Clinical Anatomy of Anaesthesia for Labour Flashcards
What are the reproductive system’s motor functions?
Uterine cramping e.g. menstruation
Uterine contraction e.g. during labour
Pelvic floor muscle contraction e.g. during sneezing
What is the reproductive system’s pain (sensory) function?
Pain from adnexal (ovaries + Fallopian tubes)
Pain from uterus
Pain from vagina
Pain from perineum
Above the levator ani muscles is referred to as?
Pelvis
Below the levator ani muscle is referred to as?
Perineum
What supplies structures of the pelvis?
Body cavity
Sympathetic, parasympathetic and visceral afferent
What supplies structures of the perineum?
Body wall
Somatic motor and somatic sensory
What structures are below and above levator ani muscle in the reproductive system?
What nerve fibres supply uterine cramping e.g. menstruation?
Hormonal (symp/parasymp)
What nerve fibres supply uterine contraction e.g. during labour?
Hormonal (symp / parasympathetic)
What nerve fibres supply pelvic floor muscle contraction e.g. during sneezing?
Somatic motor
What nerve fibres supply pain from adnexae?
Visceral afferents
What nerve fibres supply pain from uterus?
Visceral afferents
What nerve fibres supply pain from vagina?
Visceral afferents (pelvic part)
Somatic sensory (perineum)
What nerve fibres supply pain from perineum?
Somatic sensory
Superior aspect of pelvic organs / touching the peritoneum are supplied by what nerve fibres?
Visceral afferents
Run alongside sympathetic fibres
Visceral afferents from the Superior aspect of pelvic organs / touching the peritoneum enter spinal cord between?
T11-L2
Pain is perceived as what from Superior aspect of pelvic organs / touching the peritoneum ?
Suprapubic
Inferior aspect of pelvic organs / not touching peritoneum are supplied by what nerve fibres?
Visceral afferents
Rung alongside parasympathetic fibres
Inferior aspect of pelvic organs / not touching peritoneum enter spinal cord at what levels?
S2, S3 and S4
Pain is perceived as what from Inferior aspect of pelvic organs / not touching peritoneum?
In S2, S3 and S4 dermatomes (perineum)
Structures crossing from pelvis to perineum above the levator ani (in pelvis) are supplied by what?
Visceral Afferents
Parasympathetic
The nerve fibres from Structures crossing from pelvis to perineum above the levator ani (in pelvis) enter spinal cord where?
Levels S2, S3 and S4
Structures crossing from pelvis to perineum below levator ani (in perineum) are supplied by what fibres?
Somatic sensory
Pudendal nerve
Nerve fibres from Structures crossing from pelvis to perineum below levator ani (in perineum) enter where in spinal cord?
Levels S2, S3 and S4
Pain from Structures crossing from pelvis to perineum below levator ani (in perineum) are perceived where?
Localised pain within perineum
The sympathetics from pelvis are supplied by what?
Sacral sympathetic trunks
T11-L2
Superior hypogastric plexus
The parasympathetics to pelvis are from where and what nerves?
Sacral outflow (S2,3,4)
Pelvic splanchnic nerves
Emerge from spinal roots
Mixes with sympathetics in inferior hypogastric plexus
What are the 2 important spinal cord levels from where pain from female reproductive system arises?
T11-L2
S2-S4
Describe the path of visceral afferents in female pelvic pain
Describe the path of the pudendal nerve in female pelvic pain
Draw out a diagram explaining the nerve supply from perineum or pelvis
What anaesthesia procedures of the pelvis exist?
A spinal block via lumbar puncture anaesthetises what?
From waist down - intra and sub peritoneal plus somatic areas
A caudal epidural block anaesthetises what?
Sub-peritoneal plus somatic areas innervated by pudendal nerve
A pudendal nerve block anaesthetises what?
Areas innervated by pudendal nerve
The spinal cord becomes caudal equine at what vertebral level?
L2 vertebra
The subarachnoid space ends at level of?
S2
Spinal and epidural Anaesthetic is injected into what region?
L3-L4 (L5) region
The needle passes through what in an epidural anaesthetic?
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space (fat and veins)
The needle passes through what in spinal anaesthetic?
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space (fat and veins)
Dura mater
Arachnoid mater
Finally reaches subarachnoid space (contains CSF)
All spinal nerves and their named nerves contain?
Sympathetic fibres
Sympathetic fibres supply all of what vascular structure?
Sympathetic fibres supply all arterioles
Blockade of sympathetic tone to all arterioles in lower limb in a spinal anaesthetic can lead to what?
Vasodilation and subsequently hypotension
Sympathetic nerves exit spinal cord with what spinal nerves?
T1-L2 spinal nerves
Sympathetic nerves travel to what?
Sympathetic chains and pass into all spinal nerves
What happens to sympathetic outflow below L2 level?
Sympathetic ganglia receive fibres from L2 level via sympathetic chain and distribute them via connections with lumbar, sacral and coccygeal spinal nerves
The pudendal nerve plays a role in?
GI system
Renal system
Role in motor control of external anal and external urethral sphincters
The pudendal nerve is the nerve of?
Perineum
The pudendal nerve is a branch of?
sacral plexus S2, S3 and S4
Describe the pathway of the pudendal nerve
Exits pelvis via greater sciatic foramen
Passes posterior to sacrospinous ligament
Re enters pelvis / perineum via lesser sciatic foramen
Travels in pudendal canal
Branches to supply structures of the perineum
The pudendal nerve crosses posterior to?
The lateral aspect of the sacrospinous ligament
What bony landmark can be used to identify pudendal nerve?
Ischial spine
When can pudendal nerve block be used?
Can be used during labour
Forceps delivery
Painful vaginal delivery
Episiotomy incision
Perineal suturing post delivery
During labour, what can be stretched?
The branches of pudendal nerve can be stretched
Fibres of what muscles can be torn during labour?
Fibres within levator ani (puborectalis) or external anal sphincter muscle could be torn
1st degree
2nd degree
3rd degree
4th degree
What is a episiotomy?
deliberate incision that is made, made from posterior forchettte out to sischioanal / ischiorectal fossae - fat filled space - prevents tearing going towards external anal sphincter. Also to avoid perineal body
Posterolateral (mediolalateral) incision