Basic Principles of Animal Form and

Function

Basic Principles of Animal Form and

Function

Taught by Dhruv, Tommy, Zach, and Butch

Taught by Dhruv, Tommy, Zach, and Butch

Physical Constraints on Size

Physical Constraints on Size

Physical laws govern strength, diffusion, movement, and heat exchange limit the range of animal forms.

Ex. Streamlined body, maximum body sizes

Physical laws govern strength, diffusion, movement, and heat exchange limit the range of animal forms.

Ex. Streamlined body, maximum body sizes

Exchange with the Environment

Exchange with the Environment

Rate of exchange proportional to surface area, amount proportional to volume.

Multicellular organization only works if every cell has access to a suitable aqueous environment, either inside or outside.

Ex. Inner, outer layers, flat body shape, extensively branched or folded exchange surfaces)

Rate of exchange proportional to surface area, amount proportional to volume.

Multicellular organization only works if every cell has access to a suitable aqueous environment, either inside or outside.

Ex. Inner, outer layers, flat body shape, extensively branched or folded exchange surfaces)

Hierarchical Organization of Body Plans

Hierarchical Organization of Body Plans

Tissues Organs Organ Systems

Tissues Organs Organ Systems

Tissue Structure and Function

Tissue Structure and Function

Four types of tissues: Epithelial Tissue Connective Tissue Muscle Tissue Nervous Tissue

Four types of tissues: Epithelial Tissue Connective Tissue Muscle Tissue Nervous Tissue

Epithelial TissueEpithelial Tissue

Covers the outside of the body and lines organs and cavities within the body.

Close packing allows enables it to function as barrier against mechanical injury, pathogens, and fluid loss.

Epithelium (the cells) form active interfaces with the environment.

Covers the outside of the body and lines organs and cavities within the body.

Close packing allows enables it to function as barrier against mechanical injury, pathogens, and fluid loss.

Epithelium (the cells) form active interfaces with the environment.

Connective TissueConnective Tissue

functions to bind and support other tissues. Sparse population of cells scattered through an extra cellular

matrix. Two types of connective tissue cells: Fibroblasts (secrete the

protein ingredients of extracellular fibers) and Macrophages (cells that roam the maze of fibers, engulfing debris)

Three types of connective tissue fibers: collagenous (provide strength with flexibility, made of collagen, are nonelastic and do not tear easily), elastic (easily stretched but are also resilient, made of elastin), and reticular (very thin and branched, form tightly woven fabric that joins connective tissue to adjacent tissue.

functions to bind and support other tissues. Sparse population of cells scattered through an extra cellular

matrix. Two types of connective tissue cells: Fibroblasts (secrete the

protein ingredients of extracellular fibers) and Macrophages (cells that roam the maze of fibers, engulfing debris)

Three types of connective tissue fibers: collagenous (provide strength with flexibility, made of collagen, are nonelastic and do not tear easily), elastic (easily stretched but are also resilient, made of elastin), and reticular (very thin and branched, form tightly woven fabric that joins connective tissue to adjacent tissue.

Muscle TissueMuscle Tissue

The most abundant tissue in animals All muscle cells consist of filaments

containing actin and myosin, which together enable contraction.

Types: Skeletal, Cardiac, Smooth

The most abundant tissue in animals All muscle cells consist of filaments

containing actin and myosin, which together enable contraction.

Types: Skeletal, Cardiac, Smooth

Nervous TissueNervous Tissue

Sense stimuli and transmit signals in the form of nerve impulses from one part of animal to another.

Sense stimuli and transmit signals in the form of nerve impulses from one part of animal to another.

A regulator uses mechanisms to regulate the internal environment in face of external change.

A conformer allows its internal environment to conform to external changes.

A regulator uses mechanisms to regulate the internal environment in face of external change.

A conformer allows its internal environment to conform to external changes.

Regulators vs. ConformersRegulators vs. Conformers

Regulator vs ConformerRegulator vs Conformer

HomeostasisHomeostasis

Homeostasis: means “steady state” or internal balance.

Homeostasis: means “steady state” or internal balance.

Feedback Feedback

Thermoregulation: process by which animal maintains an internal temperature within a

tolerable range

Thermoregulation: process by which animal maintains an internal temperature within a

tolerable range

Endothermy and Ectothermy

Endothermy and Ectothermy

Endotherm: Warmed mostly by heat generated by metabolism. Commom Examples: Mammals, birds and insects.

Ectotherms: Gain heat mostly from external sources. Common examples: Lizards, amphibians, snakes, many fish and invertabrates

Endotherm: Warmed mostly by heat generated by metabolism. Commom Examples: Mammals, birds and insects.

Ectotherms: Gain heat mostly from external sources. Common examples: Lizards, amphibians, snakes, many fish and invertabrates

Poikilotherm vs. HomeothermPoikilotherm vs. Homeotherm

Poikilotherm: Body temperature varies with the temperature of the environment

Homeotherm: Body temperature relatively constant despite temperature changes in the environment.

Poikilotherm: Body temperature varies with the temperature of the environment

Homeotherm: Body temperature relatively constant despite temperature changes in the environment.

