A&P - Nervous Tissue

What is the basic functional unit of the nervous system?

Neuron

What is the primary function of neuroglia?

Support and protect neurons

What structures make up the Central Nervous System (CNS)?

Brain and spinal cord

Where does the Peripheral Nervous System carry sensory information?

From peripheral tissues to the CNS

Where do cranial nerves connect?

Brain

Where do spinal nerves connect?

Spinal cord

What does the efferent division of the PNS do?

Carries motor commands to effectors

The somatic nervous system controls what type of muscle?

Skeletal muscle

Which nervous system division is responsible for "fight or flight"?

Sympathetic division

Which nervous system division is responsible for "rest and digest"?

Parasympathetic division

Where is the enteric nervous system located?

Walls of the digestive tract

What type of cells make nervous tissue appear gray?

Nissl bodies

What part of a neuron receives incoming signals?

Dendrites

What part of a neuron sends action potentials?

Axon

Where do action potentials begin in a neuron?

Axon hillock

What are the fine extensions at the end of the axon called?

Telodendria

Where are axon terminals located?

Tips of telodendria

What type of neuron has two processes separated by the cell body?

Bipolar neuron

What type of neuron has only dendrites and no obvious axon?

Anaxonic neuron

What type of neuron has a single long process with the cell body off to the side?

Unipolar neuron

What type of neuron has one axon and multiple dendrites?

Multipolar neuron

Sensory neurons carry information in which direction?

From receptors to the CNS

Motor neurons carry information in which direction?

From CNS to effectors

Which neurons monitor external conditions and body position?

Somatic sensory neurons

Which neurons monitor internal environment conditions?

Visceral sensory neurons

Which receptors monitor internal systems such as digestion?

Interoceptors

Which receptors monitor external environment such as temperature?

Exteroceptors

Which receptors monitor body position and muscle movement?

Proprioceptors

Which neurons innervate skeletal muscle?

Somatic motor neurons

Which neurons innervate smooth muscle and glands?

Visceral motor neurons

Where are interneurons primarily located?

Brain and spinal cord

What neurons distribute sensory info and coordinate motor output?

Interneurons

Which cells maintain the blood-brain barrier and provide structural support?

Astrocytes

Which CNS cells line ventricles and produce cerebrospinal fluid?

Ependymal cells

Which CNS cells myelinate axons?

Oligodendrocytes

Which CNS cells remove debris and pathogens by phagocytosis?

Microglia

What forms myelin sheath in the PNS?

Schwann cells

What cells surround neuron cell bodies in PNS ganglia?

Satellite cells

What part of an axon is covered in myelin?

Internodes

What gaps occur between myelinated segments?

Nodes (Nodes of Ranvier)

Areas with many myelinated axons are called what?

White matter

Areas with unmyelinated axons and cell bodies are called what?

Gray matter

What is the resting membrane potential of most neurons?

-70 mV

Which ion has an equilibrium potential of -90 mV?

Potassium (K+)

Which ion has an equilibrium potential of +66 mV?

Sodium (Na+)

What pump maintains resting membrane potential?

Sodium-potassium exchange pump

Which gated channels open due to physical distortion?

Mechanically gated ion channels

Which gated channels open when a ligand binds?

Chemically gated ion channels

Which gated channels open due to membrane potential changes?

Voltage-gated ion channels

What type of membrane change decreases with distance from stimulation?

Graded potential

What happens when membrane potential becomes less negative?

Depolarization

What happens when membrane potential returns to resting state?

Repolarization

What happens when membrane potential becomes more negative?

Hyperpolarization

What is the threshold required to trigger an action potential?

Between -60 and -55 mV

What principle states that action potentials are either fully triggered or not?

All-or-none principle

What period prevents another action potential from occurring immediately?

Absolute refractory period

What period requires a larger-than-normal stimulus?

Relative refractory period

What type of propagation occurs in unmyelinated axons?

Continuous propagation

What type of propagation occurs in myelinated axons?

Saltatory propagation

What type of synapse uses direct ion movement through gap junctions?

Electrical synapse

What type of synapse uses neurotransmitters across a synaptic cleft?

Chemical synapse

What type of postsynaptic potential causes depolarization?

Excitatory postsynaptic potential (EPSP)

What type of postsynaptic potential causes hyperpolarization?

Inhibitory postsynaptic potential (IPSP)

What is the combining of multiple EPSPs to reach threshold called?

Summation