Term
What are clusters of cell bodies in the CNS called? |
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Definition
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Term
What are groups of axons in the CNS called? |
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Definition
Pathways, tracts, or commissures |
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Term
What are clusters of cell bodies in the PNS called? |
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Definition
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Term
What are groups of axons in the PNS called? |
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Definition
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Term
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Definition
Bone that surrounds the spinal cord |
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Term
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Definition
A procedure to sample the CSF for diagnosis |
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Term
What is the function of gray matter? |
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Definition
Synaptic transmission and neural integration |
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Term
What is the function of white matter? |
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Definition
Propagate action potentials, it is white because of myelin |
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Term
Define subcortical nuclei |
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Definition
Small areas of gray matter within white matter |
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Term
How many spinal nerves are there? |
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Definition
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Term
What is the cauda equina? |
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Definition
The bottom 1/3 of the column, individual nerves but no spinal cord bone surrounding them |
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Term
Which horn of the spinal cord is posterior? |
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Definition
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Term
Which horn of the spinal cord is anterior? |
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Definition
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Term
What type of cell bodies are in the dorsal horn? |
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Definition
Interneurons on which afferent neurons terminate |
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Term
What type of cell bodies are in the lateral horn? |
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Definition
Autonomic efferent nerve fibers |
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Term
What type of cell bodies are in the ventral horn? |
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Definition
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Term
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Definition
Bundles containing afferent neurons |
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Term
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Definition
Bundles containing efferent neurons |
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Term
Where do autonomic preganglions of the sympathetic nervous system originate? |
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Definition
The thoracic and lumbar positions of the spinal cord (T1-L3) |
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Term
What part of the spinal cord do preganglionic neurons originate? |
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Definition
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Term
What is another name for preganglionic neurons of the sympathetic nervous system? |
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Definition
The thoracolumbar sympathetic nerves |
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Term
Where do preganglionic neurons of the parasympathetic nervous system originate? |
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Definition
The brainstem or sacral spinal cord |
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Term
What is another name for the preganglionic neurons of the parasympathetic nervous system? |
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Definition
Craniosacral parasympathetic nerves |
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Term
What can the adrenal medulla be called? |
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Definition
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Term
What kind of receptors are on chromaffin cells? |
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Definition
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Term
What is the effect of Ach binding to nicotinic cholinergic receptors on chromaffin cells? |
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Definition
Production of 80% epinephrine, 20% norepinephrie |
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Term
What effects does epinephrine have when released from the adrenal medulla? |
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Definition
It acts as a hormone, diffuses into the bloodstream, and increases blood glucose |
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Term
What neurotransmitter is released from all preganglionic neurons of the autonomic nervous system? |
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Definition
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Term
What kind of receptor is on postganglionic neurons in the autonomic nervous system? |
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Definition
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Term
What neurotransmitter is released primarily from parasympathetic postganglionic neurons? |
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Definition
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Term
What kind of receptor is on parasympathetic effectors? |
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Definition
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Term
What neurotransmitter is released from sympathetic postganglionic neurons? |
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Definition
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Term
What kind of receptors do sympathetic effectors have? |
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Definition
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Term
Where do motor neurons originate? |
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Definition
The ventral horn of the spinal cord or the analogous brainstem nuclei |
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Term
What is the neurotransmitter for the neuromuscular junction? |
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Definition
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Term
What kind of receptors are on the motor end plate? |
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Definition
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Term
What can the PNS be divided into? |
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Definition
