Neuron Anatomy & Physiology Study Guide

These flashcards cover key vocabulary and concepts related to neuron anatomy, neuroglial cells, and muscle physiology as part of the study guide for the exam.

Dendrites

Receive incoming signals.

Cell Body (Soma)

Integrates/processes information.

Axon Hillock

Trigger zone for the action potential.

Axon

Conducts the electrical impulse away from the soma.

Axon Terminals

Release neurotransmitters into the synapse.

Astrocytes

Support neurons and form the Blood-Brain Barrier.

Microglia

Immune defense; eat debris/bacteria.

Ependymal Cells

Produce and circulate cerebrospinal fluid (CSF).

Oligodendrocytes

Form myelin sheaths in the CNS.

Satellite Cells

Surround cell bodies in ganglia; regulate environment.

Schwann Cells

Form myelin sheaths in the PNS.

Multipolar Neurons

The most abundant type of neuron.

Somatic Function

Voluntary control of skeletal muscles.

Autonomic Function

Involuntary control of smooth/cardiac muscle and glands.

Somatic Motor Neuron Location

Located in the Anterior (Ventral) Horn of spinal gray matter.

Neuron Longevity

Can live over 100 years.

Oxygen Requirement for Neurons

High requirement; die quickly without it.

Neuron Division

Amiotic; neurons do not divide.

Metabolic Rate of Neurons

Exceptionally high.

Ganglion

A cluster of neuron cell bodies located in the PNS.

Synapse Path

Presynaptic neuron → Synaptic cleft → Postsynaptic neuron.

CNS Components

Gray matter, White matter, CNS neuroglia.

PNS Components

Autonomic ganglia, Anterior/Posterior roots, Dorsal root ganglia.

Interneurons

Located in the CNS; function as a bridge between sensory and motor.

Reflex Arc Sequence

Receptor → Sensory Neuron → Integration Center (Interneuron) → Motor Neuron → Effector.

White Matter

Represents myelinated axons.

Myelin Function 1

Electrical insulation.

Myelin Function 2

Speeds up nerve impulses.

Connective Tissue Layers

Endoneurium → Perineurium → Epineurium.

Neurotransmitters

Chemical messengers released at the synapse.

Gray Matter

Contains cell bodies; responsible for processing.

White Matter

Contains myelinated axons; allows for neural signal travel.

Frontal Lobe Functions

Motor functions and personality.

Parietal Lobe Function

Somatosensation (touch).

Temporal Lobe Function

Hearing.

Occipital Lobe Function

Vision.

Insula Function

Taste.

Broca’s Area

Responsible for physical speech.

Wernicke’s Area

Responsible for understanding language.

Meninges Layers

Pia mater → Arachnoid mater → Dura mater.

Spinal Tracts

Ascending tracts are sensory; descending tracts are motor.

Gyrus

Bump or ridge in the brain.

Sulcus

Groove or valley in the brain.

Posterior Horn Function

Sensory processing.

Lateral Horn Function

Autonomic functions.

Anterior Horn Function

Somatic motor functions.

Cause of Alzheimer’s

Buildup of beta-amyloid plaques and tau tangles.

CSF Production Site

Produced in the ventricles by the choroid plexus.

Spinal Cord Location

Located in the vertebral canal; ends at L1-L2 vertebra.

Corpus Callosum Function

White matter bridge connecting the two brain hemispheres.

Hydrocephalus Cause

Blockage or overproduction of cerebrospinal fluid (CSF).

Hypothalamus Function

Regulates temperature, hunger/thirst, sleep, hormones, and emotions.

Muscle Membranes

Endomysium (fiber), Perimysium (fascicle), Epimysium (muscle).

Sarcomere Definition

The area between two Z-discs.

Fascicle Definition

A bundle of muscle fibers.

Shortening Structures in Muscle

Sarcomere and I-band.

Calcium Importance

Initiates muscle contraction.

Sodium Importance

Involved in depolarization.

A Band in Muscle

Dark and thick band.

I Band in Muscle

Light and thin band.

H Band in Muscle

Center of A Band; thick only.

Slow Oxidative Fibers

Adapted for endurance; high O2 usage.

Fast Glycolytic Fibers

Adapted for power; high glycogen storage.

Muscle Origin Definition

Proximal and stationary attachment.

Muscle Insertion Definition

Distal and movable attachment.

Acetylcholine (ACh) Role

Neurotransmitter that triggers muscle contraction.

Myoglobin Function

Stores oxygen in muscles.

Titin Function

Elastic protein that helps muscles spring back.

Hypertrophy

Growth of muscle fibers.

Muscle Traits

Excitability, contractility, extensibility, elasticity, conductivity.

Triad Function

Releases Calcium; composed of T-tubule + 2 Terminal Cisternae.

Troponin Role

Calcium-binding protein that moves tropomyosin.

First Step of Sliding Filament Mechanism

Calcium binds to troponin.

Motor Neuron Innervation

1 motor neuron per muscle fiber; cell body in anterior horn.

Motor End Plate Definition

Part of sarcolemma with ACh receptors.

Relaxation Enzyme

Acetylcholinesterase (AChE), which breaks down ACh.

Motor Units

Small units allow for precise movement; large units produce more force.

Hypertrophy vs. Atrophy

Hypertrophy is growth; atrophy is muscle wasting.