Summary Biol 173 Exam 4 Study Guide

Exam 4 Study Guide: Chapters 12-14, Lecture Guide Pages 235-292
Anatomy and Physiology 1
Dr. Surmacz
Exam Date: December 1, 2017

Chapter 12: Neural Tissue: Part 1, Pages 389-400
 Nervous System Function
o Gains input from internal or external environment changes, sends
to be processed, and responds to that stimulus
 Nervous System Organization
o 2 Main Divisions
 Central Nervous System (CNS)
 Brain and spinal cord
 Integrating, processing and coordinating sensory data
and motor commands
 Peripheral Nervous System (PNS)
 Everything else
 Nerves extending from spinal cord and/or brain
 Sensory PNS
o Special
 Sight
 Hearing
 Balance
 Smell
 Taste
o Visceral
 Monitors internal organs
o Somatic
 Monitors muscles, joints, and skin
surface (touch)
 Motor PNS
o Somatic
 Skeletal muscles
 Voluntary
o Visceral
 “Autonomic”
 Heart, smooth muscles, glands, and
adipose
 Involuntary
 Sympathetic Motor PNS
 Parasympathetic Motor PNS
 Afferent Division
o Brings sensory information to the CNS fro
receptors in peripheral tissues and organs
 Efferent Division
o Carries motor commands from the CNS to muscles,
glands, and adipose tissue
o 2 Divisions
 Somatic NS

,  Controls skeletal muscle
contractions
 Voluntary contractions are under
conscious control
 Involuntary contractions may be
simple, automatic response or
complex movements, but they are
controlled at the subconscious
level, outside your awareness
 Autonomic NS
 Regulates smooth muscle, cardiac
muscle, glandular secretions, and
adipose tissue subconsciously
 Enteric Nervous System (ENS)
 An extensive network of neurons and nerve networks in
the walls of the digestive tract
 Cell Types
o Neurons
 Cells specialized to conduct electrical signals
 Lack centrioles
o Neuroglia
 “Glia”
 Support cells
 Common site for tumors
 Function
 Protection
 Support/framework
 Regulate composition of extracellular fluid
o 6 Kinds of Neuroglia Cells
 Astrocytes
 Maintain blood brain barrier
 Provide structural support
 Regulate ion, nutrient, and dissolved gas
concentrations
 Absorb and recycle
neurotransmitters
 Form scar tissue after
injury
 Ependymal Cells
 Line ventricles and
central canal
 Assist in producing,
circulating, and
monitoring
cerebrospinal fluid
 Oligodendrocytes
 Myelinate CNS axons
 Provide structural framework
 Microglia

,  Remove cell debris, wastes, and pathogens by
phagocytosis
 Satellite Cells
 Surround neuron cell bodies in ganglia
 Regulate oxygen, carbon dioxide, nutrients and
neurotransmitter levels around neurons in ganglia
 Schwann Cells
 Surround all axons in PNS
 Responsible for myelination of peripheral axons
 Participate in repair process after injury
 General Features of a Neuron
o Properties
 Extreme longevity
 Can survive more than 100 years
 Amitotic
 Do NOT divide because they lose their centrioles
 High metabolic rate
 Use lots of oxygen
 Can go up to 4 minutes without oxygen before
permanent damage occurs
o Parts
 Soma
 Nucleus, mitochondria, endoplasmic reticulum, Golgi
apparatus
 RER = Nissl bodies
o Gives grey appearance
 Well-developed cytoskeleton called neurofilaments and
neurotubules
 Lacks centrioles so they don’t divide
 Perikaryon
o The cytoplasm surrounding the nucleus
 Dendrites
 Receive signals
 Slender and branched
 Axon
 Initiates electrical signals and conducts them away
from soma
 2 Types
o Myelinated
 Covered with the myelin sheath
o Non-myelinated
 Naked
 NO myelin sheath
 Axoplasm
o The cytoplasm of the axon
 Axolemma
o The plasma membrane of the axon
o Surrounds the axoplasm
 Axonal (axoplasmic) transport