Nervous system Flashcards
What is included in the Central Nervous System
Brain and spinal cord
What is included Peripheral Nervous System
Everything else
Afferent Division
Part of the (PNS) Transmits impulses from peripheral organs to the (CNS)
Efferent (motor)
Transmits impulses from CNS to the peripheral organs to cause effect or action
Somatic (Part of Efferent)
supplies skeletal muscles and is mostly voluntary
Automatic System
What are the two parts of the automatic nervous system
The Sympathetic and the parasympathetic divisions, both are involuntary
What does the sympathetic division do
Controls fight or flight. Main hormones are epinephrine and nor epinephrine.
What parts of the body hold sympathetic nerves
Thoracacolubular regions
what does the Parasympathetic Division do
Relaxes the body, acetocholine is released.
Where are parasympathetic divisions
The craniosacral regions
What is the enetric nervous system
Controls digestion via nerves embedded into the digestion track
Where is 90% of the bodies serotonin stories
The digestive track
Dendrites
Branchlike extensions off of neurons, receive incoming signals from neurons or sensory cells.
Cell body
Contains the genetic information and control all activities of neurons
Axon
The part of the neuron that conducts action potentials
Synaptic end bulb
The end part of the axon, releases neurotransmitters onto a target cell
Synapse
Narrow junction which allows chemical signals to go from one neuron to another, creating new action potentials
myelin
wraps around axons, mylinated neurons all for an increased speed of action potentials. Wide diameters conduct axons more rapidly
What do Glial cells do
They act as support cells for the nervous system
Astrocytes
Control the chemical environment around neurons, form blood brain barrier.
Oligodendocytes
Make myelin on the axons in the CNS.
Microgila
Phagocyte cells in the CNS, digest waste and infections
Ependymal cells
Line ventricles of brain and the central canal of the spinal cord, made spinal fluid
PNS glial cells
Include satelitle cells and Shwann cells
Satellite cells
Provide nutrients to neurons in the PNS
Schwann cells
Make Myelin on the axons of the PNS neurons
What parts are included in Glial cells
Astrocytes, oligodrocytes, microgila, and ependymal cells
What is going on in a cell when it is at its resting membrane potential state
The cell does not conduct any action potentials therefore the sodium is greater outside the cell, and potassium is greater inside the cell, negatively charged proteins are also greater inside the cell, making the charge indie the cell -70 mV
What is a graded potential
a stimulus that allows sodium to move into the cell.
Threshold potential
If the cell reaches the threshold potential more sodium can move into the cell
What is depolarization
Occurs when NA+ diffuses rapidly into a cell which makes the inside of the cell less negative about 55 MV+ (Peaks at +30 MV)
Repolorization
Occurs when K+ moves out of the cell and the membrane potential become negative,
When does hyperpolerization occur
When the membrane potential drops to -90mV
Hyper-polarization
prevents another action potential from being generated until the neuron reaches its resting membrane potential again
Sodium potassium pump
Uses energy to move 3 NA out of the cell and to K into the cell at the same time.
Local anesthetics
block sodium channels, preventing depolarization in pain conducting nerves
What is multiple sclerosis
An autoimmune disease which destroys mylien sheets of nerve fibers interrupting
Where can depolarization occur
Occurs at the nodes of ranvier, the segments of axons that are not covered with myelin.
How do mylinated axons carry out action potentials
Salutatory conduction (used to describe depolarization at the nodes of ranvier
How do unmylinated Axons carry action potential
Continuous conduction
Continuous conduction
The slower movement of action potentials due to depolarization that occurs along the entire length of its axon terminal
presynaptic neuron
fires the neurotransmitter when an action potential enters its axon terminal
Synapse
A point of contact between neurons
Synaptic cleft
the space between pre and postsynaptic neurons
Post synaptic neuron
receives the neurotransmitter after it has crossed the synapses
What are Neurotransmitter
Chemical messengers secreted by neurons, can either excitatory or inhibitory
Excitatory neurotransmitters
Cause depolarization
what are the common excitatory neurotransmitters
Acetocholine, norepinephrine, glutamate, substance P., Nitric Oxide
Acetylcholine
CNS: Involved in memory, motivation, arousal and attention
PNS: required for skeletal muscle contraction; the main parasympathetic neurotransmitter.
Glutmate
CNS: The primary excitatory neurotransmitter of the brain
PNS: Makes rapid signaling necessary for learning memory possible
Norepinephrine
CNS: Regulates arousal, attention, cognitive function and stress reactions
PNS: The primary sympathetic neurotransmitter
Substance P
CNS: Regulates pain perception in the brain
PNS: Induces inflammation in the intestines
Nitric Oxide
CNS: Facilitates communication between neurons in the brain
PNS: Causes validations of the blood vessels in the penis and clitoris
What do inhibitory neurotransmitters do
they prevent depolarization cause hyperpolerization
Common inhibitory neurotransmitters
Serotonin, GABA, Glycine, Adenosine, endorphins, and endocannabinoids
Serotonin
CNS: Regulates mood
PNS: Regulates intestinal functions
GABA
CNS: primary inhibitor neurotransmitter induces sleep and relaxation control anxiety stress and fear.
Glycine
CNS: Involved in the processing of motor and sensory information
Adenosine
CNS: Protects the brain by preventing glumate releases during a stroke
Endorphins
CNS: Produces feeling of euphoria
PNS: Reduce pain by blocking the releases of substance P
Endocannabinoids
CNS: Involved in learning and memory; controls appetite and nausea control.
