Daniel Sanchez p.2 06 Nervous

Major functions of the nervous system

major divisions and subdivisions of the nervous system (include all subdivisions of CNS
and PNS)

Tissues (structure & function of neurons and neuroglia)

Classification of neurons

Connective Tissue Coverings

Major parts and functions of the brain

Major parts and functions of the spinal cord

Action potential & the Nerve Impulse

Cranial nerves

Spinal nerves

Neurotransmitters

Compare & contrast the autonomic nervous system

Reflex arc (major parts & functions)

Disorders/Diseases

Drugs of abuse (Mouse Party)

  • l Olfactory Nerves
  • ll Optic Nerves
  • lll Oculomotor Nevres
  • lV Trochlear Nerve
  • V Trigeminal Nerves
  • Vi Abducens Nerves
  • Vll Facial Nerves
  • Vlll Vestibulocohlear Nerves
  • lX Glossophargngeal Nerves
  • X Vagus Nerves
  • Xl Accessory Nerves
  • Xll Hypoglossal Nerves

transmits information regarding a person’s sense of smell to the brain.


transmits information to the brain regarding a person’s vision.


helps control muscle movements of the eyes.


also has a role in eye movement.

is the largest cranial nerve and has both motor and sensory functions.


The abducens nerve also helpsTrusted Source control eye movements.
It helps the lateral rectus muscle, one of the extraocular muscles, turn the gaze outward.


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The facial nerve also has both motor and sensory functions.

The facial nerve is consists ofTrusted Source four nuclei that serve different functions:

movement of muscles that produce facial expression

movement of the lacrimal, submaxillary, and submandibular glands

the sensation of the external ear

the sensation of taste

helpsTrusted Source with a person’s hearing and balance

possesses trusted Source both motor and sensory functions.


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The vagus nerve hasTrusted Source a range of functions, providing motor, sensory, and parasympathetic functions.

The sensory part provides sensation to the outer part of the ear, throat, heart, and abdominal organs. It also plays a role in taste sensation.

The motor part provides movement to the throat and soft palate.

The parasympathetic function regulates heart rhythm and innervates the smooth muscles in the airway, lungs, and gastrointestinal tract.

The accessory nerve provides trusted Source motor function to some muscles in the neck.

nerve is a motor nerve that suppliesTrusted Source the tongue muscles. It originates in the medulla.


  1. Receptor : site of stimulus action
  1. Sensory Neuron: transmits afferent impulses to CNS
  1. Integration Center : either monosynaptic or polysynaptic region within CNS

4.Motor Neuron: conducts efferent impulses from integration center to effector organ

  1. Effetor : muscle fibers or gland cells that responds to efferent impulses by contracting or secreting

Acetylcholine (ACH)

  • used by many ANS neurons and some CNS neurons
  • synthesized from acetic acid & choline by enzyme choline
  • degraded by enzyme acetylcholinesterase (ACHE)

Dopamine

  • norepinephrine (NE), & epinephrine :made from amino acids

Serotonin

  • made from amino acid trytophon

Histamine

  • made from amino acid histidine

Amino Acid

  • makeup proteins, difficult to prove which are nerotransmitter

Peptides ( neuropeptides)

  • strings of amino acids that have diverse functions

Endorphins

  • beta endorphins, dynorphins, & enkephalins : act as natural opinates ; reduce pain perception

Purines

  • monomers of nucleic acids that have an effect in both CNS & PNS
  • Epimysium
  • Perimysium
  • Endomysium

Cerebrovascular Accident (Stroke)

Description: Occurs when blood flow to a portion of the brain in nailed

  • Causes or Risk Factors (3): Hereditary, blood vessels clogged burst, and Diabetes
  • Symptoms: Severe headache, loss or coordination & balance, and confusion/memory
  • Treatment Options (3): blood thinners, surgery to repair vessels

Autism

  • Description: Brain disorders that makes it difficult to communicate
  • Causes or risk factors: family history, hereditary (mostly in males), past medical issues
  • Symptoms : delay in learning to talk/communicate
  • Treatment Options: medication, coping skills, and specialized therapy

Alzheimer's disease

  • Description: a form of dementia associated with age
  • Causes or risk factors: hereditary 60+, high insulin levels, and past head trauma
  • Symptoms: memory loss, confusion, difficulty with walking and swallowing
  • Treatment Options: incurable, medication, and removing behavior triggers

Spinal Cord Injury

  • Description : damage to spinal cord
  • Causes or risk factors: direct injury or disease
  • Symptoms: weakness, pain/numbness, and Paralysis
  • Treatment Option: Meds to reduce swelling, surgery, bed rest

