MOD 4

Subdecks (1)

Cards (149)

  • Nervous control (animals)

    An animal must be able to respond to environmental stimuli
  • Sensory receptors and motor effectors
    • Sensory receptors can detect the stimulus
    • Motor effectors can respond to it
  • Nervous system
    Consists of neurons and supporting cells
  • Types of neurons
    • Sensory neurons (afferent neurons)
    • Motor neurons (efferent neurons)
    • Interneurons (association neurons)
  • Sensory neurons
    Carry impulses from sensory receptors to the central nervous system (CNS)
  • Motor neurons
    Carry impulses from the CNS to effectors—muscles and glands
  • Interneurons
    Located in the brain and spinal cord, help provide more complex reflexes and higher associative functions, including learning and memory
  • Peripheral nervous system (PNS)
    Consists of sensory and motor neurons
  • Components of the somatic nervous system
    • Motor neurons that stimulate skeletal muscles to contract
  • Components of the autonomic nervous system
    • Motor neurons that regulate the activity of the smooth muscles, cardiac muscle, and glands
  • Sympathetic and parasympathetic divisions
    Counterbalance each other in the regulation of many organ systems
  • Structure of a typical vertebrate neuron
    • Extending from the cell body are many dendrites, which receive information and carry it to the cell body
    • A single axon transmits impulses away from the cell body
    • Many axons are encased by a myelin sheath, with multiple membrane layers that insulate the axon
    • Small gaps, called nodes of Ranvier, interrupt the sheath at regular intervals
  • Schwann cells
    Form myelin sheaths in the PNS
  • Oligodendrocytes
    Form myelin sheaths in the CNS
  • Myelinated axons
    Form the white matter in the CNS
  • Unmyelinated dendrites and cell bodies

    Form the gray matter in the CNS
  • Myelinated axons in the PNS
    Bundled together, much like wires in a cable, to form nerves
  • Nerve impulse transmission
    Neurons have a charged cellular membrane, and the charge can change in response to neurotransmitter molecules and environmental stimuli
  • Ion channels
    Allow ions to enter or exit the neuron, have different configurations: open, closed, and inactive
  • Voltage-gated ion channels
    Change their structure in response to voltage changes, regulate the relative concentrations of different ions inside and outside the cell
  • Membrane potential
    The difference in total charge between the inside and outside of the cell
  • Transmission of a signal between neurons
    Carried by a chemical called a neurotransmitter
  • Transmission of a signal within a neuron
    Carried by a brief reversal of the resting membrane potential called an action potential
  • Neurotransmitter molecules bind to receptors in a neuron's dendrites
    A change occurs in the resting membrane potential which in turn initiates action potential
  • Action potential travels along the neurons up to the axon terminal
    Triggers the release of neurotransmitters
  • Neurotransmitters travel across intercellular junctions known as synapses
    To reach another neuron, muscle cells or gland cells
  • Axons
    Transmit neurotransmitters to another axon
  • Synapses
    Intercellular junctions between neurons
  • Synaptic transmission
    Generally affects only the postsynaptic cell that receives the neurotransmitter
  • Hormone
    A regulatory chemical that is secreted into extracellular fluid and carried by the blood and can therefore act at a distance from its source
  • Endocrine glands
    • Organs specialized to secrete hormones
  • Endocrine system
    • The organs and tissues that produce hormones
  • The blood carries hormones to every cell in the body

    Only target cells with the appropriate receptor for a given hormone can respond to it
  • Hormone receptor proteins
    Function in a similar manner to neurotransmitter receptors, specifically bind the hormone and activate signal transduction pathways that produce a response to the hormone
  • Paracrine regulators

    Molecules released and act within an organ on nearby cells, do not travel through the blood to reach their target
  • Autocrine signaling

    Cells release signaling molecules that affect their own behavior
  • Senses in humans
    • Olfaction (smell)
    • Gustation (taste)
    • Equilibrium (balance and body position)
    • Vision
    • Hearing
  • General senses (somatosensation)
    • Temperature
    • Pain
    • Pressure
    • Vibration
  • Senses related to somatosensation
    • Vestibular sensation (spatial orientation and balance)
    • Proprioception (position of bones, joints, and muscles)
    • Kinesthesia (limb movement)
  • Sensory transduction
    The process of converting a stimulus (such as light, or sound, or the position of the body) into an electrical signal in the nervous system