fisiologia digestiva (bcm ii)

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FISIOLOGIA DIGESTIVA (BCM II)FISIOLOGIA DIGESTIVA (BCM II)

Clase 10: Fisiología del colonClase 10: Fisiología del colon

Dr. Michel Baró A.


The anatomy of the colon is shown


Circular and longitudinal muscle layers in colon


The layers of the colonic wall are shown


Normal colonic mucosa in biopsy specimen


Maturation process of colonic epithelial cells

(3 a 5 días)


A human rectal columnar epithelial cell


Arterial blood supply to the colon is shown


The venous system that drains the colon is shown


The extrinsic innervation of the colon


Intrinsic innervation of the colonic wall


Ganglia in submucosal and myenteric plexuses


Lymph nodal drainage of the colon and anus (a)


Lymph nodal drainage of the colon and anus (b)


Scintigraphic pattern of colonic transit


Time a substance spends in each region of colon


Distinct motor patterns as measured by manometry

Contracciones de corta duración: estacionarias, de mezclaContracciones de larga duración: estacionarias o migratorias brevesContracciones de gran amplitud: movimientos de masa


Patterns of migration of contractions


Presence and intensity of short-duration contractions


Colonic electrical control or slow-wave activity

Borde submucoso Borde mientérico


Electrical activity from the human colon

SSB: Short spike burst. LSB: Long spike burst. MLSB: Migrating long spike burst


Patterns of motor and myoelectric activity (perros)


Development of high-amplitude propagating contractions


Colonic contents and motor activity in colon


Motility of colon over 24-hour period

Colonic motilityindex


Gastrocolonic motor response to meal ingestion


Fecal bolus in the colon has been postulated


Mediation of both limbs of colonic peristaltic reflex


Motor activity of colon modulated by vagal activity (ferret)

Actividad fásica espontánea del colon proximal


Colonic motor function can be significantly altered

Am J Med 1951


Summary of small intestinal and colonic fluid balance


Major electrolyte transport mechanisms

TABLE 1 - 32. MAJOR ELECTROLYTE TRANSPORT MECHANISMS

Pumps Carriers Channels

Electrogenic Na+ absorption Na+, K+ - ATPase Na+

Electroneural Na+ absorption Na+, K+ - ATPase Na+/H+ Exchange Cl - /HCO3 - Exchange

K+ Secretion Na+, K+ - ATPase Na+, K+, Cl - Cotransport K+

Cl - Secretion Na+, K+ - ATPase Na+, K+, Cl - Cotransport Cl -

HCO3 - Secretion Na+, K+ - ATPase Cl - /HCO3 - Exchange


Proposed pathways of active sodium transport in colon (a)


Proposed pathways of active sodium transport in colon (b)


The colon exhibits a net secretion of potassium


Sodium absorption and potassium secretion


The colonic lumen possesses a luxuriant flora


Fecal flora organisms

TABLE 1 - 37. THE FECAL FLORA ORGANISMS FOUND IN HEALTHY HUMANS

Flora, %

Genus Moore and Holdeman [27]GIC01-02-01rfref27

Finegold et al.[28]GIC01-02-01rfref28

Bacteroides 30 56

Eubacterium 26 14

Bifidobacterium 11 4

Peptostreptococcus 9 4

Fusobacterium 8 0.1

Ruminococcus 4 9

Clostridium 2 2

Lactobacillus 2 1

Unclassifiable 2 -

Streptococcus 2 6

Facultative gram - negatives 0.5 0.1

Propionibacterium and Actinomyces

0.3 0.6

Staphylococcus 0.1 0.01

Coprococcus 0.1 0.1

Acidaminococcus - 0.2

Organisms found to make up 0.1% or more of the flora


The anatomy of the rectum and anus


The muscular arrangement of the levator ani muscles


The histology of the rectal and anal mucosae


The arterial blood supply specific for the anus


Factors necessary for maintenance of fecal continence


The pressure profile of the anal canal


Triple loop mechanism of external anal sphincter


Epithelial nerve endings provide a specialized system


Fecal continence aided by highly compliant rectum (a)


Fecal continence aided by highly compliant rectum (b)


