12- Nervous System

Neurons

The functional cells of nervous tissue reasonable for receiving interpreting and sending stimuli

Glial cells

Feed, protect and insulate neurons

Soma

large cell body where the nucleus is located

Axon

generates action potential and transmits nerve impulses away from, from the cell body

Dendrite

neuron processes that possess large surface because of numerus branches, receives chemical stimuli, and electrical signals

Gray matter

Regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter

Ganglion

a cluster of neuron cell bodies in the PNS

Nucleus

a cluster of neuron cell bodies in the CNS

 Afferent neurons

 Bring signals from the sensory receptors to the CNS

Efferent neurons

Motor pathways that carry commands from the CNS to muscles and glands

Sensory functions

Receiving information about the environment (5 senses)

Motor functions

A response based on the stimuli (movement of muscles)

Integration

The process of information like memory or learning

Conscious Perception

The things that we recognize and can make voluntary responses about

Voluntary response of muscles

Us being able to control our movement

Reflexes

involuntary movement that happens without our conscious control

What is the role of the ANS? (Autonomic Nervous System)

Responsible for involuntary control of the body, usually for the sake of homeostasis

Synapse

Specialized areas of contact

Axon hillock

The tapering of the cell body toward the axon fiber

Node of Ranvier

Gaps along they myelin that allow electrical signals to travel down the axon

Axon terminal

The end of the axon

Synaptic end bulb

An enlargement that connect the target cell with the synapse

Unipolar

One process that includes axon and dendrite

Bipolar

Have 2 cell process

Multipolar

Multiple processes

Astrocyte

Regulates the Blood Brain Barrier (BBB)

Oligodendrocyte

Myelin in CNS

Microglia

Immune support

Ependymal cell

Cerebrospinal fluid (CFS), Ventricle, and Choroid plexus

Satellite cell (PNS)

Similar to astrocyte minus the BBB

Schwann cell

Myelin in PNS

Thermoreceptor

sensitive to temperature

Graded Potential

The amount of charge which is dependent on the strength of the stimuli

Threshold

The voltage at which a signal is generated

Neurotransmitter

A signaling molecule

Thalamus

A part of the brain that acts as relay for sensory information

Cerebral cortex

The area of the brain for conscious perception

Upper Motor Neuron

Movement neurons

Precentral Gyrus of the Frontal Cortex

Region of the cortex specialized for sending signals down spinal cord for movement

Lower Motor Neuron

Causes muscle fibers to contrast

Non-specific channel

Selective for charge but not necessarily size

Ligand-gated channel

Opened by a signaling molecule (ligand) binds to the extracellular region

Ionotropic receptor

Like an ligand channel but when bonded that ion membrane changes charge

Mechanically gated channel

Opened by a physical distortion of the cell membrane

Voltage-gated channel

Opens in response to changes in the electrical properties of the membrane

Leakage channel

Opens and closes at random

Resting Membrane Potential

-70mV (the difference in charge when ions are distributed across the membrane)

Depolarization

The membrane potential moves towards 0

Repolarization

The membrane potential moves back towards -70mV

Activation Gate

Opens when the membrane potential crosses -55mV

Inactivation Gate

Closes after a specific period of time

Absolute refractory period

Another action potential will not start

Relative refractory period

Time during the refractory period when a new action potential can only be initiated by a stronger stimulus than the current action potential

Propagation of the Action Potential

movement of an action potential along the length of an axon

Continuous Conduction

propagation along an unmyelinated axon

Saltatory Conduction

propagation along a myelinated axon

Graded potentials

Can be depolarizing or hyperpolarizing

Excitatory Postsynaptic Potential (EPSP)

Depolarization because it causes the membrane potential to move toward threshold

Inhibitory Postsynaptic Potential (IPSP)

Hyperpolarization because it causes the membrane potential to move away from the threshold

Summation

The combined effects of different types of graded potential that lead to the neuron reaching threshold

Cholinergic system

System based on acetylcholine

Nicotinic receptor

Nicotine drug binds to nicotine receptor, will not bind to muscarinic receptor

Muscarinic receptor

Muscarinic drug binds to muscarinic receptor, will not bind to nicotine receptor

What receptors do these use: Glutamate, Glycine, and GABA

Amino acids

G protein

A guanosine triphosphate (GTP) hydrolase that physically moves from the receptor protein to the effector protein to activate the latter.

What are some features of Alzheimer’s and Parkinson’s diseases?

Proteins that don’t behave the way they're supposed to. Such as toxic proteins or them not functioning properly

The ________ is the glial cell that forms the BBB

Astrocytes

The ________ is the glial cell that forms the myelin in the PNS

Schwann cell

The _____ is the glial cell that forms the myelin in the CNS

Oligodendrocyte

The _______ is the glial cell that forms CSF

Ependymal cells

The action potential originates at the _________ and travels down the

_______ of the neuron, until it reaches the __________, which

contains vesicles filled with _______, which are then released

Axon Hillock—> Axon—> Axon Terminal—>Neurotransmitters

The space where two neurons communicate is the ________

Synapse

Which neuron makes skeletal muscles contract: Upper Motor Neuron or Lower Motor Neuron?

Lower Motor Neuron

If a channel excludes certain ions, but allows others to pass, what kind of channel is it?

Ionotropic receptor

What type of channel opens because a signaling molecule binds to it?

 Ligand-gated channel

What type of channel responds to changes in the electrical properties of the membrane?

Voltage Gated Channel

What is an action potential?

Change in voltage of a cell membrane in response to a stimulus that results in transmission of an electrical signal;

What is the difference between Saltatory conduction and continuous conduction?

Saltatory= Myelinated Axon

Continuous= Unmyelinated Axon

What are the two types of receptors that acetylcholine can bind to?

Nicotine and Muscarinic

Which one uses a G protein: ionotropic or metabotropic receptors?

Metabotropic