Autonomic nervous system Flashcards
(39 cards)
1
Q
What are general charecteristics of the Somatic Nervous System
A
- Voluntary or subconscious control single nueron pathway
- No ganglia involved in pathway
- Sensory input from general and special senses , motor output to skeletal muscle
- Excites using acetylcholine
- Axons are thick and myelinated=fast condution
- come conscious control
2
Q
Autonomic Nervous System
A
- INvoluntary or unconscious control two neuron pathway
- Ganglia involved in pathway
- Sensory input from general and vsiceral senses motor output to cardiac ,smooth muscle and glands
- can excite or inhibit function using acetylcholine and norepinephrine
- axons are thin, some are myelinated , others are not=slower conduction
3
Q
Autonomic Plexuses
A
- Collection of sympathetic postaganglionic axons(already synapsed aka grey) and parasympathetic preganglionic axons, as well as some visceral sensory axons
- Sympathetic(from spinal cord via sympathetic trunk) and parasympathetic(from cranial and caudal repositories) plexuses are close to one another, but they do not interact or synapse with one another
- Provide a complex innervation pattern to their target organs
4
Q
Where do the prevertibral ganglia located?
How about hte paraverterbral ganglia?
A
- Prevertrebral ganglia only show up in the abdomen
- Paravertrebral ganglia run all the way from superior cervical ganglia down to the tailbone
5
Q
Cardiac plexus
A
- Increased sympathetic activity increases heart rate blood pressure,while
- Increased parasympathetic activity decreases heart rate
6
Q
Pulmonary plexus
A
- Parasympathetic pathway causes bronchoconstriction and increased secretion from mucous glands of hte bronchial tree
- sympathetic innervation causes bronchodilation
- when you inhale you are acting on the sympathetic
7
Q
Esophageal plexus
Abdominal aortic plexus
hypogastric plexus
A
- Parasympathetic axons control the swallowing reflex
- Consisst of the celiac plexus,superior mesenteric plexus, and inferior mesenteric plexus=autonomic control of digestion
- Innervates pelvic viscera=autonomic control of urinary and reproductive function
8
Q
Two Nuerotransmitters used in the ANS
A
- Acetylcholine(ACh)
- norepinephrine(NE)
- Neurotrnsmitters released by the presynaptic cell
- bind to specific receptors in the postsynaptic cell membrane
- binding has eitehr an excitattoyr or an inhibitory effect on the effector depending on the specific receptor
9
Q
Is parasympathetic division release acetycholine and if so which axons?
A
- Both preganglionic and postganglionic axons release acetylcholine and thus are called cholinergic
10
Q
Does hte sympatehtic release acetycholine and norepinephrine
A
- Only the preganglionic axons in the sympatehtic division release acetycholine and are thus cholinergic
- Most of the postganglionic axons of the sympathetic division release norepinephrine and are called adrenergic
11
Q
What is this ?
A
Parasympathetic
- Long preganglionic fibers
- myelinated
- very short postganglionic fiber
- many of postganglionic fibers are very short
12
Q
What is this ?
A
Sympathetic
- Multiple axons from a single cell body-that makes it react a little quicker reaction
- short preganglionic,linger ,and multi axialted post ganglion
- One single cell can act on multiple axons
13
Q
Autonomic(Visceral)nervous system explain
A
- Preganglionis autonomic motor neuron
- motor information is passed through preganglionic and ganglionic neurons
- Ganglionic autonomic motor nueron
- Sends nerve impulses to smooth msucle , cardiac muscle and glands
- Visceral sensory neuron
- Receives sensory information from blood vessels and visceral walls
- Follows the same pathway as the somatic sensation-goes through the dorsal root,has a cell boy in the dorsal root ganglia
14
Q
Dual innervation
A
- Many visceral effectors(organs) are innervated by postganglionic axons from both ANS divisions
- Actions of the divisions usually oppose each other
- Opposing effects are also achieved by increasing or decreasing activity in one division(one division can up-regulate-or down regulate the other)
15
Q
Autonomic Reflexes
A
- ANS helps maintain homeostasis through the involuntary ativity of autonomic reflexes or visceral refelxes
- Consist of smooth muscle contractions,cardiac muscle contractions ,or secretion by glands that are medaited by autonomic reflex arcs in response to a specific stimulus
- ex. Micrturition refelx,which partly controls the release of urine
- Other reflexes include alteration of heart rate ,cahgnes in respiratory rate and depth, regluation of digestive system activities , and alteration of pupil diamter
- comparable to spinal refelxes
- Classic autonomic relfex invovles the reduction of BP
16
Q
CNS contorl of Autonomic function
A
