Anatomy 3 - Anaesthesia for Labour

Question 1

What nerve fibre types cause uterine cramping e.g. in menstruation?

Answer 1

Autonomic control - parasympathetic/ sympathetic causing hormone release

Question 2

What nerve fibre types cause uterine contraction?

Answer 2

Autonomic control - parasympathetic/ sympathetic causing hormone release (oxytocin)

Question 3

What nerve fibre types cause pelvic floor contraction e.g. which sneezing?

Answer 3

Somatic motor

Question 4

What nerve fibre types sense pain from adnexae?

Answer 4

Visceral afferents (i.e. organ to spinal cord)

Question 5

What nerve fibre types sense pain from uterus?

Answer 5

Visceral afferents

Question 6

What nerve fibre types sense pain from vagina?

Answer 6

Pelvic part - visceral afferents

Perineum - somatic sensory

Question 7

What nerve fibre types sense pain from perineum?

Answer 7

Somatic sensory

Question 8

What nerve fibres are associated with structures in the pelvis (body cavity)?

Answer 8

Sympathetic
Parasympathetic
Visceral afferent

Question 9

What nerve fibres are associated with structures in the perineum (body wall)?

Answer 9

Somatic motor

Somatic sensory

Question 10

How does pain sensation travel from the superior aspect of pelvic organs/ touching the peritoneum to CNS?

Answer 10

Visceral afferents

Question 11

What do the visceral afferent nerve fibres from from the superior aspect of pelvic organs/ touching the peritoneum run alongside?

Answer 11

Sympathetic fibres

Question 12

Where do the visceral afferents from the superior aspect of pelvic organs/ touching the peritoneum enter the spinal cord?

Answer 12

Between T11 and L2

Question 13

How is pain from between T11 and L2 perceived by patient?

Answer 13

Suprapubic pain

Question 14

How does pain sensation travel from the inferior aspect of pelvic organs/ NOT touching the peritoneum to CNS?

Answer 14

Visceral afferents

Question 15

What do the visceral afferent nerve fibres from the inferior aspect of pelvic organs/ NOT touching the peritoneum run alongside?

Answer 15

Parasympathetic fibres

Question 16

Where do the visceral afferents from the inferior aspect of pelvic organs/NOT touching the peritoneum enter the spinal cord?

Answer 16

S2, S3, S4

Question 17

Where is the S2, S3, S4 dermatome?

Answer 17

Perineum

Question 18

How does pain sensation travel from the structures crossing pelvis to perineum below levator ani (i.e. in the perineum) to CNS?

Answer 18

Somatic sensory - pudendal nerve S2, S3, S4

Question 19

Where do the somatic sensory nerve fibres from structures in the perineum enter the spinal cord?

Answer 19

S2, S3, S4

Question 20

How does pain sensation travel from the structures crossing pelvis to perineum above levator ani (i.e. in the pelvis - urethra, vagina) to CNS?

Answer 20

Visceral afferents

Question 21

What are the 2 important spinal cord levels with regards to pain from the female reproductive system?

Answer 21

T11 - L2

S2 - S4

Question 22

Where is the ‘pelvic pain line’?

Answer 22

Peritoneum

Question 23

Where does sympathetic outflow go from?

Answer 23

T1 - L2/L3

Question 24

What are splanchnic nerves?

Answer 24

Paired visceral nerves

Question 25

What do splanchnic nerves carry?

Answer 25

Fibres of the autonomic nervous system (visceral efferents) - all sympathetic except pelvic splanchinc which carry parasympathetic fibres Sensory fibres from the organs (visceral afferents)

Question 26

What are pelvic splanchnic nerves?

Answer 26

Splanchnic nerves that arise from sacral spinal nerves S2, S3, S4 to provide parasympathetic innervation to the hindgut

Question 27

Where do the sympathetic nerves synapse?

Answer 27

Anterior to aorta - prevertebral ganglia

Question 28

What do sympathetic nerves form at prevertebral ganglia?

Answer 28

Superior and inferior mesenteric ganglia

Question 29

How do the sympathetic nerves reach the distal aspect of the fallopian tube?

Answer 29

'Hitch a ride' on periarticular plexis

Question 30

What is the hypogastric nerve?

Answer 30

Transition between superior and inferior hypogastric plexuses

Question 31

Where does the hypogastric nerve enter sympathetic chain?

Answer 31

T10 - L2

Question 32

Where is the superior hypogastric plexus situated?

Answer 32

On vertebral bodies anterior to bifurcation of abdominal aorta

Question 33

What does the superior hypogastric plexus contain?

Answer 33

Parasympathetic fibres which arise form pelvic splanchnic nerves S2 - S4 p - parasympathetic p - pelvis

Question 34

What does the inferior hypogastric plexus supply?

Answer 34

Viscera of pelvic cavity (visceral afferents)

Question 35

What is the ilioinguinal nerve a branch of?

Answer 35

Lumbar plexus

Question 36

What nerve root is ilioinguinal nerve?

Answer 36

L1

Question 37

What modality is ilioinguinal nerve?

Answer 37

Motor | Sensory

Question 38

What is the motor function of ilioinguinal nerve?

Answer 38

Internal oblique | Transverse abdominis

Question 39

What is the sensory function of ilioinguinal nerve?