The reflex responsiveness of the anal region

Reflejo inhibitorio rectoanal


Defecation involves a coordinated interaction


Summary of muscular actions required for defecation


Manometric and electromyographic responses to defecation


Alteraciones motoras del colon


Sagittal view of anorectal anatomy


Incontinencia fecal


Anorectal continence mechanisms

TABLE 5 - 2. ANORECTAL CONTINENCE MECHANISMS

Reservoir elements

Rectal compliance/accomodation

Colonic compliance/accomodation

Sensorimotor elements

Anorectal angle

Rectal sensation

Anal sensory nerves

Internal anal sphincter

External anal sphincter


Diagnostic studies for fecal incontinence

TABLE 5 - 3. DIAGNOSTIC STUDIES FOR FECAL INCONTINENCE

Tests Information Obtained

Sigmoidoscopy Inflammation, strictures, tumors

Anorectal manometry Sphincter pressures

Rectal sensation, compliance

External sphincter responses

Pelvic floor neurophysiology External sphincter electromyography

Puborectalis electromyography

Pudendal nerve conduction

Proctography Rectal capacity

Anorectal angle

Perineal descent

Retention of contrast

Anal ultrasonography Anal sphincter integrity


Diagnostic studies for fecal incontinence


Anorectal function in neurogenic disorders


Fecal incontinence associated with spinal cord injury


Anorectal findings in spinal cord injuries

TABLE 5 - 7. ANORECTAL FINDINGS IN SPINAL CORD INJURIES

Parameters Sacral Suprasacral

Rectal sensation Usually absent Absent

Basal anal pressure Normal or low Normal

Anal squeeze pressure

Probably absent Absent

Reflex defecation Usually absent Present

Impending defecation

No warning, but occasionally abdominal pain is present

Often no warning; autonomic signs present


Fecal incontinence associated with pudendal neuropathy (A)


Fecal incontinence associated with pudendal neuropathy (B)


Fecal incontinence associated with pudendal neuropathy (C)


Fecal incontinence associated with pudendal neuropathy (D)


External sphincter electromyographic patterns (A)


External sphincter electromyographic patterns (B)


External sphincter electromyographic patterns (C)


Pudendal nerve latencies


Anal endosonography


Normal anatomy as viewed by anal endosonography (A)


Normal anatomy as viewed by anal endosonography (B)

Esfinterotomía(interno)


Normal anatomy as viewed by anal endosonography (C)

Desgarro obstétrico


Anorectal manometry in fecal incontinence (A)


Anorectal manometry in fecal incontinence (B)

normal


Biofeedback (A)


Biofeedback (B)


Constipación


Colonic scintigraphy (A)


Colonic scintigraphy (B)


Colonic transit of markers


Colonic transit patters in chronic constipation (A)

TABLE 5 - 17A. NORMAL TRANSIT CONSTIPATION–WILLFUL DECEPTION

Complaint: 32 - year - old female; infrequent defecation for several years; all tests normal

Colon transit study:

Day R L RS Total

1 10 9 1 20

2 0 2 7 9

3 0 0 0 0

Bowel diary: one stool in 14 days


Colonic transit patters in chronic constipation (B)

TABLE 5 - 17B. SLOW TRANSIT CONSTIPATION–COLONIC INERTIA

Complaint: 22 - year - old female; infrequent defecation for 4 years; increasingly disabled

Colon transit study:

Day R L RS Total

1 12 8 0 20

3 6 9 5 20

5 2 9 4 15

7 0 10 5 15

Bowel diary: two stools in 14 days


Colonic motor activity can be studied (A)


Colonic motor activity can be studied (B)


Propagating contractions in healthy control subjects vs constipated


Colonic motility within 30 mins after breakfast


Distal bowel in Hirschsprung's disease (A)


Distal bowel in Hirschsprung's disease (B)


Balloon manometry


Idiopathic megacolon


Rectal compliance in idiopathic megarectum


Using the Schuster-type balloon manometer

y puborectal


Pressure changes and electromyographic recordings


Rectocele (A)


Rectocele (B)


Subtotal colectomy with ileorectal anastomosis


Diagnostic or Rome criteria

TABLE 5 - 29. DIAGNOSTIC OR ROME CRITERIA FOR IRRITABLE BOW EL SYNDROME

At least 3 months of continuous or recurrent symptoms of:

Abdominal pain or discomfort

Relieved with defecation and/or

Associated with change in stool frequency

Associated with change in stool consistency

Two or more of the following symptoms at least 1/4 of the time

Altered stool frequency (< 3/wk or > 3/day)

Altered stool form (hard or loose)

Altered stool passage (staining, urgency, incomplete evacuation)

Passage of mucus

Bloating/abdominal distension


Barium enema in irritable bowel syndrome patient


Emotions and colon motility


Emotions and colonic motility (A)

Delay stressor

motor

EMG

Pneumograma


Emotions and colonic motility (B)


Emotions and colonic motility (C)


Visceral sensations


A 73-year-old woman with constipation


Fin

fisiologia digestiva (bcm ii)

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