EHS_385_nervous_s25_cfs

Homeostasis

The ability of the body to maintain a stable internal environment.

Central Nervous System (CNS)

Composed of the brain and spinal cord, it processes information and coordinates activity throughout the body.

Peripheral Nervous System (PNS)

Links the CNS to limbs and organs; comprised of afferent and efferent nerves.

Afferent Nerves

Nerves that carry sensory signals from the body to the brain.

Efferent Nerves

Nerves that carry motor signals from the brain to the body.

Sensory Neurons

Neurons that transmit sensory information to the CNS.

Mechanoreceptors

Receptors that respond to mechanical stimuli such as pressure or vibration.

Thermoreceptors

Receptors that detect changes in temperature.

Nociceptors

Receptors that respond to damaging or potentially damaging stimuli.

Photoreceptors

Receptors that respond to light stimuli.

Chemoreceptors

Receptors that respond to chemical stimuli.

Autonomic Nervous System

Part of the PNS that controls involuntary body functions.

Sympathetic Nervous System

Part of the autonomic nervous system that prepares the body for 'fight or flight' responses.

Parasympathetic Nervous System

Part of the autonomic nervous system that conserves energy and maintains 'housekeeping' activities.

Neuron

The functional unit of the nervous system, responsible for transmitting information.

Dendrites

Branch-like structures of a neuron that receive messages from other neurons.

Axon

The long, slender projection of a neuron that transmits electrical impulses away from the cell body.

Myelin Sheath

Insulating layer around axons that speeds up nerve impulse transmission.

Nodes of Ranvier

Gaps in the myelin sheath that facilitate rapid impulse conduction.

Resting Membrane Potential

The electrical charge across a neuronal membrane when the neuron is not firing.

Depolarization

The process by which the inside of a neuron becomes more positively charged.

Action Potential

A rapid rise and fall in electrical potential across a neuronal membrane that signals a nerve impulse.

All-or-Nothing Response

The principle that a neuron either fires completely or does not fire at all.

Repolarization

The return of a neuron's membrane potential to its resting state following depolarization.

Neurotransmitter

Chemical messengers released from neurons to transmit signals across synapses.

Excitatory Postsynaptic Potential (EPSP)

A postsynaptic potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A postsynaptic potential that makes a neuron less likely to fire an action potential.

Synapse

The junction between two neurons where neurotransmitters are released.

Temporal Summation

The process of summing several postsynaptic potentials from one presynaptic neuron.

Spatial Summation

The process of summing postsynaptic potentials from several different presynaptic neurons.

Multiple Sclerosis

A disease characterized by the loss of myelin around nerves, affecting nerve impulse transmission.

Na/K Pump

A cellular pump that uses ATP to maintain the balance of sodium and potassium ions across the membrane.

Signal Transmission

The process by which neural signals are conveyed from one neuron to another across synapses.

Ion channels

Proteins that allow ions to pass through the neuronal membrane, crucial for generating action potentials.

Neural communication

The process through which neurons transmit information through electrical and chemical signals.