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Term
What can the autonomic nervous system be divided into? |
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Definition
Sympathetic and parasympathetic
Also, enteric (digestive system) |
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Term
Define sympathetic nervous system |
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Definition
Autonomic flight or fight response, expends energy |
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Term
Define the parasympathetic nervous system |
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Definition
Autonomic system for rest, digest, divest(eliminating), conserve/replenish energy |
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Term
How many neurons does the somatic nervous system have in a single pathway? How many does the autonomic? |
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Definition
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Term
What kind of receptor is on the effector in the somatic nervous system? For the autonomic nervous system? |
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Definition
Somatic: nicotinic
Autonomic: Muscarinic, adernergic |
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Term
Do preganglionic nerves have myelin? Do postganglionic? |
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Definition
Pre-ganglionic nerves do, post-ganglionic do not |
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Term
Compare and contrast sympathetic vs parasympathetic postganglionic nerves |
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Definition
Parasympathetic are very short, often on the organ
Sympathetic are longer
Both are unmyelinated |
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Term
Define intermediolateral nucleus |
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Definition
Small protrusion of gray matter in the spinal cord where preganglionic sympathetic neurons originate |
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Term
Define paravertebral ganglia and prevertebral ganglia |
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Definition
Paravetebral ganglia are higher up on the spinal cord
Prevertebral ganglia are lower on spinal cord
Both are where sympathetic ganglia originate from the chain |
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Term
What is the effect of nicotine on skeletal muscle? |
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Definition
A low dose contracts muscle, a high dose blocks |
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Term
Give an example of a nicotinic antagonist at the neuromuscular junction |
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Definition
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Term
Give an example of a nicotinic antagonist at the autonomic ganglia |
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Definition
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Term
Describe the drug Trimethphan (Arfondad) |
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Definition
A nicotinic antagonist at the autonomic ganglia
Previously used to lower emergency HBP, but not anymore because it removes the autonomic nervous sytem |
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Term
Give an example of an antagonist for muscarinic cholinergic receptors |
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Definition
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Term
What is the effect of atropine? |
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Definition
As an antagonist for muscarinic cholinergic receptors, it blocks the parasympathetic nervous system |
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Term
What is the primary neurotransmitter for sympathetic postganglionic neurons? |
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Definition
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Term
What releases epinephrine? |
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Definition
The adrenal medulla, NOT sympathetic postganglionic nerves |
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Term
By what method does most NE deactivate? |
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Definition
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Term
Do the sympathetic and parasympathetic nervous systems both have adrenergic and cholinergic receptors? |
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Definition
Adernergic are just in sympathetic, cholinergic are in both |
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Term
Give an example of an Adrenergic α receptor agonist and describe it |
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Definition
Phenylephrine (Neosynephrine), the active ingredient in many decongestants |
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Term
Give an example of an Adrenergic α receptor antagonist |
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Definition
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Term
Give an example of an Adrenergic β receptor agonist and describe it |
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Definition
Isoproterenol (Isuprel), a drug not used too much because it stimulates all of the Beta receptors |
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Term
Give an example of an Adrenergic β receptor antagonist and describe it |
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Definition
Propanolol (Inderal), blocks β1 and β2 |
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Term
Do α receptors produce excitatory or inhibitory responses? |
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Definition
α receptors produce excitatory effects everywhere except in GI, where they produce inhibitory effects |
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Term
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Definition
α-2s are on presynaptic terminals and act as a negative feedback system
However, they are still on effector organs and tissues and have the same responses as α-1s |
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Term
Do β receptors produce excitatory or inhibitory responses? |
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Definition
β receptors produce inhibitory effects everywhere except in the heart, where they produce excitatory effects |
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Term
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Definition
Only on the heart, and therefore the only excitatory β receptors |
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Term
Where are β2 receptors found? |
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Definition
All over the body, they are the β receptors that produce inhibitory effects |
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Term
Where are β3 receptors found? |
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Definition
In fat, do lipolysis (we don't need to worry about those) |
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Term
Does NE excite or inhibit adrenergic receptors? |
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Definition
NE excites all α receptors and β1 receptors |
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Term
