Anatomy: Large Intestine and Ileocecal Valve Function

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What is the result of peristaltic contractions in the small intestine?

Cephalad movement

Movement towards the mouth

Mixing of luminal contents

Caudad movement (correct)

What is the role of circular smooth muscle in the small intestine?

Only participates in peristaltic contractions

Participates in both segmental and peristaltic contractions (correct)

Does not contribute to intestinal motility

Only participates in segmental contractions

Which innervation promotes intestinal motility?

Parasympathetic innervation (correct)

Somatic innervation

Sympathetic innervation

Autonomic innervation

What characterizes the myoelectric activity in the fasting state of the small intestine?

Synchronized, rhythmic changes Signup and view all the answers

Which gastrointestinal hormones promote intestinal motility?

Gastrin and CCK Signup and view all the answers

What describes the migrating motor complex (MMC) observed in the fasting state of the small intestine?

Synchronous, rhythmic contractions Signup and view all the answers

What type of muscle makes up the internal sphincter of the anal sphincter?

Smooth muscle Signup and view all the answers

Which nervous system is responsible for transmitting the defecation reflex?

Enteric nervous system Signup and view all the answers

How is the external sphincter of the anal sphincter controlled?

Subconsciously Signup and view all the answers

What triggers the defecation reflex according to the text?

Distension of the organ wall Signup and view all the answers

When feces enter the rectum, which part of the colon helps in forcing feces toward the anus?

Sigmoid colon Signup and view all the answers

What kind of control does the internal sphincter have over defecation?

Involuntary control Signup and view all the answers

What is the primary function of the ileocecal valve?

To regulate the emptying of ileal contents into the cecum Signup and view all the answers

Which region of the large intestine serves as a reservoir function?

Colon Signup and view all the answers

What happens to the ileocecal sphincter immediately after a meal?

It intensifies the emptying of ileal contents into the cecum Signup and view all the answers

Where does the conversion of liquid content of ileocecal material to solid stool primarily occur?

Colon Signup and view all the answers

Which segment has a tonically contracted region that narrows the opening between the ileum and the cecum?

Ileocecal sphincter Signup and view all the answers

What triggers the relaxation of the ileocecal valve?

Gastroileal reflex Signup and view all the answers

What can cause constipation according to the text?

Tumors obstructing intestinal movement Signup and view all the answers

Why might even a slight spasm in the sigmoid colon cause serious constipation?

Due to excess feces accumulating above the spastic sigmoid colon Signup and view all the answers

What is a consequence of excessive colonic secretions after days of constipation?

Day or so of diarrhea Signup and view all the answers

How do colonocytes utilize short-chain fatty acids produced by colonic bacteria?

As their preferred energy substrate Signup and view all the answers

What role do some lipophilic end products play in the large intestine?

They are used as energy substrates by colonocytes Signup and view all the answers

Which statement is true regarding digestion and absorption in the large intestine?

Undigested complex carbohydrates and proteins are broken down by intestinal flora Signup and view all the answers

Why is it crucial for the stomach to allow only small amounts of fat into the intestine at one time?

To slow down fat digestion in order to match the speeds of protein and carbohydrate digestion Signup and view all the answers

How do the incretin hormones GIP and GLP-1 contribute to insulin release?

By promoting insulin release from the pancreas Signup and view all the answers

What is the role of sensors in the intestine wall that are sensitive to chyme osmolarity?

To regulate gastric emptying Signup and view all the answers

What is the function of the large intestine in terms of water and electrolyte absorption?

It reabsorbs water and electrolytes from chyme Signup and view all the answers

Why does chyme usually form a hyperosmotic solution in the digestive process?

To aid in the absorption of nutrients Signup and view all the answers

What happens to the unabsorbed chyme by the end of the ileum?

It is reduced to about 1.5 liters remaining in the alimentary canal Signup and view all the answers