective hemoglobin binds as well as fluidity of membranes
B. Sources of heat:
1. Endothermic – warmed by heat generated by metabolism (birds & mammals, most insects)
2. Exothermic – gain heat from external sources (invertebrates)

18. IX. Variation in Temperature
A. An animals body temperature that varies with the environment are known as poikilotherms while homeotherms have a relatively constant body temperature.
Not directly correlated with endo- and exo- therms

19. X. Balancing Heat Loss & Gain
A. All animals exchange heat by 4 physical processes (heat always moving from hot to cold)
1. Radiation
2. Evaporation
3. Convection
4. Conduction
B. Insulation reduces heat transfer between organism and the environment (feathers & fur, vasodilation & vasoconstriction, and countercurrent exchange)

21. Behavior Responses/Adjusting Metabolic Production
Nonshivering thermogenesis
Hormones can cause mitochondria to increase activity and produce heat instead of ATP.
Bird fluttering
Pouch full of blood vessels
Alternations of Fur coat
Proportions of saturated/unsaturated fats
“Antifreeze” crystal production

23. XI. Bioenergetics
A. Bioenergetics is the overall flow and transformation of energy in an animal determined by nutritional needs and is related to the animal’s size, activity & environment.
B. Metabolic rate – sum of energy used in biochemical reactions over a given time
1. Measured by heat loss or carbon dioxide released

24. XII. Metabolic Rate & Thermoregulation
A. Basal metabolic rate (BMR) – constant rate at rest, under no stress, empty stomach under a confortable temperature range. Standard metabolic rate (SMR) is the rate at a particular temperature
B. Influences on Metabolic Rate:
1. Size – as body size decreases each gram of tissue requires more energy. (mouse vs. elephant)
2. Activity – max. metabolic rate can be sustain is inversely related to duration of activity
Torpor – a state of decreased activity (save energy & avoid difficult conditions) hibernation – extended torpor state
Estivation – same as torpor but in high temperatures/low water