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NERVOUS SYSTEM Patricia Gordon P1 - Coggle Diagram
NERVOUS SYSTEM
Patricia Gordon P1
Major Functions of the nervous system
Sensory function
Provided by sensory receptors, which detect internal or external changes
Information travels from receptors to sensory neurons, which transport information into the CNS
Integrative function
Coordinating of sensory info. in the CNS
Processing of this info. is the basis for decision-making
Motor functions
Nerve impulses (CNS) are conducted along motor neurons to effectors
Effectors are muscles or glands that respond to decision made in the CNS
Major divisions & subdivisions
Peripheral nervous system
consists of nerves that connect to the CNS to body parts
somatic nervous system; connects the CNS to skeletal muscles & the skin, & oversees conscious activities
autonomic nervous system; connects the CNS to viscera, & controls subconscious activities
consists of cranial nerves, arising from the brain & spinal nerves, arising from the spinal cord
Classification of neurons
Multipolar neurons; have many dendrites & one axon arising from cell bodies
Bipolar neurons; have 2 processes extending from the cell body, a dendrite & axon
Unipolar neurons; only one process extending from the cell body, splits into two parts that function as one axon
Function classification
Sensory (afferent) neurons; conduct impulses from peripheral receptors to CNS
Interneurons (association or internuncial neurons): multipolar neurons lying within the CNS that form links between other neurons
Motor(efferent) neurons; multipolar neurons that conduct impulses from the CNS to peripheral effectors
Connective Tissue Coverings; tissues like this are part of are daily functions, in order to provide warmth, so basically without connective coverings we wouldn't be able to fully captivate the strengths that it provides us on a daily.
Connective tissue coverings again, are valuable to the human body. But it does have it's downsides to the overall body, listening to the human functions.
Not to mention that it's unessesary ideas that individuals discuss on a daily. In order to finalize the issues with connective tissues we
Perineurium; covering around fascicles (bundles) of nerve fibers
Epineurium; outer covering of a nerve
Endoneurium; covering around individual nerve fibers (axons
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Reflex arc
Sensory receptor; detects changes
Sensory neuron; carries info. from a receptor toward the CNS
Interneuron; carries info. from sensory neuron to motor neuron
Effector; (muscle or gland that carries out reflex) responds to the initial change
Motor neuron; carries commands to effectors
Neurotransmitters
Acetylcholine
Norepinephrine
Dopamine
Serotonin
Histamine
Major parts & functions of the brain
Main parts
cerebrum; largest portion; associated with higher menta; functions & sensory & motor functions
diencephalon; processes sensory input & controls many homeostatic processes
cerebellum; coordinates muscular activity
brainstem; coordinates & regulates visceral activities, & connects different parts of the nervous system
Four lobes of the cerebrum
Frontal
Parietal
Temporal
Occipital
Brainstem
midbrain
pons
medulla oblongata
connects the cerebrum, diencephalon, & cerebellum to spinal cord
Major parts and functions of the spinal cord
white matter; made up of bundles of myelinated nerve fibers that surround a butterfly-shaped core of gray matter
gray matter; houses interneurons & neuron cell bodies
dorsal root ganglia; outside the spinal cord; cell bodies of sensory neuromns are found here
posterior & anterior horns; the upper & lower wings of gray matter
Lateral horns are located between
central canal; in the middle of the gray matter; contains cerebrospinal fluid
functions of the spinal cord
Major functions; transmit impulses to & from the brain, & to house spinal reflexes
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Asending tracts; carry sensory info to the brain; descending tracts carry motor information from brain to muscles or glands
Spinal reflexes; controlled by reflex arcs that pass through the spinal cord
Tissues
Neuroglia/structures
Central nervous system
Microglia; small cells that function as phagocytes for bacterial cells & cellular debris, & produce scar tissue
Oligodendrocytes; form the myelin sheath around axons in the brain & spinal cord
Ependymal cells; produce cerebrospinal fluid in CNS
Astrocytes; structural; support
Peripheral nervous system
Schwann cells; the myelin-producing neuroglia of the PNS
Satellite cells; provide a protective coating around cell bodies of neurons in the PNS
Neurons/structures
cell body (soma); contains major organelles including nucleus
dendrites; conduct impulses toward the cell body & provide the receptive surface for communication with other neurons
axon; conducts impulses away from cell body
myelin sheath; increases conduction speed of nerve impulses
Spinal nerves
cervical plexuses (C1-C4) lie on either side of the neck; supply muscles & skin of the neck
brachial plexuses (C5 - T1) arise from lower cervical& upper thoracic nerves; supply muscles & skin of arms, forearms & hands
lumbar plexuses (L1-S4) arise from the lower spinal cord; supply muscles & skin of the lower abdomen, eternal genitalia, buttocks, etc.