Meningitis

  • Description: infection in meningitis is surrounding the brain
  • Causes or risk factors: Bacteria, drug allergies, and tumors
  • Symptoms: Nausea and vomiting, fevers and chills, and stiff neck
  • Treatment Options: medication and vaccine

Multiple Sclerosis

  • Description: Autoimmune disease that damages the myelin sheath
  • Causes or risk factors: hereditary, nerve damage caused by inflammation
  • Symptoms: muscle weakness, tremors and spasms
  • Treatment Options: no known cure, medications to slow disease progress

Neuroglia

  • Astrocytes : most abundant,versatile, and highly branched of glial cells. Cling to neurons, snypatic endings, and capillaries. support and brace neurons

Neurons

  • Nuclei: clusters of neuron cell bodies in PNS
  • Microglial cells: Small, ovoid cells with thorny processes that touch and monitor neurons. Migrate toward inured neurons. Can transform to phayocyte microorganisms and neuronal debris
  • Ependymal Cells: Range is shape from squamous to columnar, may be ciliated, and cilia beat to circulate CSF, line the central cavitities of brain and spinal column
  • Oligodendrocytes: branched cells, processes wrap CNS nerve fibers, forming insulating myelin sheath
  • Satellite cells: surround neuron cell bodies in PNS and function similar to astrocytes of CNS
  • Schwann cells: surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers, similar to function as obligodendrocytes, and vital to regeneration of damaged peripheral nerve fibers
  • Ganglia : clusters of neuron cell bodies in PNS, CNS contains both neuron cell bodies and their processes, and PNS contains chiefly neuron processes
  • Tracts: bundles of neuron processes in CNS
  • Nerves: Bundles of neuron processes in PNS
  • Axon hillock: shaped area
  • Nerve fibers: long axons
  • Axon terminal: distal endings
  • Terminal: region that secretes neurotransmitters, which are released into extracellular space

Action Potential:

  • Action Potential: long-distance signals of axons
  • Depolarization: decrease in membrane potential; inside of membrane becomes less negative than resting membrane potentials and probability of producing impulse increases
  • Hyperpolarization: increase in membrane potential (away from zero); inside of membrane becomes more negative than resting membrane potential, probability of producing impulse decreases, and principal way neuron send signals meaning of long-distance neural communication

Generating an action potential:

    1. Resting state- all gated NA+ & K+ channels are closed
    1. Depolarization : NA+ channels open
    1. Re-polarization: NA+ channels are inactivating, & K+ channels open
    1. Hyperpolarization: Some K+ channels remain open, & NA+ channels rest
  • 31 pairs of spinal nerves; all mixed nerves named for point of issue
  • 8 pairs of cervical nerves ( C1-C8 )
  • 12 pairs of thoracic nerves ( T1-T2)
  • 5 pairs of lumbar nerves ( L1-L5)
  • 5 pairs of sacral nerves (S1-S5)
  • 1 pair of tiny coccygeal nerves (C0)

Ventral Roots: contains motor ( efferent) fibers from ventral horn motor neurons that innervate skeletal muscles

Dorsal Roots: contains sensory (afferent) fibers from peripheral receptors root ganglia that conduct impulses from peripheral receptors

  1. Sensory: transmit impulses from sensory receptors toward CNS, and almost all are uni polar, cell bodies are located in ganglia in PNS
  1. Motor: carry impulses from CNS to effector, multiploar, and most cell bodies are located in CNS
  1. Interneourons: also called association neurons, lies between motor and sensory neurons, shuttle signals through CNS pathways

around single myocyte = muscle

  • around a fascicle
  • covers the entire skeletal muscle

Heroine

  • Neurotransmitter: inhibit dopamine from being released
  • Body's natural opiates activate opiate receptors. Release of inhibitory neurotransmitters is shut down. Without inhibition, dopamine can be released
  • Heroin mimics natural opiates & binds to opiate receptors, turning off dopamine inhibition dopamine is allowed to flood synapse. producing immediate feelings of sedation of well being

Ecstasy

  • Serotonin transporters are responsible to removing serotonin molecules from the synaptic cleft after they have done their job
  • Ecstasy mimics serotonin & is taken up by serotonin transporters. In fact, ecstasy is more readily taken up than serotonin itself
  • This interaction with ecstasy alters the transporters become temporarily confused and start to do its job in reverse transporters start transporting serotonin out of cell

Marijuana

  • Before marijuana enters the system, inhibitory neurotransmitters are active in synapse. These neurotransmitters inhibit dopamine from being released
  • When activated by the body's own naive cannabinoid. Cannabinoid receptors turn off release of inhibitory neurotransmitters. Without inhibition, dopamine can be released.
  • RHC, activate chemical in marijuana, mimics around amide & bindss to cannabinoid receptors. Inhibition is turned off & dopamine is allowed to squirt into the synapse.

