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Melanie Sanchez-Zaragoza P2 Nervous System - Coggle Diagram
Melanie Sanchez-Zaragoza P2 Nervous System
Disorders/Disease
Diseases
Alheimer's Disease
progressive degenerative disease - causes dementia
symptoms- memory loss, short attention span, eventual language loss, etc
Parkinson's Disease
degeneration of dopamine-releasing neurons of substantia nigra
rhythmic shaking, usually begins in a limb, often your hand or fingers
Huntington's Disease
fatal hereditary disorder caused by accumulation of protein
symptoms- wild, jerky "flapping movements", fatal within 15 years
Disorders/Injuries
Meningitis
inflammation of the meninges
Hydrocephalus
obstruction blocks CSF circulation of drainage - leads to increase pressure
in newborns
increased pressure causes head to enlarge
adults
rigidity of skull keeps pressure within - brain damage
Concussion
temporary alteration in function
Contussion
permanent damage
Subdural or subarachnoid hemorrhage
pressure from blood may force brain stem through foramen magnum- results in death
Cerebral Edema
swelling of brain associated with traumatic head injury
Compare & Contrast the Autonomic Nervous System
sympathetic
(Fight & Flight Response)
Heart increases
Used in IMPORTANT SITUATION
Short- Pre
ganglionic Neuron
Long- Pro
ganglionic Neuron
Mobilizes body during activity
Respiratory rate decreases
Parasympathetic
Keeps body energy low
Rest & Digest system
Blood pressure, heart rate, & respiratory rates decreases
Short- Post
ganglion Neuron (
After
ganglia )
Long- Pre
ganglionic
Neuron ( Before
ganglia )
Pupils constricted
Promotes maintenance functions, conserves energy
Similarities
influence on the physiological process of the body:
Circulation, respiration, digestion, urination, & reproduction
Both include motor fibers
Tissues
Neuroglia
CNS
Microglial Cells
Move around & protects from invaders
Ependymal Cells
Makes CSF
Astrocytes
Support & hold things
Functions
Support & brace neurons
Control chemical environment around neurons
Information process in brain
Oligodendrocytes
Makes Myelin Sheaths
PNS
Schwann Cells
Vital to regeneration of damaged peripheral nerve fibers
Surrounded peripheral nerve fibers from myelin sheaths
Satellite Cells
Surround neuron cell bodied in PNS
Similar to astrocytes of CNS
Small cells that surround / wrap neurons
Neurons
Excitable cells transmit electrical signals
All have a cell body, one or more processes
High Metabolic Rate : requires oxygen & glucose
Nuclei-
cluster neurons cell bodies in
CNS
Ganglia-
clusters neuron cell bodies in
PNS
Tracts -
Bundle neuron process in
CNS
Nerves-
Bundle neuron process in
PNS
Dendrites -
impulse towards cell bodies
Axon -
impulse away cell bodies
Major Functions of the Nervous System
Sensory Input
information gathered by sensory receptors about internal and external changes
Integration
processing and interpretation of sensory input
Motor Output
activation of the effector organs and produces a response
Divided into 2 Principal Parts
CNS
brain and spinal cord of dorsal body cavity
integration and control center- interprets sensory input
PNS
consists of mainly nerves that extend from brain to spinal cord
PNS has 2 functional divisions
Sensory (afferent) division
Somatic Sensory fibers
convey impulses from skin to skeletal muscles
Visceral Sensory fibers
convey impulses from vvisceral organs to CNS
Motor (efferent) division
Somatic Nervous System (voluntary)
somatic motor nerve fibers conduct impulses from CNS to skeletal muscles
Autonomic Nervous System (involuntary)
regulates smooth muscle, cardiac, and glands
Sympathetic Division (Active)
Parasympathetic (Low energy, passive)
Functions :
1) Detection of both internal & external environment changes of the body
2) Conduction of information
3) Integration of information
4) Respond to stimuli
5) special sense : vision, hearing, smell, & taste
Major Divisions & Subdivisions of the Nervous System
CNS / SPINAL CORD & BRAIN
