AP Biology, Chapter 40
An Introduction to Animal Structure and Function

SUMMARY
INTRODUCTION
	1. Define bioenergetics.
		a. = study of how organisms manage their energy resources
		b. Two aspects
			i. Budgeting (allocation): energy input = energy output + storage
			ii. Adaptation
				.Altering input, output, and storage
				.In response to internal and external conditions

LEVELS OF STRUCTURAL ORGANIZATION
	Introduction
		2. Distinguish between anatomy and physiology. 
			a. Anatomy = structure
			b. Physiology = the chemistry and physics of biological function
	Function correlates with structure in the tissues of animals
		3. Define a tissue.
			a. A group of cells with a common structure and function
4. Differentiate the four basic animal tissue types and their most important functions.
	a. Epithelium
		i. Highly cellular, covers surfaces, regenerates well, avascular, attached 
		to molecular basement membrane
		ii. Functions: protection, filtration, secretion
	b. Connective
		i. Variable extracellular matrix, regeneration depends on vascularity
		ii. Functions: support, bind, protect
	c. Nervous
		i. Highly cellular, composed to branched neurons and glial cells
		ii. Functions: coordination and control by storage, transmission, and 
		processing data 
	d. Muscular
		i. Highly cellular, elongated cells with actin and myosin
		ii. Function: generate force 
		5. Describe the characteristics used to differentiate epithelia.
			a. Number of layers of cells: simple (1), stratified (>1)
			b. Shape of cells: squamous (flat), cuboidal, columnar 
		6. Differentiate the relationship between structure and function for simple versus 
		stratified epithelia.
			a. Simple are thin for rapid passage of materials
			b. Stratified are thick for protection
		7. Explain how structure relates to function for the following connective tissues: bone, 
		blood, adipose, cartilage, fibrous. 
			a. Bone
				i. Structure: hard protein and calcium salt matrix, cells in lacunae
				ii. Function: protect, resist compression, resist tension
			b. Blood
				i. Structure: fluid matrix with fibrinogen, specialized cells
				ii. Function: specialized bulk transport, protection, clotting 
			c. Adipose
				i. Structure: highly cellular, large vacuoles filled with neutral fats
				ii. Function: store energy, cushion, insulate
			d. Cartilage
				i. Structure: flexible to brittle slippery matrix with chondroitin, cells in 
				lacunae
				ii. Function: flexible protection, reduces friction 
			e. Fibrous
				i. Structure: mainly composed of collagen, maintained by fibroblasts
				ii. Function: protects, transmits force, connects bones
	The organ systems of animals are interdependent

INTRODUCTION TO THE BIOENERGETICS OF ANIMALS
	Animals are heterotrophs that harvest chemical energy from the food they digest
	Metabolic rate provides clues to an animal's bioenergetic strategy
		8. Define metabolic rate and explain how it can be determined for animals.
			a. = total amount of energy an animal uses in a unit of time
			b. Ways to measure
				i. Calorimeter: rate of heat loss
				ii. Rate of oxygen consumption 
		9. Distinguish between endothermic and exothermic organisms.
			a. Endothermic: maintain relatively constant temperature by metabolism
			b. Exothermic: absorb most of their heat from their environment
		10. Distinguish between basal metabolic rate and standard metabolic rate. Describe the 
		major factors that influence energy requirements.
			a. Distinction
				i. Basal: endotherm at rest, empty stomach, without stress
				ii. Standard: ectotherm at rest, empty stomach, without stress at a 
				specific temperature
			b. Influencing factors: external temperature, body temperature, activity level, 
			body size and shape
	Metabolic rate per gram is inversely related to body size among similar animals
		11. Describe the relationship between metabolic rate and body size.
			a. Energy required per gram is inversely related to body size
			b. Smaller animals have higher pulse, relative blood volume, respiratory rate
			c. Not surface-to-volume ratio and heat loss

BODY PLANS AND THE EXTERNAL ENVIRONMENT
	Introduction
	Physical support on land depends on adaptations of body proportions and posture
		12. Explain how physical laws constrain animal form.
			a. Diffusion rates depend on surface area
			b. Resistance to compression varies with the cross-sectional area of the 
			supporting bones
			c. Shape and position of supporting elements is also important  
	Body size and shape affect interactions with the environment
		13. Explain how the size and shape of an animal's body affect its interactions with the 
		environment.
			a. Cells require an aqueous environment
				i. Membrane structure depends on aqueous solution inside and out
				ii. Exchanges across membranes occur by diffusion between aqueous 
				solutions
			b. Body shape and structure allows exchange with the environment across wet 
			membranes
				i. Hydra cells exchange directly, inside and out
				ii. Flat planaria have enough surface close to its cells to exchange
				iii. Otherwise organisms rely in folded/branched internal wet 
				membranes
					.Gills/lungs for gas exchange
					.Digestive system for breakdown, absorption, and elimination
					.Excretory system to eliminate nitrogen waste 

REGULATING THE INTERNAL ENVIRONMENT
	Mechanisms of homeostasis moderate changes in the internal environment
		14. Define homeostasis. Describe the three functional components of a homeostatic 
		control system.
a. Homeostasis is the ability to maintain relatively stable internal conditions 
	b. Components 
	i. Receptor
	.Senses the variable 
	.Responds to stimulus by sending information to the control 
	center 
	ii. Control center 
	.Determines set point for the variable 
	.Receives information from the receptor on afferent pathway 
	.Analyzes information 
	.Determines response based on set point 
	.Sends information to the effector on efferent pathway 
	iii. Effector 
					.Means of control of the variable 
					.Receives information from the control center 
					.Acts to decrease or increase the variable
	Homeostasis depends on feedback circuits
		15. Distinguish between positive and negative feedback mechanisms.
a. Two ways to distinguish:  effect on stimulus, type of use 
b. Negative 
i. Decreases stimulus, used continuously to prevent sudden changes 
ii. Body temperature goes up, sweat, body temperature decreases 
c. Positive 
i. Increases stimulus, used for explosive reactions 
ii. Baby's head pushes down, neural feedback to brain, oxytocin makes uterus contract harder