8: Anatomy - pain and urinary continence Flashcards
What are the five types of nerve fibre?
Somatic sensory
Somatic motor
Visceral afferents / sensory
Sympathetic
Parasympathetic
What are the two types of sensory nerve?
Somatic sensory
Visceral afferent
What are the three types of motor nerve?
Somatic motor
Sympathetic
Parasympathetic
Which type of nerve receives sensation from the body wall?
Somatic sensory
Which type of nerve receives sensation from the internal organs?
Visceral afferent
What type of nerve innervates skeletal muscle?
Somatic motor
What types of nerves send motor impulses to the internal organs?
Sympathetic
Parasympathetic
Which nerves control peristalsis of the ureters and contraction of the bladder?
Sympathetic
Parasympathetic
motor to internal organs
Which nerves control the
a) internal urethral sphincter in males
b) external urethral sphincter and levator ani?
a) Sympathetic / parasympathetic (internal organs)
b) Somatic motor (as they’re in the perineum)
Which nerves pick up sensation from the kidneys, ureters, bladder, testes and pelvic urethra?
Visceral afferents
The distal urethra, found in the perineum, has a somatic sensory innervation
Which nerves are found in the lumbar and sacral plexuses?
Somatic sensory
Somatic motor
supplying perineum and lower limbs
How many pairs of cranial nerves are there?
12
At which levels do sympathetic nerves leave the spinal cord?
T1 - L2
THORACOLUMBAR OUTFLOW
Where do sympathetic nerves leave the spinal cord?
Anterior horns
Where do sympathetic nerves synapse after leaving the spinal cord from T1 - L2?
Sympathetic chain
Where can post-synaptic sympathetic nerves travel?
Up and down the full length of the spinal cord
Every spinal level has a ___ for post-synaptic sympathetic nerves.
What is the exception?
ganglion
Head and neck - superior, middle and inferior cervical ganglia
How do post-synaptic sympathetic nerves travel to organs in the
a) head and neck
b) thorax
c) abdomen?
a) Periarterial plexuses
b) Cardiopulmonary splanchnic nerves
c) Abdominopelvic splanchnic nerves
(c) NOT the same as parasympathetic pelvic splanchnic nerves
What are the two types of sympathetic splanchnic nerve?
a) Cardiopulmonary splanchnic nerve
b) Abdominopelvic splanchnic nerve
How do post-synaptic sympathetic nerves reach the organs of the head and neck?
Hitch a ride on arteries
Periarterial plexuses
Where does the spinal cord end?
L1
Conus medullaris, then cauda equina to S1
The sympathetic chains run along how much of the vertebral column?
The whole thing
How do sympathetic nerve fibres get to the kidneys, ureters and bladder?
Abdominopelvic splanchnic nerves
synapsing at abdominal sympathetic ganglia on the way
then passing along periarterial plexuses
Which cranial nerves do parasympathetic nerves come from?
Where else do they come from?
CN III, VII, IX and X
oculomotor, facial, glossopharyngeal and vagus nerves
Sacral spinal nerves
Keeping in mind where parasympathetic nerves come from, what is their outflow called?
Craniosacral outflow
How do parasympathetic nerves reach the pelvic organs?
Pelvic splanchnic nerves
What is the difference between pelvic and abdominopelvic splanchnic nerves?
Pelvic - parasympathetic, come from sacral spinal nerves
Abdominopelvic - sympathetic, come from all over the place
Which parasympathetic nerves supplies the
a) kidneys and ureters
b) bladder?
a) Vagus nerve CN X
b) S2 - 4
What pelvic organs are supplied by the
a) sacral spinal nerves
b) vagus nerve?
a) Bladder
b) Kidneys and ureters
Which spinal nerves supply the pudendal nerve?
S2, 3, 4
What organs do somatic sensory fibres supply?
None
supply body wall only
What aspect of the skin is supplied by pelvic somatic sensory nerves?
Perineum
What renal structures are supplied by somatic sensory fibres?
Distal urethra
External urethral sphincter
What fibres do visceral afferents run alongside?
Sympathetic fibres
OR
Parasympathetic fibres
depending on where they are
What can happen when visceral afferents plug in to specific spinal nerves?
Referred pain
What is pain arising from the kidneys felt?
Loin
Posterior flank on the affected side
What is pain arising from the bladder usually felt?
Suprapubic region
in the midline
Where is pain felt when a renal calculus obstructs the ureter?
Radiating pain from LOIN to GROIN
on affected side
Where is urethral pain felt?
Perineum
Which organs are affected if pain is felt in the
a) loin
b) loin radiating to the groin
c) suprapubic area
d) perineum?
a) kidneys
b) ureters
c) bladder
d) urethra
Why is kidney pain felt in the loin?
Travel alongside sympathetic fibres and plug into spine at T11 - L1 dermatomes
Which are posterior flanks
Why is ureter pain felt between the loin and groin?
Visceral afferents travel alongside sympathetics and plug into spinal cord between T11 - L2
i.e posterior flanks and suprapubic
Visceral afferents supplying the bladder run alongside ___ nerves for the inferior aspect and ___ nerves for the superior aspect.
run alongside sympathetic nerves for superior aspect
run alongside parasympathetic nerves for inferior aspect
Visceral afferents supplying the urethra run alongside ___ nerves to plug into the spinal cord.
parasympathetic nerves
i.e sympathetic nerves until halfway down bladder, then parasympathetic nerves
EXCEPT the testes, because they originate from the abdomen (sympathetic nerves)
Which nerve do somatic sensory nerves supplying the distal urethra travel in?
