NS=Nervous System, B/w= Between
SLOW onset
LONG LASTING effects
(Minutes-days )
Endocrine system has a ____ onset and _____ effects
FAST onset
SHORT TERM effects
Nervous system has a ____ onset and _____ effects
Central Nervous System (CNS)
Brain & Spinal cord
Processing & coordinates SENSORY input
all higher thinking & func
Peripheral Nervous System (PNS)
Peripheral nerves
Provides SENSORY info to the CNS
Carries out MOTOR commands sent down by the cns
Afferent Division
Carries info FROM:
SOMATIC sensory receptors monitor and send info abt muscles, joints and skin
VISCERAL sensory receptors monitor other internal organs from systems (Ex. Cardiovascular & Respiratory)
Efferent Division
Divided into 2 systems:
SOMATIC Nervous System (NS): Controls muscle CONTRACTIONS (voluntary/involuntary)
AUTONOMIC NS: Regulates smoot & cardiac muscle & glandular activity (INvoluntary)
Afferent Example
Touching the stove gives info, to the brain, on the texture/ temp/ feel
Efferent Example
Touching the stove gives info, to the brain, to reflex the hand AWAY from the hot stove
Neuroglia
Support and Protect nervous system and neurons
4 Types of Neural Glial Cells
Astrocytes
Oligodendrocytes
Microglia
Ependymal Cells
Astrocyte Characteristics
Largest & most numerous
Functions:
Control INTERSITIAL environment
Maintain Blood-Brain Barrier
Form 3D framework for the CNS
Repair damaged nervous tissue
Guide neural development EMBRYONICALLY
Oligodendrocytes Characteristics
Improve conduction of the axon
thru MYELIN SHEATH
Wrapped areas = INTERNODES
Myelin sheath Gaps = Nodes of Ranvier
Microglia Characteristics
Act as PHAGOCYTIC cells of CNS
Attack viruses, microorganisms, tumor cells
5% of CNS cells (#s increase when needed)
(Keep the CNS clean)
Ependymal Cells Characteristics
Lines ventricles of the brain & central canal of spinal cord
Assist in producing, circulating, monitoring CEREBROSPINAL Fluid
The Peripheral Nerves
Axons of the PNS group together to form ____
SATELLITE Cells & SCHWANN Cells
Peripheral Nervous System is composed of
Neurolemma
Schwann Cell’s membrane is _____
Extends & Wraps around PART of axon of single nerve cell
SINGLE nerve axon
MULTIPLE axons at once
Multiple Schwann line a _____ nerve axon
Oligodendrocytes encircle ______ axon at once
Neurons
Responsible for transfer/processing of info in the Nervous system
thru ELECTRICAL Impulses
4 Classifications of STRUCTURAL Neurons
Anaxonic
Bipolar
Pseudounipolar
Multipolar
Anaxonic Neurons
Small & found ONLY in CNS
Bipolar Neurons
Cell body lies b/w the Dendrite & Axons
Pseudounipolar Neurons
Cell body lies OUTSIDE the plane of the Dendrite & Axons
Multipolar Neurons
The most common neuron in the CNS (Unidirectional)
3 FUNCTION Neuron Classifications
Sensory
Motor
Interneurons
Sensory
Form AFFERENT Division of PNS
Deliver info abt Internal & External environment to the CNS
Motor
Form EFFERENT Division of CNS
Stimulate activity of peripheral motor or organ systems
Divided into SOMATIC (body) & VISCERAL (organ) motor
Interneurons
B/w Sensory and Motor neurons
Found within brain & Spinal cord
Analyze sensory input and organize motor outputs
Either EXCITATORY or INHIBITORY based on post synaptic membranes
Excitability
Ability of the plasma membrane to conduct electrical Impulses
Action Potential
Change in membrane potential AFTER the membrane stimulation reaches THRESHOLD
Synapse
Site of cellular/neuronal communication
May be chemical (VESICULAR) or Electrical
BOUND tightly together
At an electrical synapse, the PRESYNAPTIC and POSTSYNAPTIC membranes are
COMMUNICATION Junctions
Allow for passage of the electrical signals b/w cells
Elec. Synapses convey info BOTH directions
Chem. Synapses CANNOT