Unit 5: Nervous Tissue

A comprehensive set of vocabulary flashcards covering key concepts and definitions related to nervous tissue and anatomy.

Central Nervous System (CNS)

Includes the brain and spinal cord.

Peripheral Nervous System (PNS)

Comprises everything outside the CNS.

Afferent Division

Transmits sensory information from receptors to the CNS.

Efferent Division

Carries motor commands from the CNS to effectors.

Somatic Nervous System (SNS)

Involves voluntary control and voluntary reflexes.

Autonomic Nervous System (ANS)

Governs involuntary control including smooth muscle, cardiac muscle, glands, and adipose tissue.

Neurons (Nerve Cells)

Basic functional units of the nervous system; responsible for transfer and processing of information.

Neuroglia (Glial Cells)

Supporting cells that separate and protect neurons.

Soma (Cell Body)

Contains the nucleus and organelles.

Axon

Long cytoplasmic extension that conducts electrical impulses away from the cell body.

Astrocytes

Maintain the blood-brain barrier and regulate nutrients.

Oligodendrocytes

Form myelin in the CNS.

Microglia

Immune defense cells that engulf pathogens.

Ependymal Cells

Line ventricles of the brain and produce cerebrospinal fluid (CSF).

Schwann Cells

Form myelin sheath around peripheral nerves.

Myelin Sheath

Acts as an insulator for electrical signals.

Action Potential

A rapid change in membrane potential essential for nerve impulse conduction.

Graded Potential

Temporary localized change in resting potential due to stimuli.

Refractory Periods

Periods where neuron responsiveness is impaired.

Synapse

Specialized sites where neurons communicate with other cells.

Electrical Synapses

Use gap junctions for rapid signaling.

Chemical Synapses

Seperated by synaptic clefts where neurotransmitters are released.

Excitatory Neurotransmitters

Promote depolarization and action potential generation.

Inhibitory Neurotransmitters

Cause hyperpolarization, suppressing action potential generation.

Cerebrospinal Fluid (CSF)

Cushions the brain, supplies nutrients, and removes waste.

Blood-Brain Barrier

Protects the CNS from the general circulation; transport across the barrier is highly selective.

Monosynaptic Reflex

Reflex that involves only one synapse.

Polysynaptic Reflex

Reflex that involves multiple synapses.

Dura Mater

The outer layer of the spinal meninges.

Arachnoid Mater

The middle layer of the spinal meninges.

Pia Mater

The inner layer of the spinal meninges.

Cranial Nerves

Includes 12 pairs of nerves with various sensory and motor functions.

Sympathetic Nervous System (SNS)

Also known as the Thoracolumbar Division, involved in fight-or-flight.

Parasympathetic Nervous System (PNS)

Also known as Craniosacral Division, involved in rest and digest functions.

Neurotransmitters

Chemicals released by neurons affecting membrane potential of other neurons.

Sensation

The stimulus reaching the CNS.

Perception

Conscious awareness of a stimulus.

Interneurons

Neurons situated between sensory and motor neurons.

Reflex Arc

Neural wiring of a single reflex.

Cerebrum

Largest portion of the brain responsible for sensory input and cognitive functions.

Cerebellum

Adjusts muscle tone and coordinates movements to maintain balance.

Hypothalamus

Regulates various autonomic functions.

Higher Order Functions

Involves cognitive processes requiring the cerebral cortex.

Aging and the Nervous System

Involves anatomical changes affecting memory and sensory processing.