- Autonomic function is influenced by the cerebrum, hypothalamus , brainstem,and spinal cord
- Sensory processing in the thalamus and emotional state controlled in the limbic system directly affect the hypothalamus
- the integration and command center for autonomic functions
- contains nuclei that conrol visceral functions in both divisions of the ANS
- communicates with other CNS regions,including the cerebral cortex, thalamus,brainstem,cerebellum,and spinal cord
17
Q
Organization and anatomy of the sympathetic divsion
A
- More complex thatn the parasympathetic division , both anatomically and functionally
- Sympathetic preganglionic neuron cell bodies are housed in the lateral horns of hte T1-L2 regions of the spinal cord
- CEll bodies in the brain are influencing these cell bodies in the spinal cord
- Only place you have the actual sympathetic preganglionic neuron cell bodies is in the spinal cord from T1-L2
- Preganglionic sympathetic axons travel with somatic motor neuron axons to exit the spinal cord and first enter the anterior roots and then the T1-L2 spinal nerves
- Its with the spinal neve until it goes into the sympathetic trunk
- Preganglionic sympathetic axons remain with the spinal nerve for a short distance before they branch off and leave the spinal nerve
18
Q
Related to the sympatehtic division
A
- T1-T4: head heart lungs
- T5-T9: upper portions
- T11-L2: lower part of gut and pelvis
19
Q
Left and Right sympathetic Trunks
A
- Immediately anterior to the paired spinal nerves are the left and right sympathetic trunks
- EAch is loacted immediately alteral to the vertebral column
- A sympathetic trunk looks much like a string of beads
- Strin is composed of axons
- beads the sympathetic trunk(or paravertebral)ganglia, whch house sympathetic ganglion neuron cell bodies
- one sympathetic trunk ganglion is approximately associated with each spinal nerve
- Cervical portion of each sympathetic trunk is partitioned into only three sympathetic trunk ganglia– the superior, middle , and inferior cervical ganglia– as opposed to the eight cervical spinal nerves
20
Q
White Rami
A
- Connecting the spinal nerves to each sympathetic trunk are rami communicantes
- connect spinal nerves to each sympathetic trunk
- Carry preganglionic sympathetic axons from T1-L2 spinal enrves to the sympathetic trunk
- Asoociated only with T1-L2 spinal nerves
- Preganglionic axons are myelinated
- White ramus has a whitish appearance
- similar to entrance ramps on a highway
21
Q
Gray Rami
A
- Carry postganglionic sympathetic axons from the sympathetic trunk to the spinal nerve
- Axons are unmyelinated
- gray rami have a grayish appearance
- similar to exit ramps on a highway
- connect to all spinal nerves,including the cervical,sacral, and cocygeal spinal nerves
- In this way sympathetic information that tarted out in the thoracolumbar region can be dispersed to all parts of the body
22
Q
Splanchic nerves
A
- Composd of preganglionic sympatehtic axons
- they are myelinated come out ofthe sympathetic trunk unsynapsed to go to other ganglia elsewhere
- Run anteriorly from the sympathetic trunk to the most of hte viscera
- should not be confused with the pelvic splanchnic nerves associated with the parasympathetic division
- Larger Splanchnic nerves(all of theese sympathetic)have specific names
- Greater thoracic splanchnic nerves
- Lesser thoracic splanchnic nerves
- least thoracic splanchnic nerves
- lumbar splanchnic nerves
- sacral splanchnic nerves
- Terminate in prevertebral(or collateral) ganglia
- Called prevertebral because they are immediately anterior to the vertebral column on the anterolateral wall of the abdominal aorta
- Prevertebral ganglia typically cluster around the major abdmoinal arteris and are named for these arteries
- Piggyback on those arteries to get to their organs
- Sympathetic postganglionic axons extend away from the ganglionic neuron cell bodies in these ganglia and innervate many of hte abdominal organs
23
Q
What are prevertebral ganglia and the types?
A
- Differ from the sympathetic trunk ganglia
- Are single strucutres ,rather then paired
- Anterior to the vertebral column on the anterior surface of the aorta
- Located only in the abdominopelvic cavity
- Prevertebral ganglia include the celiac ,superior mesenteric , and inferior mesenteric ganglia
24
Q
Sympathetic pahways
A
- Spinal nerve pathway
- postganglionics come out of the sympathetic system and the bulk fo them go to the skin,vessels, etc
- postganglionic sympatehtic nerve pathway
- Splanchnic nerve pathway
- they don’t synapse in the sympathetic trunk–they go to the gut and synapse in pre-vertebral ganglia
- Adrenal medulla pathway
- Essentially a splanchnic pathway
- Specific to a specific organ, the only time where there is no synapsing before it ges to the organ.
