MARIEB - NERVOUS SYSTEM copy

Nervous System

The system that gathers, processes, and responds to sensory information in the body, consisting of the central and peripheral nervous systems.

Autominic Nerurotransmitters

use acetylcholine, epinephrine, or norepinephrine

Somatic Nerurotransmitters

always use acetylcholine

Autonomic nerve

preganglionic and postganglionic nerves

Somatic nerves

one motor neuron

Ventral rami

forms a complex of networks (plexus) for the anterior

Dorsal rami

serve the skin and muscles of the posterior trunk

Spinal Nerves

There are 31 pairs of ?, one for each vertebra, formed by the combination of ventral and dorsal roots, and named for their originating region.

Mixed nerves

both sensory and motor fibers

epineurium

Fascicles are bound together by

perineurium

Groups of fibers are bound into fascicles by

Endoneurium

surrounds each fiber

Internal gray matter

mostly cell bodies of spinal cord

Exterior white mater

conduction tracts of spinal cord

cauda equina

collection of spinal nerves

Cerebral edema

Swelling from inflammation can compress and damage brain tissue.

Contusion

Nervous tissue destruction occurs, and it does not regenerate.

Pia mater

Internal layer of meninges that clings to the surface of the brain

Arachnoid layer

web like middle layer of meninges

Meningeal layer

outer covering of the brain

Periosteum

attached to surface of the skull

Dura mater

Double-layered external covering

Reticular Formation

A diffuse mass of gray matter in the brain stem involved in motor control of visceral organs and the reticular activating system, which regulates wakefulness and consciousness.

Medulla Oblongata

The lowest part of the brain stem merges into the spinal cord and contains crucial fiber tracts and control centers for heart rate, blood pressure, breathing, swallowing, and vomiting.

Pons

The bulging center of the brain stem, mainly composed of fiber tracts, includes nuclei that control breathing.

corpora quadrigemina

four rounded protrusions of midbrain ; Reflex centers for vision and hearing

cerebral peduncles

two bulging fiber tracts of midbrain

Midbrain

Mostly composed of tracts of nerve fibers

choroid plexus

forms cerebrospinal fluid

Epithalamus

Forms the roof of the third ventricle and houses the pineal body.

Thalamus

Surrounds the third ventricle and serves as a relay station for sensory impulses to the cortex for localization and interpretation.

Diencephalon

Sits atop the brain stem, enclosed by the cerebral hemispheres.

Basal nuclei

internal islands of gray matter

White matter

Fiber tracts inside the gray matter

Broca’s area

involved in our ability to speak

Primary motor area

sends impulses to skeletal muscles

Somatic sensory area

receives impulses from the body’s sensory receptors

gyri

ridges of brain

sulci

grooves of brain

Fissures

deep grooves of brain

Autonomic reflexes

Regulation of smooth muscle affects heart function, blood pressure, glands, and the digestive system.

Reflex

rapid, predictable, and involuntary responses to stimuli

Nerve Impulse Propagation

Impulses move toward the cell body and travel faster along myelinated fibers.

Depolarization

a stimulus depolarizes the neuron’s membrane

Conductivity

ability to transmit an impulse

Irritability

ability to respond to stimuli

Unipolar neurons

have a short single process leaving the cell body

Bipolar neurons

one axon and one dendrite

Multipolar neurons

extensions from the cell body

Nuclei

clusters of cell bodies within the white matter of the central nervous system

Gray matter

cell bodies and unmylenated fibers

Nodes of Ranvier

gaps in myelin sheath along the axon

Synaptic cleft

gap between adjacent neurons

Neurofibrils

intermediate cytoskeleton that maintains cell shape

Nissl substance

specialized rough endoplasmic reticulum

processes

fibers that extend from the cell body

Cell body

nucleus and is the metabolic center of the cell

Satellite cell

Protect neuron cell bodies

Ependymal cells

Glial cells lining the brain and spinal cord cavities have cilia that circulate cerebrospinal fluid, providing a protective cushion for the CNS.

