Biopsychology

psych 1000

Neuron 

Specialized cells capable of transmitting electrical impulses and translating those impulses to chemical signals 

The average human has approximately how many neurons

the average human has approximately 86 billion neurons

Cell body/ soma

Contains the nucleus of the cell

Dendrites

receives incoming messages from other cells

Axon Hillock

Intergrates incoming signals from the cell body

Axon

Passes messages away from the cell body to the neurons, muscles, glandsM

Myelin Sheath

Covers the axon and help speed up neural impulse

Nerve terminal

Form junctions with other neuron cells( enlarged and flattened to maximize transmission of signals to other neurons and ensure proper release of neurotransmitters)

Nodes of ranvier

small breaks of myelin sheath with exposed axon membrane

Synaptic cleft

Gap between nerve terminal of presynaptic neuron and dendrite of postsynaptic neuron

Synapse

Comprised of the synaptic cleft, postsynaptic membrane and nerve terminal

Presynpatic neuron does what

Presynaptic neuron sends the message

Postsynaptic neuron does what

Postsynaptic neuron receives the message 

Distant projecting neurons do what

These neurons send signals over long distances in the nervous system

Local projecting neurons

These neurons send signals only short distances, staying in a specific area

Multipolar neuron 

Multiple branches 

Bipolar

Two extensions

Unipolar

One extension

Sensory neuron (also called afferent neurons)

transmit sensory information from sensory receptors to the spinal cord and brain

Motor neuron (also called efferent neurons)

Transmit information from brain and spinal cord to muscles and glands

interneurons

found between other neurons ( typically located in the brain and spinal cord and linked to reflexive behaviour Gial

Gilal cells

The other cell in the nervous system, they play both structural and supportive roles

Astrocytes

Nourish neurons and form blood-brain barrier 

Ependymal Cell

lines the ventricles and produce cerebrospinal fluid which serve as a shock absorber Mir

Microgila Cell

Phagocytic cells that ingest and break down waste products and pathogens in the CNS

Oilgodendra

produce myelin sheaths in the CNS

Schwann Cells

Produce myelin sheaths in the PNSAction Potential

Neurons use all or nothing messages called

Action potentical

What is a neuron’s resting membrane potential and what causes it?

It’s the difference in charge between the inside and outside of the cell. The semi-permeable membrane allows certain ions to pass, making some ions more concentrated inside or outside.

What is the typical resting potential of a neuron, and which ions are involved?

The resting potential is -70 mV, and it’s mainly maintained by sodium (Na⁺) and potassium (K⁺) ions.

How do sodium and potassium affect the resting potential?

Potassium’s equilibrium potential is -90 mV and pulls the potential down, while sodium’s is +60 mV and pulls it up. The balance between the two creates the resting potential of -70 mV.