Brainscape's Knowledge GenomeTM

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


See full index

Gastrointestinal > Lecture 15- Rectum and anal canal anatomy > Flashcards

Lecture 15- Rectum and anal canal anatomy Flashcards

1
Q

how long is the rectum

A

12-15cm long passes through the pelvic floor

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

anatomy of the rectum

A
  • Has a continuous band of outer longitudinal muscle
  • Curved shape anterior to sacrum
  • Parts covered in peritoneum (some parts extraperitoneal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

function of the rectum

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

where does the anal canal start

A
  • Starts at the proximal border of the anal sphincter complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

anatomy of the anal canal

A
  • Rectum points anteriorly
  • Puborectalis sling changes the direction of anatomy
  • Ana canal points posteriorly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Anal is involved in continence

  • Factors required:
A
  • Distensible rectum
  • Firm bulky faeces
  • Normal anorectal angle
  • Anal cushions
  • Normal anal sphincters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

blood supply the rectum

A

blood supply to rectum is from sevral arteries that for a plexus

  • superior rectal artery
  • middle rectal artery
  • inferiro rectal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

superior rectal artery is a continuation of the

A

inferior mesenteric artery

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

middle rectal artery is a continuation of the

A

internal iliac

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

inferior rectal artery is a contiuation of the

A

pudendal artery

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

venous drainage of the rectum

A
  • portal draiange through superior rectal vein
  • systemic driange through internal iliac vein
    • portional for porto-systemic anastomosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

anal sphincter complex comprises

A
  • internal involuntary sphincter
  • external anal sphincter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

internal involuntary sphincter

A
  • thickening of circular smooth muscle
  • under autonomic control (80% of resting anal pressure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

External anal sphincter is

A

striated muscle–> under more voluntary control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  • External anal sphincter is striated muscle
A
  • Deep section
    • Upper anal canal
    • Mixes with fibres from Levator ani
    • Joins with puborectalis to form sling
  • Superficial and subcutaneous section
  • Nerve supply- pudendal nerve- conscious control
  • 20% of resting pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

process of dafaecation

A
  1. mass movement
  2. defecation reflex
    • stimulus= distension in rectum
    • responses
      • contraction in rectum and sigmoid colon
      • relaxation of internal anal sphincter
      • contraction of external anal sphincter
  3. increased pressure in rectum
  4. delay of defaecate
  5. delay
    • contraction of external anal sphincter
    • contraction of puborectalis muscle
    • reverse peristalsis in rectum
  6. defaecate
    • relaxation of external anal sphincter
    • relaxation of puborectalsis muscle
    • forward peristalisis in rectum and sigmoid colon
    • valsalva maneuver (increased abdominal pressure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

valsalva maneuver

A

increased abdominal pressure

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

where is the dentate canal found

A

the anal canal

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

what is the dentate line in the anal canal

A

junction of hindgut and proctodaeum (ectoderm)

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

above the dentate line what sort of pain receptors are there

A

visceral pain receptors

21
Q

above the dentate line what sort of cells are found

A

columnar epithelium

22
Q

below the dentate line what sort of pain receptors are found

A

somatic pain receptors

23
Q

below the dentate line what sort of epithelium is found

A

stratified squamous epithelia

24
Q

visceral opain receptors type of pain

A

vague, not localized

25
Q

somatic pain

A

sharp well localised- very painful

26
Q

haemorrhoids are caused by

A

problems with anal cushions

27
Q

anal cushions

A
  • (PLEXUS OF BLOOD VESSELS FORMS PART OF CONTINCNECE)
28
Q

plexus of blood vessels which form anal cushions

A
  • Divided into 3+ areas of tissues called anal cushions
    • posterior
    • antirior
    • lateral
  • Play a role in anal continence
  • There are connections between the veins and some arteries
  • Present from birth and a normal finding
29
Q

haemorrhoids can be classified as…

A

internal or external haemorrhoids

30
Q

Internal haemorrhoids found

A

above the dentate line

31
Q

external haemorrhoids

A

found below the haemorrhoid line

32
Q

features of internal haemorrhoids

A
  • Loss of connective tissue support
  • Above dentate line
  • Relatively painless
  • Enlarge and prolapse through anal canal
  • Bleed bright red blood
  • Pruritus’
33
Q

treatment for internal haemorrrhoids

A
  • Increased hydration/ high fibre diet - soften stool
  • Avoid straining
  • Rubber band ligation
  • Surgery
34
Q

grading of haemorrhoid: grade 1

A

no prolapse just prominent blood vessels

35
Q

stage 2 internal hameorrhoids

A

prolapse upon bearing down, but spontaenous reduction

36
Q

grade 3 internal haemorrhoids

A

prolapse upon bearing down requiring manual reduction

37
Q

stage 4 intenral haemorrhoid

A

prolapse with inability to be manually reduced

38
Q

external haemorrhoids are found

A

below dentate line

39
Q

features of external hameorrhoids

A
  • below dentate line
    • swelling o anal cushions which may then thrombose
    • painful ++
    • surgery has good outcome
40
Q

anal fissure

A

linear tear in andoderm (usually posterior midline)

41
Q

cause of anal fissure

A
  • High internal and sphincter tone
  • Reduced blood flow to anal mucosa
  • passing of hard stool
42
Q

symtoms of anal fissure

A
  • Pain on defaecation ++
  • Haematochezia
43
Q
  • Haematochezia
A

Hematochezia is the passage of fresh blood per anus, usually in or with stools.

44
Q

causes of haemotochezia most common

A

diverticulitis

45
Q

other causes of haematochexia

A
  • Diverticulitis’s
  • Angiodysplasia (small vascular malformation in boewl wall)
  • Colitis
    • IBD
    • Infective
  • Colorectal cancer
  • Anorectal disease
    • Haemorrhoids
    • Anal fissure
  • Upper GI bleeding (least common)
    • Large bleed with fast transit
46
Q

malaena

A
  • Black tarry stools
    • Offensive smelling
    • Due to Hb being altered by digestive enzymes and gut bacteria
47
Q
  • Common causes of melaena
A
  • Upper GI bleeding
    • Peptic ulcer disease
    • Variceal bleeds
    • Upper GI malignancy
    • Oesophageal/ gastric cancer
48
Q
  • Uncommon causes of melaena
A
  • Gastritis
  • Meckels diverticulum
  • Iron supplements

Gastrointestinal (35 decks)

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