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Miabella Aguilar & Period 5 Nervous System - Coggle Diagram
Miabella Aguilar & Period 5
Nervous System
1. Major functions of the nervous system
Nervous System
: Is mater controlling and communicating system o the body
2. Integration:
Processing and interpretation of sensory input
3. Motor output:
Activation of effector organs (muscle and glands) produces a response
1. Sensory Input:
Information gathered by sensory receptors about internal and external changes
13. Reflex arc (major parts & functions)
Componets of a reflex arc (neutral path)
:
Receptor
: site of stimulus action
Sensory neurons
: transmits a afferent impulses to CNS
Integration center
: either
monosynaptic
or
polysynaptic
region within CNS
Motor neuron
: conducts efferent impulses from integration centers to effector organs
Effector
: muscle fiber or glands cells that responds to efferent impulses by contracting or secreting
Reflexes are classified functionally as:
Somatic reflexes
-Activate skeletal muscle
Autonomic (visceral) refelxes
-Activate visceral effectors (smooth or cardiac muscles or glands)
4. Classification of neurons
Motor
:
Carry impulses from CNS to effectors
Multipolar
Most cell bodies are located in CNS (except some automatic neurons)
Interneurons
:
Also called association neurons
Lie between motor and sensory neurons
Shuttle signals through CNS pathways
Most are entirely within CNS
99% of body's neurons are interneurons
Sensory
:
Transmit impulses from sensory receptors toward CNS
Almost all are unipolar
Cell bodies are located in ganglia in PNS
15. Drugs of abuse (Mouse Party)
Methamphetamine
: this drug interferes with the neurotransmitter dopamine.
the meth pushes dopamine molecules out of the vesicles this causes transporters to work in reverse pumping dopamine out of the cell.
destroying makes users feel intense pressure and exhilaration
Alcohol
: this drug interferes with the Neuro transmitters GABA and glutamate.
alcohol interacts with the GABA receptors making them even more inhibitory. It binds to glutamate receptor is preventing the glutamate from exciting the cell
affects areas of the brain involved in memory formation, decision making an impulse control
Marijuana
: destroyed interferes with the Neuro transmitters dopamine and cannabinoid.
marijuana makes THC mimics and anamide and binds to cannabinoid receptors turning off allowing doppamine to squirt into the synapse
this drug slows down or movement and makes us feel calm and relaxed
Cocaine
: this drug interferes with the neurotransmitter dopamine.
cocaine blocks transporters leaving the opening trapped and dopamine binds again and again to the receptors
cocaine affects voluntary movements mostly because abusers are fidgety and unable to be still
Ecstasy
: this drug interferes with the transmitter serotonin.
Ecstasy temporally confuses the transporter causing it to do its job and reverse. The transporter starts transporting serotonin out of the cell
Ecstasy affect serotonin pathways responsible for mood sleep perception and appetite
LSD
: this drug interferes with the neural transmitter serotonin.
LSD may inhibit receptors and sometimes LSD
may excite them LSD causes the feeling of wakefulness and invoke a startle response to unexpected stimulus
Heroine
: this drug interferes with the Neuro transmitters dopamine and opiate.
