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Joan Torres 5th Period Nervous System - Coggle Diagram
Joan Torres
5th Period
Nervous System
Major Functions
Sensory Input - Information obtained from receptors about internal and external receptors
Integration - Interpretation process of sensory input
Motor Output - Activation of effector organs (muscles/glands) produces response
Major Divisions
and Subdivisions
Central Nervous System - Consists of brain and spinal cord; has integrative & control centers
Peripheral Nervous System - Cranial and Spinal nerves; communication lines between CNS & body
Sensory Afferent Division - Somatic/Visceral sensory nerve fibers; conducts impulses from receptors to CNS
Motor Efferent Division -
Motor nerve fibers;
conducts impulses
from CNS
to effectors
Somatic Nervous System -
Somatic voluntary motor nerve fibers; conducts
impulses from CNS to
muscles
Autonomic Nervous System -
Visceral involuntary
motor nerve fibers; conducts
impulses from CNS to
cardiac/smooth muscle
and glands
Parasympathetic Division - Conserves energy and promotes house-keeping functions in rest
Sympathetic Division - Mobilizes body system during activities
Tissues (Neurons
and Neuroglia)
Motor Neurons - Carry impulse from CNS to effector, multipolar, cell bodies inside CNS
Inter-neurons - Between motor and sensory neurons, signals through CNS paths, entirely in CNS, 99% of body are inter-neurons
Sensory Neurons - Transmit impulse from receptor to CNS, unipolar, cell bodies inside ganglia in PNS
Astrocytes - Abundant, versatile, highly branched cells; clings to neurons synaptic endings, and capillaries; supports neurons, processes info, and controls chemical environment
Microglial Cells - Ovoid cells with thorny processes that monitor neurons; migrate to injured neuron
Ependymal Cells - Squamous/column shaped; acts as barrier between CSF and tissue fluid
Oligodendrocytes - Branched cells that wrap CNS fibers forming myelin sheathes
Satellite Cells - Surround neuron bodies in PNS; similar function to astrocytes
Schwann Cells - Surround peripheral nerves; similar function to oligodendrocytes, vital for regeneration
Classification of Neurons
Multipolar - 3 or more processes which are common in the CNS (1 axon and multiple dendrites
Bipolar - 2 processes and are rare (1 axon and dendrite)
Unipolar - 1 T-like process which are also called "pseudo-unipolar" (2 axons)
Sensory - Transmits from receptors to CNS; are all unipolar, cell bodies are in ganglia in PNS
Motor - Transmits from CNS to effector; multipolar, cell bodies are in CNS
Interneurons - Also called "Association Neurons"; are between motor and sensory neurons; entirely in CNS; make up majority of neurons (99%)
Connective Tissue Coverings
Arachnoid Mater - Middle layer with spiderweb extensions; separated from dura mater by subdural space
Pia Mater - Delicate connective tissue following every convolution
Dura Mater - Strongest Matrix; most superficial layer
Major Parts/Functions of Brain
Cerebrum - Regulates temperature, assists with speech, rational thinking, and emotions
Brainstem - Controls most of the functions relating to automatic systems such as respiratory
Cerebellum - Assists and regulations many functions including movement as well as balancing
Major Parts/Functions of Spinal Cord
Thoracic - Assists with maintaining the body and keeping it upright
Lumbar - Provides stability to the back of body and is an area where many muscles and ligaments attach
Cervical - Provide foundation and stability to head and connects the head to the main spine
Action Potentials & Nerve Impulses
Resting State - All Na and K channels closed
Depolarization - Na channels open
Repolarization - Na inactive; Ka channels open
Refractory Period - Neuron cannot trigger AP; Na channels open so neuron cannot respond to another
Hyperpolarization - Some K channels stay open, Na channels reset
Cranial Nerves