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Action potential & the Nerve Impulse
Action protentional
reaching action potential is an all or nothing response
either occurs or does not
occurs when charge reaches -55 mV
when reached, cells respond by returning to resting potential by repolarization
Nerve impulse
Types
Continuous; occurs in unmyelinated axons & conducts impulses sequentially over the entire length of their membrane
Saltatory; occurs in unmyelinated axons; myelin sheath insulates axons; impulses "jump" from one node of ranvier to next
Cranial nerves
I Olfactory; sensory f. conduct impulses associated with sense of smell
II Optice; sensory f. conduct impulses associated with the sense of vision
III Oculomotor; motor fibers conduct impulses to muscles that raise eyelids, sensor f. conduct impulses associated with the condition of muscles
IV Trochlear; motor fibers conduct impulses to muscles that move the eyes.
some sensory fibers conduct impulses associated with the condition of muscles.
VI Abducens; motor fibers conduct impulses to muscles that move the eyes.
some sensory fibers conduct impulses associated with the condition of muscles.
VII Facial; 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
IX Glossopharyngeal; sensory fibers conduct impulses from the pharynx, tonsils, posterior tongue, etc. motor f. conduct impulses to muscles of pharynx
X Vagus; associated with speech and swallowing;
XI Accessory
XII Hypoglossal; impulses to the tongue
Disorders/Diseases
Cerebrovascular accident; loss of blood flow to part of the brain
symptoms; severe headache, change is hearing, touch & vision, etc
treatment options; blood thinners, hospitalization from stroke, stroke rehabilitation, etc.
causes/risk factors; age, hereditary, high cholesterol, etc.
Autism; a developmental disability caused by differences in the brain
symptoms; repetitive behaviors, delay learning, anxiety, etc
treatment; meds, coping mechanisms, etc.
causes/risk factors; hereditary, mostly in males, environmental
Alzheimer's disease; disease that affects memory
symptoms; memory loss, confusion & disorientation, etc.
treatment; uncurable, meds, etc.
causes/risk factors; age over 60, past head trauma, etc
Spinal cord injury; damage to the bundle of cells & nerves
symptoms; weakness, loss of feeling below damaged site, etc.
treatment; meds to reduce pain, surgery, etc.
cause/risk factors; assault, fall or accident, fluid build up around spinal cord
Meningitis; an inflammation of the protective covering the brain & spinal cord
symptoms; nausea, fever, chills, stiff neck, etc.
treatment; antibiotics, prevention with vaccination, etc.
causes/risk factors; bacteria or viral infection, drug allergies, etc.
Multiple sclerosis; condition that can affect the brain & spinal cord
symptoms; muscles weakness, tremors, numbness
treatment; meds to slow spread, phyical therapy, etc.
causes/risk factors; hereditary, never damage by inflammation, etc.
Drug of abuse
Heroine; produces feelings of sedation & well being, interferes with dopamine & inhibitory neurotransmitters
Ecstasy; affects mood, sleep, perception & appetite, interferes with serotonin neurotransmitters
Marijuana; responsible for making a persons mood more relaxated & calm, interfers with inhibitory & dopamine neurotransmitters.
Methamphetamine; produces intense pleasure & exhilaration, interferes with dopamine neurotransmitters
Alcohol; affects areas that involve memory, decisions making & impulse control, interferes with inhibitory & GABA neurotransmitters
Cocaine; makes a person fidgety & unable to stay still, interferes with dopamine neurotransmitters
LSD; responsible for wakefulness, interferes with serotonin neurotransmitters