Type of heat loss to the Environment

Type of heat loss to the Environment

Insulation reduces Heat Loss to the Environment. Seen in birds in the form of feathers, in marine mammals in the form of blubber and land mammals in the form of fur

Insulation reduces Heat Loss to the Environment. Seen in birds in the form of feathers, in marine mammals in the form of blubber and land mammals in the form of fur

Countercurrent ExchangeCountercurrent Exchange

Countercurrent exchange is flow of adjacent fluids in opposing directions in order to maximize transfer rates of heat or solutes.

Antiparallel arrangement so that heat transfer occurs along entire exchanger

Countercurrent exchange is flow of adjacent fluids in opposing directions in order to maximize transfer rates of heat or solutes.

Antiparallel arrangement so that heat transfer occurs along entire exchanger

CoolingCooling

Some animals sweat; as the water evaporates, it absorbs heat and cools the animal

Panting is important in many birds and mammals (birds have a pouch): water evaporates from the pouch or tongue

Some animals, like honeybees, flap their wings to improve evaporation and convection

Some animals sweat; as the water evaporates, it absorbs heat and cools the animal

Panting is important in many birds and mammals (birds have a pouch): water evaporates from the pouch or tongue

Some animals, like honeybees, flap their wings to improve evaporation and convection

Thermoregulatory Behavioral Responses

Thermoregulatory Behavioral Responses

Move to warm or cool areas, move into or out of wind

Some animals, like honeybees, huddle together to better retain heat

Move to warm or cool areas, move into or out of wind

Some animals, like honeybees, huddle together to better retain heat

Metabolic Heat ProductionMetabolic Heat Production

Shivering raises body temperature Some mammals can cause mitochondria to

produce heat instead of ATP Some reptiles become endothermic and produce

heat through shivering under special conditions, such as when incubating eggs

In insects, wing muscles are very important for heat production.

Shivering raises body temperature Some mammals can cause mitochondria to

produce heat instead of ATP Some reptiles become endothermic and produce

heat through shivering under special conditions, such as when incubating eggs

In insects, wing muscles are very important for heat production.

AcclimatizationAcclimatization

Adjust to seasons by growing or shedding fur or feathers

Ectotherms are better at acclimatization and often produce variants of enzymes that have the same function but different optimal temperatures

Change amount of saturated lipids in membrane; saturated lipids decrease fluidity and unsaturated lipids increase fluidity

Adjust to seasons by growing or shedding fur or feathers

Ectotherms are better at acclimatization and often produce variants of enzymes that have the same function but different optimal temperatures

Change amount of saturated lipids in membrane; saturated lipids decrease fluidity and unsaturated lipids increase fluidity

Hypothalamus and FeverHypothalamus and Fever

Hypothalamus: region of the brain that functions as the thermostat

Some endotherms develop fever to kill off a bacteria infection; some ectotherms seeks warmer environmental temperatures to kill off a bacteria infection

Hypothalamus: region of the brain that functions as the thermostat

Some endotherms develop fever to kill off a bacteria infection; some ectotherms seeks warmer environmental temperatures to kill off a bacteria infection

Metabolic RateMetabolic Rate

A bigger organism has a higher metabolic rate than a smaller organism

For some unknown reason, bigger animals have a smaller metabolic rate per kg than smaller animals, despite the fact that a greater percentage of their body mass is devoted to locomotion. This is all true for both ectotherms and endotherms.

Metabolic rate is roughly proportional to body mass to the three-quarter power

Animals typically have an average daily metabolic rate that is 2 to 4 times their BMR or SMR. Humans’ average daily metabolic rate is 1.5 times their BMR- indicating their sedentary lifestyles

A bigger organism has a higher metabolic rate than a smaller organism

For some unknown reason, bigger animals have a smaller metabolic rate per kg than smaller animals, despite the fact that a greater percentage of their body mass is devoted to locomotion. This is all true for both ectotherms and endotherms.

Metabolic rate is roughly proportional to body mass to the three-quarter power

Animals typically have an average daily metabolic rate that is 2 to 4 times their BMR or SMR. Humans’ average daily metabolic rate is 1.5 times their BMR- indicating their sedentary lifestyles

Energy budgetsEnergy budgets

Ectotherms have smaller average daily metabolic rates than endotherms of similar size because they do not spend energy on thermoregulation

Smaller organisms must spend more energy on thermoregulation because they have a high surface to volume ratio, causing them to lose or gain heat more easily

Animals, such as penguins, that have to swim to catch their food spend a large fraction of their energy on movement, because water has more resistance to movement than air

Ectotherms have smaller average daily metabolic rates than endotherms of similar size because they do not spend energy on thermoregulation

Smaller organisms must spend more energy on thermoregulation because they have a high surface to volume ratio, causing them to lose or gain heat more easily

Animals, such as penguins, that have to swim to catch their food spend a large fraction of their energy on movement, because water has more resistance to movement than air

Energy ConservationEnergy Conservation

Torpor: a physiological state in which activity is low and metabolism decreases

Hibernation: during the winter; Estivation: during the summer

Torpor: a physiological state in which activity is low and metabolism decreases

Hibernation: during the winter; Estivation: during the summer

Diseases/DisordersDiseases/Disorders

Amyotrophic Lateral Sclerosis Ross Syndrome Parkinson’s Disease Schizophrenia Lymphocyte Homeostasis

Syndrome

Amyotrophic Lateral Sclerosis Ross Syndrome Parkinson’s Disease Schizophrenia Lymphocyte Homeostasis

Syndrome