I. Olfactory Nerves - Smell; Fiber synapse; purely sensory olfactory function
II. Optic Nerves - Retinas in brain tract; cross at chiasma; purely sensory visual function
III. Oculomotor Nerves - Fibers extend from ventral midbrain through superior orbital fissures; raise eyelid,direct eyeball, constrict iris, control lens shape
IV. Trochlear Nerves - Innervates superior oblique muscle; motor nerve directs eyeball
V. Trigeminal Nerves - Opthalmic, Maxillary, Mandibular; supply motor fibers for mastication
VI. Abducens Nerves - Fibers from inferior pons enter orbit by superior orbital fissures; primarily motor fibers innervating lateral rectus muscle
VII. Facial Nerves - Facial expression, parasympathetic impulse to lacrimal and salvatory glands
VIII. Vestibucochlear Nerves - Afferent fibers from hearing and equilibrium receptors; adjusts receptor sensitivity
IX. Glossopharyngeal Nerves - Medulla fibers leave skull, innervate tongue, pharynx of swallow, parasympathetic fibers to salivary glands (motor); taste/sensory impulse (sensory)
X. Vagus Nerves - Parasympathetic fibers help regulate heart, lungs, abdominal viscera (motor); sensory fibers impulse from thoracic/abdominal and taste buds
XI. Accessory Nerves - Ventral rootlets; innervate trapezius and sternocleidomastoid muscle
XII. Hypoglossal Nerves - Innervate extrinsic and intrinsic muscles of tongue (swallowing/speech)
Spinal Nerves
Cervical Nerve Pairs: C1-C8
Thoracic Nerve Pairs: T1-T12
Lumbar Nerve Pairs: L1-L5
Sacral Nerve Pairs: S1-S5
Coccygeal Nerve Pair: C0
Neurotransmitters
Acetylcholine - Released at NM junctions and degraded by acetylcholinesterase
Biogenic Amines - Catecholamines (Dopamine, norepinephrine, epinephrine), Indolamines (Serotonin, Histamine)
Amino Acids - Peptides, Purines, Gases/Lipids, Endocannabinoids
Autonomic Nervous System vs. Somatic Nervous System
The autonomic nervous system controls the involuntary viscera and motor fibers. They also make impulses from the central nervous system towards towards cardiac muscle, smooth muscle, and glands
The somatic nervous system consists of somatic voluntary motor nerve fibers. They create impulses from the central nervous system towards the skeletal muscles.
Reflex Arc
Receptor - Site of stimulus
Sensory Neuron - Transmits afferent impulse to CNS
Integration Center - Either mono-synaptic or poly-synaptic region in CNS
Motor Neuron - Efferent impulse from integration center to efferent organ
Effector - Muscle effector or gland that responds to efferent impulse by contracting or secreting
Disorders & Diseases
Cerebrovascular Accident (Stroke) - When blood flow in brain is halted; loss of coordination, confusion, headache
Autism - Brain disorder that makes it difficult to communicate; repeated behaviors, anxiety, depression
Alzheimer's Disease - Form of dementia associated with age; memory loss, confusion, mood changes
Spinal Cord Injury - Damage to the spinal cord; weakness, spastic muscles, paralysis
Meningitis - Infection in the meninges surrounding brain; nausea/vomit, fevers/chills, irritation
Multiple Sclerosis - Autoimmune disease that damages myelin sheath; muscle weakness, incontinence, and tremors
Drugs of Abuse
Heroine - When blocking the opiate receptor, dopamine creates feeling of sedation and well being
Ecstasy - It affects mood, sleep, perception, and appetite. It also effects the award pathway with dopamine, giving ecstasy an addictive trait
Marijuana - THC removes unnecessary short term memories and reduces movement to make people relax. THC also does not break down quickly resulting in a "high"
Methamphetamine - Is addictive due to its affects towards the reward pathway which makes people feel exhilaration
Alcohol - It affects decision making, memory formation, and impulse control
Cocaine - It affects the reward pathway and voluntary movement, causing people to fidget
LSD - It affects the locus coeruleus, which is responsible for wakefulness and response to stimulus