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Evie Ramos Per 3 Nervous system - Coggle Diagram
Evie Ramos
Per 3
Nervous system
Major functions of the nervous system
thinking, movement, internal
processes of physiology.
sensory input, integration and decision-making (processing), and response (motor output).
Sensory function
detects internal or external
changes with receptors
info travels to sensory neurons from receptors, and from the sensory neurons the info travels to the CNS
Integrative function
Coordination of sensory information in the CNS.
processes info for decision-making
Motor function
Nerve impulses (CNS) are conducted along motor neurons to
effectors
Effectors are muscles or glands that respond to decisions made in the Cns
Major divisions and subdivisions of the nervous system
Central nervous system (CNS)
Made up of the brain and spinal cord.
Information and decision-making
Peripheral nervous system (PNS)
Cranial and spinal nerves that connect the CNS to the rest of
the body.
sensory (afferent) and motor (efferent) divisions.
Motor Functions
Somatic nervous system
controls voluntary skeletal muscles
Autonomic nervous system
controls involuntary effectors (smooth, cardiac muscles, glands).
Tissues
Neuron contains cell body, dendrites, axon.
Dendrites conduct impulses toward the cell body and communicate with other neurons.
Axon conducts impulses AWAY from the cell body and the axon hillock arises from the cell body
Cell body (soma) contains the nucleus and other major parts
Neuroglia
helps and support neurons like glue
Neurons
cells communicate with other neurons or other tissues
Classification of neurons
Multipolar neurons
many dendrites, one axon arising from
their cell bodies, most neurons with cell bodies in CNS
Bipolar neurons
2 processes extending from the cell body, dendrite and an axon
Unipolar neurons
1 process extending from the cell body, splits into 2 parts that function as 1 axon, cell bodies are found in ganglia outside the CNS (sensory neurons)
Connective Tissue Coverings
Epineurium
outer covering of a nerve.
Perineurium
covering around fascicles (bundles) of nerve fibers.
Endoneurium
covering around individual nerve fibers (axons)
Major parts and functions of the spinal cord
Major parts of the spinal
Meninges: dura mater, arachnoid mater, pia mater.
White matter and gray matter (bundles of myelinated nerve fibers)
Cervical enlargement
Provides nerves to upper limbs, thickened area near top of spinal cord
Lumbar enlargement
thickened region near the bottom of the spinal cord,rise to nerves that serve the lower limbs
Cauda equina
formed where spinal cord tapers to a point inferiorly,spinal nerves in the lumbar & sacral areas
Major functions
transmit impulses to and from the brain, and to house spinal
reflexes.
Ascending tracts carry sensory info to the brain descending tracts carry motor info from brain to muscles or glands.
Action potential & the Nerve Impulse
excitatory stimulus opens chemically-gated Na+ channels
a stimulus strong enough to cause so many Na+
ions to enter neuron called threshold potential
threshold potential voltage-gated Na+ channels open changing charge to about +30 mV causing action potential
Nerve impulse is a signal transmits along a nerve fiber a wave of electrical depolarization that reverses the potential difference across the nerve cell membrane
Cranial nerves
There are 12 pairs of cranial nerves, most mixed of sensory and motor nerve fibers
II Optic Sensory Sensory fibers conduct impulses associated with the sense of vision.
III Oculomotor Primarily
motor
Motor fibers conduct impulses to muscles that raise eyelids, move eyes, adjust
the amount of light entering the eyes, and focus lenses.
Some sensory fibers conduct impulses associated with the condition of muscles.
IV Trochlear Primarily
motor
Motor fibers conduct impulses to muscles that move the eyes.
Some sensory fibers conduct impulses associated with the condition of muscles.
V Trigeminal Mixed
Ophthalmic division Sensory fibers conduct impulses from the surface of the eyes, tear glands, scalp,
forehead, and upper eyelids.
Maxillary division Sensory fibers conduct impulses from the upper teeth, upper gum, upper lip,
lining of the palate, and skin of the face.
Mandibular division Sensory fibers conduct impulses from the skin of the jaw, lower teeth, lower
gum, and lower lip.
Motor fibers conduct impulses to muscles of mastication and to muscles in the
floor of the mouth.
VI Abducens Primarily
motor
Motor fibers conduct impulses to muscles that move the eyes.
Some sensory fibers conduct impulses associated with the condition of muscles.
VII Facial Mixed Sensory fibers conduct impulses associated with taste receptors of the anterior tongue. Motor
fibers conduct impulses to muscles of facial expression, tear glands, and salivary glands.
VIII Vestibulocochlear Sensory
Vestibular branch Sensory fibers conduct impulses associated with the sense of equilibrium.
Cochlear branch Sensory fibers conduct impulses associated with the sense of hearing.
IX Glossopharyngeal Mixed Sensory fibers conduct impulses from the pharynx, tonsils, posterior tongue, and carotid
arteries.
Motor fibers conduct impulses to muscles of the pharynx used in swallowing and to salivary
glands.
X Vagus Mixed Somatic motor fibers conduct impulses to muscles associated with speech and swallowing;
autonomic motor fibers conduct impulses to the heart, smooth muscle, and glands in the thorax
and abdomen.
Sensory fibers conduct impulses from the pharynx, larynx, esophagus, and viscera of the thorax
and abdomen.
