Anatomy of Anaesthesia for Labour Flashcards Preview

Y3 Obs and Gynae Anatomy > Anatomy of Anaesthesia for Labour > Flashcards

Flashcards in Anatomy of Anaesthesia for Labour Deck (37)
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1

List nerves associated with the perineum

BODY WALL
Somatic motor
Somatic sensory

2

List nerves associated with the pelvis

BODY CAVITY
Sympathetic
Parasympathetic
Visceral afferent

3

Which nerve structures transmit pain from the pelvis?

Visceral afferents - sympathetic or parasympathetic

4

Which nerve structures transmit pain from the perineum?

Pudenal nerve - somatic sensory

5

Where do visceral afferents enter the spinal cord for pelvic organs that TOUCH THE PERITONEUM? Where is pain perceived? List these organs

T11-L2 via sympathetic fibres
Suprapubic region
Uterine tubes, uterus, ovaries

6

Where do visceral afferents enter the spinal cord for pelvic organs that are not touching the peritoneum (ABOVE LEVATOR ANI)? Where is pain perceived? List these organs

S2-S4 via parasympathetic fibres
S2,3,4 dermatome
Cervix and superior vagina

7

Where does the pudenal nerve enter the spinal cord for structures in the perineum (BELOW LEVATOR ANI)? Where is pain perceived? List these organs

S2-S4 via somatic sensory fibres
Localised pain in perineum
Inferior vagina, perineal muscles, glands, skin

8

Structures above levator ani are supplied by which nerve fibres?

IN PELVIS
Visceral afferents

9

Structures below levator ani are supplied by which nerve fibres?

IN PERINEUM
Pudenal nerve

10

What type of anaesthesia targets intraperitoneal, subperitoneal and somatic structures?

Spinal anaesthetic

11

What type of anaesthesia targets subperitoneal and somatic structures?

Epidural anaesthetic

12

What type of anaesthesia targets somatic structures only?

Pudenal nerve block

13

Spinal cord becomes cauda equina at what vertebral level?

L2 vertebra

14

SAS ends at which vertebral level?

S2

15

Anaesthesia is injected into which vertebral region?

L3-L4 to anaesthetise cauda equina

16

What is the surface landmark for injecting anaesthesia?

L4 spinous process
Superior point on iliac crests

17

Describe the layers a needle passes through for spinal anaesthetic

Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space
Dura matter
Arachnoid matter
SAS with CSF

18

Describe the layers a needle passes through for epidural anaesthetic

Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space

19

What is the distinguishing feature of ligamentum flavum?

Yellow as it is elastic

20

Describe sympathetic outflow below L2 vertebra

Sympathetic ganglia receive fibres from L2 via sympathetic chain
Distribute to lumbar, sacral, coccygeal spinal nerves

21

All spinal nerves and named nerves contain sympathetic fibres. True/ False?

True

22

What do sympathetic fibres supply, creating sympathetic tone? Blockage of sympathetic tone causes...

All arterioles
Vasodilatation

23

List signs that spinal anaesthetic is working

Flushed lower limbs
Warm lower limbs
Reduced sweating

24

The pudenal nerve supplies all of the perineum. True/False?

False
Supplies most of it - also supplied by ilioinguinal nerve

25

Outline the route taken by the pudenal nerve to structures of the perineum

Exits pelvis via greater sciatic foramen -->
Passes posterior to sacrospinous ligament -->
Reenters pelvis/ perineum via lesser sciatic foramen -->
Travels in pudenal canal -->
Branches supply perineum

26

What is the pudenal canal?

Passage in obturator fascia containing internal pudenal artery and vein, pudenal nerve and nerve to obturator internus

27

Which bony landmark is used in the administration of pudenal nerve block?

Ischial spine

28

List instances in which a pudenal nerve block can be applied

Labour
Forceps delivery
Vaginal delivery
Epiostomy

29

During labour, branches of which nerve can be torn?

Pudenal nerve (supplying levator ani and external anal sphincter)

30

Which component of the levator ani is typically torn fist during labour?

Puborectalis