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194 Cards in this Set
- Front
- Back
- 3rd side (hint)
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The central nervous system includes these two organs...
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The Brain and Spinal Cord
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come on now this is easy
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There are two types of matter in the CNS; white and gray. Gray matter is made of and white matter is .
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1. Nerve cell bodies
2. Myelinated axons |
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Nerve tracts are to the CNS, as
are to the PNS. |
Nerves
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A nerve tract is a
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group of nerve fibers within the CNS with a common origin and destination.
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A nerve is a group of nerve fibers in the ( ) with a common origin and destination.
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PNS
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Ganglion is to the PNS, as Nucleus is to ( ).
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CNS
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Remember that you can crush nerves ganglionic cysts on your wrist with a phonebook, but you would never want to crush a nucleus in the CNS.
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Who many pairs of cranial nerves are there in the human body?
Spinal Nerves? |
12 pairs of cranial nerves
31 pairs of spinal nerves 43 pairs total |
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What is the autonomic nervous system?
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The autonomic nervous system is a group of specific structures in the CNS and PNS. They are divided into the sympathetic and parasympathetic
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The Autonomic Nervous System controls functions that occurs
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automatically!
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The somatic nervous system controls the
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skeletal muscles with are under voluntary control.
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The nervous system orients the body to the
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internal and external environments.
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Cerebral Palsy is pathology of the brain causing
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paralysis, lack of coordination and other dysfunctions of the motor and sensory mechanisms.
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Coma can be caused by a number of causes and is characterized by varying degrees of
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unconsciousness
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When a neurological exam is conducted following trauma to the CNS these five categories are addresses...
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Reflexes (pupil dilation)
Sensory (pinching ankle) Motor (wiggle your toes) Cranial nerves (smell) Mental status (where do you live?) |
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Paraplegia is paralysis of both legs following damage or disease of the
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spinal cord
Quadriplegia is paralysis of both arms and legs. |
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The three main components of the neuron are
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cell body
dendrites axons |
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What is a Nissl body?
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layered rough ER
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A neuron cell body contains the
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nucleus
nissl bodies neurofibrils(strands of protein) and other organelles |
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dendrites are cyctoplasmic extensions which
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receive stimuli and conduct impulses to the cell body
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The may extend laterally from an axon
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Short Axon Collaterals
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In the PNS these cells myelinate the axon
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Schwann cells
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schwann frozen foods are not central
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Oligodendrocytes in the CNS are responsible
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for myelinating the axons. (nerve tracts)
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Rodes of Ranvier
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segments in myelin sheath
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Axon terminates at the
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presynaptic terminals. Which look like roots of a tree.
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Neurons are classified into three different groups based on impulse conduction, number of processes and area of enervation.
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3 types of classification of neurons
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Impulse Conduction can be
1. 2. 3. |
1.Sensory- to CNS
2.Interneurons- between sensory and motor 3. Motor- away from CNS |
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Number of Neuron Processes:
1. 2. 3. |
1. Unipolar- single process that branches into axon and dendrite
2. Bipolar- axon and dendritic processes 3. Multi- one axon multi dend. |
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Area of Enervation
1. 2. 3. 4. |
1. Somatic afferent
2. Somatic efferent 3. Visceral Afferent 4. Visceral Efferent |
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Resting Membrane Potential
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difference in electrical charge between inside and outside of cell membrane
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Resting Membrane Potential is due to
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an imbalance of charged particles, there are more cations outside and more anions inside the cell (polarized)
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What does the sodium-potassium pump do?
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Transports Na+ outside the cell and K+ into the cell
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Two K+ in for every three Na+ out
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Is the cell membrane more permeable to Na+ or K+?
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The cell membrane is more permeable to K+ ions than Na+ during rest
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What is the voltage inside of a neuron?
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Sixty-five to 85 mv
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Nerve and muscle cells have the ability to in response to appropriate stimuli.
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Nerve and muscle cells have the ability to alter their resting membrance potential in response to appropriate stimuli
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The neurological code
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is constituted by the frequency and pattern of action potentials as well as the destination of the impulses.