Central Nervous System (CNS)

Composed of the brain and spinal cord; responsible for integrating and controlling activities.

Peripheral Nervous System (PNS)

Nerves outside the brain and spinal cord that provide communication between the CNS and the rest of the body.

Sensory Input

The gathering of information from sensory receptors to monitor changes in the environment.

Integration

The process of interpreting sensory information and deciding if action is necessary.

Motor Output

The response generated by the nervous system to stimuli, activating muscles or glands.

Somatic Nervous System

The part of the PNS that controls voluntary movements of skeletal muscles.

Autonomic Nervous System (ANS)

The part of the PNS that controls involuntary body functions such as heart rate and digestion.

Sympathetic Division

A subdivision of the ANS that prepares the body for 'fight or flight' responses.

Parasympathetic Division

A subdivision of the ANS that conserves energy and promotes 'rest and digest' functions.

Neurons

Specialized cells that transmit messages within the nervous system.

Neuroglia

Support cells of the nervous system that provide structural and functional support to neurons.

Axon

The long, threadlike part of a neuron that conducts impulses away from the cell body.

Dendrite

The short branched extensions of a neuron that receive impulses from other neurons.

Synapse

The junction between two nerves, where neurotransmitters are transmitted to pass signals.

Cerebrospinal Fluid

Fluid surrounding the brain and spinal cord that provides cushioning and nourishment.

Blood Brain Barrier

A selective barrier that prevents certain substances in the blood from entering the brain tissue.

Reflex Arc

The neural pathway that controls a reflex action; it includes a sensory neuron, interneurons, and an effector.

Cerebrum

The left and right parts of the brain that oversee different functions including movement, speech, and emotion.

Thalamus

The brain structure that serves as a relay station for sensory information to the cortex.

Hypothalamus

A brain region that regulates body temperature, water balance, and other autonomic functions.

Alzheimer’s Disease

A progressive brain disease characterized by memory loss, confusion, and physical decline.

Concussion

A slight brain injury that may temporarily affect brain function but does not cause permanent damage.

Ganglia

Clusters of neuron cell bodies located outside the CNS.

Cranial Nerves

Twelve pairs of nerves that primarily serve the head and neck.

Action Potential

A rapid change in membrane potential that occurs when a neuron sends information down the axon.

Myelin Sheath

An insulating layer that surrounds axons, increasing the speed of impulse transmission.

Neurotransmitters

Chemical messengers that transmit signals between neurons at synapses.

Brain Stem

The part of the brain that connects the brain to the spinal cord, controlling vital functions such as breathing and heart rate.

Cerebellum

A brain structure that coordinates voluntary movements and maintains posture and balance.

Limbic System

A group of structures involved in emotion, memory, and arousal, including the amygdala and hippocampus.

Somatic Reflexes

Reflexes that involve skeletal muscles responding to stimuli, often processed through the spinal cord.

Spinal Cord

The structure that transmits signals between the brain and the rest of the body, also involved in reflex actions.

Choroid Plexus

A network of cells in the ventricles of the brain that produces cerebrospinal fluid (CSF).

Neuroplasticity

The brain's ability to reorganize itself by forming new neural connections throughout life.

Neurotransmission

The process by which neurotransmitters are released from neurons and bind to receptors on target cells to transmit signals.

Brain Mapping

A technique used to study the functional areas of the brain, identifying regions responsible for specific tasks.

Synaptic Plasticity

The ability of synapses to strengthen or weaken over time, which is crucial for learning and memory.

Glial Cells

Non-neuronal cells in the nervous system that provide support, protection, and insulation for neurons.

Cerebral Cortex

The outer layer of the brain involved in complex functions such as reasoning, problem-solving, and decision-making.

Hippocampus

A region of the brain associated with memory formation and spatial navigation.

Somatic System

The part of the nervous system associated with the voluntary control of body movements via skeletal muscles.