heroin mimics natural opiate and binds to opiate receptors. The dopamine is allowed to flood the synapse which produces immediate feeling of sensation and well-being
it affects the transmissions of pain signals, stress response, and emotional attachment
2. Major divisions and subdivisions of the nervous system (include all subdivisions of CNS
and PNS)
Central Nervous System (CNS)
:
brain and spinal cord of dorsal body cavity
Integration and control center: Interprets sensory input and dictates motor outputs
Peripheral Nervous System (PNS)
:
The portion of the nervous system outside the CNS
Consists mainly of nerves that extend from the brain and spinal cord
Spinal nerves:
to and from spinal cord
Cranial nerves:
To and from brain
Sensory division:
Somatic and visceral sensory nerve fibers
Conducts impulses from receptors to the CNS
Motor division:
Motor nerve fibers
Conducts impulses from the CNS to effectors (muscle and glands)
Somatic nervous system:
Somatic (voluntary) motor nerve fibers
Conducts impulses from the CNS to skeletal muscles
Automatic nervous system (ANS):
Visceral (involuntary) motor nerve fibers
Conducts impulses from the CNS to cardiac muscles, smooth muscles, and glands
Sympathetic division:
Mobilizes body systems during activity
Parasympathetic division:
Conserves energy
Promotes house-keeping functions during test
14. Disorders/Diseases
Transient ischemic attacks (TIA's)
: Temporary episodes of reversible cerebral ischemia
Tissue plasminogen activators (TPA): is only approved of treatment for stroke
Alzheimer's disease (AD):
Progressive degenerative disease of the brain that results in dementia
key protein appears to be misfolded and malfunction
memory loss, short attention span, disorientation, eventual language loss, irritability, moodiness, confusion and hallucinations
Hemiplegia
: (paralysis on one side) or sensory and speech deficits may result
Neurofibrilary tangles:
inside neurons interfere with transport mechanism eventually killing neurons
as brain cells die brain shrinks
Ischemia
: tissue deprived of blood supply leading to death of tissue brain
-can be caused by a blockage of cerebral artery by blow clock
Parkinsons disease:
degeneration of dopamine releasing neurons of substantia yet nigra
basil nuclei deprive of dopamine becomes overactive resulting in temor at rest
Hydrocephalus
: obstruction block CSF circulation or drainage resulting in increased pressure
-In newborns skull bones are infused so increase pressure causes had to enlarge
Huntingtons disease:
fatal hereditary disorder caused by accumulation of protein Huntingtin in brain cells
leads to degeneration of basal nuclei and cerebral cortex
Meningitis
: inflammation of the meninges
May spread to CNS which would lead to inflammation of the brain referred to as encephalitis
Cerebral palsy:
neuromuscular disability involving poorly controlled or paralyzed voluntary muscles
due to brain damage possibly from lack of oxygen during birth
Epileptic seizure
: current of electrical discharges by group of neurons
-prevent any other messages from getting through victim of epilepsy may lose consciousness fall stiffly and have uncontrollable jerking
Multiple Sclerosis
: Autoimmune disease that damages the myelin sheath.
Causes: not when understood, hereditary, family history
Symptoms: Depends on location, muscle weakness, vision and hearing loss
Treatment: no cure, medication, physical therapy
Autism
: Brain disorder that makes it difficult to communicate
Causes: Family history, hereditary, and mostly in males
Symptoms: Anxiety, depression, delay in learning to talk/non-communicative
Treatments: Medication, coping skills, specialized therapy
3. Tissues (structure & function of neurons and neuroglia)
Neuroglia (glial cells):
Small cells that surround and wrap delicate neurons
Microglial cells:
Small, ovoid cells with thorny processes that touch and monitor neurons, and migrate toward injured neurons
Ependymal cells:
Range in shapes from squamous to columnar, and may be ciliated
Astrocytes
: Most abundant, versatile, and highly branched of glial cells, and cling to neurons, synaptic endings, and capillaries
Oligodendrocytes
: Branched cells, and processes wrap CNS nerve, forming insulating myelin sheaths in thicker nerve fibers
Neurons (nerve cells):