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During the action potential the inside of the neuron becomes
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Positive.
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How fast do action potentials occur?
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2msec or 1000 per second
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In response to an action potential the membrane becomes more permeable to what ion?
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Sodium, sodium channels open at the site of stimulation
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As sodium ions move inwards the inside of the membrane becomes
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less negative
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Threshold level or generator potential must be crossed in order to trigger an action potential, what is that voltage?
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-55mV
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What is reverse polarization?
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Sodium ions continue to move inward after depolarization and the inside of the membrane becomes positive relative to the outside
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Reverse polarization acts as a
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stimulus to the adjacent regions and decreased permeablity of sodium channeld and increased voltage gated potassium channels are opened
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Repolazation occurs as a result of K+ ions moving in making the
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outside of the cell positive once again
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Absolute refractory period
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During the interval from the onset of an action potential until repolar is 1/3 complete a secaond impulse can not take place because channels stil open
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Relative Refractory Period
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Only a very strong stimulus can depolarize the membrane and produce an action potential because the cell is hyperpolarized.
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Sodium Channel Structure
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The Na+ channel is formed by a single, long polypeptide.
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The pores of the sodium channel
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twist open and strip most of their associated water molecules.
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Tetrodotoxin (TTX)
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japanese puffer fish ovaries
binds to and physically BLOCKS the Na+ pores |
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Saxitoxin
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Red Tide
Dinoflagellates Blocks Na+ pores |
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Batrachotoxin
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Columbian frogs
Na+ channels stay OPEN altering action potentials (veratridine/lilies and aconitine/buttercups also) |
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Delayer Rectifier
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Movement of K+ during repolarization
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Orthodromic Conduction
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Natural in one direction
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Backward Propagation
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Antidromic Conduction
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Continuous Conduction
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In an unmyelinated neuron the impulse travels along the entire membrane surface
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Nodes of Ranvier
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Interuptions in the myelin sheath from which action potentials leap ffrom node to node
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Saltatory Conduction
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With nodes, up to 100m/sec or 225 mile and hour
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Saltatory conduction
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conserves energy because the Na+ and K+ pumps only have to re-establish concentration differences at the Nodes of Ravier
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Multiple Sclerosis (MS)
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maybe an autoimmune disease in which the bodies natural defenses attack the myelin in CNS
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First Symptom of MS
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disturbances in vision
more common in cold zones |
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Treatment of MS
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exercise
ACTH physical therapy |
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Tay-Sachs disease
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inherited disease in which myelin sheaths are destroyed because of excessinve accumulation of lipids withine membrane layers
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Local Anesthesia
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physically blocks the sodium channels and action potential in neurons, Cocaine and Lidocaine
smaller axons affected first, pain neurons are small:) |
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Axon Terminal
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Small rounded or oval knobs which contain synaptic vesicles filled with neurotransmitters
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Synaptic Cleft
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Microscopic space between neurons
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Postsynaptic Membrane
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cell membrane which receptors for neurotransmitter
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Calciums role in synapse
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Calcium enters the presynaptic neuron causing the release of the neurotransmitter into the synaptic cleft
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Two common neurotransmitters
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ACH- Acetyl Choline
and Norepinephrine |
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ACh and Norepi are broken down by
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cholinesterase and monoamine oxidase
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Three Characteristics of a Synapse
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1.Delay
2.Fatigue 3.One-way conduction |
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Drugs influence synaptic transmission by
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1. Synthesis of Neurotrans
2. Release of NT 3. Binding 4. Destruction |
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Parkinsons
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lack of NT dopamine
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Myasthenia Gravis
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block of NT ACH receptors
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Botulism
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inhibits Ach release
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Synaptic Excitation
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NT that increase the postsynaptic membrane to Na+ ions (EPSP)hypopolarized
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Spatial Summation
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several presynaptic neurons to single post
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Temporal Summation
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Rapid successive discharge of NT from same presynaptic membrane
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Synaptic Inhibition (IPSP)
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Hyperpolarization, increase in postsynaptic membranes perm. to chloride and potassium.
