Physio Ch. 10

What 2 ways does NEJ differ from a typical neuron-to-neuron synapse?

- The axon terminals of the postganglionic neuron lack synaptic end bulbs; instead, they exhibit swollen regions called varicosities, which contain synaptic vesicles with neurotransmitter - In this effector, the receptors for the neurotransmitters are not confined to a specific receptor region; rather, they are located along the entire surface of the cell.

The _____ NS stimulates the organ to increase its activity; promotes fight-or-flight response --> prepares the body for emergency situations

Sympathetic

_____ neurons are neurons that release the neurotransmitter NE

adrenergic neurons

The physiological effects of the sympathetic NS are:

fight-or-flight responses

In order to slow an increased heart rate there needs to be a(n) __(increased/decreased)__ parasympathetic activity and __(increased/decreased)__ sympathetic activity

increased; decreased

Nerve agents that are able to inflict extreme pain interrupt normal communication at the NMJ by inhibiting AChE activity. Therefore, _______ ACh levels and causing muscle spasms

increasing

The axon length of a neuron in the parasympathetic NS is: _____ preganglionic axons _____ postganglionic axons

long; short

Binding of ACh to _____ receptors will activate either the inhibitory or excitatory G protein.

muscarinic

The physiological effects of the parasympathetic NS are:

rest-and-digest activities

The parasympathetic nervous system originates in the brain stem and ____ region of the spinal cord.

sacral

The origin of the postganglionic neuron in the sympathetic NS is the ____.

sympathetic trunk or collateral ganglion or adrenal medulla

______ stimulation are longer lasting & more widespread than the effects of ______ stimulation

sympathetic; parasympathetic

The origin of the preganglionic neuron in the sympathetic NS is the ____ and the ___ spinal cord.

thoracic + upper lumbar spinal cord (T1-L2)

The sympathetic nervous system originates in the ____ and ____ regions of the spinal cord.

thoracic; lumbar

The sympathetic NS is aka the _____ division due to the location where its preganglionic nerves emerge from the spinal cord.

thoracolumbar

Autonomic motor pathways all consist of ____ autonomic motor neurons, while somatic motor pathways consist of ___ somatic motor neuron

two; one

Autonomic postganglionic neurons release neurotransmitters from ______, which are swollen regions found at the end of axon terminals.

varicosities

Postganglionic neurons relay APs from autonomic ganglia to _____.

visceral effectors

Trace the path of an AP going through the autonomic motor pathway

1. Preganglionic neuron (first neuron) has its cell body in the brain or spinal cord - it extends to an autonomic ganglion, where it synapses with a 2nd neuron 2. The postganglionic neuron (2nd neuron) lies entirely in the PNS. - it's cell body is located in the autonomic ganglion, and its axon extends from the ganglion to the visceral effector. Preganglionic neurons convey APs from the CNS to autonomic ganglion. Postganglionic neurons relay APs from autonomic ganglia to visceral effectors.

What are the 2 main branches of ANS?

1. Sympathetic NS 2. Parasympathetic NS

Explain the 3 reasons why sympathetic stimulation are longer lasting & more widespread than the effects of parasympathetic stimulation

1. Sympathetic postganglionic axons diverge more extensively --> many tissues are activated simultaneously 2. AChE quickly inactivates ACh, but NE lingers in the synaptic cleft for a longer period 3. Epi + NE secreted into the blood from the adrenal medulla intensify + prolong the responses caused by NE liberated from sympathetic postganglionic axons

Which 3 things does the ANS innervate and regulate?

1. smooth muscle 2. cardiac muscle 3. glands

Cholinergic neurons release ____

ACh

In the parasympathetic NS, preganglionic + postganglionic neurons release ____.

ACh

In the sympathetic NS, postganglionic neurons that innervate most sweat glands + some blood vessels in skeletal muscle release ______.

ACh

____ is a neurotransmitter released from preganglionic sympathetic + parasympathetic fibers

ACh

In the sympathetic NS, preganglionic neurons release ___ + most postganglionic neurons release ____.

ACh, NE

______ cells are modified sympathetic postganglionic neurons that release the hormones epinephrine and norepinephrine into the blood

Chromaffin

What are the E situations for symapthetic responses?

