URI BIO 220 Final Exam Verified Answers And Questions 2026

URI BIO 220 Final Exam
Peripheral Nervous System (PNS) - CORRECT ANSWER-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 - CORRECT ANSWER-Bundles of axons with connective tissues and blood
vessels
Carry sensory information and motor commands

Neuroglia (glial cells) - CORRECT ANSWER-Essential to survival and function of
neurons
Preserve structure of nervous tissue

Central Nervous System (CNS) - CORRECT ANSWER-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


Cranial nerves - CORRECT ANSWER-Connect to brain

Spinal nerves - CORRECT ANSWER-Attach to spinal cord

Afferent division - CORRECT ANSWER-Carries sensory information
From receptors in peripheral tissues and organs to CNS

Efferent division - CORRECT ANSWER-Carries motor commands
From CNS to muscles, glands, and adipose tissue

Receptors - CORRECT ANSWER-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 - CORRECT ANSWER-Target organs that respond to motor commands

Somatic nervous system (SNS) - CORRECT ANSWER-Controls skeletal muscle
contractions
Both voluntary and involuntary (reflexes)

,Autonomic nervous system (ANS) - CORRECT ANSWER-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 - CORRECT ANSWER-Ganglia are collections of neuron bodies in the
PNS

White matter - CORRECT ANSWER-Nerves - Buncles of axons in the PNS

Enteric nervous system (ENS) - CORRECT ANSWER-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 - CORRECT ANSWER-

Neurons - CORRECT ANSWER-Basic functional units of the nervous system
Send and receive signals
Function in communication, information processing, and control

Dendrites - CORRECT ANSWER-Short and highly branched processes extending from
cell body

Axon - CORRECT ANSWER-Single, long cytoplasmic process
Propagates electrical signals (action potentials)

Axolemma - CORRECT ANSWER-Plasma membrane of the axon
Covers the axoplasm

axon hillock - CORRECT ANSWER-Thick region that attaches initial segment to cell
body

Anaxonic neurons - CORRECT ANSWER-Small
All cell processes look similar
Found in brain and special sense organs

bipolar neurons - CORRECT ANSWER-Small and rare
One dendrite and one axon
Found in special sense organs (sight, smell, hearing)

Unipolar neurons - CORRECT ANSWER-Axon and dendrites are fused
Cell body to one side

, Most sensory neurons of PNS

multipolar neurons - CORRECT ANSWER-Have one long axon and two or more
dendrites
Common in the CNS
All motor neurons that control skeletal muscles

Somatic sensory neurons - CORRECT ANSWER-Monitor external environment

Visceral sensory neurons - CORRECT ANSWER-Monitor internal environment

Interoceptors - CORRECT ANSWER-Monitor internal systems (e.g., digestive, urinary)
Internal senses (stretch, deep pressure, pain)

Exteroceptors - CORRECT ANSWER-Monitor external environment (e.g., temperature)
Complex senses (e.g., sight, smell, hearing)

Proprioceptors - CORRECT ANSWER-Monitor position and movement of skeletal
muscles and joints

Motor neurons (efferent neurons) - CORRECT ANSWER-Carry instructions from CNS
to peripheral effectors
Via efferent fibers (axons)

Somatic motor neurons of SNS - CORRECT ANSWER-Innervate skeletal muscles

Visceral motor neurons of ANS - CORRECT ANSWER-Innervate all other peripheral
effectors
Smooth and cardiac muscle, glands, adipose tissue

Interneurons - CORRECT ANSWER-Most are in brain and spinal cord
Some in autonomic ganglia
Located between sensory and motor neurons
Responsible for
Distribution of sensory information
Coordination of motor activity
Involved in higher functions
Memory, planning, learning

Functional neuron classification - CORRECT ANSWER-

Astrocytes - CORRECT ANSWER-Have large cell bodies with many processes
Maintain blood brain barrier (BBB)
Create three-dimensional framework for CNS
Repair damaged nervous tissue
Guide neuron development