Neuroglia (glial cells) - Answers Essential to survival and function of neurons
Preserve structure of nervous tissue
Central Nervous System (CNS) - Answers Associated with the brain and the spinal cord
Consists of nervous tissue, connective tissue, and blood vessels
Functions to process and coordinate sensory data from inside and outside body
Motor commands control activities of peripheral organs (e.g., skeletal muscles)
Higher functions of brain include intelligence, memory, learning, and emotion
Peripheral Nervous System (PNS) - Answers Associated with the tissue outside the CNS
Includes all nervous tissue outside CNS and ENS
Delivers sensory information to the CNS
Carries motor commands to peripheral tissues
Nerves - Answers Bundles of axons with connective tissues and blood vessels
Carry sensory information and motor commands
Cranial nerves - Answers Connect to brain
Spinal nerves - Answers Attach to spinal cord
Afferent division - Answers Carries sensory information
From receptors in peripheral tissues and organs to CNS
Efferent division - Answers Carries motor commands
From CNS to muscles, glands, and adipose tissue
Receptors - Answers Detect changes or respond to stimuli
May be neurons or specialized cells
May be single cells or complex sensory organs (e.g., eyes, ears)
Effectors - Answers Target organs that respond to motor commands
Somatic nervous system (SNS) - Answers Controls skeletal muscle contractions
, Both voluntary and involuntary (reflexes)
Autonomic nervous system (ANS) - Answers Controls subconscious actions, contractions of
smooth and cardiac muscle, and glandular secretions
Sympathetic division has a stimulating effect
Parasympathetic division has a relaxing effect
Gray matter - Answers Ganglia are collections of neuron bodies in the PNS
White matter - Answers Nerves - Buncles of axons in the PNS
Enteric nervous system (ENS) - Answers 100 million neurons in walls of digestive tract
As many or more than in spinal cord
Use the same neurotransmitters as the brain
Initiates and coordinates visceral reflexes locally
Without instructions from CNS
Can be influenced by ANS
Overview of nervous system - Answers
Neurons - Answers Basic functional units of the nervous system
Send and receive signals
Function in communication, information processing, and control
Dendrites - Answers Short and highly branched processes extending from cell body
Axon - Answers Single, long cytoplasmic process
Propagates electrical signals (action potentials)
Axolemma - Answers Plasma membrane of the axon
Covers the axoplasm
axon hillock - Answers Thick region that attaches initial segment to cell body
Anaxonic neurons - Answers Small
All cell processes look similar
Found in brain and special sense organs