excitable cells that transmit electrical signals
Nuclei
: Cluster of neuron cell bodies in CNS
Ganglia
: Cluster of neuron cell bodies in PNS
8. Action potential & the Nerve Impulse
Action Potential:
Long-distance signals of axons
Changes in membrane potential are used as signals to receive, integrate, and send information
Principal way neurons send signals
-means of long-distance neural communication
Nerve Impulse:
Are structural units of the nervous system
Large, highly specialized cells that conduct impulses
In neurons, aka
nerve impulse
involves the opening of specific voltage-gated channels
11. Neurotransmitters
:
Language of nervous system
50 or more neurotransmitters have been identified
Most neurons make 2 or more neurotransmitters
-neurons can exert several influences
Biogenic amines
Catecholamines
Dopamine, norephrine (NE) and epinephrine*: made from the amino acid tyrosine
Indolamines
:
Serotonin
: made from the amino acid tryptophan
Histamine
: made from the amino acid histidine
peptides (neuropeptides)
-strings of amino acids that have diverse functions
Endorphins: beta endorphins, dynorphin, and enkephalins act as natural opiates; reduce pain perception
Acetylcholine (ACh)
:
First identified and best understood
Released at neuromuscular junctions
-also used by many ANS neurons and some CNS neurons
Synthesized from acetic acid and choline by enzyme choline acetyltransferase
5. Connective Tissue Coverings
Meninges
:
Functions:
Covers and protects CNS
Protects blood vessels and encloses venous sinuses
Contain cerebrospinal fluid (CSF)
Form partitions in the skull
Consists of 3 layers (from external to internal): Dura mater, arachnoid mater, and pia mater
Arachnoid Mater:
Middle layer with spiderweb-like extensions, and seperated from dura mater by subdural space
Pia Mater:
Delicate connective tissue that clings tightly to brain, following every convolution, and con
Dura Mater:
Strongest meninx
9. Cranial nerves
6. Abducens nerves
: Fibers from inferior pons enter orbits via superior orbital fissures, primarily a
motor, innervating lateral rectus muscle
7. Facial nerves
: Fibers from pons travel through internal acoustic meatures and emerge through stylomastoid foramina to lateral aspect of face,
sensory function (taste) from anterior two-thirds of tongue
5. Trigeminal nerves
:
Largest cranial nerves
; fibers extend from pons to face.
3 Divisions:
1) ophthalmic (V1) passes through superior orbital fissure
2) Maxillary (V2) passes through foramen rotundum
3) Mandibular (V3) passes through the foramen ovale
8. Vestibulocochlear nerves
: Afferent fibers from hearing receptors (cochlear division) and equilibrium receptors (vestibular division) pass from inner ear through internal acoustic meatuses and enter brain stem at pons-medulla borded,
formerly auditory nerve
4. Trochlear nerves
: Fibers from dorsal midbrain enter orbits via superior orbital fissures to innervate superior oblique muscle, primarily
motor nerve that directs eyeball
9. Glossopharyngeal nerves:
Fibers from medulla leave skull via jugular foramen and run to throat.
Motor functions:
innervate part of tongue and pharynx for swallowing and provide parasympathetic fibers to parotid salivary glands
Sensory functions:
Fibers conduct taste and general sensory impulses from pharynx and posterior tongue, and impulses from carotid chemoreceptors and baroreceptors
3. Oculomotor nerves
: Fibers extend from ventral midbrain through superior orbital fissures to 4 of 6 extrinsic
eye muscles
10. Vagus nerves:
Only cranial nerves that extend beyond head and neck region,
fibers from medulla exit skull via jugular foramen, most motor fibers are parasympathetic fibers that help regulate activities of heat, lungs, and abdominal
2. Optic nerves
: Arise from retinas; really brain tract, pass through optic canals, converge, and partially cross over at
optic chiasma
11. Accessory nerves:
Formed from ventral rootlets from C1 to C5 region of spinal cord (not brain), rootlets pass intocranium via each foamen magnum,
formerly spinal accessory nerve
1. Olfactory nerves
: Sensory nerves of
smell
, fibers synapse in olfactory bulbs, pathway terminates in primary olfactory cortex
12. Hypoglassal nerves:
Fibers from medulla exit skull via hypoglassal canal,
