_A&P II_ Practical #1 Study Guide

Central Nervous System (CNS)

Comprises the brain and spinal cord.

Peripheral Nervous System (PNS)

Includes the 12 cranial nerves and 31 spinal nerves.

Afferent Nerves

Also known as sensory nerves; carry signals to the CNS.

Efferent Nerves

Also known as motor nerves; carry signals away from the CNS.

Somatic Nervous System

Controls voluntary movements involving skeletal muscles.

Autonomic Nervous System (ANS)

Controls involuntary actions, managing organs, glands, and smooth muscles.

Neurons

Cells that transmit nerve impulses.

Dendrites

The parts of a neuron that receive signals.

Soma

The cell body of a neuron, containing the nucleus and organelles.

Axon

The part of a neuron that sends signals away from the soma.

Interneuron

Neurons that connect sensory and motor pathways.

Neuroglia

Supportive cells in the nervous system that assist neurons.

Astrocytes

Glial cells that maintain the blood-brain barrier and provide structural support.

Oligodendrocytes

Glial cells responsible for myelination in the CNS.

Schwann Cells

Glial cells that produce myelin in the PNS.

Dura Mater

The outermost layer of the meninges, providing tough protection.

Arachnoid Mater

The middle layer of the meninges, which contains cerebrospinal fluid.

Pia Mater

The innermost layer of the meninges that directly covers the brain.

Gyri

Ridges on the surface of the brain.

Sulci

Shallow grooves between the gyri.

Fissure

A deep groove or cleft in the brain.

Cranial Nerves

Twelve pairs of nerves that emerge directly from the brain.

Monosynaptic Reflex

A reflex pathway with only one synapse, e.g., knee-jerk reflex.

Polysynaptic Reflex

A reflex pathway with multiple synapses, e.g., withdrawal reflex.

Taste Buds

Sensory organs for taste, located on the tongue.

Mechanoreceptors

Receptors that respond to mechanical pressure or distortion.

Nociceptors

Pain receptors that respond to harmful stimuli.

Thermoreceptors

Receptors that detect temperature changes.

Ganglia

Clusters of neuron cell bodies located in the PNS.

Choroid Plexus

A structure in the brain that produces cerebrospinal fluid (CSF).

Cerebrospinal Fluid (CSF)

A fluid that surrounds and protects the brain and spinal cord.

Babinski Reflex

A reflex in which a newborn's toes fan out, while an adult's toes curl.

Nissl Bodies

Structures in the neuron composed of rough endoplasmic reticulum and ribosomes.

Olfactory Nerve (I)

Responsible for the sense of smell.

Optic Nerve (II)

Primarily responsible for vision.

Oculomotor Nerve (III)

Controls eye movement and pupil constriction.

Trochlear Nerve (IV)

Innervates the superior oblique muscle of the eye.

Trigeminal Nerve (V)

Involved in facial sensation and controls muscles for chewing.

Abducens Nerve (VI)

Facilitates lateral eye movement.

Facial Nerve (VII)

Controls facial expressions and contributes to taste sensation.

Vestibulocochlear Nerve (VIII)

Responsible for hearing and balance.

Glossopharyngeal Nerve (IX)

Involved in swallowing and taste sensations.

Vagus Nerve (X)

Regulates autonomic functions and carries taste sensations.

Accessory Nerve (XI)

Controls shoulder movement.

Hypoglossal Nerve (XII)

Controls tongue movement.