Central Nervous System

Functions of the Spinal Cord

Conducts sensory and motor information, integrates neural input, supports locomotion, and facilitates reflex responses.

Ascending Tracts

Carry sensory information up the spinal cord.

Decussation

Crossing of the midline that occurs in many tracts, allowing brain to sense and control the contralateral side of the body.

Meninges

Three fibrous membranes enclosing the brain and spinal cord, consisting of dura mater, arachnoid mater, and pia mater.

Cerebrospinal Fluid (CSF)

Clear, colorless liquid that fills the ventricles and canals of the CNS and surrounds the brain.

Lumbar Puncture

A medical procedure used to collect cerebrospinal fluid from the subarachnoid space for diagnostic purposes.

Ganglion

A cluster of neuron cell bodies located outside the central nervous system.

Reflexes

Involuntary responses to stimuli that are essential for posture, coordination, and protection.

White Matter

Myelinated axons that carry signals between different parts of the CNS.

Gray Matter

Neuron cell bodies with little myelin, involved in information processing and synaptic integration.

Cerebrum

The largest part of the brain, accounting for 83% of its volume, containing gyri and sulci.

Meningitis

Inflammation of the meninges, often caused by bacterial or viral infection.

Choroid Plexus

A spongy mass of blood capillaries in the ventricles of the brain responsible for producing cerebrospinal fluid.

Blood Barrier System

Regulates substances moving from the bloodstream into the brain tissue, selectively allowing beneficial substances while blocking harmful ones.

Cerebellum

Second largest brain region that contains 50% of the brain's neurons, important for coordination.

Dura Mater

The outermost layer of the meninges that is closely adhered to the cranial bones.

Epidural Space

The space between the dural sheath and the vertebrae that is filled with fat.

Pia Mater

The delicate innermost membrane that closely follows the contours of the brain and spinal cord.

Function of the Brainstem

Controls basic life functions such as breathing, heartbeat, and blood pressure.

Cerebral Cortex

The outer layer of the cerebrum, responsible for higher brain functions including thought, action, and sensory processing.

Somatic Nervous System

Part of the peripheral nervous system that controls voluntary movements via skeletal muscles.

Autonomic Nervous System

Regulates involuntary physiological functions, including heartbeat and digestion.

Spinal Reflex Arc

The neural pathway that controls a reflex action, involving sensory neurons, interneurons, and motor neurons.

Corpus Callosum

A band of fibrous tissue that connects the left and right hemispheres of the brain, facilitating interhemispheric communication.

Peripheral Nervous System (PNS)

The part of the nervous system that connects the CNS to the rest of the body, including limbs and organs.

Neurotransmitters

Chemical messengers that transmit signals across a synapse from one neuron to another.

Demyelination

The loss or destruction of the myelin sheath surrounding nerves, which can disrupt signal transmission.

Central Nervous System (C

Synapse

The junction between two neurons, where neurotransmitters are released to transmit signals.

Neuroplasticity

The ability of the brain to reorganize itself by forming new neural connections throughout life.

Glial Cells

Supporting cells in the nervous system that provide support, nutrition, and insulation for neurons.

Action Potential

A rapid change in membrane potential that propagates along the axon, allowing signal transmission.

Somatic Reflexes

Reflex actions that involve skeletal muscles and are under conscious control.

Autonomic Reflexes

Reflex actions that control involuntary responses like heart rate and digestion.

Spinal Nerves

Pairs of nerves that arise from the spinal cord and transmit sensory and motor information.

Peripheral Neuropathy

A condition resulting from damage to the peripheral nerves, leading to weakness, numbness, and pain.

Receptor Potential

The initial change in membrane potential in response to a stimulus at the sensory receptor.

Central Canal

A small canal in the center of the spinal cord that contains cerebrospinal fluid.

Reflex Arc Components

The key components of a reflex arc include sensory neurons, interneurons, motor neurons, and the effector.

Types of Neuroglia

Neuroglia, or glial cells, include astrocytes, oligodendrocytes, and microglia, playing various supportive roles in the nervous system.

Sensory Pathways

Sensory pathways transmit sensory information from the peripheral nervous system to the central nervous system for processing.

Motor Pathways

Motor pathways convey signals from the central nervous system to muscles, facilitating movement.

Somatic Nervous System Function

The somatic nervous system is responsible for voluntary muscle movements and transmitting sensory information from external stimuli.

Autonomic Nervous System Divisions

The autonomic nervous system is divided into the sympathetic and parasympathetic systems, regulating involuntary functions.

Role of the Cerebellum

The cerebellum coordinates muscle movements, maintains posture, and ensures balance.

Nerve Regeneration

Nerve regeneration is the process of repairing and regrowing damaged nerve fibers, mostly occurring in the peripheral nervous system.

Role of Acetylcholine

Acetylcholine is a neurotransmitter critical for muscle contraction and communication between neurons.

Glial Cell Types

Types of glial cells include astrocytes (support), oligodendrocytes (myelination in CNS), and Schwann cells (myelination in PNS).

Neurons

Nerve cells that transmit information through electrical and chemical signals.

Action Potential Threshold

The minimum membrane potential that must be reached to trigger an action potential.

Myelin Sheath

An insulating layer that surrounds the axon of some neurons, increasing the speed of signal transmission.

Nodes of Ranvier

Gaps in the myelin sheath where action potentials can jump, facilitating rapid conduction.

Synaptic Transmission

The process through which neurotransmitters are released from one neuron and bind to receptors on another.

Electroencephalogram (EEG)

A test that detects electrical activity in the brain using electrodes placed on the scalp.

Plexus

A network of intersecting nerves or vessels, such as the brachial or lumbar plexus.

Nerve Fiber Types

Nerve fibers are classified as A, B, or C, based on their diameter and conduction velocity.

Cognitive Functions

Mental processes including perception, memory, reasoning, and decision-making, predominantly carried out by the cerebral cortex.

Basal Ganglia

A group of nuclei in the brain involved in coordinating movement and cognitive functions.