ap 4 2 Flashcards
What are the three main sections of the small intestine?
Duodenum, jejunum, ileum
What is the primary function of the small intestine?
Absorption of nutrients and minerals from food
What structures in the small intestine increase surface area for absorption?
Villi and microvilli
What digestive enzyme is primarily secreted in the small intestine?
Pancreatic enzymes (amylase, lipase, proteases), and brush border enzymes
What is the role of the duodenum in digestion?
The duodenum receives chyme from the stomach and secretions from the pancreas and gallbladder to begin chemical digestion.
How does the small intestine move food along its length?
Peristalsis and segmentation
What is the primary function of the large intestine?
Absorption of water, electrolytes, and formation of feces
What are the main sections of the large intestine?
Cecum, colon (ascending, transverse, descending, sigmoid), rectum, and anal canal
How does the large intestine differ from the small intestine in function?
The large intestine is primarily involved in water absorption and waste formation, while the small intestine is responsible for nutrient absorption.
What are the main anatomical differences between the small intestine and large intestine?
The small intestine is longer, has villi and microvilli for nutrient absorption, and has a narrower diameter. The large intestine is shorter, lacks villi, and has a wider diameter.
How many lobes does the liver have?
Four lobes: right, left, caudate, and quadrate
What is the role of the liver in digestion?
The liver produces bile, processes nutrients from the digestive tract, detoxifies substances, and stores vitamins and minerals.
What is the function of the gallbladder?
The gallbladder stores and concentrates bile produced by the liver.
How does bile aid in digestion?
Bile emulsifies fats, breaking them into smaller droplets for easier digestion by enzymes.
What is the pathway of bile from the liver to the small intestine?
Bile flows from the liver through the hepatic ducts, into the common bile duct, and into the small intestine via the sphincter of Oddi.
What is the biliary system composed of?
The biliary system includes the liver, gallbladder, bile ducts (hepatic, cystic, and common bile duct), and the pancreas.
What is the function of bile?
Bile helps in the digestion and absorption of fats by emulsifying them and aiding in fat-soluble vitamin absorption (A, D, E, K).
How does blood flow through the liver?
Blood enters the liver through the hepatic artery (oxygenated blood) and the portal vein (nutrient-rich blood from the GI tract). It passes through liver sinusoids and drains into the hepatic veins, which lead to the inferior vena cava.
What is the function of the portal vein in the liver?
The portal vein carries nutrient-rich blood from the digestive organs to the liver for processing and detoxification.
What role do hepatocytes play in the liver?
Hepatocytes are responsible for processing nutrients, detoxifying substances, producing bile, and storing glycogen.
What is the anal canal?
The anal canal is the final part of the digestive tract that controls the excretion of feces.
What is the function of the internal and external anal sphincters?
The internal anal sphincter (involuntary) controls automatic release, while the external anal sphincter (voluntary) allows conscious control of defecation.
How does defecation occur?
When feces enter the rectum, stretch receptors signal the need to defecate, leading to the relaxation of the internal anal sphincter and voluntary control of the external anal sphincter.
