8: Anatomy - Faecal continence

Question 1

What structures are included in the distal GI tract?

Answer 1

Rectum

Anal canal

Anus

Question 2

What is the function of the distal GI tract?

Answer 2

Excrete stool

Question 3

What is the holding area for faeces?

Answer 3

Rectum

Question 4

Which nerve fibres supply the rectum to detect its level of “fullness”?

Answer 4

Visceral afferents

Question 5

Muscle sphincters in the distal part of the anus (contract / relax) to prevent defecation.

Answer 5

contract

Question 6

Muscle sphincters in the distal part of the anus (contract / relax) to allow defecation.

Answer 6

relax

Question 7

The rectum is located within the ___ cavity.

Answer 7

pelvic

Question 8

Which muscle forms the pelvic floor?

Answer 8

Levator ani muscle

Question 9

Which tracts pass through the levator ani?

Answer 9

GI tract

Renal tract

Reproductive tract

Question 10

At which line does the sigmoid colon become the rectum?

Answer 10

Recto-sigmoid junction

Question 11

At which vertebral level is the recto-sigmoid junction found?

Answer 11

S3

Question 12

Which part of the rectum stores most of the faecal material and is found superior to the levator ani?

Answer 12

Rectal ampulla

Question 13

The walls of the rectal ___ can relax to accomodate faeces.

Answer 13

ampulla

Question 14

What lies anterior to the inferior rectum in males?

Answer 14

Prostate gland

Question 15

What lies anterior to the inferior rectum in females?

Answer 15

Vagina and cervix

Question 16

When naming pouches, what does “vesico/vesical” mean?

Answer 16

Bladder

Question 17

What is the pouch found in the abdominal cavity of males?

Answer 17

Rectovesical pouch

Question 18

What are the two pouches found in the abdominal cavity of females?

Answer 18

Rectouterine pouch (of Douglas)

Vesicouterine pouch

Question 19

Which muscle supplies support for the pelvic organs?

Answer 19

Levator ani

Question 20

Which branch of the sacral plexus supplies the levator ani?

Answer 20

“Nerve to levator ani”

not joking

Question 21

The pudendal nerves supply the levator ani. At which vertebral levels do these nerves originate?

Answer 21

S2,3,4

s2,3,4 keeps the pelvis off the floor

Question 22

Which muscle of the levator ani acts like a sphincter to constrict the rectum voluntarily?

Answer 22

Puborectalis

Question 23

Which two anal sphincters maintain faecal continence?

Answer 23

Internal anal sphincter

External anal sphincter

Question 24

Which type of muscle makes up the internal anal sphincter?

Answer 24

Smooth muscle

Question 25

Which type of muscle makes up the **external anal sphincter**?

Answer 25

**Skeletal muscle**

Question 26

The **anal canal** is found inferior to the ___ junction.

Answer 26

**anorectal**

Question 27

Which **autonomic** nerves **contract** the internal anal sphincter?

Answer 27

**Sympathetic nerves** fight or flight - why would you defecate while running away from a lion

Question 28

Which autonomic nerves **relax** the **internal anal sphincter**?

Answer 28

**Parasympathetic nerves**

Question 29

Which stimulus **relaxes** the **internal anal sphincter**?

Answer 29

**Distension of the rectal ampulla**

Question 30

Which nerve stimulates the **contraction** of the **external anal sphincter**?

Answer 30

**Pudendal nerve** S2,3,4

Question 31

Which part of the body is found **below** the **levator ani**?

Answer 31

**Perineum**

Question 32

Generally, which arms of the nervous system supply structures in the **pelvis**?

Answer 32

**Visceral afferents** **Sympathetic** **Parasympathetic**

Question 33

Generally, which arms of the nervous system supply the **perineum**?

Answer 33

**Somatic motor** **Somatic sensory**

Question 34

**Sympathetic nerves** from which **spinal cord levels** supply the rectum and anal canal?

Answer 34

**T12 - L2**

Question 35

Where do rectum / anal canal **sympathetic nerves** synapse?

Answer 35

**Inferior mesenteric ganglia**

Question 36

How do **post-synaptic sympathetic nerves** travel to the rectum and anal canal?

Answer 36

**Periarterial plexuses**

Question 37

**Sympathetic nerves** (contract / relax) the **internal anal sphincter**.

Answer 37

**contract**

Question 38

**Sympathetic nerves** (inhibit / stimulate) **peristalsis.**

Answer 38

**inhibit**

Question 39

**Parasympathetic fibres** supply the rectum / anal canal from which **spinal cord levels**?

Answer 39

**S2 - S4**

Question 40

How do **parasympathetic nerves** travel to the rectum / anal canal from S2 - S4?

Answer 40

**Pelvic splanchnic nerves**

Question 41

Where do **parasympathetic nerves** supplying the rectum / anal canal **synapse**?

Answer 41

**In the walls of the rectum / anal canal**

Question 42

**Parasympathetic nerves** (contract / relax) the **internal anal sphincter****.**

Answer 42

**relax**

Question 43

**Parasympathetic nerves** (inhibit / stimulate) **peristalsis**.

Answer 43

**stimulate**

Question 44

Which nerves **piggy-back** on the parasympathetic nerves as they return back to S2-S4 on the way to the CNS?

Answer 44

**Visceral afferents**

Question 45

Which **somatic nerves** travel from S2-S4 to contract the external anal sphincter and puborectalis?

Answer 45

**Somatic motor** (via the pudendal nerves, S2-S4)

Question 46

Which nerve, a branch of the **sacral plexus**, supplies the **external anal sphincter**?

Answer 46

**Pudendal nerve**

Question 47

Which two holes in the **pelvis** transmit the **pudendal nerve**?

Answer 47

**Greater sciatic foramen** **Lesser sciatic foramen**

Question 48

In women, which event can damage **pudendal nerve** fibres or **external anal sphincter** muscles?

Answer 48

**Childbirth**

Question 49

Why may a woman be **incontinent** after childbirth?

Answer 49

**Tearing of perineum** inc. nerves, muscle and external anal sphincter

Question 50

What is the **pectinate line?**

Answer 50

**Line between endoderm and ectoderm** arterial, venous, lymphatic and nerve supplies differ above and below

Question 51

What are the major lymph nodes draining pelvic organs, from inferior to superior?

Answer 51

**External iliac** **Internal iliac** **Common iliac** **Lumbar**

Question 52

Which artery supplies the **hindgut** organs?

Answer 52

**Inferior mesenteric artery**

Question 53

Which **artery** supplies the **remainder** of the GI tract after the hindgut?

Answer 53

**Internal iliac artery**

Question 54

Which arteries anastomose to supply the rectum and anal canal?

Answer 54

**Inferior mesenteric artery** **Internal iliac artery**

Question 55

Which vein drains the rectum and anal canal **above** the pectinate line?

Answer 55

**Inferior mesenteric vein**

Question 56

Which venous **system** drains the hindgut?

Answer 56

**Portal venous system**

Question 57

Which vein drains the anus **below** the pectinate line?

Answer 57

**Internal iliac vein**

Question 58

Which venous **system** drains below the pectinate line?

Answer 58

**Systemic venous system**

Question 59

Are **rectal varices** and **haemorrhoids** the same thing?

Answer 59

**No**

Question 60

What are **rectal varices**?

Answer 60

**Dilation of portal-systemic anastomoses due to portal hypertension**

Question 61

What are **haemorrhoids**?

Answer 61

**Prolapses of rectal venous plexuses**

Question 62

Which areas, near the anal canal, are filled with fat and loose connective tissue?

Answer 62

**Ischioanal fossae**