Glycine is NT involved. |
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Six Classes of Neurotransmitters
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1.Acetylcholine
2.Amino Acids 3.Amines 4.Polypeptides 5.Purines 6.Gases |
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At least four amino acids function as Neurotransmitters the most common two are
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1. GABA- inhibitory
2. Glycine- Mainly inhibitory |
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Five Neurotransmitters derived from a single amino acid
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1.Norepinephrine
2.Epinephrine-Adrenaline 3.Dopamine 4. Serotonin 5. Histamine |
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Polypeptide NT's are related to pain, the two most important ones are
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Substance P
Endorphins and Enkephalins |
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Purines includes two substances based ATP and AMP
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adenosine tri/monophosphate
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Common Gaseous NT
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Nitric Oxide
has a half-life of only 2-30sec and is difficult to study |
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Cerebrum
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Largest part of brain 80% mass
Longitudinal fissure central fissure lateral fissure |
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Corpus Callosum
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connects the two hemispheres, made of 300 million neural axons
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Frontal Lobe
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motor area, elaborate thought, speaking ability
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Parietal Lobe
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sensory area
somesthetic (body feeling-touch, pressure, heat, cold, pain) proprioception (body positions) |
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Temporal Lobe
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hearing
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Occipital Lobe
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visual lobe
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Functions of the Cerebrum
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1. all conscious functions
2. interpretations of sensations 3. Understanding Language 4. Intelligence, memory and emotional feeling |
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Cerebral Cortex
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outer portion of cerebrum, six layers of neurons
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sensory area
motor area |
?
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Thalamus
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recognition of pain, temp. touch, pleasant, unpleasant, all complex reflex movements, relay for all sensory except for smell (input-thalamus-sensory cortex)
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Hypothalamus
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controls pituitary
hormones (thyroid/growth/ reproduction/adrenal) water balance appetite body temp |
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Cerebellum
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control muscle action (planning and execution of voluntary movement)
postural reflexes equilibrium |
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Medulla Oblongata
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heart rate, blood pressure, respiration, vomit, coughing and hiccuping
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Reticular Formation includes these three things
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1. Medulla
2. Pons 3. Midbrain |
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Pons
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center for the 5th, 6th, 7th and 8th cranial nerves
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Midbrain
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center for 3rd and 4th cranial nerves
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Brain Stem (pons, medulla, midbrain)
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reticular formation which contains the reticular activating center.
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Reticular Activating Center
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controls the overall degree of alertness, wakefulness and sleep.
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General Anesthesia
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suppresses the neurons in the R.A.C. and damage to these neurons may lead to a coma
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Major nerve of the parasympathetic system
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Vagus (80% of all parasymp nerves are in the vagus nerves)
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Dorsal Root Ganglion
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where nerve cell bodies clump (PNS)
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Dorsal=
Ventral= |
sensory
motor (no ganglion) |
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Movement of Eyeball
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III Oculomotor
IV Trochlear VI Abducens |
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Olfactory Nerve
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One-
smell mucosa in nose |
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Cranial Nerve Two
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Optic
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Cranial Nerve Four
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Trigeminal
sensation from face, teeth and tongue movement of jaw, chewing muscles |
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Facial nerve
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Number 7
Movement of facial muscles, saliva and tears sensation from front taste buds |
lucky to have a pretty face
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Vestibulocochlear
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Number 8
hearing, balance and posture |
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Number Nine-
Glossopharyngeal |
Taste buds in back,
swallowing and secretion of saliva |
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Number 10- Vagus Baby!
