Week 6

• What is the definition of behavior?


  Action carried out by muscles, under control of the nervous system.
• What are the different behavior states?

  • Travel
  • Forage
  • Social
  • Play
  • Rest
• What are some behavioral events observed in killer whales?

  • Spy hop
  • Fluke slap
  • Tail slap
  • Pec slap
  • Rub
  • Breach
  • Synchronous surface
  • Submerge in place
• Why is it important to study behavior?

  To understand the relationship between behavior and physiology.
• What does muscle cell contraction rely on?

  Interaction between thin and thick filaments.
• What are the two types of filaments involved in muscle contraction?

  Thick filaments and thin filaments.
• What powers the movement of filaments during muscle contraction?

  Chemical energy.
• What is skeletal muscle made up of?

  Bundles of long muscle fibers running along the length of the muscle.
• What is a myofibril?

  A structural unit of a muscle fiber.
• What is a sarcomere?

  The basic contractile unit of muscle tissue.
• What does the sliding filament model explain?


  The mechanism of muscle contraction based on muscle proteins sliding past each other.
• What happens to myosin and actin during muscle contraction?

  Myosin slides past actin while the filaments remain at relatively constant length.
• What role does calcium play in muscle contraction?

  It interacts with regulatory proteins to allow actin and myosin to interact.
• What is the function of tropomyosin in muscle contraction?

  Tropomyosin covers myosin-binding sites along the thin filament.
• What is a motor unit?

  A single motor neuron and all muscle fibers it controls.
• How is muscle contraction regulated in vertebrates?

  By how many motor units are activated.
• How is muscle contraction regulated in invertebrates?

  By regulating the balance between excitatory and inhibitory signals.
• What is tetanus in muscle physiology?

  When the rate of stimulation is so high that muscle fibers cannot relax between stimuli.
• What are the types of skeletal muscle fibers?

  • Oxidative fibers: rely mostly on aerobic respiration.
  • Glycolytic fibers: have larger diameter and less myoglobin.
• What are fast-twitch fibers known for?

  Enabling brief, rapid, powerful contractions.
• What are slow-twitch fibers characterized by?

  Having less sarcoplasmic reticulum and pumping calcium ions more slowly.
• What are the three types of muscle in vertebrates?

  1. Skeletal Muscle
  2. Smooth Muscle
  3. Cardiac Muscle
• What are the characteristics of skeletal muscle?

  • Voluntary movement
  • Controlled by primary motor cortex & motor neurons
  • Obvious striations (bands)
• What are the characteristics of smooth muscle?

  • Involuntary movement
  • Encircles blood vessels and found in walls of digestive, respiratory, urinary & reproductive organs
  • No striations

  
• What are the characteristics of cardiac muscle?

  • Involuntary beating of the heart
  • Branched cells with single nuclei
  • Regulated by intrinsic factors, hormones & autonomic nervous system
• What is the role of the skeleton in muscle movement?

  • Support and protection
  • Prevents collapse of animals
  • Protects soft tissues (e.g., skull protects brain)
• What are the types of skeletal systems?

  • Hydrostatic skeletal systems
  • Exoskeletons
  • Endoskeletons
• What is a hydrostatic skeletal system?

  • Main type of skeleton in cnidarians, flatworms, nematodes, and annelids
  • Muscles change the shape of fluid-filled compartments for movement
• What is an exoskeleton?

  • External skeleton that supports body shape and protects internal organs
  • Examples: insects, crustaceans, mollusks
• What is an endoskeleton?

  • Internal structural frame usually composed of mineralized tissue
  • Provides attachment sites for skeletal muscles
• What are the types of locomotion?

  • On land: walking, hopping, crawling, running
  • Swimming: adaptations for sleek body shape
  • Flying: evolved in few groups (insects, reptiles, birds)
• What are the challenges of locomotion on land?

  Working against gravity and maintaining balance.
• What are the challenges of swimming?

  Overcoming buoyancy and density of water.
• What are the methods of swimming in different animals?

  • Insects and invertebrates use legs
  • Cartilaginous and bony fishes use strong tails
  • Whales and dolphins undulate their tails
  • Squid and scallops use jet propulsion

  
• What is behavioral ecology?

  • Study of ecological and evolutionary basis for animal behavior
  • Proximate versus ultimate causation
• What is the difference between proximate and ultimate causation?

  Proximate is HOW behavior occurs, while ultimate is WHY behavior occurs.
• What are fixed action patterns?

  • Responses to well-defined stimuli
  • Triggered under certain conditions
  • Require no learning and run to completion
• What is an example of a fixed action pattern in animals?


  Kelp gull chicks pecking at the red spot on their mother's beak.
• What is migration?

  A regular, long-distance change in location.
• What cues do animals use for migration?

  • External cues: photoperiod, shifting seasonality, food/water availability
  • Internal cues: fat reserves, circadian rhythms