Lecture 4 - Visceral pain and Pelvis

Question 1

What is the enteric NS?

Answer 1

‘Brain of the gut’, consisting of more than 100m intrinsic neurones that extend most of the GIT

Question 2

How is the ENS arranged?

Answer 2

In ganglionated plexuses with interconnecting bundles of unmyelinated nerve fibres

Question 3

What does the ENS allow the GIT to do?

Answer 3

Perform basic reflex functions of secretion, absorption, mixing and gut movements without the influence of CNS or ANS

Question 4

How does the CNS communicate with the ENS?

Answer 4

Via para/sympathetic nerves with intrinsic neurones of ENS to bring about modulation GIT functions

Question 5

Where do axons of intrinsic neurones of ENS project to?

Answer 5

Sympathetic ganglia, pancreas, gall bladder, trachea, spinal cord and brain stem

Question 6

What is the general plan of the GIT? FITB

Answer 6

Question 7

Where is the ENS distributed?

Answer 7

Intrinsic network of neurones is in the tissues of the gut wall from oesophagus to anus

Question 8

Where does the ANS innervate?

Answer 8

It has 2 divisions which innervate organs of abdomen and pelvis

Question 9

Where does the ANS arise from?

Answer 9

Different anatomical regions of CNS -> sympathetic arising from spinal cord segments T1-L2 and the parasympathetic system arising from cranial nerves III, VII, IX and X and spinal cord segments S2-4

Question 10

What is the function of the efferent autonomic nerves in the abdomen?

Answer 10

Motor to smooth muscle and secretomotor to glands

Question 11

What is the function of the afferent autonomic nerves in the abdomen?

Answer 11

Sympathetic: pain Parasympathetic: specific functional sensation (stretch)

Question 12

What are the sympathetic nerves to the abdomen? FITB

Answer 12

Question 13

At what spinal level does the greater splanchnic nerve emerge?

Answer 13

T5-9

Question 14

At what spinal level does the Lesser splanchnic nerve emerge?

Answer 14

T10-11

Question 15

At what spinal level does the least splanchnic nerve emerge?

Answer 15

T12

Question 16

Where does the parasympathetic supply come from in the organs of the abdomen and pelvis?

Answer 16

Vagus nerve (CNX) and sacral outflow (S2-4)

Question 17

How are the sympathetic autonomic nerves to peripheral vessels and skin distributed?

Answer 17

Sympathetic nerves run with somatic nerves to the same region

Question 18

How are the autonomic nerves to organs lacking somatic innervation distributed?

Answer 18

Most nerves run with arteries to same organs, with few cases where autonomic nerves run seperately

Question 19

What is a nerve plexus?

Answer 19

Interconnecting network of nerves

Question 20

How are the autonomic nerves to the abdomen routed?

Answer 20

Via plexuses surrounding the aorta and its branches

Question 21

Where do the sympathetic nerves synapse?

Answer 21

At the ganglia associated with these plexuses

Question 22

How are plexuses and ganglia named?

Answer 22

According to associated blood vessels

Question 23

What are the 9 main plexuses/ganglia in the abdomen?

Answer 23

Anterior vagal trunk, superior mesenteric ganglion, coeliac trunk and ganglion, renal plexus and ganglion, inferior mesenteric ganglion, sympathetic trunk and ganglion, superior hypogastric plexus and inferior hypogastric plexus

Question 24

Where are the 9 important plexuses/ganglia located? FITB

Answer 24

Question 25

Which nerve plexuses and ganglia surround the aorta and where do they innervate?

Answer 25

Question 26

Why is referred pain caused?

Answer 26

The cerebral cortex of the brain hasn't got a sensory map for visceral organs and diaphragm, so can't localise the pain from these, hence the pain is referred

Question 27

Where is the pain from visceral organs referred to?

Answer 27

Regions of skin supplied by nerves with the same segmental supply (dermatomes)

Question 28

What is a dermatome?

