bio114- chapter 11

CNS - Central Nervous System

CNS - Central Nervous System

Consists of the brain and spinal cord

PNS - Peripheral Nervous System

Includes all other nervous tissue outside of the CNS

Sensory

Afferent- Neurons that carry information to the CNS

Motor

Efferent- Neurons that carry information from the CNS

Effectors

Target organs that respond to signals from motor neurons

Sensory stimuli

Afferent- Sensations received from the skin

Visceral stimuli

Afferent- Sensations received from deep inside the body, including internal organs

Somatic

Efferent- Motor neurons that control skeletal muscles and voluntary movements

Autonomic

Efferent- Involuntary control of bodily functions

Sympathetic

Part of the autonomic nervous system responsible for the "fight or flight" response

Parasympathetic

Part of the autonomic nervous system responsible for the "rest and digest" response

Typical Neurons

Neurons with distinct structures including dendrites, cell body, and axon

Synapse

Located on axon terminal; The junction between two neurons where signals are transmitted

Neurons cannot be replaced since they do not have _______.

Centrioles

Anaxonic

Neurons with no distinct axon, found in the brain and special senses

Bipolar

Rare neurons with distinct processes and the cell body in the middle, found in the retina

Unipolar

Neurons with the cell body on the side, involved in sensory functions

Multipolar

The most common type of neuron, found in the CNS and involved in motor functions

Sensory

Neurons that bring in sensory information to the CNS

Interneurons

Neurons that interpret and process information within the CNS

Motor

Neurons that send out commands from the CNS to effectors

Neuroglia

Non-neuronal cells that support and protect neurons

Oligodendrocytes

Neuroglia cells that produce myelin in the CNS

Astrocytes

Neuroglia cells that protect the CNS from chemicals and hormones in the blood

Microglia

Neuroglia cells that remove debris, waste, and pathogens in the CNS

Ependymal Cells

Neuroglia cells that line fluid-filled passageways in the CNS

Satellite Cells

Neuroglia cells in the PNS that surround cell bodies and regulate the environment

Schwann Cells

Neuroglia cells in the PNS that cover axons and assist in axon repair

Wallerian Degeneration

The process of axon regeneration only in the PNS

Neuronal action potential

The electrical signal that travels along a neuron

All or none

The principle that an action potential either occurs fully or does not occur at all

Spreading of Action Potential

The propagation of an action potential along a neuron

Continuous Propagation

Slow propagation of an action potential in unmyelinated neurons

Saltatory Propagation

Fast propagation of an action potential in myelinated neurons

Synapse Chemical

The type of synapse where neurotransmitters are released (ACh)

Synaptic Fatigue

Chemical- When there is not enough neurotransmitter to send signals effectively

Synapse Electrical

A gap junction is present and no neurotransmitter is released

Neurotransmitter

Chemical messengers that transmit signals across synapses

EPSP (Excitatory Post Synaptic Potential)

Depolarizes the postsynaptic neuron

IPSP (Inhibitory Post Synaptic Potential)

Hyperpolarizes the postsynaptic neuron

Regulatory Neurons

Neurons that affect the presynaptic neuron and can facilitate or inhibit its activity

Myelin

Speeds nerve impulse