Lecture 24 - Pelvic Neuroanatomy Flashcards Preview

Viscera & Visceral Systems > Lecture 24 - Pelvic Neuroanatomy > Flashcards

Flashcards in Lecture 24 - Pelvic Neuroanatomy Deck (22):

The inferior hypogastric plexus (IHP) is vulnerable to ...

surgical injury


Within the IHP there are thousands of...

autonomic neurons - the key to understanding

its not just tracts, its a ganglionated plexus

there is potential to damage cell BODIES


INHP damage can damage what..

motor pathway:

postgangionic axons, ganglion cell bodies, preganglionic axons

Sensory pathways: lumbar and sacral sensory axons


What does sympathetic nerves do to the bladder?

contraction of bladder base - continence


What does parasympathetic nerves do to the bladder?

contraction of bladder dome - micturition


What does the sympathetic input do to the reproductive organs in males

ejaculation - contraction of smooth muscle in prostate gland, seminal vesicle, vas, urethea


What does the parasympathetic input do to the reproductive organs in males

stimulates prodction of secretions from prostate gland

vasodilation - increased uterine and penile blood flow


Sympathetic and parasympathetic axons look __ ___ but can have different _______

Sympathetic and parasympathetic axons look the same but can have different distribution


True or false

There is no easily visible synaptic junction



True or false

there is more than one transmitter release site per axon



True or false

IHP contains both sympathetic parasympathetic ganglion neurons



Autonomic neurons in the IHP are sexually dimorphic, meaning...

there are many more neurons in the male.


True or false

Receptors for sex steroids do not continue to be expressed in adults


they do

steroid levels or drugs that influence steroid actrivity, affect neuron strucutre and fucntion


What are some things to consider when investigating ways to undertake safer surgical operations?

the extent of neuron damage - do they die?

understand the innate potential for recovery - can they regrow

Find ways to make damaged axons grow better/faster - clues from developmental neuroscience

Enhance the potential of undamaged axons - indetify compensatory mechanisms, how do we increase the amount of them?


What is a way to identify the spinal connectivity of the nerves in the IHP?

microsurgical lesion of the hygogastric nerve will denervate sympathetic neurons - can then identify

can also put in retrograde tracers to trace organ connectivityi


With identification of neurons what can then be achieved?

pre-labl then injure selected target-specific neurons - can then compare different types of injury and see the effects:

nerve regrowth
neural activity
drug activation of tissue
contribution of spared nerves


the impact of injuring pelvic visceral sensory nerves is likely to be occurring in parallel with..

injuring autonomic nerves


What are the potential problems of pelvic sensory nerve damage

loss/reduction of sensroy fucntion to initiate reflexed and tissue receovery from injury/inflammation

initiate state of visceral pain - can be chronic


true or false

[retrograde labeling from pelvic organs simultaneously labels autonomic and sensory neurons



The sensory innervation of pelvic organs originates from ....

dorsal root ganglia of two spinal levels (upper lumbar and sacral)


The sensory nerves from pelvic organs are not just sending information about pain, but also

reflex information to do with normal autonomic function


visceral sensory neurons branch profused in the SC compared to....

what does this mean for pain?

somatic sensroy neurons

visceral pain more diffuse, poorly localised and often referred

makes sense, the many fibres converge on other sensory fibres.