Embarrassment, excitement, exercise, emergency

Which neurotransmitter is primarily secreted by axon endings of sympathetic postganglionic neurons?

NE

______ is the synapse between autonnomic postganglionic neuron and a visceral effector.

Neuroeffector junction (NEJ)

The _____ is the site where a somatic motor neuron communicates with a skeletal muscle fiber

Neuromuscular Junction (NMJ)

The ____ NS decreases the organ's activity; promotes rest-and-digest activities --> conserve + restore body energy during times of rest + recovery

Parasympathetic

______ neurons of the parasympathetic NS primarily secrete ACh; while postganglionic neurons of the sympathetic NS primarily secrete ___.

Postganglionic; NE

List the 5 parasympathetic responses.

SLUDD 1. Salivation 2. Lacrimation 3. Urination 4. Digestion 5. Defecation

How do chromaffin cells differ from other sympathetic postganglionic neurons?

Unlike most sympathetic postganglionic neurons, chromaffin cells lack dendrites + axons and they release hormones into the blood rather than extending to another organ.

The activity of ACh at a synapse is terminated by enzymatic degradation via _____.

acetylcholinesterase (AChE)

Adrenergic neurotransmitters use ____ receptors.

alpha & beta

Preganglionic neuron convey APs from the CNS to ______.

autonomic ganglion

An ________ consists of a sensory receptor, sensory neuron, integrating center, autonomic motor neurons, and a visceral effector

autonomic reflex arc

The balance between parasympathetic + sympathetic activity is called ______

autonomic tone

Some autonomic responses can be voluntarily controlled via _____, in which electronic-monitoring devices display information about a body function such as heart rate or blood pressure, enhances the ability to learn such conscious control

biofeedback

The origin of the preganglionic neuron in the parasympathetic NS is the ____ and the ___ spinal cord.

brain stem + sacra spinal cord (s2-S4)

An increase in the _____ concentration serves as a signal that triggers exocytosis of the synaptic vesicles, liberating ACh into the synaptic cleft

calcium

The ANS uses 2 types of neurotransmitters + receptors, which are classified as:

cholinergic + adrenergic

_____ are modified sympathetic postganglionic cells that are located within the adrenal medulla

chromaffin cells

At the NMJ, ACh has an excitatory effect and causes skeletal muscle fibers to ____.

contract

The axons of the preganglionic neuron exit the CNS via a ____ or ____ nerve.

cranial; spinal

The parasympathetic NS is aka the ______ division due to the location where its preganglionic nerves emerge from the spinal cord.

craniosacral

Physiological stressors will cause parasympathetic NS activity to __(increase/decrease)__.

decrease

What are the 3 decreases in the parasympathetic response?

decrease in heart rate decrease in pupil diameter decrease in bronchial diameter

In sympathetic responses there's an increase in all of the following, except: a. pupillary dilation b. heart rate c. blood pressure d. glucose production e. all of the above

e. all of the above

A majority of the endocrine hormone released from the adrenal medulla is ____.

epinephrine (85%) - aka adrenaline

Autonomic tone (balance between parasympathetic + sympathetic activity) is regulated by the _____

hypothalamus

Where are chromaffin cells located

in the adrenal medulla

The _____ system is able to alter autonomic nervous activity through its effect on emotion.

limbic

The synapse formed between a somatic motor neuron and a skeletal muscle fiber is called the ______.

neuromuscular junction

Cholinergic neurotransmitters use _____ receptors.

nicotinic

Binding of ACh to _____ receptors on the motor end plate causes the formation of an ______ which initiates muscle action potential

nicotinic; end plate potential (EPP)

Adrenergic neurons release _____

norepinephrine

The parasympathetic system synapses close to or in the effector and so the _____ neuron will be much shorter

postganglionic

The _____ neuron lies entirely in the PNS.

postganglionic neuron

The ____ neuron has its cell body in the brain or spinal cord.

preganglionic neuron

The axon length of a neuron in the sympathetic NS is: _____ preganglionic axons _____ postganglionic axons

short; long

The somatic NS conveys output from the CNS to ______.

skeletal muscle.

The origin of the postganglionic neuron in the parasympathetic NS is the ____.

terminal ganglion

The ____ is the part of the brain that is considered to be the major control + integrating center of the ANS

the hypothalamus