9-20b Integrating Autonomic and Volitional Control Flashcards
Biomedical
What is inside the forebrain (cerebral cortex)?
basal ganglia, white matter, diencephalon
What makes up the brain stem?
the midbrain, pons (bulbous), and the medulla
What is the major role of the autonomic NS?
communicates with internal organs and glands
What does the SNS respond to? What does it do? (generally)
challenging situations; arousing, expends energy
What does the PNS allow for?
conservation of energy for regular function
What region does the SNS come from on the spinal cord?
T1-L2/L3
Thoracolumbar outflow
What is the pathway for a SNS neuron?
Synapses at the pre/paravertebral chain of ganglia
then leave and supply organs
What region does the PNS come from on the CNS/spinal cord?
From brainstem nuclei (III, VII, IX, and X) and S2-S4
Craniosacral outflow
mostly grey matter
What is the pathway of a PNS neuron?
Synapses at the parasympathetic ganglia (on the organ) and then supplies the organ
How many neurons are involved in efferent pathways of the PNS?
a pre-ganglionic n. synapses on an autonomic ganglion and a post-ganglionic n. (visceral effector/efferent n.) supplies the body
How do ANS efferent n. pathways compare to the Somatic NS?
Somatic: one preganglionic, somatic m. neuron
ANS: one pre-ganglionic n. and a post-ganglionic efferent neuron
What are SNS and PNS ganglia controlled by? Where are their cell bodies? What NT do they release?
pre-ganglionic n.
spinal cord and brain stem
Release Ach onto post-ganglionic n. in ganglia, that produce effects on end organs
What are the different regions on the grey matter?
Posterior, later and anterior horns
Where do the autonomic preganglionic n. reside? What region do they exit from?
The lateral horn of the grey matter
They exit from the ventral root then innervate the autonomic ganglia
What does the paravertebral chain house?
post-ganglionic n.
What are the regions of ganglia in the paravertebral sympathetic chain?
Superior Cervical ganglia
Middle Cervical ganglia
Inferior Cervical ganglia
How many ganglia are in each region of the paravertebral sympathetic chain?
11 thoracic
4 lumbar
4-5 sacral
What are the regions of the prevertebal sympathetic chain? Where are they?
Celiac ganglia
superior mesenteric ganglia
inferior mesenteric ganglia
anterior to spinal cord
What is the three possible trajectories for pre-ganglionic sympathetic (in regards to sympathetic trunk route)?
- leaves through anterior n. route (efferent), the preganglionic n. goes to the same level paravertebral ganglion (PVG), and the post-ganglionic n. leaves and innervates the organ
- Axons of the pre-ganglionic n. leave the anterior n. route, preganglionic n. goes to the same level PVG, and then goes either up or down the paravertebral sympathetic chain and THEN synapses on a PVG at a different level
- Goes up or down the sympathetic chain/PVC, and then exits the PVG and synapses in the prevertebral ganglion
What percent of parasympathetic nerve fibers come from cranial n. X (vagus nerve)?
75%
What are the ganglia that are innervated by preganglionic n. in the parasympathetic NS? Where are they located?
ciliary ganglion, pterygopalatine ganglion, submaxiliary ganglion, otic ganglion
there are many specific ganglia for the thoracoabdominal and pelvic viscera
these are located very close to the organs they’re innervating
What are the cranial parasympathetic preganglionic nuclei called and where are they located?
Edinger-Westphal nucleus (N. III)
Superior (VII) and Inferior (IX) Salivatory nucleus
Dorsal motor nucleus of the vagus (X)
What does the hypothalamus play a role in integrating?
autonomic, behavioral (somatic), and neuroendocrine responses
What are the five roles of the hypothalamus?
Food Furnace (body temperature) Fight Flight Fuck Sleep
What are the main NT for the ANS?
NE, E, Ach
What n. is Ach transmitted from? What are the neurons that release Ach?
pre-ganglionic to post-ganglionic n.
cholinergic n.
What are the two groups of cholinergic receptors?
Nicotinic: in autonomic ganglia
Muscarinic: in heart, smooth m., and glands
What receptors accept Ne and E? What are the five known types?
Adrenergic n.
Alpha and Beta
Describe the NT and receptors for parasympathetic neurons
Ach-Ach: The pre-ganglionic n. release Ach onto nicotinic r. of a post-ganglionic n., which releases Ach onto muscarinic receptors (glands, smooth m., heart)
Describe the three pathways for sympathetic neurons
Ach-Ach: pre-ganglionic synapses onto post-ganglionic nicotinic receptors via Ach, then the post-ganglionic n. onto sweat glands and blood vessels via Ach onto muscarinic receptors of sweat glands and blood vessels
Ach-NE: pre-ganglionic synapses onto post-ganglionic nicotinic receptors via Ach, and then the post-ganglionic n. synapses via NE onto adrenergic receptors on the heart and blood vessels
Ach-E: Pre-ganglionic n. synapses onto post-ganglionic nicotinic receptors of the adrenal medulla via Ach, and then the adrenal medulla secretes E to freely flow in circulation (acts more like a hormone) and is accepted by adrenergic receptors on the heart and blood vessels
How does the hypothalamus achieve homeostasis?
adjusting physiological processes:
IMBALANCE > STIMULUS produces a change > change detected by receptor (SENSOR) > change is sent along the afferent pathway to the CONTROL CENTER > efferent info is sent along a pathway to an EFFECTOR > response of the effector feeds back to influence the magnitude of the stimulus and returns variable to homeostasis
predominantly feedback
What are the autonomic reflexes?
Mechanoreceptors: respond to mechanical stimuli (ex. aortic baroreceptors, carotid sinuses, lungs, bladder, veins, intestines)
Chemoreceptors: sense amount of CO2/O2 in blood and level of pH (carotid/aortic bodies, medulla, hypothalamus, stomach, taste buds, olfactory bulbs
Nocioceptors: pain (viscera, arterial wall)
Thermoreceptors: temperature (hypothalamus, cutaneous)
Examples of ANS dysfunction
stress, anxiety, hypertension, orthostatic hypertension