Answer 28

An area of skin supplied by a single spinal nerve (i.e. single segment of the spinal cord)

Question 29

How do dermatomes prevent complete anaesthesia in a region?

Answer 29

Adjacent dermatomes overlap so that on the trunk at least 3 spinal nerves would have to be blocked to produce a region of complete anaesthesia

Question 30

What does the dermatomal map of the body look like?

Answer 30

Question 31

What are the 9 abdominal regions and how are they formed (which lines)?

Answer 31

Question 32

In which of the 9 regions is the appendix?

Answer 32

Top right of the suprapubic region, nearly part of right inguinal region (main)

Question 33

What pain is referred to the epigastric region?

Answer 33

T7/8 - pain from foregut structures -\> including stomach, proximal duodenum, pancreas, liver, gall bladder

Question 34

What are the dermatomes of the abdominal wall?

Answer 34

Question 35

What pain is referred to the umbilical region?

Answer 35

From midgut structures (duodenal papilla to splenic flexure) including inflamed appendix referred to periumbilical region -\> usually colicky

Question 36

Where do the afferent pain fibres from the midgut enter the spinal cord?

Answer 36

Afferent pain fibres from midgut enters spinal cord at T10 and skin of umbilical region is also supplied by T10

Question 37

How does the pain in appendicitis progress?

Answer 37

Inflammation of appendix spreads to surrounding peritoneum, becoming localised and constant at right inguinal region -\> movement of hip joint, coughing eliciting pain

Question 38

What structures refer pain to the suprapubic region?

Answer 38

Pain from hindgut structures (descending colon to anal canal) -\> T12/L1-2)

Question 39

Fill in the blanks of the visceral referred pain map

Answer 39

Question 40

Fill in the blanks of the pelvic girdle structures

Answer 40

Question 41

Fill in the structures of the right hip bone

Answer 41

Question 42

What are the main structures of the pelvic wall?

Answer 42

Sacrum and coccyx, pelvic bones and sacrospinous and sacrotuberous ligaments

Question 43

Fill in the structures of the right hip bone and sacrum

Answer 43

Question 44

What is the difference in the axis of the pelvic and abdominal cavity?

Answer 44

45 degrees further backwards from the abdominal cavity

Question 45

Where is the pelvic inlet and outlet located?

Answer 45

Question 46

What does the iliac fossae form?

Answer 46

Shallow basin containing lower abdominal viscera

Question 47

How is the axis of the pelvic cavity inclined?

Answer 47

Anteroinferiorly

Question 48

What shape is the pelvic cavity?

Answer 48

Conical or cylindrical

Question 49

What lines the pelvic cavity?

Answer 49

Muscles and nerves

Question 50

Fill in the blanks of the pelvic wall structures

Answer 50

Question 51

What covers most of the pelvic bone facing the pelvic cavity?

Answer 51

Obturator internus muscle and its fascia

Question 52

Fill in the blanks of the pelvic wall muscles and ligaments

Answer 52

Question 53

What are the names of the ligaments and muscles in the pelvic wall?

Answer 53

Piriformis muscle, obturator internus muscle, sacrospinous ligament and sacrotuberous ligament

Question 54

Fill in the muscles forming the pelvic diaphragm in a medial aspect

Answer 54

Question 55

What muscles does the levator ani muscle consist of - from the pelvic diaphragm muscles?

Answer 55

Iliococcygeus, pubococcygeus, puborectalis

Question 56

What is the tendinous arch formed from?

Answer 56

Obturator internus fascia

Question 57

What does the pelvic diaphragm consist of?

Answer 57

Bowl-like pair of skeletal muscles -\> levator ani which are slung from the pelvis and sacrum

Question 58

What is the function of the levator ani?

Answer 58

Support the main pelvic organs

Question 59

What are the pelvic organs?

Answer 59

Bladder, cervix/uterus and rectum

Question 60

What is the nerve supply to the pelvic diaphragm?