Does Epi excite or inhibit adrenergic receptors? |
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Definition
Epi excites all adrenergic receptors, but has a greater potency for β over α |
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Term
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Definition
The primary receptor on effector organs and tissues mediating alpha-aderenergic responses
(α-2 are for feedback on preganglion terminals, but are still on effector organs) |
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Term
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Definition
Organs which receive innervation from both the sympathetic and parasympathetic systems have dual innervation |
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Term
Define single innervation |
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Definition
When tissues receive innervation from only one autonomic system, such as the blood vessels that control peripheral resistance which receive only sympathetic innervation |
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Term
Define functional synergism |
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Definition
Functional synergism: This occurs in dual innervated organs when the sympathetic and parasympathetic systems work together to produce an effect. A good example is the control of heart rate. |
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Term
Define intrinsic heart rate |
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Definition
Once atropine and propanolol are given to the heart, no autonomic influence, just pacemaker rate |
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Term
If a heart was transplanted and did not have nerve endings, could HR still be raised? |
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Definition
Yes, by epinephrine from the chromaffin cells |
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Term
Define tonic/basal efferent activity |
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Definition
A continuous resting level of autonomic neural activity to an organ or tissue. This means that there is almost always some autonomic nerve activity from both the SNS and PNS under all types of conditions |
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Term
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Definition
Contraction of the pupil radial muscle |
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Term
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Definition
Contraction of the pupil circular muscle
Also, a symptom of Horner's syndrome, due to unopposed parasympathetic innervation to the iris. |
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Term
Is pupil dilation an excitatory or inhibitory response? |
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Definition
Inhibitory by definition- the pupil is overall relaxing and expanding in size; anologus to an arteriole, for example |
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Term
Describe autonomic control of blood vessels |
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Definition
Sympathetic innervation constricts with α-1 and α-2 and dilates with β-2 to direct blood flow to areas needed
No parasympathetic innervation |
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Term
In arterioles, how does the sympathetic nervous system distinguish between α-1 and α-2 (dilating) and β-2 (constricting) during a response? |
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Definition
β-receptors are more strongly stimulated by Epi than α, so there is a contest |
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Term
What is the most prominent inhibitory sympathetic response? |
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Definition
β-2 dilation in the lungs |
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Term
What do inhalers act on in asthmatics? |
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Definition
β-2 receptors in the lungs |
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Term
What sympathetic receptors decrease motility in the GI tract? |
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Definition
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Term
In the male reproductive tract, what does the parasympathetic system control and what does the sympathetic system control? |
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Definition
Parasympathetic: erection
Sympathetic: ejaculation |
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Term
What is the major exception of the sympathetic effector receptor? |
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Definition
Eccrine sweat glands have muscarinic receptors for thermoregulation, and therefore respond to Ach not NE |
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Term
Where are the stretch sensors that sense blood pressure located? |
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Definition
The carotid sinus and aortic arch |
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Term
Describe the neural pathway of the baroreflex from the carotid sinus to the nucleus of solitary tract |
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Definition
1. Carotid sinus mechanoreceptors
2. Carotid sinus nerve
3. Glossopharengeal nerve into brainstem
4. Nucleus of solitary tract (NTS) in brainstem
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Term
Describe the neural pathway of the baroreflex immediately after the nucleus of solitary tract (NTS) |
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Definition
The nucleus of solitary tract goes to both
A. The nucleus ambiguss B. The Caudal ventral lateral medulla (CVLM) |
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Term
Describe the neural pathway of the baroreflex after the nucleus ambiguss |
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Definition
The nucleus ambigus nerves act on postganglionic parasympathetic neurons to the heart, lowering blood pressure |
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Term
Describe the neural pathway of the baroreflex after the Caudal ventral lateral medulla (CVLM) |
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Definition
The CVLM acts on the Rostal ventral lateral medulla (RVLM) in the ONLY inhibitory reaction in the baroreflex
RVLM acts on the intermediolateral nucleus (IML)in the spinal cord
The IML uses parasympathetic ganglia to decreases constriction in arterioles and slow heart rate |
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Term
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Definition
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Term
What produces bladder contraction? |
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Definition
Excitation of parasympathetic neurons via the Sacroparasympathetic nucleus |
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Term
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Definition
An area near the bladder that contains a lot of parasympathetic and sympathetic nerves |
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Term
What senses how full the bladder is? |
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Definition
The mechanosensors on the bladder wall |
