Skip to main content
Back

Anatomy & Physiology Key Concepts

Control buttons has been changed to "navigation" mode.
1/30

  • Functions of prime movers

    Prime movers cause the main movement

  • Functions of antagonists

    antagonists oppose the movement

  • Functions of synergists

    synergists assist the prime movers by stabilizing joints or adding extra force

  • How muscle position affects its action

    determines the direction and type of movement it produces when it contracts.

  • Criteria used in naming skeletal muscles

    Muscles are named by location, shape, size, direction of fibers, number of origins, location of attachments, and action.

  • Definition of a lever in the musculoskeletal system

    A lever is a rigid structure (bone) that moves on a fixed point (fulcrum) when force (effort) is applied to overcome a load (resistance).

  • Mechanical advantage vs. mechanical disadvantage in levers

    mechanical advantage moves a large load with less effort/ mechanical disadvantage, more effort moves a smaller load faster or farther.

  • Three types of lever systems

    First-class: fulcrum between effort and load.

    Second-class: load between fulcrum and effort

    Third-class: effort between fulcrum and load.

  • Basic functions of the nervous system

    The nervous system receives, integrates, and responds to sensory information to maintain homeostasis and coordinate body functions.

  • Structural divisions of the nervous system

    Central nervous system (CNS): brain and spinal cord.

    Peripheral nervous system (PNS): all nerves outside the CNS.

  • Types and functions of neuroglia

    Neuroglia support neurons by protecting, nourishing, insulating, and maintaining the environment arou`1nd neurons.

  • Definition and structure of a neuron

    A neuron is a nerve cell with a cell body, dendrites (receive signals), and an axon (sends signals).

  • Difference between nucleus and ganglion

    A nucleus is a cluster of neuron cell bodies in the CNS; a ganglion is a cluster in the PNS.

  • Difference between nerve and tract

    A nerve is a bundle of axons in the PNS; a tract is a bundle of axons in the CNS.

  • Importance and formation of the myelin sheath

    The myelin sheath insulates axons to speed signal conduction; formed by oligodendrocytes in CNS and Schwann cells in PNS.

  • Classification of neurons by structure and function

    By structure: multipolar, bipolar, unipolar. By function: sensory, motor, and interneurons.

  • Relationship between current, voltage, and resistance

    Current is flow of ions, voltage is electrical potential difference, and resistance opposes current flow.

  • Types of membrane ion channels

    Include leak channels, gated channels (voltage-, ligand-, mechanically-gated), which regulate ion flow across membranes.

  • Resting membrane potential and its basis

    The resting membrane potential is the voltage across the membrane at rest, caused by ion concentration differences and selective permeability.

  • Definition and examples of graded potentials

    Graded potentials are short, localized changes in membrane potential, such as postsynaptic potentials and receptor potentials.

  • Differences between graded potentials and action potentials

    Graded potentials vary in size and decay with distance; action potentials are all-or-none, propagate without loss, and travel long distances.

  • Generation and propagation of action potentials

    Action potentials are generated by voltage-gated Na+ channels opening, depolarizing the membrane, and propagated along the axon by sequential channel activation.

  • Absolute and relative refractory periods

    Absolute refractory period: no new action potential possible.
    Relative refractory period: a stronger stimulus can trigger an action potential.

  • Saltatory conduction vs. conduction in nonmyelinated axons

    Saltatory conduction occurs in myelinated axons, where impulses jump between nodes of Ranvier, speeding transmission compared to continuous conduction.

  • Definition and events at a synapse

    A synapse is a junction where neurons communicate via neurotransmitter release or electrical coupling.

  • Differences between electrical and chemical synapses

    Electrical synapses use gap junctions for direct ion flow; chemical synapses use neurotransmitters to transmit signals across a synaptic cleft.

  • Excitatory vs. inhibitory postsynaptic potentials

    Excitatory postsynaptic potentials (EPSPs) depolarize the membrane; inhibitory postsynaptic potentials (IPSPs) hyperpolarize it.

  • Integration and modification of synaptic events

    Neurons integrate multiple synaptic inputs through summation, which can be spatial or temporal, modifying the postsynaptic response.

  • Definition and classification of neurotransmitters

    Neurotransmitters are chemical messengers classified by structure (e.g., amino acids, amines) and function (excitatory, inhibitory, modulatory).

  • Action of neurotransmitters at receptor types

    At channel-linked receptors, neurotransmitters open ion channels; at G protein–coupled receptors, they activate signaling cascades.