Term
What are the two central components to the human nervous system? |
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Definition
Somatic (sensory/motor information)
Autonomic (neuroendocrine) |
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Term
What characteristics can be associated with the somatic nervous system? |
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Definition
Direct pathways, fairly convergent, requires signaling to function
muscles die if not innervated |
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Term
What characterizes the autonomic nervous system? |
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Definition
Deals with the viscera (the interstitial tissue)
One system for dealing with food (enteric)
Divergent
Preganglion -> spinal ganglion -> post ganglion
Neuroeffector junctions (axon to axon) |
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Term
What are some anatomical features of the sympathetic nervous system? |
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Definition
Travel along nerves or blood vessels to organs they innervate
Viscerotopic organization, ipselateral leisions produce some ipselateral deficits
Ach preganglions
Mainly norepinephrine based postganglions, (Ach for goosebumps) |
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Term
What are some characteristics of neuromodulatory function? What are some common neuromodulators |
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Definition
long duration effects, peptides
Neuropeptide Y
VIP
Substance P
CGCRP |
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Term
What substances allow the autonomic nervous system to be overridden locally? |
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Definition
nitrous oxide
VIP to a lesser extent |
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Term
Describe the spinal innervation of the parasympathetic and sympathetic nervous system |
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Definition
Sympathetic (middle spine) [thoracic-lumbar]
Parasympathetic [cranial-sacral]
No overlapping innervation! |
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Term
Describe the parasympathetic neurotransmitters. |
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Definition
Preganglion -> Ach (nicotinic receptors)
Postganglionic -> Norepinephrine, except sweat glands which are Ach |
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Term
Name the parasympathetic Efferents functions |
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Definition
CN III -> pupilary constrictor
CN VII -> Crying and salivating (submaxillary)
CN IX -> Parotid salivary
CN X -> Vagus motor ganglion -> heart, lung, intestine, pangcreas
Sacral Spinal cord -> Colon, rectum, bladder, sex |
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Term
How do visceral afferents ascend usually? |
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Definition
following back sympathetic efferents to the ganglions (pain fibers), and then the spinal cord
follow Cranial nerves to brainstem |
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Term
Describe what causes referred pain |
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Definition
Divergence in the pain pathway, primarily in the spinothalamic tract
Gall bladder pain stabs you in the back! |
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Term
What is the information carried by the autonomic system called? |
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Definition
Interoception
Takes the form of distension of smooth muscle, chemical, injury, inflamation (tumors don't cause pain until they swell on something) |
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Term
What are the main principles of autonomic function? |
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Definition
Target organs function independently of innervation, loss of innervation means a loss of coordination
Sympathetic (fight/flight) and parasympathetic (relax) have opposite effects generally
Maintains homeostasis
Local environment influences firing probability of autonomic neurons |
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Term
Describe the direct pathway of the fight or flight response |
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Definition
Hypothalamus -> sympathetic activation -> activates adrenal medula, releasing norepinephrine and epinephrine into bloodstream |
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Term
What happens when you put norepinephrine into a smooth muscle? |
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Definition
Vascular -> contracts, increases Blood pressure
Bronchiolar -> relaxes, vasodilates (increases blood exposure to air)
Completely different effects! |
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Term
How is thermoregulation accomplished by the skin? |
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Definition
arteriovenous anastemoses
like a radiator bringing water to a heatsink |
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Term
Describe autonomic functioning of the male sex function |
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Definition
Erection is parasympathetic! allows blood to pool in penis, pinching off veins (nitrous oxide with cGMP)
Ejaculation is sympathetic, contracting the muscle, and then return of the unerect muscle tone, blood drains. |
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Term
Describe Horner's syndrome |
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Definition
Unopposed parasympathetic stimulation
droopy lids, no sweating, small pupils, localized
no variability in breathing rates, heart rates
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Term
Describe the baroreceptor reflex pathway (sympathetic) |
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Definition
carotid aretery pressure receptor
Nucleus of the solitary tract
Rostralventrolateral Medula
Reticulospinal tract
intermediolateral spinal column
sympathetic ganglion
Heart and arteries
All excitatory |
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Term
Describe the baroreceptor reflex pathway (parasympathetic) |
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Definition
Carotid artery pressure sensor
Nucleus of the solitary tract
Vagal motor nuclues
Vagus nerve
inhibitory interneuron
heart
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Term
What feedback is utilized in the baroreceptor reflex? |
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Definition
negative feedback
application of a signal produces a reduction in the original signal |
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Term
How is blood pressure regulated? |
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Definition
Kidneys retain water to increase blood pressure
ADH prevents water excretion along with NaCl (osmolarity conserving), thirst increased |
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Term
How is autonomic control facilitated? |
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Definition
Nucleus of the solitary tract receives visceral input, cascade to different limbic nuclei which result in hormonal and other autonomic output |
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Term
How can pavlovian conditioning affect the immune system? |
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Definition
When introduced, a immune response can be supressed if there was a immunosuppressant associated with a taste, even though the immunosupressant was not actually given. |
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