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visceral sensations
visceral muscle movement |
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Eleven XI- Accessory
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swallowing, head and neck movements
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hypoglossal
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speech and swallowing
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The spinal cord has a grey H at the center made of
the white part is |
neuron cell bodies, the central canal is filled with CSF
myelinated axona |
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posterior, lateral, and anterior Funiculi
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are where nerve tracks are located
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Ascending Tracts
Descending Tracts |
to CNS
away from CNS |
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Two main ascending tracts
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Anterior Spinothalamic
and Lateral Spinothalamic |
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Two main Descending Tracts
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Anterior Costicospinal
and Lateral Corticospinal |
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Anterior Spinothalamic Tract
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Conducts sensory impulses for crude touch and pressure
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Lateral Spinothalmaic
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Conducts pain and temp. impulses
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Descending Anterior Corticospinal Tract
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Conducts motor impulses from the cerebrum to spinal nerves and outward through anterior horns for coordination of movements
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Descending Lateral Corticospinal Tract
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Conducts motor impulses from the cerebrum to spinal nerves through the anterior horns for coordination of movements
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Reflex Arc
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1.Receptor
2.Sensory Neuron transmits 3.Interneuron- in brain or cord 4.motor neuron 5.effector- muscle or gland |
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Alpha waves
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(8-12 waves/sec)
parietal and occipital lobes awake and relaxed eyes closed up body temp and blood sugar |
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Beta Waves
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(13-25 waves/minute)
frontal lobe thinking or visually orienting |
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Theta Waves
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(5-8) temporal and occipital lobes
newborns, severe emotional stress |
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Delta Waves
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(1-5) cerebrum
common in infants and sleeping adults may indicate abnormal in adults who are awake |
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Brain Death
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1. Unresponsiveness
2. No respiration 3. No reflexes 4. Flat EEG for ten minutes |
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Blood Brain Barrier
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made from astrocytes (glia cells)
Tight junctions develops early in life |
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CSF is produced by
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active transport and ultrafiltration from materials within the blood at specialized capillaries called choroid plexuses
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Choroid Plexuses
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along the roofs of the ventricles of the brain where CSF is produced
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Normal Fluid Pressure of CSF is
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10mmHG, way less than blood
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Flow of Cerebrospinal Fluid
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lateral ventricles-foramen
Third Ventricle- Cerebral aqueduct Fourth Ventricle Subarachnoid space-reapsorption |
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Functions of Cerebrospinal Fluid
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1.Cushions the brain
2. Allows for exchange of nutrients and wastes 3. Buoys the brain (50g vs 1500g) |
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Hydrocephalus
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Accumulation of CSF caused by excessive production or blocked flow of CSF. Causes bones to thin and cerebral cortex to atrophy
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Lumbar Puncture
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Used to look for infection
and To see if a stroke is from bleeding or a clot, RBC indicate hemorrage |
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Acute Hydrocephalus
Normal-Pressure Hydrocephalus |
occurs after head injury
volume increase but pressure may not |
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Noncommunicating
Communticating |
Obstruction of CSF flow between ventricles
Impaired absorption or increased secretion (tumor in choroid plexus) |
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When relaxed brain waves are
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Alpha
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Non-REM sleep is
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5% Theta
50% Spindles 20% Delta |
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Non-REM Sleep is
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slow, deep, regular respiration
decreased H.R. and B.P. Cerebral Blood Flow, Brain Temp. Few eye movements Large Waves |
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REM Sleep
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active sleep
d state Decreased muscle tone- except mastication muscles |
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Autonomic Nervous System
Effector Organs |
1. Cardiac Muscle
2. Smooth Muscle 3. Visceral Organs and Glands |
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Division of Autonomic Nervous System
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1. sympathetic division
2. parasympathetic division |
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Homeostasis- Role of ANS
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Impulses from one division activate the effector organs, while impulses from the other division inhibits them.
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Sympathetic Division
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prepares the body for intense physical activity through adrenergic effects
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Neurotransmitter in Sympathetic
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Norepinephrine (adrenaline)
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Neurotransmitter in ParaSympathetic
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Acetylcholine
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The anatomical origin in
SYMP PARA |
thoracic and lumbar regions
cranial and sacral regions (longer preganglionic neurons) |
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Exceptions in the Sympathetic Nervous System that do not use Norepinephrine (ACH)
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1. Sweat Glands
2. Smooth muscle in blood vessels going to skeletal muscles 3. The adrenal Medulla (+ fedbk) |
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Exception to the ACh rule for Parasympathetic
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None always acetylcholine
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Similarities between the two division of the ANS
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1. Pre-gang myelinated, post non
2. Efferent outflow divided into pre- and post- ganglionic neurons 3. Pre-gang ACH |
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Mechanoreceptors
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touch, deep pressure, hearing, equilibrium, arterial pressure
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Thermoreceptors
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changes in temp. some cold some warmth.