Made up of the brain & spinal cord and responsible for integration of info and decision making
PNS / SPINAL NERVE & BRAIN NERVES
Somatic Nervous System
Fibers connecting to skin and skeletal muscles
Autonomic Nervous System
Sympathetic nervous system ( fight or flight )
Parasympathetic nervous system ( calms body down )
Fibers connecting to viscera / innervate smooth & cardiac muscle & glands
Major Parts and Functions of the Spinal Cord
Anatomy and Perception
Epidural Space
cushion of fat & network of veins in space between vertebrae
Filum Terminale
fibrous extension of conus covered with pia mater (extends to coccyx)
Denticulate Ligaments
extensions of pia mater that secure cord to the duramater
CSF fills subarachnoid space betweem arachnoid & pia maters
Spinal nerves
Part of the PNS and it is attached to the spinal cord by 31 paired roots
Cauda Equina
collection of nerve roots at inferior end of vertebral canal
Spinal cord terminates in cone-shaped structure called conus medullaris
Spinal Cord Cross-Sectional Anatomy
Ventral (anterior) median fissure
Dorsal (posterior) median sulcus
gray matter in the core, white matter on the outside
Central Canal runs length of cord (filled with CSF)
Gray matter & spinal roots
Dorsal horns- interneurons that receive somatic and visceral sensory input
ventral horns- some interneurons; somatic motor neurons
lateral horns- sympathetic neurons
Gray Commissure- bridge of gray matter that connects masses of gray matter on either side
Ventral Roots- bundle of motor neuron acons that exit spinal cord
dorsal roots- sensory input to cord
Dorsal root(spinal)- cell bodies of sensory neurons
spinal nerves- formed by fusion of dorsal and ventral roots
Cranial Nerves
IV
Trochlear Nerve
Eye movement : up-down, back-forth
V
Trigeminal Nerve
Facial sensation, jaw movements, & taste
III
Oculomotor
Eye movement , blinking, & pupil reflex
VI
Abducens Nerve
Eye movement
II
Optic Nerve
Vision
VII
Facial Nerve
Facial expression &sense of taste
I
Olfactory Bulb-
Smell
VIII
Vestibulocochlear Nerve
Hearing & balance
XII
Hypoglossal Nerve
Tongue movement
IX
Glossopharyngeal Nerve
Throat sensation, taste, & swallowing
XI
Accessory Nerve
Neck / shoulder Movement
X
Vagus Nerve
Movement, sensation, & abdomical organs
Classification of neurons
Structural
Bipolar
2
processes
( 1 Axon & 1 Dendrite )
Rare
Unipolar
1 T-like process
( 2 Axons)
Called
PSEUDOUNIPOLAR
Multipolar
3
or
more
processes
( 1 Axon, other Dendrites)
Most Common & major neuron type in CNS
Function
Motor
Multipolar
Carry
impulses from
CNS to Effectors
Inter-neurons
Called Association neurons
Connected
between
motor & sensory neuron
s
Sensory
Cell bodies
located
in
ganglia in PNS
Transmit
impulses from sensory receptors toward
CNS
Major Parts and Functions of the Brain
Regions
Diencephalon
Thalamus
act as a relay station for info coming into cortex
acts to mediate sensation, motor activities, cortical arousal, learning, and memory
Hypothalamus
the regulating center vital to homeostasis
initiates physical responses to emotions
Epithalamus
forms roof of third ventricle
contains the pineal gland body
Brain Stem
Pons
between midbrain and medulla
Medulla
Functions
Cardiovascular Center
adjusts blood vessels and rate of heart contraction
Respiratory Centers
generate respiratory rhythm, control rate of breathing
Various other centers
vomiting, swallowing, sneezing, etc
Contains 4th ventricle
medulla and pons form ventral wall
Choroid Plexus
capillary- rich membrane that forms CSF
Midbrain
Cerebral Penduncles
two vertical bulges that contain pyramidal motor tracts
Cerebral aqueduct
channel running through midbrain that connects 3rd and 4th ventricles
Corpora Quadrigemina
paired dorsal protrusions
Superior colliculi
visual reflex center
substania nigra
functionally linked to basal nuclei
inferior colliculi
auditory relay center
Cerebral Hemishpere
Surface markings:
Sulci - shallow grooves ( dark lines / indents )
Fissures - deep grooves
Longitudinal
: Separates frontal lobe from Parietal lobe
Transverse :
Separates Cerebrum & Cerebellum