Pudendal nerve
S2,3,4
The visceral afferents supplying the testes run alongside ___ fibres to reach the spinal cord.
sympathetic
Where can testicular pain be felt?
Groin
Scrotum (if it’s affected)
Which autonomic nerves do visceral afferents supplying the
a) testes
b) superior bladder
c) proximal urethra
d) ureters
e) inferior bladder
f) distal urethra
run alongside to reach the spinal cord?
a) Sympathetic
b) Sympathetic
c) Parasympathetic
d) Sympathetic
e) Parasympathetic
f) Distal urethra is supplied by somatic sensory, which plug into pudendal nerve
How does
a) visceral
b) somatic
pain feel?
a) Dull, achey
b) Sharp, stabbing
What is micturition?
Urination
Which spinal nerves are vital in controlling micturition?
S2, 3, 4
Where do visceral afferents from the proximal urethra enter the spinal cord?
S2,3,4
Where does the pudendal nerve originate from?
What type of nerve does it carry?
S2,3,4
Somatic motor (to MOVE the levator ani, open external urethral / anal sphincters etc.)
Where do pelvic splanchnic nerves exit the spinal cord?
What type of nerve do they contain?
S2,3,4
Parasympathetic nerves
What types of nerve plug in to or leave S2, 3 and 4?
Parasympathetic via pelvic splanchnic nerves
Somatic sensory from proximal urethra
Somatic motor in pudendal nerve, supplying external urethral sphincter, levator ani
What are the important spinal levels for micturition?
S2 - S4
What is urinary continence?
Ability to control flow of urine
What is potty training?
Ability to inhibit natural emptying of the bladder when it is stretched
Which fibres detect stretching of the bladder?
Visceral afferent fibres
Which spinal levels do visceral afferents from the bladder plug into?
S2 - S4
Which muscle constricts to empty the bladder after an unopposed stretch reflex?
Detrusor muscle
Which autonomic fibres control the contraction of the detrusor muscle and the opening of the internal urethral sphincter in males?
Parasympathetic
Which fibres control the opening of the external urethral sphincter and relaxation of the levator ani muscle?
Somatic motor via the pudendal nerve
Which abdominal muscles contract to increase micturition?
Which nerve fibres are involved?
Anterolateral abdominal muscles
Somatic motor
What is formed by the tons of nerves which are found in the abdomen and pelvis?
Lumbar plexus
Sacral plexus
forming Lumbosacral plexus
Which spinal nerves are involved in the lumbosacral plexus?
L1 - S4
Remember brachial plexus (C5 - T1)
What is the big thick nerve which arises from the sacral plexus at L4 - S3?
Sciatic nerve
The nerves of the sacral plexus have a close association with which muscle?
Psoas major
Which nerves of the lumbar plexus come from L1?
Iliohypogastric nerve (L1)
Ilioinguinal nerve (L1)
Which nerve of the lumbar plexus arises from L2 - 3 and supplies the lateral skin of the thigh?
Lateral cutaneous nerve of the thigh (L2 - 3)
Which nerve of the lumbar plexus arises from L1 - 2 and runs on the surface of psoas major?
Genitofemoral nerve
Which nerve of the lumbar plexus arises from L2 - 4 and runs lateral to psoas major?
Femoral nerve (L2 - 4)
Which nerve of the lumbar plexus arises from the same levels as the femoral nerve, runs medial to psoas major and goes through its own foramen in the pelvis?
Obturator nerve (L2 - 4)
What are the nerves of the lumbar plexus and their spinal levels?
Iliohypogastric nerve (L1)
Ilioinguinal nerve (L1)
Lateral cutaneous nerve of the thigh (L2 - 3)
Genitofemoral nerve (L1 - 2) - surface of psoas major
Femoral nerve (L2 - 4) - lateral to psoas major
Obturator nerve (L2 - 4) - medial to psoas major
Which compartment does the femoral nerve supply?
Anterior compartment of thigh
What compartment does the obturator nerve supply?
Medial compartment of thigh
What compartment does the unbranched sciatic nerve supply?
What are its spinal levels?
Posterior compartment of the thigh
L4 - S3
What compartments of the leg do the
a) tibial
b) superficial fibular
c) common fibular
branches of the sciatic nerve supply?
a) Posterior
b) Lateral
c) Anterior
Which nerve supplies the plantar surface of the foot?
Tibial nerve
Which nerve supplies the medial aspect of the leg and ankle and is a branch of the femoral nerve?
Saphenous nerve
Which nerve supplies the dorsal surface of the foot?
Superficial fibular nerve
Which nerve supplies the lateral aspect of the foot?
Sural nerve
Which nerve supplies the 1st web space of the foot?
Deep fibular nerve
What aspects of the foot do the
a) tibial
b) saphenous
c) sural
d) deep fibular
e) superficial fibular nerves supply?
a) Plantar surface
b) Medial aspect
c) Lateral aspect
d) 1st web space
e) Dorsal surface
When do sympathetic fibres close the internal urethral sphincter in males?
Ejaculation
to prevent retrograde ejaculation into bladder
Which nerves
a) relax the internal urethral sphincter
b) constrict the external urethral sphincter?
a) Parasympathetic
b) Somatic motor