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Term
What nerves transmit sympathetic innervation to the bladder? |
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Definition
The hypogastric nerve and other preganglions from intermediolateral nucleus eventually transmit to bladder wall
Onuf's nucleus transmits to external urethral sphincter |
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Term
Is sympathetic input required for bladder filling? |
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Definition
Currently, the best evidence is that
the sympathetic nervous system is not required for bladder filling, but can
assist
This is indicated by people with diseases of the SNS that still can have bladder filling |
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Term
Where in the body do the (sympathetic) hypogastric nerve (and other preganglions from intermediolateral nucleus) transmit signals? |
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Definition
They transmit signals to bladder postganglionic neurons and also transmit inhibition to parasympathetic presynaptic terminals in the pelvic plexus |
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Term
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Definition
A sympathetic sacral ganglion that constricts the external urethral sphincter |
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Term
Define supraspinal reflex |
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Definition
A reflex that needs to travel to the brain to function (ex. micturition) |
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Term
Where do bladder wall mechanoreceptors terminate? |
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Definition
All the way in the midbrain, the mechanoreceptors activate the periaqueductal gray
Also, to the intermediolateral nucleus in the spine |
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Term
Define the periaqueductal gray |
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Definition
The area in the dorsal midbrain that is activated by bladder mechanoreceptors
With enough innervation, it activates the pontine micturition center |
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Term
Define the Pontine micturition center |
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Definition
A region in the dorsal pons that, with sufficient innervation from the periaqueductral gray, will(via sacral neurons)contract the bladder wall and inhibit Onus nucleus |
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Term
Define the Pontine continence center |
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Definition
An area in the dorsal pons that is active during rest to excite the Onus nucleus to keep the sphincter closed |
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Term
What happens if the bladder gets too full? |
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Definition
The Pontine continence center is overriden by the Pontine micturition center
Then the Onus nucleus is overpowered and the bladder wall contracts |
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Term
Can the parasympathetic innervation of the micturition reflex be overidden? |
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Definition
Yes, by higher areas of the brain (Cerebral cortex)to a point |
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Term
Why do young babies lack control over their bladders? |
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Definition
The micturition reflex descending pathways have not developed |
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Term
Do we have control over the urethral sphincter? |
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Definition
Cerebral cortex control over the internal urinary sphincter (to a point), and skeletal muscle contol over the external urinary sphincter |
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Term
What causes hypertension? |
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Definition
While there are many causes, one contributory mechanism is an increase in the tonic or basal level of sympathetic tone to the heart and/or blood vessels. |
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Term
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Definition
This is a tumor of the chromaffin cells in the adrenal gland, releasing more epinephrine.
This
accounts for only 0.1% of hypertensive patients. |
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Term
Define Postural (orthostatic) hypotension |
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Definition
A drop in arterial pressure of 30 mmHg or more upon standing |
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Term
What causes Postural (orthostatic) hypotension? |
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Definition
Dizziness is felt upon standing due to an inadequate perfusion of the CNS. Orthostatic hypotension is due to inadequate reflex control of blood pressure. |
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Term
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Definition
Loss of sympathetic innervation to the head
Can occur from damage in any part of the total pathway from hypothalamus to spinal cord and back up to the brain |
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Term
What are three signs of Horner's syndrome? |
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Definition
Miosis, Ptosis (eyelid drooping), and anyhydrois (loss of sweating in head and neck)
Ptosis and anhydrosis occur from loss of sympathetic innervation/tone |
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Term
In Horner's syndrome, will Miosis cause permanent damage to the iris? |
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Definition
Possibly, but miosis will subside (but not completely disappear) due to the development of increased sensitivity to circulating catecholamines. |
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Term
Define Autonomic diabetic neuropathy |
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Definition
Degeneration of small nerve fibers in diabetics
Possibly due to inadequate blood perfusion or neuron metabolism problems |
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Term
What are some symptoms of Autonomic diabetic neuropathy? |
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Definition
Impaired swallowing, delayed gastric emptying, diarrhea, orthostatic hypotension, bladder dysfunction, and erectile dysfunction. |
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Term
What causes Autonomic dysreflexia (aka sympathetic hyperreflexia) |
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Definition
Some patients with a spinal cord lesion at the T6 level or above may develop this condition, presumably due to the plasticity/"rewiring" that occurs after the injury |
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Term
What are some symptoms of Autonomic dysreflexia (aka sympathetic hyperreflexia)? |
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Definition
Extremely high blood pressure, activated by stimuli such as bladder/colon distention, pregnancy, or touching the lower abdomen |
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