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Nervous System By Adrian Leandro - Coggle Diagram
Nervous System By Adrian Leandro
Major Divisions/Subdivisions
CNS
Spinal cord
Brain
Cerebral hemispheres: Frontal, parietal, temporal, occipital, insular
Diencephalon
Brain stem, consisting of: medulla, midbrain, pons
Cerebellum
PNS
Sensory (afferent)
Motor (efferent)
Somatic
Autonomic
Sympathetic
Parasympathetic
Classifications of neurons
Multipolar: 3 or more processes(1 axon, other dendrites)
Bipolar: 2 processes(1 axon, 1 dendrite)
Unipolar: 1 T-like process (2 Axons)
Sensory
transmits impulses from sensory receptors toward CNS; unipolar
Motor
carry impulses from CNS to effectors; multipolar
Interneurons
shuttle signals through CNS pathways
Major functions
Brain
Limbic system: the limbic system is the structures on the medial part of the cerebral hemispheres and the diencephalon. The limbic system puts emotions on order. The limbic system also allows us to emotionally react to things we consciously understand. .
Fornix: The Fornix is the fiber tract that links the limbic system regions which include a large part of the diencephalon and some cerebral structures that encircles the brain stem.
Reticular formation: The Reticular formation extends from the central core of the brain stem. Helps control coarse limb movement
Basal nuclei: controls skeletal muscle movements.
Thalamus: The Thalamus relays sensory information to the cerebral cortex to be processed. Thalamus involves memory processing
. Hypothalamus: The Hypothalamus is the chief integration center of the autonomic nervous system. The Hypothalamus regulates body temp, food intake, water balance, & thirst
Limic system: The Limbic system mediates emotional response and is involved with memory processing.
Midbrain: The Midbrain has visual and auditory reflex centers.
Pons: The pons relays info from the cerebrum to the cerebellum and works with the medulla respiratory centers to control the breathing rate and depth
Medulla oblongata: The medulla oblongata relays ascending sensory pathways impulses from the skin & proprioceptors through nuclei cutaneus and gracillis.
Spinal Cord
Epidural space: Cushion of fat and network of veins in the space between the vertebrae and the duramater
Filum terminale: extends to the coccyx, so fibrous extension of conus covered with Pia matter.
Spinal Nerves: Are a part of the PNS there are 31 paired roots and each spinal cord segment is designated by paired spinal nerves
Cauda equina: Collection of nerve roots at inferior end of the vertebral canal
Nervous system
Controlling & communicating system of body, and to transmit signals from the brain to the rest of the body
Tissues
Neuroglia
Small cells that surround and wrap delicate neurons
astocytes: support neurons, exchanges between capillaries and neurons, control chemical environment, respond to nerve impulses
Microglial cells: monitor neurons; can transform to phagocytize microorganisms
Oligodendrocytes: branched cell processes wrap CNS nerve fibers, forming insulating myelin sheaths
ependymal cells: form permeable barrier between cerebrospinal fluid in cavity and tissue
Neurons
excitable cells that transmit electrical signals
Connective Tissue Coverings
Duramater
strongest meninx; outermost layer
Arachnoid mater
middle layer with spiderweb like extensions
Pia mater
delicate, clings to brain, follows every convolution
Action Potential /Nerve Impulse
Resting state: All gated Na+ and K+ channels are closed
Depolarization: Na+channels open. Depolarizing local currents open voltage-gated Na+channels, and Na+rushes into cell
Repolarization: Na+ channels are inactivating, and K+ channels open
Hyperpolarization: Some K+ channels remain open, and Na+ channels reset
Spinal Nerves
31 spinal nerves
8 pairs of cervical nerves (C1–C8)
12 pairs of thoracic nerves (T1–T12)
5 pairs of lumbar nerves (L1–L5)
5 pairs of sacral nerves (S1–S5)
1 pair of tiny coccygeal nerves (C0)
Connected via ventral/dorsal roots
Cranial nerves
VIII: Vestibulocochlear
hearing & balance
IX: Glossopharyngeal
taste. swallowing
VII: Facial
taste, facial expressions
X: Vagus
taste, regulate heart & lungs
VI: Abducens
abduction of the eyes
XI: Accessory
shrugging shoulders/ turning head
V: Trigeminal
sensory impulses in jaw
IV: Trochlear
Directs eyeballs
XII: Hypoglossal
swallowing & speech
III: Oculomotor
raise eyelid, constricting iris
II: Optic
vision
I:Olfactory
Smell
Reflex Arc
1, Receptor: Site of stimulus action
Sensory neuron: transmits afferent impulses to CNS
Integration center: either monosynaptic or polysynaptic region within CNS
Motor Neuron: conducts efferent impulses from integration center to effector organ
Effector: muscle fiber/gland cell that responds to efferent impulses by secreting
Disorders/Diseases
Autism
Brain disorder that makes it difficult to communicate. Symptoms: depression, anxiety, delay in learning
Alzheimer's Disease
A form of dementia associated with age. Symptoms: memory loss, confusion, unfounded suspicion
Cerebrovascular Accident (Stroke)
occurs when blood flow is a portion of the brain.
Symptoms: severe headaches, memory loss, muscle weakness
Spinal Cord injury
Damage to spinal cord. Symptoms: paralysis, weakness, loss of bladder control
Meningitis
Infection in the meninges surrounding the brain. Symptoms: Nausea, irritation, fever
Multiple Sclerosis
Autoimmune disease that damages myelin sheath. Symptoms: muscle weakness, constipation, vision/hearing loss
Drugs of abuse
Ecstasy
Interferes with serotonin, affects mood, sleep, and appetite
Marijuana
interferes with dopamine & cannabinoid receptor. Removes short term memory, makes people more relaxed
Methamphetamine
interferes with dopamine, causes user to feel intense pleasure
heroine
Interferes with dopamine/optic receptor. Prevents dopamine from being released. Gives feelings of sedation
Alcohol
Interferes with Glutamate receptor and GABA receptor, affects memory & decision making
Cocaine
interferes with dopamine, causes people to get fidgety
LSD
interferes with serotonin, causes feelings of wakefulness, & startle response to unexpected stimulus
Compare & Contrast ANS
Higher brain centers regulate and coordinate both system
Parasympathetic: promotes maintenance functions, conserves energy. Keeps body energy as low as possible, even while carrying out maintenance activities
Sympathetic: mobilizes body during activity. Exercise, excitement, embarrassment, activates sympathetic system. More complex and innervates more organs than parasympathetic.
^some innervated are sweat glands, arrector pili muscle of hair follicle, and smooth muscle of all blood vessels
Neurotransmitters
Language of the nervous system; classified by chemical structure and function
Functions
Effects: excitory versus inhibitory
Actions: direct versus indirect
Direct action: neurotransmitter binds directly to and opens ion channels
Indirect action: neurotransmitter acts as intracellular second messengers
Plays role in emotional behaviors, biological clock & imbalances are associated with mental illness