innervate extrinsic and intrinsic muscles of tongue that contribute to swallowing and speech
7. Major parts and functions of the spinal cord
Filum terminate:
Extends to coccyx
fibrous extension of conus covered with pia mater
Anchors spinal cords
Denticulate ligaments
: Extensions of pia mater that secure cord to dura mater
cervical and lumbar enlargements: areas where nerves serving upper and lower limbs arise from spinal cord
Epidural space:
Cushion of fat and network of veins in space between vertebrae and spinal dura mater
Spinal nerves
:
Parts of PNS
attach to spinal cord by 31 paired roots
Each spinal cord segment is designated by paired spinal nerves that arise from it
Spinal cord:
in closed in vertebral column
begins at the foramen magnum
ends at L1 or L2 vertebra
Functions
provides two-way communication to and from brain and body
Cauda equina:
Collection of nerve roots at inferior end of vertebral canal
12. Compare & contrast the autonomic nervous system
Autonomic Nervous system (ANS)
consists of motor neurons that:
Innervate smooth muscle, cardiac muscles and glands
Make adjustments to ensure optimal support for body activities
shunts blood to areas that need it and adjust heart rate blood pressure and digestive processes
Operate via subconscious control
Also called
involuntary nervous system or general visceral motor system
Autonomic Nervous system vs. Somatic Nervous system:
They both have motor fibers but differ in:
Effectors
-somatic nervous system innervate skeletal muscles
-ANS innervates cardiac muscle smooth muscle and glands
Efferent Pathways and ganglia
-SNS: Cell body is in CNS and a single thick myelinated group a axon extends in spinal or cranial nerves directly to skeletal muscle
-ANS pathway uses a two neuron chain
Preganglionic neurons:
Cell body in CNS with thin, lightly myelinated preganglionic axon extending to ganglion
Postganglionic (ganglionic) neuron (outside CNS)
: Cell body synapses with preganglionic axon in autonomic ganglion with nonmyelinated postganglionic axon that extends to effector organs
Target organ responses to neurotransmitter
-somatic nervous system
-All somatic motor neurons release acetylcholine (ACh)
-Effect is always stimulatory
ANS
-Preganglionic fibers release ACh
-Postganglionic fibers release Norephrine or Ash at effectors
-Effect is either stimulatory or inhibitory depending on type of receptors
Overlap of somatic and autonomic functions
Higher brain centers regulate and coordinate both systems
Both spinal and many cranial nerves contain both somatic and automatic fibers
Adaptations usually involve both Seattle muscles and visceral organs
6. Major parts and functions of the brain
Cerebral hemispheres
: Form superior part of brain.
accounts for 83% of brain mass
Surface Markings:
-Gyri: ridges
-Sulci: shallow grooves
-Fissures: deep grooves
Basic regions:
White matter
internally
Basal nuclei
deep within white matter
Cerebral cortex
of gray matter superficially
Diencephalon
consists of 3 paired gray-matter structures:
Hypothalamus
: Located below the thalamus, forms cap over brain stem and forms inferolateral walls of third ventricle, and controls endocrine system functions.
Epithalamus
: Most dorsal portion of diencephalon, forms roof of third ventricle, and contains pineal gland
Thalamus
: Main thalamic function is to act as relay station for informing coming into cortex
Brain Stem
Pons
: Located between midbrain and medulla oblangata
Medulla
: Blends into spinal cord at forarmen magnam and contains 4th ventricle
Midbrain
: Located between diencephalon and pons.
Cerebrellum
:
11% of brain mass
located dorsal to pons and medulla
cerebellum hemispheres connected by wormlike vermis
Functions
:
Processes input from cortex, brain stem, and sensory receptors to provide precise,coordinated movements of skeletal muscles
Plays role in thinking, language, and emotions
Balance and coordination
10. Spinal nerves
:
Part of PNS
attach to spinal cord by 31 paird roots
each spinal cord segment is designated by paired spinal nerves that arise from it
Spinal nerves
: formed by fusion of dorsal and ventral roots
gray matter divided into 4 groups based on of somatic or visceral innervation
-somatic sensory (SS), Visceral sensory (VS), Visceral (autonomic) motor (VM), and somatic motor (SM)