23 - ANS Flashcards
The ______ can change visceral function rapidly and intensely:
– Heart rate can be increased to twice normal within 3-5 seconds
– Arterial pressure can be doubled within 10-15 seconds
– Sweating can begin within seconds
ANS
In the ANS, terminal ends of these fibers usually have enlarged varicosities where neurotransmitter and large numbers of _______ are stored.
Mitochondria
The efferent activity of the ANS is largely regulated by reflexes (not spinal reflexes). A ________ reflex is located in the major systemic arteries sensing blood pressure. If BP decreases, sensory impulses to the vasomotor center of the brainstem decrease. Heart rate increases and vascular resistance increases.
Baroreceptor
The ANS pathways consist of two ______ in sequence.
Neurons
The ANS preganglionic neuron cell bodies are located within the ______, its axons are ________ and its neurotransmitter is _______.
CNS
Myelinated
ACh
The ANS postganglionic neuron cell bodies are located in the ________ ________, its axons are not ________, and its neurotransmitter is ______ in the parasympathetic system and ________ (usually) in the sympathetic system.
Peripheral ganglia
Myelinated
ACh
Norepinephrine
In the ANS, (PARASYMPATHETIC/SYMPATHETIC) glands cause secretion of large amounts of sweat. (CHOLINERGIC/ADRENERGIC) to most sweat glands, which means they are sympathetic neurons using ACh. There are a few (CHOLINERGIC/ADRENERGIC) fibers in palms and soles. This is actually a parasympathetic function distributed via sympathetic fibers.
Sympathetic
Cholinergic
Adrenergic
In the ANS, (PARASYMPATHETIC/SYMPATHETIC) glands strongly stimulates the lacrimal, nasal, salivary and GI glands of upper tract. Note that glands of lower GI tract are mostly stimulated via the _______ system.
Parasympathetic
Enteric
In the heart, (PARASYMPATHETIC/SYMPATHETIC) stimulation increases heart rate and strength of contraction.
Sympathetic
In the heart, (PARASYMPATHETIC/SYMPATHETIC) stimulation decreases heart rate and strength of contraction.
Parasympathetic
In the systemic blood vessels, (PARASYMPATHETIC/SYMPATHETIC) stimulation constricts most blood vessels while (PARASYMPATHETIC/SYMPATHETIC) stimulation has almost no effect.
Sympathetic
Parasympathetic
In arterial pressure, (PARASYMPATHETIC/SYMPATHETIC) stimulation decreases pumping of heart but has little effect on blood pressure.
Parasympathetic
In arterial pressure, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in acute increase in arterial pressure but little effect long term.
Sympathetic
In general, the (PARASYMPATHETIC/SYMPATHETIC) stimulation inhibits most of the endodermal structures (GI, Respiratory, Endocrine, Auditory, Urinary).
Sympathetic
In general, the (PARASYMPATHETIC/SYMPATHETIC) stimulation excites most of the endodermal structures.
Parasympathetic
In the eyes, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in pupil constriction and lens focusing.
Parasympathetic
In the eyes, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in pupil dilation.
Sympathetic
In the GI tract, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in a strong stimulation that inhibits peristalsis. The GI tract is normally not dependent on this type of stimulation.
Sympathetic
In the GI tract, (PARASYMPATHETIC/SYMPATHETIC) stimulation promotes peristalsis and relaxes sphincters.
Parasympathetic
The cell body of each sympathetic preganglionic neuron lies in the intermediolateral horn of the ______ _____ (CNS).
Spinal cord
The sympathetic preganglionic fiber can synapse with postganglionic neurons upward or downward in the paravertebral chain, interconnected with _______ nerves.
Spinal
T/F. The sympathetic preganglionic fiber can pass for variable distances through the chain and then through one of the sympathetic nerves to synapse in a peripheral sympathetic ganglion.
True
All preganglionic nerves are (CHOLINERGIC/ADRENERGIC).
Cholinergic
Postanglionic sympathetic fibers pass through the ______ rami, are type C fibers, and make up about 8 percent of the fibers in the average nerve.
Gray
(PREGANGLIONIC/POSTGANGLIONIC) sympathetic fibers innervate muscle to constrict blood vessels, piloerect hair, and change heart rate and force of contraction.
Postganglionic
The ________ sympathetics supply the face and thoracic viscera and are considered postsynaptic.
Cervical
The cervical sympathetic postganglionics are from what ganglia?
Superior, middle, and inferior cervical ganglia
T1-T5 paravertebral ganglia
The cervical sympathetic postganglionics exit the chain as direct fibers and travel downwards to enter the thorax as cardiopulmonary _________ nerves.
Splanchnic
The cardiopulmonary ________ nerves travel on their own and do not accompany other nerves or vessels. They function in coronary artery dilation, increase heart rate, and bronchodilation.
Splanchnic
The thoracic sympathetic chain lies against the neck of ribs and costovertebral junctions. They are made up of 12 thoracic ganglia pairs, the first one is often fused with inferior cervical ganglion going to the head and is referred to as the ________ ganglion collectively.
Stellate
Splanchnic nerves are composed of preganglionic fibers and visceral sensory fibers. They supply the abdominal viscera and synapses in the prevertebral ganglia. All preganglionic neurons are _________.
Cholinergic
This splanchnic nerve is from T5-T9 and synapses in the celiac ganglion.
Greater
This splanchnic nerve is from T10-T11 and synapses in the superior mesenteric ganglion.
Lesser
This splanchnic nerve is from T12 and synapses in the aorticorenal ganglion.
Least
This splanchnic nerve is from L1-2 and synapses in the superior and inferior mesenteric ganglion.
Lumbar
Put the following steps of post-ganglionic neurotransmitter synthesis of norepinephrine in order:
A. Hydroxylation of dopamine to norepinephrine
B. Hydroxylation of tyrosine to dopa
C. Transport of dopamine into the vesicles
D. Decarboxylation of dopa to dopamine
E. Once the neuron is stimulated, NE is released, where it binds to receptors depending on affinity
- B
- D
- C
- A
- E
After its release, norepinephrine is broken down in the cleft and recycled via the norepinephrine transporter. Then its taken up into circulation. With recycling, small amounts are returned to vesicles. Most is metabolized by ________ ________ to dihydroxyphenylglycol, which is released into circulation. It’s eventually broken down by _______, which is found in all tissues.
Monoamine Oxidase
COMT
Adrenergic receptors can be either _______ or _______.
Alpha (Alpha1 or Alpha2)
Beta (Beta1, Beta2, or Beta3)