- take a myelenated track to go stratight in
- Don’t syanpse
25
Spinal nerve pathway
* The grey postsynaptic axons are going to jump back on the spinal nerve to get were they want to go
* they go out the blood vessels and the skin or anywhere else
* They go out the vetnral ramus, they get on the spinal proper
* Goes in the white synapse , then goes out the grey rami
* For the lower one , you don't syanpse at that one , you go up and syanpase at the upper one and in this isntance it goes through the dorsal ramus
26
Postganglionic sympathetic nerve pathway
* These synapse at the superior cervical ganglion in neck
* Doesn't get on anything else
* Hops on a vessel , an unmeyelinated axon on the artiers and get to salivary gland or whereever it needs to go
* This isn't the spinal nerve pathway because it is hopping onto an axon to get where it wants to go , not on the spinal nerve
* get to glands in the head , heart and lung
* There is no splanchnic nerve nor spinal nerve used
* just syanpse in the trunk adn send out
* They dont' get back on the spinal nerve nor do they use the pslanchnic nerves
* Can be ascending or descending
27
Adrenal Medulla Pathway
* They join a thoracic splanchnic nerve here , then pass out of there and go straight to the adrenal medulla
* There is no synapsing
28
Splanchnic Nerve Pathway
* Aminopelvic thorasic planchnic myelinated,pre-ganglionic axons
* Doesn't syanpse until the prevertebral ganglion
29
Flight or Fight function fo the ANS
* May involve a single effector or many effectors
* In mass activation, a large number of ganglionic neurons activate many effector organs
* Cause a heightened sense of alertness due to stimulation of the reticular activation system
30
Parasympathetic Division
* AKA the craniosacral division
* nothing in the thoracic or lumbar region! only in the cranial and sacral region
* Primarily concerned with conserving energy and replenishing nutrient stores
* Is most active when the body is at rest or digesting a meal
* nicknamed the rest and digest division
* Particpates along with teh sympathetic division in maintaining homeostasis (a constant internal environment)
31
Cranial nerves related to parasympathetic
* 12 Cranial neves total, but there are only 4 cranial nerves that have presynaptic pre ganglionic parasympathetic axons in them and visceral motor preganglionic axons
* CN3,7,9,10
* do everything down to the descending colon
* CN3: occulomotor-ciliary ganglion
* CN7:-Facial-related with the pterygopalitine ganglion and also the submandibular ganglion
* First three of these nerves convey paraysmpathetic innervation to the head
* CN9: Glosspharyngeal nerve-otic ganglion-close to the ear
* CN10: Vegas Nerve-it's the ganglion are literally at the organ of where they go so they do nto have names
* Just syanpase at the tissue where they're going
* Other 8 have motor ,sensory, special sense but they don't have visceral motor
* not parasympathetic
*
32
Oculomotor nerve
* CIliary ganglion
* Pupil constriction(when you'r firghtented parasympatehtic kicks in and dialtes your pupil)
* Ciliary muscles of lens for accommodation(near vision/reading)
* CN 3
33
Facial Nerve
* CN VII
* Pterygoplaatine ganglion
* Lacrimal gland(tear production)
* Nasal cavity(mucous production)
* ORal cavity(saliva/mucous production)
* Submandibular ganglion
* submandibular and sublingual glands(saliva production
34
Glossopharyngeal Nerve
* Otic Ganglion
* Parotid gland(saliva production)
35
Vagus Nerve
* CN 10
* Multiple terminal and intramural ganglia
* heart(decrease rate)
* respiratory organs(decrease respiration)
* bronchial passags(constrict ,excites mucous production)
* esophagus(promotes swallowing and peristalsis)
* abdominal viscera(promotes digestion)
36
Trigeminal nerve
* Postsynaptic parasympathetic axons from the three cranial nerves that stay in the head "hitch-hike"to their target branches of the trigeminal nerve(CN V)
* Parasympathetic ganglia that are assocaited with each of these three nerves"hang" off of the trigemnial nerve
* doesn't ahve any aprasympathetics in it ;simply piggybacks on them to get where they need
* Massive nerve that travels across your face ; helps with muscles (chewing)
37
Caudal Contribution of Parasympathetic:Via Pelvic Splanchnic Nerves
* Distal portion of large intestine(you're colon)
* Rectum
* Most reproductive organs
* urinary bladder(contracts)
* distal ureters
38
Caudal Contribution of Parasympathetic: Via Pelvic Splanchnic Nerves& Sacral Spinal Nerves
* Apart from the Cranial nerve componetns, the rest of the parasympathetic innervation in the body comes from the sacral region of the spinal cord(S2-S4)
* Preganglionic parasympathetic axons from neuron cell bodies in the lateral horn contribute to the formation of the superior and inferior hypogastric plexus
* From here,preganglionic axons travel to the organs and synapse with ganglia close to , orin the walls of the organs
39
Efects and GEneral functions of the Parasympathetic Division
* Parasympatehtic division is most active durign times when the body must process nutrients and conserve energy
* Lack of extensive divergence in preganglionic axons prevents the mass activation seen in the sympathetic division
* Effects fo hte parasympatehtic nervous system tend to be discrete and localized
* Parasympathetic activity can effect one group of organs without necessarily having to "turn on" all otehr organs
* ex. When pupil constricts, don't start salivating