Methamphetamine

  • Dopamine transporters are responsible for removing dopamine from synaptic cleft. Because meth mimics dopamine, it is taken into the cell by dopamine transporters
  • Once inside the cell, meth enters the dopamine vesicles forcing the dopamine molecules out
  • The excess dopamine in the cell causes the transporters to short working in reverse, activating pumping dopamine out of cell and into synaptic

Alcohol

  • Inhibitory neurotransmitters, called GAB, are active throughout the brain. Neurotransmitters out to control neural activity along many brain pathways, when GABA binds to its receptors, cels less likely to fire
  • When alcohol enters the brain it delivers a double sedative punch. First, it interacts with GABA receptors to make them ever more inhibitory
  • alcohol particularly affect area of the brain involved in memory formation, decision making and impulse control

Cocaine

  • Dopamine, transporters are responsible for removing dopamine molecules from synaptic cleft after they have done their job
  • cocaine blocks these transporters, leaving dopamine trapped in the synaptic cleft. As a result dopamine binds again and again to the receptors overstimulating the cell
  • cocaine concentrates in reward pathways. however, it also active in part of brain controlling voluntary movements. This is way cocaine abusers are fidgety and unable to be still

LSD

  • LSD acts almost exclusively on serotonin neurons. LSD chemically resembles serotonin and elicits its effect by binding to serotonin receptors
  • There are several types of serotonin receptors in the brain. Each is responsible for performing specific functions
  • LSD interacts, with particular receptors, but not always in the same ways sometimes LSD many inhibits them. This is 1 reason why LSD has complex sensory effects

CNS:

  • brain and spinal cord of dorsal body cavity
  • integration and control center -> interprets sensory input and dictates motor output

PNS

  • the portion of nervous system outside cns
  • consist mainly of nerves that extend from brain and spinal cord

Spinal cord, midbrain, medulla, pons, cerebellum, diencephalon, and the cerebral hemispheres

Somatic nervous system (SNS): Voluntary somatic motor nerve fibers conduct impulses form cns to skeletal muscle

Automatic nervous system (ANS): involuntary consists of visceral motor berve fibers and regulates smooth muscle , cardiac and glands

Sympathetic and parasympathetic

  • The somatic nervous system has sensory and motor pathways, whereas the autonomic nervous system only has motor pathways.
  • The autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles and movement.
  • SNS is voluntary
  • ANS is involuntary
  • Sensory input
  • Motor output
  • information from external and internal changes integration
  • processes and interprets input
  • produces and reponses

Cerebrum: Your cerebrum interprets sights, sounds and touches. It also regulates emotions, reasoning and learning

Cerebellum: Your cerebellum maintains your balance, posture, coordination and fine motor skills

Brainstem: Your brainstem regulates many automatic body functions

Frontal lobes: The frontal lobes are in the front part of your brain, right behind your forehead. This is the largest lobe and it controls voluntary movement, speech and intellect.

Occipital lobes: These lobes in the back of your brain allow you to notice and interpret visual information. Your occipital lobes control how you process shapes, colors and movement.

Parietal lobes: The parietal lobes are near the center of your brain. They receive and interpret signals from other parts of your brain.

Temporal lobes: These parts of the brain are near your ears on each side of your brain. The temporal lobes are important in being able to recall words or places that you've been.

layers of the brain

Dura mater: The outermost layer lines your entire skull. Parts of the dura mater form folds that separate the right half of your brain from the left.

Arachnoid: The middle layer of the meninges is a thin, fragile layer of tissue that covers your entire brain.

Pia mater: The innermost layer contains blood vessels that run into your brain’s surface.

Thalamus: is a structure residing deep in your cerebrum and above your brainstem. This structure is sometimes referred to as the switchboard of the central nervous system.

Hypothalamus: Your hypothalamus sits below your thalamus. It's important in regulating various hormonal functions, autonomic function, hunger, thirst and sleep.

Neurons: send and receive electric nerve signals

Glial cells help maintain your brain, form myelin and provide nutrition to your brain.

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Cervical (neck).

Thoracic (chest).

Lumbar (lower back).

  • Spinal nerve: The posterior and anterior roots come together to create a spinal nerve. There are 31 pairs of spinal nerves. These control sensation in the body, as well as movement.
  • White matter: The white matter surrounds the gray matter in the spinal cord and contains cells coated in myelin, which makes nerve transmission occur more quickly.
  • Gray matter: The gray matter is the dark, butterfly shaped region of the spinal cord made up of nerve cell bodies.

Carrying signals from the brain: The spinal cord receives signals from the brain that control movement and autonomic functions.
Carrying information to the brain: The spinal cord nerves also transmit messages to the brain from the body, such as sensations of touch, pressure, and pain.