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Nociceptors
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pain receptors which detect damage in the tissues, whether it is physical or chemical damage.
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Electromagnetic or Photoreceptors
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detect light on the retina of the eye
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Chemoreceptors
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taste, smell, oxygen/co2 levels in blood
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tonic receptors
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do not adapt or adapt slowly
muscle stretch receptors |
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phasic receptors
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adapt rapidly, respond to off set
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three types of pain
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1.Cutaneous- surface of the body
2.Deep Pain 3. Visceral Pain |
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Cutaneous Pain
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localized on the surface
prickling, sharp, burning fast pain, A-delta myelinated |
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Deep Pain
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From muscles, tendons and joints
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Visceral Pain
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poorly localized
dull, aching, nauseous, throbbing beta neurons, unmyelinated and slow |
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Four substances released from Damaged Cells
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Prostaglandins
Bradykinin Substance P Glutamate |
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Prostaglandins
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a special group of fatty acid derivatives that are cleaved from the lipid bilayers of plasma membranes
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Bradykinin
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activated by enzymes released from damaged cells
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Substance P
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pain neurotransmitter
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Glutamate
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pain neurotransmitter
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Analgesic System
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The CNS contains a neuronal system the suppresses pain. Response to exercise, stress endorphins and enkephalines are released. Block substance P
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Chronic Pain
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damage within the pain pathways, or neuropathic pain.
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Aspirin, Tylenol(acetaminophen), Ibuprofen (advil)
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diminish pain by inhibiting prostaglandin production and release.
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Opiate Drugs
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act directly on pain centers in the brain
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Referred Pain
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1. Embryonic Origin of the organ
2. Cross over of first order neurons w/ second order neurons in the spinal cord |
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Epilepsy
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sudden uncontrolled discharge of activity by the neurons in the brain (seizure)
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Alzheimer's
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1.Great loss of neurons in the hippocampus and cerebral cortex
2.Plaques of abnormal proteins 3. Tangled protein filaments with neurons |
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Organs that recieve only sympathetic innervation
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adrenal medulla
arrector pili muscles sweat glands and many blood vessels |
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There are two types of Cholinergic Receptors
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Nicotinic Receptors
and Muscarinic Receptors |
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Nicotinic Receptos are
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located at the ganglia in both sympathetic and parasympathetic divisions
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Muscarinic Receptors
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are located on all effector organs innervated by postganglionic neurons of the parasympathetic division.
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All preganglionic autonomic neurons and all postganglionic parasympathetic neurons are
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Cholinergic. The effect is excitatory, with exceptions of parasymp. in the heart which cause it to slow.
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Muscarinic Receptor Antagonists
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Atropine, treat parkinsons, dilate pupils, control motion sickness, treat peptic ulcers and hypermobility of intestines
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Muscarinic Receptor Stimulates
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Acetylcholine, carbachol, metacholine, bethanechole: stimulate intestines
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no poo, no leaving hosptial
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Alpha and Beta Receptors
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are adrenergic Recepotors in the Sympathetic Nervous system only
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Andrenergic receptors are
Regulated by? |
membrane receptors proteins located on autonomic effector organs
catecholamines |
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Alpha receptors are located on
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Smooth muscles, stimulate vasocontriction, uterine contraction, dilation of pupil, intestinal sphincter contraction and pilomotor contraction
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Beta One
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Cardiac Muscle, stim increase in heart rate and force of contraction
Equal NE=EPI |
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Beta two
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Smooth Muscle, inhibition of smooth muscle
Epi>>>NE |
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Isoproterenol
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a synthetic catecholamine that stimulates mainly beta 2 receptors stronger than alpha 1 receptors
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Alpha Receptor Stimulators
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cause vasocontriction and are used as decongestants
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Alpha REceptor Blockers
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are used to lower high blood pressure
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Beta Receptor Stimulates
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are used to stim heart and cause bronchodilation
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Beta Blockers
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are used to slow the heart
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