Nervous System.txt

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Nervous System.txt
2012-05-02 02:59:52
Nervous System

Nervous System (A&P)
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  1. Functions of the Nervous System
    • Gather Info
    • Process Info (internal/external)
    • Coordinating all body systems
  2. Structural & Functional divisions of the Nervous System
    • Central Nervous System: Brain & Spinal Cord
    • Peripheral Nervous System: Nerves outside of brain
    • ~Sensory (afferent) nerves: messages going to CNS
    • ~Motor (efferent) nerves: messages going away from CNS
    • **Somatic Nervous System: Skeletal Muscle
    • **Autonomic Nervous System: Smooth Muscle, Cardiac Muscle, glands
  3. Types of cells that make up the nervous system
    • Neurons: Functional unit of nervous system specialized to recieve and send information
    • Neuroglia: Cells that support and protect neurons (outnumber neurons 9:1)
  4. Components of a Neuron
    • Cell Body: Have components of all other cells
    • Axon: Impulse goes away from cell body
    • Dendrites: Receive info from other neurons and send to cell body
  5. Structure of a Neuron
    • Unipolar Neuron: Most of Sensory Neurons
    • Bipolar Neuron: Very specialized Neurons
    • Multipolar Neuron: Most cells are
  6. Function of a Neuron
    • Sensory Neurons (afferent): Sends impulse to CNS, mostly unipolar
    • Motor Neurons (efferent): Sends impulse away from CNS to muscles and glands, mostly unipolar
    • Interneurons: Recieve and send messages between neurons ~found in CNS, 99% of neurons are interneurons
  7. Function of Neuroglia
    • PNS:
    • Neuoglia that form the mylan sheeths
    • 80% lipids & 20% proteins
    • (Schwann Cell) Neurolemmocyte, creates the husk
    • CNS:
    • Makes mylan sheeths
    • provides/monitors cerebral spinal fluid
    • line interior & exterior of spinal cord
    • help form the blood brain barrier
    • hold neurons to capalaries
    • recycle neurotransmitters
    • type of macrophage
  8. Nerve message transmitted from neurons dendrites to its axon terminal
    • Resting membrane potential: Outside is positive inside is negative
    • Action potential: causes the release of a neurotransmitter from a presynaptic neuron (difuses across the synaptic cleft)
    • neurotransmitter binds to a receptor on a post synaptic membrane
    • a threshold potential is reac hed
    • Ion channels open in post synaptic neuron
    • action potential (nerve impulse, depolarization)
    • neurotransmitters are removed from synaptic cleft
    • repolarization is going back to the resting membrane potential
  9. Synapses
    • Where neurons meet and communicate
    • Presynaptic Neuron: Sends the message
    • Postsynaptic Neuron: receives the message
    • Synaptic Cleft: space between
  10. Neurotransmitters
    • Chemical messengers released by a presynaptic neuron
    • ~dopamine
    • ~adreneline
    • ~seratonin
  11. Salatory Conduction
    when action potential jumps between gaps in the mylan sheeth
  12. Ganglion vs neucleus & Nerve vs tract/column & Cranial Nerves vs Spinal Nerves
    • Ganglion is a group of cell bodies in the PNS
    • Nucleus is a group of cell bodies in the CNS

    • Nerve is a bundle of nerve fibers in PNS
    • Tract/Column is a bundle of nerve fibers in CNS

    • Cranial Nerves go to and from brain
    • Spinal nerves go to and from spinal cord
  13. Nerve Cell Injury
    • Pressure: Reduce the blood supply and conduction is impaired
    • Cut Injury: Regeneration is more likely in the periferal nervous system
    • Ischemic Injury: Lack of blood-No blood supply
  14. Neuron Regeneration
    • CNS - Unlikely
    • PNS - as long as the body is aligned
  15. Anatomy of the Spinal Cord
    • 31 segments:
    • ~8 cervical spinal nerves
    • ~12 Throacic spinal nerves
    • ~5 Lumbar spinal nerves
    • ~5 Sacral spinal nerves
    • ~1 Coccygeal spinal nerves
    • Spinal cord made of cell bodies
    • Costesequina at L1
    • Cervicle & Lumbar enlargements that go out to the limbs
  16. Difference between Gray Matter & White Matter & the distribution of each in the spinal cord
    • Gray Matter:
    • found on interior of spinal cord and surrounds the central canal
    • Unmylenated
    • Mostly cell bodies
    • posterior side is sensory info
    • anterior are somatic and motor neurons
    • lateral gray horns are autonomic
    • Function of gray matter is passing information
    • White Matter:
    • Mylanated
    • Function to carry infro from one place to another
  17. 3 Layers of Meninges & their structures
    • Pia Mater: binds to spinal cord
    • Arachnoid: Sub Arachnoid Space, Cerebral spinal fluid, blood vessels
    • Dura Mater: Thick protective outer layer
  18. Describe Spinal Nerves
    • Carry Information to and from spial cord and the rest of the body
    • 3 pairs of nerves for each spinal segment each pair of nerve will have a dorsal root
  19. Define Sensory Receptor
    a cell or nerve ending of a sensory neuron that responds to a specific stimulous
  20. Classification of Sensory receptors - TOUCH
    • Touch (Parietal Lobe):
    • Pressure Receptors-Mechanoreceptors notice pressure & touch
    • temperature receptors-thermoreceptors notice cold & warmth
    • Pain receptors (nociceptors)-chemoreceptors notice when tissues are damaged and will send out pain receptors
    • Proprioceptors-type of mechanoreceptors, tension and stretch of tendons and muscles (spoon to mouth)
  21. Classification of sensory receptors - SIGHT & TASTE
    • Sight: (Occipital lobe) Photo receptors
    • rods (see gray) - see shape and movement
    • cones (see colors) cones don't work in the dark

    • Taste (Parietal lobe)
    • Taste goes with smell
    • Taste salt, sweet, bitter, sour, umami (savory)
  22. Classification of sensory receptors SMELL & HEARING
    • Smell (temporal lobe)
    • Olfactory receptors
    • smell is 10,000 times more powerful than taste (emotion & memories)

    • Hearing (temporal lobe)
    • Sound waves hit the tempanic membrane
    • stimulate the ossicle, hit the cochlea
    • Typanic membrane (eardrum)
    • Ossicles (3 ear bones-malleous, incus, stape)
    • Cochlea
    • Organ or corti (go the the auditory receptors (hairs)
  23. Receptor Stimulation
    • If the stimulous is strong enough, an action potential occurs
    • action potential either happens or it doesn't
    • the stronger the stimulous the greater the frequency of the action potential
  24. Define Dermatone
    Dermatones are regions of skin served by the sensory neurons of a single segment (1pair of nerves)
  25. Define Nerve Plexuses. Name the plexuses and the nerves that arrise from each
    • Nerve Plexuses: Complex networks of intertwining spinal nerves
    • Cervical Plexus: c1-c5, burried under SCM goes to head & neck
    • Brachial Plexus: C5-T1 under armpit, goes to upper extremity
    • Lumbosacral Plexus: T12-S4 sciatic nerve comes here (largest nerve in the body)
  26. Define Reflex. List the components of a reflex arc and explain reciprocal innervation
    • Automatic motor response to a specific sensory signal specific set of neuropathways
    • Sense organ or recepor-stretch, pain, or pressure receptors
    • Sensory Neuron- Sends message to the CNS
    • Central Nervous System-either brain or spinal cord send info to motor neuron
    • Motor Neuron-sends message to the effector
    • Effector-Muscle or gland tha receives the message

    • Reciprocal innervation (reciprocal inhibition):
    • Neuron to antagonist is inhibited
  27. Describe the stretch reflex. Explain how muscle spindles are involved
    • Prevents over stretching of skeletal muslces.
    • stimulous is stretching muslce or tendon
    • receptor is a muslce spindle
    • response is contracting the stretched muslce
  28. Describe the inverse stretch (tendon) reflex. Explain how golgi tendon organs are involved
    • Prevents excess tension (lifting something too heavy & drop it)
    • stimulous is muslce tension
    • receptor is golgi tendon organ
    • response is to relax the contracted muscle

    Wihdrawl reflex - pain, hot, automatic reflex too hot too painful
  29. Explain the concept of final common pathway
    A somatic motor neuron that goes to a skeletal muslce that is the final common pathway
  30. Explain the pathways of sensory information in the spinal cord
    • Sensory pathways (how it gets from here to there)
    • Sensory messages coming through the dorsal route getting carried to the brain on different tracts on the spinal cord, messages first go to the thalamus then the sensory cortex
  31. List the four major divisions of the brain
    • cerebellum
    • cerebrum
    • diencephalon
    • brain stem
  32. Identify the major landmarks and divisions of the cerebrum
    • Lobes: temporal lobe, frontal lobe, occipital lobe, parrietal lobe
    • Sulcus: (Groove) central sulcus divides the frontal & parrieal lobes
    • Gyrus: (ridge) pre central gyrus, post central gyrus
    • Fissure: (deep sulcus) divides left and right hemispheres
    • Hemispheres:
    • Left-Speech, Language, Analytical skills, holds world view
    • Right-Spacial, intuition, insight, subtle aspects of language (metaphors) reads facial expressions
  33. Describe the distribution of gray matter and white matter in the cerebrum
    • Gray Matter:
    • Cerebral corex-this exterior layer of the cerebrum -a concious thought
    • basal nuclei (basal ganglia)-Planning, starting, stopping and monitoring the intensity of movement (soccer w/3yr old vs. adults)

    • White Matter:
    • Corpus Calosum-fibers that communicate between the hemispheres
    • association fibers-within the same hemisphere
    • projection fibers-outside of hemispheres
  34. Describe he location and function of the primary motor cortex
    in the pre-central gyrus of the frontal lobe, voluntary muscles that are working
  35. distinuish between primary sensory areas and sensory association areas.
    • Primary areas-taking raw data, make it concious (i see this (drink))
    • association areas-I've seen something like this before based on experience, understanding the sensations
  36. name the lobes of the cerebral cortex involved with different sensations
    • touch and proprioception - in the post central gyrus
    • taste (Gustatory) - in the parrietal lobe
    • hearing (auditory) - in the temporal lobe
    • smell (olfactory) - in the temporal lobe
    • vision ( ) - in the occipital lobe
  37. describe the location and function of the major integrative areas of the cerebral cortex
    • Integrative areas of cerebral cortex-how we integrate infor, processing info from many sources
    • prefrontal cortex: highly developed in humans, intelect, mood, personality, abstract thought, concience, predict a response to something
    • general interpretive area: making sense of info, left hemisphere
    • language area: left hemisphere, understanding written and spoken langualge. Broca's area involved in speech
  38. Describe the location and function of the limbic system
    • (basic survival)
    • Emotion, memory, sexual behavior, fear, rage, motivation (rewards vs. punishment...enough not to make behavior to happen again)
  39. describe the locaion and function of the cerebellum
    coordinates skeletal muscle movements, makes them smooth (piano)
  40. name two main divisions of the diencephalon and give the functions of eaach
    • Thalamus: relay point for sensor information
    • Hypothalamus: (housekeeping, make sure everything works) homeostatic control center: blood bressure, heart rate, digestion, temp, sleeping, hormones
  41. Name the three divisions of the brainstem from superior to inferior. Describe the functions of the brainstem
    • Brainstem: connects the brain to the spinal cord
    • Divisions: mid-brain, Pons, Medula Oblongotta (gets instruction from hyposthalamus to cough, sneeze, hiccup)
    • functions: skeletal motor control, reticular activationg system (helps keep cortex alert)
  42. Define "cranial nerve". Give the distribution, major functions, and comon names of cranial nerves I, II, V, VII, VIII, X
    • Cranial Nerves: Cell body in brainstem
    • I (olfactory nerves) - sensory fibers for smell
    • II (optical nerves) - sensory fibers for sight
    • V (trigeminal nerves) - mostly sensory fibers to the face, some motor nerves for he face
    • VII (faacial nerves) - mostl motor fibers for facial expression a few sensory taste fibers
    • VIII (vestibulocochlear nerves) - sensory from the ears & equilibrium
    • X (Vagus nerves) Parasympathetic & motor info (to heart lungs & kidney
  43. Describe the structures and pathways involved in skeletal muscle control
    • Skeletal motor neurons (lower motor neurons) - final common pathway, cranial nerves: cell bodies in brainstem, Spinal nerves, cell bodies in spinal cord
    • Primary motor cortex (upper motor neurons) - sending messages to motor neurons of the brainstem and the spinal cord
    • Cerebellum - coordinates and makes skeletal muscle ativity smooth(drunk) info from proprioceptors eyes & inner ear
    • Basal Nuclei (basal ganglia) - receiving info from all different parts of brain (starting, stopping, monitoring intensity of movements, maintaining muslce tone)
  44. Describe the formation, circulation and function of cerebrospinal fluid in the brain
    • cerebrospinal fluid - watery fluid bathes and protects brain, makes about 700ccs
    • Formation: choroid plexuses - specialized capalaries that filter plasma and takes the proteins out
    • Circulation: goes from ventricals down central canal of spinal cord back up through the subarachnoid space (craniosacral work)
    • Functions: to give brain boyancy to keep brain from squishing its self, protects against trauma nutrients, chemicals are carried in cerebral spinal fluid
  45. Describe how the autonomic nervous system differs from the somatic nervous system
  46. Name the two divisions of the autonomic nervous system, compare them in terms of structure and function. name the neurotransmitters used by each
    • Sympathetic Division (thoracolumbar division):
    • Function: fight or flight, deal w/threat, heart rate increase & force of contraction goes up, blood pressure increase, inhibit digestion and move blood to skeletal muscles, open up bronchioles, dialated pupils
    • location of cell bodies in CNS: preganglionic cell body is inside T1-T12, most of the post ganglionic cell bodies are right next to the spine
    • Neurotransmitters: preganglionic is acedocoline, postganglionic is epinephrin
    • receptors: for acedocoline (ach) are cholinergic, adrenergil go with epinephrin

    • Parasympathetic Division (craniosacral division):
    • Function: rest & digest/repair, digestion, repair, blod pressure decrease, heart rate decrease, breathing slows
    • Location of cell bodies in CNS: pregangliotic cell bodies- brain stem and sacral segments, postgangliotic cell bodies- ganglia in walls of organs
  47. Describe how autonomic function is controlled
    • the hypothalimus is boss
    • autonomic areas of brainstem can have an influence
    • defication, urination, controlled at spinal cord level
  48. describe age-related changes in the nervous system
    • loss of sensory-hearing, vision, taste, smell
    • declines of some autonomic functions-constipation, dry eyes, incontenance
    • problems with balance
    • reflexes slow
    • memory loss
  49. describe the possible effects of massage on the nervous system
    • reduces stress to increase the brains abilities/life
    • increase nerve function by increase blood flow
    • Parasymathetic - stimulate to get relaxation and better digestion stimulates which then...
    • interrupts pain/spasm cycle