Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS1 > Large intestine > Flashcards

Large intestine Flashcards

1
Q

What are the 3 parts of the large intestine?

A
  1. Caecum (to which the appendix is attached)
  2. Colon (ascending, transverse, descending, sigmoid)
  3. Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which feature prevents the reflux of chyme from the large intestine into the small intestine during peristalsis?

A

ileocecal valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is the ileocecal valve located?

A

In the ileocecal junction in the right iliac fossa. Located at the junction between the caecum and ascending colon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where is the caecum located?

A

In the right iliac fossa between the ileum (distal small intestine) and the ascending colon. It is inferior to the ileocecal junction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When can the caecum be palpated?

A

When it is enlarged enough from faeces, inflammation or a malignancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which parts of the large intestine are retroperitoneal (behind peritoneum)?

A

Ascending and descending colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which parts of the large intestine are intraperitoneal (completely wrapped in visceral peritoneum)?

A

Caecum, transverse colon and sigmoid colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which part of the large intestine is the least fixed and can therefore dip down into the pelvis in tall, thin individuals?

A

Transverse colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Between which flexures does the transverse colon lie?

A

The right colic / hepatic flexure and the left colic / splenic flexure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How long is the colon?

A

About 1.5m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which structures meet at the hepatic / right colic flexure?

A

Ascending colon turns 90 degrees when it meets the right lobe of the liver to move horizontally as the transverse colon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which structures meet at the splenic / left colic flexure?

A

Transverse colon turns 90 degrees to point inferiorly which becomes the descending colon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which section of the abdomen is the spleen located in?

A

Left hypochondrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which 3 structures are used to differentiate between the small and large intestine?

A

The large intestine contains taenia coli, haustra / haustrations and appendices epiploicae / omental appendices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the taenia coli?

A

3 longitudinal bands of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colon. Taenia coli contract to shorten the large intestine walls, propelling the faecal matter within by peristalsis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are haustra / haustrations?

A

Pouches / sacculations created by semilunar folds on the internal surface of the large intestine. They aid the circumferential contraction of the muscular layer of colon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are appendices epiploicae / omental appendices?

A

Fat filled pouches of the peritoneum attached externally to the walls of the colon (not the rectum). Function is unclear.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which is the most proximal part of the large intestine?

A

Caecum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which is the most distal part of the large intestine?

A

Rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is the rectum macroscopically distinct from the large intestine?

A

Absence of taenia coli, haustra and appendices epiploicae / omental appendices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Structure of the rectum and anus

A

The rectum is continuous with the sigmoid colon and contains rectal valves. The rectum terminates into the anal canal which contains the internal hemorrhoidal plexus, rectal sinus and sphincters. Terminates at the anus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Function of the rectum

A

Temporary store of faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Function of rectal valves

A

Support the weight of the faeces and slows the movement into the anal canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are rectal valves made of?

A

Inner circular muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Features of the anal canal

A

Internal hemorrhoidal plexus, rectal sinus, internal and external sphincters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the internal hemorrhoidal plexus?

A

A venus plexus (collection of veins) that surrounds the rectum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why are drugs given rectally faster acting than orally?

A

The drug enters the internal hemorrhoidal plexus which drains into the portal and systemic venus system (towards liver and heart) bypassing the the gut (oesophagus, stomach, small intestine).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Causes of haemorrhoids

A

Dilation of internal hemorrhoidal plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which sphincter in the anal canal is smooth muscle?

A

Internal sphincters - involuntary control by ANS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which sphincter in the anal canal is striated muscle?

A

External sphincters - voluntary control gained about age 2.

31
Q

How would you diagnose disorders of the large intestine, rectum and anal canal?

A

Barium enema - liquid containing barium is injected into the rectum and coats the colon lining. X-rays are taken.

32
Q

Examples of disorders of the large intestine, rectum and anal canal that can be investigated by barium enema

A

Colonic tumours, polyps, diverticula (out-pouches), anatomical abnormalities

33
Q

What forms the ileocaecal valve?

A

A fold of mucosa

34
Q

Where is the vermiform (worm-like) appendix found?

A

Attached to the caecum

35
Q

Similarities in the basic structure of the small and large intestine

A

Both have simple columnar epithelium with goblet cells, intestinal crypts of Leiberkuhn, and mucosal glands (mucous secretions)

36
Q

Differences in the structure of the small and large intestine

A

The large intestine doesn’t contain villi, has an incomplete layer of longitudinal muscle (taenia coli), has a ring-like arrangement of circular muscle (haustra) and has appendices epiploicae.

37
Q

Which 2 types of epithelial cells line crypts and intestinal villi?

A

Goblet cells (secrete mucus) and enterocytes (secrete water and electrolytes - doesn’t stain)

38
Q

What are enterocytes?