XI Accessory Primarily
motor
Cranial branch Motor fibers conduct impulses to muscles of the soft palate, pharynx, and larynx.
Spinal branch Motor fibers conduct impulses to muscles of the neck and back.
XII Hypoglossal Primarily
motor
Motor fibers conduct impulses to muscles that move the tongue.
Neurotransmitters
synapse is a junction between 2 communicating neurons
small gap between the neurons is called the synaptic cleft
neuron sending the impulse is the presynaptic neuron
neuron receiving the impulse is the postsynaptic neuron
The nuerotransmitter is the chemical that communicates
Neurotransmitters are released in response to a nerve impulse diffusing across the cleft and binding to receptors of the postsynaptic neuron.
Reflex arc
The routes nerve impulses travel are called neural pathways
A sensory receptor that detects changes
A sensory neuron, that carries the information from a receptor toward the CNS
An interneuron in the CNS (reflex center)
A motor neuron carries a command to effectors
An effector (muscle or gland that carries out the reflex) that responds to the initial change
Disorders/Diseases
cerebrovascular accident stroke
occurs when blood flow to a portion of the brain is halted
high cholestrol, increasing age, diabetes,
severe head aches, change in hearing, taste, touch, vision, confusion/memory loss
hospitalization, blood thinners, blood clots = clot busting
Autism
brain disorder that makes it difficult to communicate
family history, hereditary, past medical issue
delay in learning, repeated behaviors, anxiety
medication, coping skills, specialized therapy
alzheimer disease
a form of dementia associated with age
heridatory, family history, age over 60
memory loss, mood changes, confusion
incurable, medication, removing behaviors triggers
Spinal cord injury
damage to the spinal cord
direct injury, assault, fall, accident, fluid build up
weakness, loss of feeling, loss of bladder/bowel control
surgery, bed rest, spinal traction
meningitis
infection in the meninges surrounding
drug allergies, tumors, chemical irritations
nausea, stiff neck, fever/chills
anti biotics, bacteria-hospitalization, medications to treat symptoms
multiple sclerosis
auto immune diseases that damage the myelin sheath
hereditary, family history, diagnosed 20-40
muscle weakness, constipation, vision/hearing loss
no known cure, medication to slow progress down, healthy life syle
Drugs of abuse
Heroine
interferes with dopamine the release of inhibitory neurotransmitters is shut down dopamine floods immediately producing immediate feelings of sedation and well-being
Ecstasy
Interferes with serotonin, the transporter gets confused and does its job in reverse starts transporting serotonin out and overstimulating a cell it; affects sleep, perception and appetite and excess serotonin gives addictive properties
Marijuana
Interferes with dopamine anandamide mimics and binds to cannabinoid receptors, inhibition is turned off, and dopamine is allowed to squirt into the synapse causes of short-term memories, making them feel relaxed/calm.
Methamphetamine
Interferes with dopamine meth mimics dopamine and is taken by dopamine transporters meth enters dopamine vesicles taking the dopamine out of the cell into synapses traps excess dopamine and overstimulates a cell making them highly addictive because the user feels pleasure and exhilaration
Alcohol
Interferes with GABA and Glutamate Making them more inhibitory and binds to glutamate receptors, prevents gluten from exciting the cell Affects memory area decision-making and impulse control
Cocaine
Interferes with dopamine cocaine blocks the transporters leaving dopamine in the synaptic cleft dopamine overstimulates the celll affects controlling voluntary moments making the user fidgety and unstill
LSD
Interferes with serotonin neurons LSD resemble serotonin and elicit by binding to serotonin receptors LSD may inhibit or excite them affecting the feeling of wakefulness and evoking a start of a response to an unexpected stimulus
Compare & contrast the autonomic nervous system
Controls heart rate, blood pressure, breathing rate, body temperature
PNS that functions constantly and independently,
without conscious effort.
Helps maintain homeostasis, responds to emotional stress, and prepares the body for strenuous activity
Sympathetic division: active in conditions of stress oremergency (fight or flight)
Parasympathetic division: active under normal, restful conditions (rest and digest).
Major parts and functions of the brain
Meninges: dura mater, arachnoid mater, pia mater.
Cerebrum: largest portion; associated with higher mental functions, and sensory & motor functions
Diencephalon: processes sensory input and controls many homeostatic processes
Cerebellum: coordinates muscular activity
Brainstem: coordinates and regulates visceral activities, and connects different parts of the nervous system
Spinal nerves
31 pairs of spinal nerves arise from spinal cord
8 pairs of cervical nerves, 12 pairs of thoracic nerves, 5 pairs of lumbar nerves, 5 pairs of sacral nerves and 1 pair of coccygeal nerves.
Each arises from two roots, a sensory dorsal root and a motor ventral root
Cervical Plexuses (C1-C4): lie on either side of the neck supply muscles and skin of the neck, control the diaphragm.
Brachial Plexuses (C5 –T1): arise from lower cervical and upper thoracic nerves; supply muscles and skin of arms, forearms, and hands; lead into the upper limbs
• Lumbosacral Plexuses (L1-S4): arise from the lower spinal cord; supply muscles and skin of the lower abdomen, external genitalia, buttocks, and leg