Bs545 - Autonomic Nervous System And Hypothalamus

Front 1

What are the three general components of an ANS reflex arc?

Back 1

Comprised of sensory, integrative elements, and motor.

Front 2

Give an example of an ANS arc. Include the circuit.

Back 2

Neuron from sensor for body temperature => dorsal ganglion => synapse in ventral horn => gangion => viseral muscle of blood vessel.

Front 3

What is the overall function of the parasympathetic NS?

Back 3

It delivers signals to various visceral organs and glands. By analogy, it can be deseribed as "rest/digest".

Front 4

With what nerves/spinal cord segments are the parasympathetic fibers associated?

Back 4

III - pupillary constrictor, cillary body

VII - Lacrimal gland, some salivary glands.

IX - Salivary glands

X - thoracic and abdominal viscera

S1-3 - pelvic viscera (Pelvic N.)

Front 5

What is the overall function of the sympathetic NS?

Back 5

Deals with "Fight or Flight". In more normal situations, it opposes the parasympathetic system and will tend to shut down things that are turned on by the PSNS.

Front 6

With what spinal cord segments are the fibers of the sympathetic NS associated?

Back 6

thoracic and lumbar spinal cord segments, T1-L2/L3

Front 7

What are the two functions of the ANS?

Back 7

Internal homeostasis

Response to stressors.

Front 8

Where are the peripheral efferents for the PSNS?

Back 8

Craniosacral regions

Front 9

What is the fanout of parasympathetic effects versus sympathetic efferents?

Back 9

PSNS: tend to act locally. Pre-ganglionic to post-ganglionic ratio is 1:3

SNS: tend to act more diffusely. Pre-ganglionic to post-ganglionic ratio is 1:10.

Front 10

From what part of the cord do SNS pre-ganglionic fibers arise?

Back 10

Lateral horn.

Front 11

What is a terminal ganglion?

Back 11

The target area for a post-ganglionic parasympathetic fiber. It is often a diffuse set of neurons located within the target.

Front 12

What is a paravertebral ganglion?

Back 12

A line of SNS ganglia which follow the spinal colum. Pre-ganglion and post-ganglion fibers synapse here.

Front 13

What is a prevertebral (collateral) ganglion?

Back 13

For deeper organs, like the heart and digestive system, SNS pre-ganglionic fibers skip the paravertebral ganglia and synapse a ganglia closer to the target.

Front 14

Trace the circuit for the autonomic innervation fo the pupil (start at the nasal part of the retina)

Back 14

Optic nerve -> descussate optic chiasm -> optic tract -> synapse in pretectal nuclei to bi-lateral parasympathetic fibers of III -> snapse to neurons in the Edinger-Westphal nucleus -> synapse in ciliary ganglion (right and left) -> muscles of iris on each side.

Front 15

Identify the neurotransmitters released on the peripheral autonomic nerve fiber termni.

Back 15

ACh.

Front 16

Define the signs of Horner's syndrome.

Back 16

miosis (small pupil), ptosis (drooping eyelid), anhidrosis (lack of perspiration on the skin).

Front 17

What is the basic cause for Horner's syndrome?

Back 17

Loss of sympathetic innervation to the head.

Front 18

What is the basic circuit in which a leison can occur which leads to Horner's syndrome?

Back 18

hypothalamus -> brainstem/spinal cord -> sympathetic pathways between the eye/face through T1/T2 spinal cord segments.

Front 19

What causes miosis, ptosis, and anhidrosis in Horner's syndrome?

Back 19

miosis - unopposed parasympathetic innervation

ptosis - loss of sympathetic input to the smooth muscle of the upper eye lid.

Anhidrosis - Lack of sympathetic input to the sweat glands of the face.

Front 20

List the three functions of the hypothalamus.

Back 20

Coordinator of the endocrine system

Coordinator of the ANS

Coordinator of the limbic system

Front 21

In the hypothalamus, the medial and lateral zones are defined by the location of what structure?

Back 21

columns of the fornix

Front 22

What are the three regions in the medial zone of the hypothalamus?

Back 22

posterior (mamillary) region

tuberal region

anterior (supra optic) region

Front 23

What are the two nuclei in the posterior region of the hypothalamus?

Back 23

posterior nucleus and mamillary nucleus

Front 24

What structure passes through the lateral zone of the hypothalamus.

What is its orgin and destination?

What is its function?

Back 24

Medial forebrain bundle.

From basilar parts of forebrain to brainstem.

"highway" for autonomic control

Front 25

What are the three nuclei in the tuberal region of the hypothalamus?

Back 25

dorsalmedial and ventralmedial nuclei. arcuate nucleus

Front 26

What are the four nuclei in the anterior (supra optic) region of the hypothalamus?

Back 26

Parventricular nucleus
Supraoptic nucleus
Anterior nucleus
Suprachiasmatic nucleus

Front 27

What is the function of the parventricular and supraoptic nuclei?

Back 27

Neuroendocrine functions

Front 28

What is the function of the Suprachiasmatic nucleus?

Back 28

circadian rhythms

Front 29

What is the function of the Dorsomedial and Ventromedial nuclei?

Back 29

Satiety (possibly appetite)

Front 30

What is the function of the acruate nucleus?

Back 30

Relase of factors influencing the anterior pituitary.

Front 31

What is the function of the posterior nucleus?

Back 31

sympathetic activity

sleep-wake cycles

Front 32

What is the function of the mamillary nuclei?

Back 32

Memory

Front 33

What are the two neurosecretory systems that influence the pituitary?

Back 33

Magnocellular

Parvocellular

Front 34

Where are parvocellular nuclei found? What is their size? Where do their axons descend? What happens to the neurotransmitters they release?

Back 34

Arcuate
Small nuclei
Anterior pituitary (adenohyphysis)
NT (releasing/inhibiting factors) released into portal system.
Pituitary will release various hormones into the blood depending upon the factors stimulating it.

Front 35

Where are the Magnocellular nuclei found? What is their size? Where do their axons descend? What happens to the neurotransmitters they release?

Back 35

Paraventricular and Supra Optic regions.

Axons descend into the posterior pituitary (Neurohypophysis)

They release ADH and ocytocin directly into the blood stream.

Front 36

What is the name of the tract that carries information from the hypothalamus to/from the brainstem and spinal cord? What do the descending fibers do?

Back 36

dorsal longitudinal fasciculus

Descending fibers: control of GVE neurons.

Front 37

What is the largest input tract to the hypothalamus? What two bodies are connected by this? What system is connected by this?

Back 37

fornix

hippocampus to mammillary bodies

link between limbic system and hypothalamus.

Front 38

What is the principle center and integrator of ANS activity?

Back 38

hypothalamus

Front 39

What are the three primary areas or systems that feed the hypothalamus?

Back 39

RF

limbic system

GVA (spinal cord and brain stem)

Front 40

What part of the hypothalamus drives the sympathetic NS? The parasympathetic NS?

Back 40

posterior - sympathetic

anterior - parasympathetic