Please enable JavaScript.

Coggle requires JavaScript to display documents.

Gael Parra Per 5. Nervous System - Coggle Diagram

- - - - The parasympathetic division promotes maintenance functions and conserves energy. Its role in the body is to keep body energy as low as possible even while carrying out maintenance activities.
    - - The sympathetic division mobilizes body during activity and is referred to as the "fight or flight" system. Activities like exercise, excitement, emergency, and embarrassment all activate this division.
- - - - Microglial Cells: Small, ovoid shaped cells with theory processes that touch and monitor neurons. These cells migrate toward injured neurons and can transform to phagocytize microorganisms and neuronal debris.
      - Oligodendrocytes: Branched cells that process wrap CNS nerve fibers, forming insulating myelin sheaths in thicker nerve fibers.
      - Ependymal Cells: Range in shape from squamous to columnar and may be ciliated. The Cilia beat to circulate the CSF. These cells line the central cavities of the brain and spinal column and form a permeable barrier between cerebrospinal fluid (CSF) in cavities and tissue fluid within CNS cells.
      - Astrocytes: These are the most abundant, versatile, and highly branched of the glial cells. These cells cling to neurons, synaptic endings, and capillaries. It has multiple functions including: supporting and bracing neurons, playing a role in the exchanges between capillaries and neurons, guiding migration of young neurons, controlling chemical environments around the neurons, responding to nerve impulses and neurotransmitters, influencing neuronal function, and to participate in information processing in the brain.
  - - - Ganglia: Clusters of neuron cell bodies in PNS.
      - Nuclei: clusters of neuron cell bodies in the CNS.
    - - The Axon
        
        Structure: Each neuron has one axon that starts at a cone-shaped area called the axon hillock. In some neurons, the axons are shorts or absent and in others the axon comprises almost the entire length of the cell. Long axons are called nerve fibers. Axons branch profusely at their end (terminal) and can have numbers as many as 10,000 terminal branches. Distal endings of an axon are called axon terminals or terminal boutons.
        
        Function: The axon is the conducting region of the neuron. It generates nerve impulses and transmits them along the axolemma (neuron cell membrane) to the axon terminal. The terminal is the region that secretes neurotransmitters which are released into extracellular space. The impulses can either excite or inhibit neurons it contacts. The axon carries multiple conversations within different neurons at the same time and quickly decay if cut or damaged. The movement of the axon occurs in towards and away from the cell body.
      - Dendrites: Motor neurons can contain 100s of these short tapering, diffusely branched processes. Dendrites are the receptive (input) region of neurons that convey incoming messages toward cell body as graded potentials (short distance signals). In many brain areas, dendrites are highly specialized to collect information.
- - - - Acetylcholine: First identified and best understood. It is released at the neuromuscular junction and is synthesized from acetic acid and by enzyme choline. Degrades due to enzyme acetylcholinesterase.
      - Amino Acids
        
        Make up all proteins and therefore are difficult to prove which are neurotransmitters. Amino acids that are proven neurotransmitter.
      - Biogenic Amines
        
        Catecholamines
        
        Dopamine: Made from amino acid tyrosine
        
        Indoleamines
        
        Serotonin: Made from amino acid trypotophon
        
        Histamine: Made from amino acid histidine
      - Peptide
        
        Strings of amino acids that have diverse functions.
        
        Endorphins: Beta endorphins, dynorphin, and enkephalins: act as natural opiates; reduce pain perception
      - Purines
        
        Monomers of nucleic acids that have an effect in both CNS and PNS.
      - Gases and Lipids
      - Endocannabinoids
        
        Act at same receptors as THC
- - - - Affect: Heroine mimics natural opiate which turns off dopamine inhibition. Dopamine floods the synapse causing the feeling of sedation and well-being.
  - - - Affect: Ecstasy mimics serotonin. This causes serotonin transporters to become confused causing seekers to be transferred out of cell instead of in. People who use this drug may feel mad, sleepy, and appetite changes.
  - - - Affect: Marijuana binds to cannabinoid receptors and inhibition is turned off and dopamine is allowed to squirt into synapse. People who use marijuana may experience slowed down movement causing a sense of calmness and relaxation.
  - - - Affect: Meth forces dopamine molecules out of the vesicle which causes dopamine to be pumped into the synapse. People who use this drug will feel intense pleasure and exhibition.
  - - - Affect: Alcohol delivers a double sedative punch and makes gaba receptors more inhibitory and it prevents glutamate from exciting the cell. Using alcohol affects a persons memory formation, decision making, and impulse control.
  - - - Affects: Cocaine causes overstimulation of cells as dopamine continues to bind again and again to receptors. People who use cocaine will often feel fidgety and will be unable to be still.
  - - - Affects: LSD elicits serotonin effect by binding to its receptors. LSD may inhibit or excite receptors resulting in complex sensory effects. People who use this drug may feel weak, and evoke a startle response to unexpected stimulus.
- - - - Somatic Sensory Fibers: Convey impulses from skin, skeletal muscles, and joints to CNS.
      - Visceral Sensory Fibers: Conveys impulses from visceral organs to CNS
    - - Autonomic Nervous System (involuntary): Consists of visceral motor nerve functions. It regulates smooth muscle, cardiac muscle, and glands. This system has two functional subdivisions:
        
        Sympathetic: Mobilizes body systems during activity
        
        Parasympathetic: Conserves energy and promotes housekeeping functions during rest.
      - Somatic Nervous System (voluntary): Somatic motor nerve fibers conduct impulses from CNS to skeletal muscle. Consists of conscious control of skeletal muscle.
- - - - Both hemispheres consist of the cerebral cortex (gray matter), White matter, and the Basal Nuclei.
  - - - Functions: The cerebellum processes input from the cortex, brain stem, and sensory receptors in order to provide precise, coordinated movements of the skeletal muscle.