Answer 39

Skin on upper medial thigh Skin over root of penis and anterior scrotum Skin over mons pubis and labia majora

Question 40

What nerve root is iliohypogastric nerve?

Answer 40

First major root of lumbar plexus - L1 | Also T12

Question 41

What modality is iliohypogastric nerve?

Answer 41

Motor | Sensory

Question 42

What is the motor function of iliohypogastric nerve?

Answer 42

Internal oblique | Transverse abdominis

Question 43

What is the sensory function of iliohypogastric nerve?

Answer 43

Posterolateral gluteal skin in pubic region

Question 44

What sacral nerves is pudendal from?

Answer 44

S2, S3, S4

Question 45

What modality is pudendal nerve?

Answer 45

Motor | Sensory

Question 46

Does the pudendal nerve carry sympathetic and parasympathetic nerve fibres?

Answer 46

Sympathetic yes | Parasympathetic no

Question 47

Name all the layers a needle passes through for a spinal anaesthetic (7)

Answer 47

``` Supraspinous ligament Interspinous space Ligamentum flavum Epidural space Dura mater Arachnoid mater Subarachnoid space (CSF) ```

Question 48

At what vertebral level does the spinal cord become the cauda equina?

Answer 48

L2

Question 49

At what vertebral level does the subarachnoid space end?

Answer 49

S2

Question 50

At what vertebral level should spinal anaesthesia be injected?

Answer 50

L3 - L4 (L5)

Question 51

What does a spinal anaesthetic anaesthetise?

Answer 51

Cauda equina (waist to toes)

Question 52

What surgeries is spinal anaesthetic used for?

Answer 52

Prolapse repairs Some hysterectomies C-sections

Question 53

What levels does the needle pass through in an epidural anaesthetic?

Answer 53

Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural space

Question 54

At what vertebral level should epidural anaesthesia be injected?

Answer 54

L3 - L4

Question 55

What is the aim of epidural?

Answer 55

Analgesia rather than complete lack of feeling

Question 56

How can an epidural stop a patient feeling contractions?

Answer 56

Target specific nerves

Question 57

Where does sympathetic outflow originate in the brain?

Answer 57

Autonomic centres

Question 58

At what spinal nerve level does the sympathetic outflow exit?

Answer 58

T1 - L2

Question 59

Once the sympathetic outflow exits the T1 - L2 spinal nerves, where does it travel?

Answer 59

To the sympathetic chains | That run the length of the vertebral column

Question 60

Once the sympathetic outflow reaches the sympathetic chains, where does it pass into?

Answer 60

All spinal nerves - anterior and posterior rami and named nerves

Question 61

How do sympathetic ganglia receive fibres below the L2 level?

Answer 61

From L2 level via sympathetic chain | Distributed via connections with lumbar, sacral and coccygeal spinal nerves

Question 62

What is sympathetic tone?

Answer 62

Sympathetic fibres supply all arterioles

Question 63

What effects does spinal anaesthetic have on sympathetic tone?

Answer 63

Blocks all sympathetic tone to all arterioles in lower limb

Question 64

What vaso- effect does spinal anaesthetic have on sympathetic tone of aterioles?

Answer 64

Vasodilation

Question 65

What are 3 signs that spinal anaesthetic is working? (i.e. signs of vasodilation)

Answer 65

Skin of lower limbs looks flushed Warm lower limbs Reduced sweating

Question 66

Why does spinal anaesthetic cause reduced sweating?

Answer 66

No sympathetic input to glands

Question 67

What is a risk/ complication of spinal anaesthesia?

Answer 67

Hypotension

Question 68

What is the aim of a pudendal nerve block?

Answer 68

Anaesthetise majority of perineum

Question 69

What surgeries/ procedures is a pudendal nerve block used for?

Answer 69

Episiotomy incision Forceps use Perineal stitching post-delivery Painful delivery

Question 70

What route is taken by pudendal nerve?

Answer 70

Exit pelvis via greater sciatic foramen Passes posterior to sacrospinous ligament Re-enters pelvis/ perineum via lesser sciatic foramen Travels within Alcock's canal

Question 71

What is Alcock's canal?

Answer 71

Passageway within obturator fascia | Pudendal nerve, internal pudendal artery and vein and nerve to obturator internus

Question 72

What do branches of the pudendal nerve supply?

Answer 72

Perineum

Question 73

What can be used as a landmark in a pudenal nerve block?

Answer 73

Ischial spine

Question 74

What 2 incisions can be used for an episiotomy?

Answer 74

Medial | Mediolateral

Question 75

Why is a medial incision episiotomy not used often?

Answer 75

Further tearing can occur that involves the anal sphinchter

Question 76

Why is a mediolateral incision episiotomy used?

Answer 76

Incises into safe fat filled fossa | Avoids extension into rectum

Question 77

What is a 1st degree perineal tear?

Answer 77

Through skin

Question 78

What is a 2nd degree perineal tear?

Answer 78

Skin and mucosa

Question 79

What is a 3rd degree perineal tear?

Answer 79

Severely through muscle

Question 80

What is a 4th degree perineal tear?

Answer 80

Involves anal sphincter and rectal mucosa | Rare in UK

Question 81

What can be the result of a perineal tear?

Answer 81

Weakened pelvic floor | Faecal incontinence