Motor Mechanisms and Behavior

Skeletal muscle

Skeletal muscle

Striated, multinuclear, voluntary control

Cardiac muscle

Striated, single nucleus, involuntary control

Smooth muscle

Non-striated, single nucleus, involuntary control

Sarcolemma

Specialized plasma membrane

Sarcoplasmic reticulum

Specialized smooth endoplasmic reticulum and site for calcium storage

Sarcomere

The contractile unit of a muscle fiber

Thick filaments

Myosin filaments composed of the protein myosin with ATPase enzymes

Thin filaments

Actin filaments composed of the protein actin

Bare zone

A zone of the myosin filaments that lacks actin filaments at rest

I band

A band of thin filaments

A band

A band of thick and thin filaments

H band

A band in the middle of the A band where only thick filaments are present

Z line

A line in the middle of the I band that anchors thin filaments

Titin

A protein that spans from the Z line to the M line and helps stabilize the position of the thick filaments

Motor unit

One neuron and the muscle cells it stimulates

Sliding Filament Theory

The theory that muscle contraction occurs when thin filaments slide past thick filaments

Ethology

The study of animal behavior

Behavior

What an animal does and how it does it, influenced by genetic and environmental factors

Proximate cause

The immediate cause of a behavior, how it occurs or is modified

Ultimate cause

The evolutionary reason for a behavior in the context of natural selection

Innate behaviors

Developmentally fixed behaviors that are not learned

Fixed action patterns (FAPs)

Sequences of unlearned acts that are unchangeable and usually carried to completion

Kinesis

A simple change in activity or turning rate in response to a stimulus

Taxis

Automatic movement oriented toward or away from a stimulus

Migration

Regular, long-distance change in location

Circadian Rhythm

Internal biological clock that regulates daily cycles

Signal

A stimulus that causes a change in behavior and serves as the basis of animal communication

Pheromones

Chemicals emitted by members of a species that affect other members of the species

Visual signals

Signals conveyed through sight, such as the warning flash of a mockingbird's wing

Tactile signals

Signals conveyed through touch, such as a male fruit fly tapping a female fly

Auditory signals

Signals conveyed through sound, such as the screech of a blue jay or the song of a warbler

Habituation

Loss of responsiveness to stimuli that convey little or no information

Imprinting

Learning that occurs during a sensitive period and is generally irreversible

Spatial Learning

The ability to form an internal representation of spatial relationships among objects

Associative Learning

The ability to associate one stimulus with another

Classical conditioning

Learning in which an arbitrary stimulus is associated with a particular outcome

Operant conditioning

Trial-and-error learning in which an animal associates its own behavior with reward or punishment

Cognition

The process of knowing that involves awareness, reasoning, recollection, and judgment

Social learning

Learning by observing others

Foraging

Food-obtaining behavior that involves recognizing, searching for, capturing, and consuming food

Mating Behavior

Behavior related to seeking and attracting mates, choosing and competing for mates

Sexual selection

The process of individuals with certain traits being more likely to find mates and reproduce

Agonistic behavior

Behavior related to threats, rituals, and sometimes combat to settle disputes over resources

Altruism

Selfless behavior that reduces individual fitness but increases fitness of others in the population

Inclusive fitness

The total effect of producing one's own offspring and helping close relatives

Kin selection

A type of natural selection in which altruistic behavior enhances the reproductive success of relatives