Lecture 16 notes Colon and adaptations for herbivory

Mesentery

A fold of tissue that attaches the intestines to the abdominal wall and contains blood vessels, nerves, and lymphatics.

Mesenteric vessels

Blood vessels that supply the intestines.

Major functions of the colon

Absorbs water and ions to form solid feces and stores feces until removal.

Haustrations

The bulging caused by the contraction of the smooth muscle ring in the large intestine.

Mass movements

Propulsive movements occurring in the large intestine, typically 1-3 times per day, that force feces down the colon.

Defecation

The process that occurs when the rectum is full, leading to the desire for bowel movement.

Internal anal sphincter

The sphincter that is under involuntary control and remains closed until defecation.

External anal sphincter

The sphincter that is under voluntary control and remains closed at all times.

Colonic bacterial flora

The diverse community of bacteria in the gut, essential for fermentation and immune function.

Functions of colonic bacteria

Ferment carbohydrates, provide a barrier to harmful bacteria, and stimulate the immune system.

Cecal feces

A special type of feces produced by hindgut fermenters, which is eaten for nutrient absorption.

Coprophagy

The act of eating one's own feces to reabsorb nutrients.

Cecotropes

Special fecal material produced by rabbits, rich in nutrients.

Stretch Receptors

Sensory cells signaling fullness in the rectum

Foregut Fermenters

Animals like sheep that ferment food before stomach

Hindgut fermenters

animals like horses that ferment food after stomach

TLRs

proteins recognizing pathogens in the gut