Gyri - Ridges (pink parts)
Cerebral White Matter
Responsible for communication
consists of myelinated fibers bundles into large tracts
Cerebellum
Cerebellar Hemispheres
connected by wormllike structure called vermis
arbor vitae- cortex of gray matter with a treelike pattern of white matter
Purkinje fibers
originate in cortex, synapse with cerebellum
Functions
processes input from cortex, brainstem, and sensory receptors to provide precise, movements of skeletal muscles
plays role in thinking, language, and emotion
balance and coordination
Functions
Breathing
Motor skills
Thinking / Memory
Hunger
Emotion
Temperature
Reflex Arc
Components
3) Integration Center -
MONOSYNAPTIC
or
POLYSYNAPTIC
within CNS
4) Motor Neuron -
CONDUCTS EFFERENT
impulses from integration center to
EFFECTOR
organ
2) Sensory Neuron-
TRANSMIT
afferent impulses to CNS
5) Effector -
Muscle fiber or gland cell that
RESPONDS
to
EFFERENT
impulses by
contracting or secreting
1) Receptor-
Site of stimulus
ACTION
Is a Neural pathway that controls a reflex
Neurotransmitters
Both CNS & PNS
Acetylcholine
Controls skeletal muscles, stimulates contractions at neuronmucluar junction, & may excite autonomic system
Dopamine
motor control, motivation, arousal, reinforcement, and reward,
Norepinephrine
Makes people happy, may excite autonomic nervous system
CNS
Histamine
Released in hypothalamus & promotes alertness
Serotonin
Leads to sleepiness, blocked by LSD, & can be enhanced with selective serotonin inhibitor drugs
Connective Tissue Coverings
Meninges
Arachnoid Mater
The middle layer that is a web-like structure filled with a fluid that cushions the brain
Pia Mater
The delicate layer that is first wrapped on the brain / Deepest layer of the 3
Dura Mater
The tough & first outter layer that protects the brain
CSF fluid
Covers both spinal and brain
Spinal Nerves
8 pairs
Cervical Nerves
5 pairs
Sacral Nerves
12 pairs
Thoracic Nerves
5 pairs
Lumbar Nerves
1 pair
Coccygeal nerves
Drugs of Abuse
Methamphetamine
Mimics
dopamine, invades vesicles forcing dopamine molecules out of the cell into synapse
Affects:
brain reward pathways, makes pleasure, & exhilaration intense
Interferes
w dopamine neurotransmitters
Alcohol
Delivers double sedative punch, interacts with GABA receptors first to move them more inhibitory
Affects:
memory formation, decision making, & impulse control
Interferes
w GABA receptors
Marijuana
Interferes
w cannabinoid receptors & inhibitory neurotransmitters
Mimics
anadamide & binds to cannabinoid receptors. Turns off inhibition & dopamine squirts into synapse
Affects:
memory, learning, and impulse control
Cocaine
Blocks
dopamine transporters leaving dopamine trapped in synaptic cleft, causing over-stimulation of cell
Affects:
Users become fidgety & unable to stay still
Interferes
with dopamine transporters
Ecstasy
Interferes
w serotonin neurotransmitters
Alters
transporters & kicks out serotonin from cell
Affects
: serotonin, sleep, mood, & eating habits
LSD
Mimics
serotonin neurons & elicits bind to serotonin receptors
Affects:
responsible for feelings of wakefulness & evokes startle response to unexpected stimulus
Effects
serotonin receptors
Heroine
Mimics
natural opiates & binds to opiate receptors, turns off dopamine inhibition
Affects
: pain signals, emotional attachment, & stress response
Interferes
w opiate receptors & inhibitory neurotransmitters
Action Potential & the Nerve Impulse
Hyperpolarization
A slight overshoot after repolarization
An action potential at a trigger zone causes electrical currents to flow adjacent regions of axons membrane
Refactory Period
Limits frequency of action potentials
Ensures the impulse is only transmitted in one direction down the axon
Period during & after an action potential, during which a threshold stimulus will not cause another action potential
Depolarization
Change from negative to positive change inside neuron
Threshold stimulus
Stimulus strong enough to cause so many Na+ ions to ente
r
Repolarization
Returns to Polarized state