Answer 60

Pudendal S2-4 and directly by S4

Question 61

Fill in the blanks of the pelvic diaphragm in a sagittal plane

Answer 61

Question 62

Fill in the blanks of the pelvic diaphragm inferior view

Answer 62

x

Question 63

What are the openings in the levator ani muscle for?

Answer 63

Urethra, vagina (female) and anal canal

Question 64

What is the perineal membrane?

Answer 64

Inferior layer of the fascia of the urogenital part of the pelvic diaphragm

Question 65

What is underneath the pelvic diaphragm?

Answer 65

Perineum which contains voluntary sphincters and external genitalia

Question 66

Where is the urinary apparatus located?

Answer 66

Lower part is located in the pelvic cavity

Question 67

Fill in the blanks of the male pelvis in sagittal section

Answer 67

Question 68

Fill in the blanks of the male pelvis in a coronal section

Answer 68

Question 69

What is the fat filled space in the male pelvis called?

Answer 69

Ischio-anal fossa

Question 70

Fill in the blanks of the urethral sphincters in males

Answer 70

Question 71

What kind of muscle makes up the internal and eternal urethral sphincter?

Answer 71

Internal: Smooth External: skeletal

Question 72

Fill in the blanks of the female pelvis

Answer 72

Question 73

How are the internal urethral sphincter in the female organised?

Answer 73

The internal sphincter isn't well organised

Question 74

What are the urethral sphincters present in the female?

Answer 74

Internal/external urethral sphincter, sphincter urethrovaginalis and compressor urethrae

Question 75

What is the external urethral sphincter made of?

Answer 75

Skeletal muscle surrounding the urethra in the deep perineal pouch

Question 76

Fill in the blanks of the urethral sphincters in the female

Answer 76

Question 77

What is the shape of the bladder?

Answer 77

Tetrahedral (when empty), with a structure at each corner of the tetrahedron

Question 78

Fill in the blanks of the urinary bladder

Answer 78

Question 79

What structures enter at each corner?

Answer 79

Ureters at supero-posterior angles. Urethra leaves through inferior angle

Question 80

What covers the superior surface of the bladder?

Answer 80

Peritoneum

Question 81

Where does the bladder expand to?

Answer 81

Between transversalis fascia and lining peritoneum

Question 82

Where is the location of the 2 sphincters?

Answer 82

Smooth muscle (vesicae) sphincter at neck and skeletal muscle (urethrae) sphincter in perineum

Question 83

What is the shape of the rectum?

Answer 83

Double-S bend -\> probably acting as an anti-gravity device keeping the load off the sphicter

Question 84

Fill in the blanks of the rectum

Answer 84

Question 85

What is the rectum innervated with and what is it mainly sensitive to?

Answer 85

By autonomic NS and mainly sensitive to filling

Question 86

What is the anal canal innervated with and what is it mainly sensitive to?

Answer 86

By somatic nerves and extremely sensitive to injury

Question 87

Which muscles are important for faecal continence?

Answer 87

Sphincter ani is less important (surrounds anal canal) and puborectalis part of levator ani, which puts a sharp angle into the recto-anal junction

Question 88

How can the puborectalis be injured?

Answer 88

In a badly performed episiotomy

Question 89

How does the rectum become the anal canal?

Answer 89

Rectum descends within the concavity of sacrum, showing 3 lateral curvatures, with right angle bend back at recto-anal junction

Question 90

What types of muscles form the external and internal sphincters of the rectum?

Answer 90

Smooth muscle - internal and skeletal muscle - external

Question 91

What is the main functional sphincter?

Answer 91

Pubo-rectalis sling of levator ani

Question 92

What type of nerves supply the rectum and anal canal?

Answer 92

Rectum -\> visceral Anal canal -\> somatic

Question 93

What artery supplies the pelvic organs?

Answer 93

Internal iliac artery supplies pelvic organs (all but the ovaries), pelvic walls and much of the gluteal region

Question 94

Fill in the blanks of the arterial supply of the pelvic organs

Answer 94