altered neuronal function

Afferent neuron

Sensory neuron that carries information from the body to the central nervous system

Efferent neuron

Motor neuron that carries signals from the central nervous system to muscles and organs

Interneuron

Neuron located within the central nervous system that connects sensory and motor neurons

Membrane potential

Difference in electrical charge between the inside and outside of a neuron

Resting membrane potential

Normal polarized state of a neuron before an impulse is generated

Depolarization

Sodium enters the neuron causing the inside to become more positive and initiating an action potential

Repolarization

Potassium leaves the neuron restoring the negative membrane potential

Myelin sheath

Insulating layer around axons that increases the speed of nerve impulse conduction

Nodes of Ranvier

Gaps in the myelin sheath where action potentials are regenerated during saltatory conduction

Saltatory conduction

Rapid conduction of nerve impulses by jumping from one node of Ranvier to the next

White matter

Region of the nervous system composed primarily of myelinated axons that transmit signals

Gray matter

Region composed primarily of neuron cell bodies dendrites and synapses that processes information

Central nervous system

Brain and spinal cord responsible for integrating and processing information

Peripheral nervous system

Cranial nerves spinal nerves and peripheral nerves that connect the central nervous system to the body

Somatic nervous system

Division of the peripheral nervous system responsible for voluntary skeletal muscle movement

Autonomic nervous system

Division of the peripheral nervous system responsible for involuntary body functions

Sympathetic nervous system

Fight or flight division that increases heart rate blood pressure and respiratory rate while decreasing digestion

Parasympathetic nervous system

Rest and digest division that slows heart rate and promotes digestion and bladder emptying

Frontal lobe

Controls personality judgment voluntary motor function decision making and expressive speech

Parietal lobe

Processes touch pain temperature pressure proprioception and spatial awareness

Temporal lobe

Responsible for hearing memory and language comprehension

Occipital lobe

Primary center for vision and visual processing

Cerebellum

Coordinates balance posture and smooth voluntary movement

Brainstem

Controls vital functions including breathing heart rate blood pressure swallowing and consciousness

Pyramidal motor system

Motor pathway responsible for precise voluntary movement originating in the motor cortex

Extrapyramidal motor system

Basal ganglia system responsible for posture coordination balance and automatic movements

Cerebral palsy

Nonprogressive disorder caused by injury to the developing brain resulting in permanent motor impairment

Spastic cerebral palsy

Most common type of cerebral palsy characterized by increased muscle tone and muscle stiffness

Hydrocephalus

Excess accumulation of cerebrospinal fluid in the ventricles causing increased intracranial pressure

Ventriculoperitoneal shunt

Device that diverts excess cerebrospinal fluid from the ventricles to the peritoneal cavity

Parkinson disease

Progressive neurodegenerative disorder caused by loss of dopamine-producing neurons in the substantia nigra

TRAP

Mnemonic for Parkinson disease symptoms Tremor Rigidity Akinesia or Bradykinesia and Postural instability

Dopamine

Neurotransmitter required for smooth coordinated movement that is deficient in Parkinson disease

Multiple sclerosis

Autoimmune disease causing destruction of the myelin sheath within the central nervous system

Plaque

Area of demyelination and scar tissue found in the brains and spinal cords of patients with multiple sclerosis

Relapse-remission pattern

Disease course in which symptoms worsen during exacerbations and improve during remissions commonly seen in multiple sclerosis

Cerebrospinal fluid

Fluid that cushions the brain and spinal cord and circulates nutrients and waste products

Blood-brain barrier

Protective barrier that regulates which substances enter the brain from the bloodstream

DKA versus Parkinson versus MS

DKA causes metabolic acidosis Parkinson is caused by dopamine deficiency and MS is caused by autoimmune demyelinatio