A

Simple columnar epithelial cells lining the small and large intestine. Secrete water and electrolytes and absorb nutrients.

39
Q

Where is the anal canal located?

A

Extraperitoneal between the recto-anal junction and anus

40
Q

What is the change in epithelium at the recto-anal junction?

A

In the rectum / large intestine the epithelium is simple columnar which changes to stratified squamous epithelium in the external anal canal.

41
Q

What are the 3 zones of the anal canal?

A

Colorectal (columnar) zone - anal columns, anal valves, sinuses, crypts of Morgagni, pectinate line
Intermediate zone - anoderm
Squamous / cutaneous zone - perianal skin

42
Q

How is the anal column divided?

A

The superior 2/3 is divided from the inferior 1/3 by the pectinate / dentate line which lies inferior to the crypts of Morgagni.

43
Q

Blood supply above the pectinate line (upper 2/3 of anal canal

A

Superior rectal artery

44
Q

Blood supply below pectinate line (inferior 1/3 anal canal)

A

Middle and inferior rectal arteries

45
Q

Venous drainage above pectinate line (superior 2/3 anal canal)

A

Superior rectal vein followed by hepatic portal circulation

46
Q

Venous drainage below pectinate line (inferior 1/3 anal canal)

A

Middle and inferior rectal veins followed by vena cava circulation

47
Q

Innervation above the pectinate line (superior 1/3 anal canal)

A

inferior mesenteric plexus, pelvic splanchnic nerves, inferior hypogastric plexus

48
Q

Innervation below the pectinate line (inferior 1/3 anal canal)

A

Pudendal nerve

49
Q

Epithelium in the colorectal zone of the anal canal

A

Simple columnar epithelium

50
Q

Epithelium in the transitional zone of the anal canal

A

Simple columnar and stratified squamous epithelium

51
Q

Epithelium in the anoderm zone of the anal canal

A

Stratified squamous non-keratinised epithelium

52
Q

Epithelium in the cutaneous / squamous zone of the anal canal

A

stratified squamous keratinised epithelium

53
Q

Function of anal canal

A

Fecal continence and defecation

54
Q

Function of colon

A

Absorb fluid and electrolytes from chyme, mixing chyme, peristalsis, mass movements

55
Q

Illness caused by the colon failing to reabsorb water

A

Diarrhoea

56
Q

What are intestinal / bacterial flora?

A

Resident microbial populations in the large intestine

57
Q

Functions of intestinal flora in the large intestine

A

Ferment dietary fibre (cellulose) and lipid, produce gases (flatus), synthesis vitamins (vit B complex and vit K)

58
Q

Which vitamins are synthesised in the large intestine by intestinal flora?

A

Vitamin B complex and vitamin K

59
Q

Function of vitamin B complex

A

Impact energy levels, brain function, cell metabolism, RBC growth, nerve function, preventing infections, cell health

60
Q

Function of Vitamin K

A

Important for blood clotting and wound healing. It is fat-soluble.

61
Q

Two aspects of motility function of large intestine

A

Mixing/squeezing chyme via circular muscles contraction to break down large faecal material for defaecation. Propulsive movements

62
Q

Two aspects of propulsive movements of the large intestine

A

Peristalsis and mass movements

63
Q

Function of peristalsis in large intestine

A

propels semi-solid faecal matter towards rectum. Is short range in the transverse and descending colon.

64
Q

What are mass movements?

A

Infrequent, more sustained contractions usually after meals (gastro-colic reflex). Moves chyme/faeces from proximal colon to distal colon

65
Q

What triggers the desire to defaecate?

A

Rectal distension

66
Q

What is defaecation?

A

An involuntary reflex that ejects faecal matter from the rectum via the anal canal.

67
Q

What is an ileostomy?

A

The ileum (proximal end of small intestine) is brought out through the abdominal wall. The opening is called a stoma and the faecal matter is collected in a bag.

68
Q

Name of procedure in which the proximal end of the colon is diverted through an opening in the abdominal wall to an external bag

A

Colostomy

69
Q

Why would an ileostomy or colostomy be carried out?

A

As a temporary or permanent measure after bowel cancer, to relieve inflammation or due to inflammatory bowel disease e.g. ulcerative colitis.

70
Q

What is diarrhoea?

A

Excessively watery stools 3 or more times a day

71
Q

Causes of diarrhoea

A

Mainly GIT infections. Results in failure of fluid absorption and reduced colonic motility

72
Q

Results of diarrhoea

A

Dehydration, electrolyte imbalance (need electrolyte replacement - cause of 1 in 9 children deaths worldwide)

73
Q

What is constipation?

A

Not defaecating at least 3 times a week. Hard, dry faeces that is difficult to pass.

74
Q

Cause of constipation

A

Increased fluid absorption, GIT spasm, drug side effect e.g. opiates (morphine), lack of dietary fibre.

BDS1 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions