McClure Quiz 2 4/13/11

Aha! Finally getting around to another study guide. Her questions have become better and I need a change of pace from just reading the notes.
Also, will post what I currently have but will take it down, finish the questions tomorrow, and repost.

31. Describe the lobes and ligament of the liver.
Four lobes: left, right, caudate and quadrate (just like in lab...).
Falciform ligament divides right and left lobes, and circle lig. used to be the umbilical cord.


32. Explain the structure anatomically anchors the liver to the stomach.
The lesser omentum!

33. Describe the anatomical relationship between the liver and the gallbladder.
Gallbladder sits directly underneath liver and is connected most directly via the common bile duct.

34. Describe the microscopic structure of the liver? Name the components of portal
triads.
Lobules are the functional units- hexagon in shape, connected by central veins, and made up of smaller hepatocytes.

35. Describe the functions of hepatocytes.
Process nutrients, store fatty vitamins, detoxify the blood, and produce bile

36. Describe the duct system transporting bile.
Gathered from lobules, filtered down to gallbladder via bile ducts (part of the portal triad), secreted into duodenum, reabsorbed in ileum, gathered in hepatic portal system and returned to liver.

37. Describe the compositions and functions of bile.
Made of bile salts (breaking down fats), bilirubin, neutral fats, phospholipids and electrolytes.
Green-yellow color and basic (alkaline) in nature.
Used mainly for breaking down fat.

38. Explain the chemical and neural regulations of bile release, and list the functions
of cholecystokinin.
Refer to q41

39. List the exocrine functions of pancreas.
Acini secrete the pancreatic juices and zymogen granules (found within the acini) release digestive enzymes.

40. Describe the composition of pancreatic juice. Explain the functions of trypsinogen
and procarboxypeptidase in digestion.
It is a watery solution that is slightly basic (for neutralizing chyme). Also full of electrolytes, mainly bicarbonate (HCO3-), and a variety of enzymes like amylase, lipase, nuclease, and the inactive form of protease.

Trypsinogen, procarboxypeptidase, and chymotropsinogen are all proteases and activated in the duodenum by trypsin, which is naturally located on the walls there.

41. Describe the chemical and neural regulation of pancreatic secretion.
There are a few different ways it is activated. It starts with either a buildup of bile salts in the enterohepatic circulation, or cell exposure to fatty chyme and HCl in the duodenum.
Next once these intestinal cells, specifically cholecystokinin, have been exposed to proteins and fat in chyme it causes the hepatopancreatic sphincter to relax and secrete juices. Pressure in this area also produces minor vagal nerve stimulation which does nearly the same thing.
CCK -> enzyme-rich pancreatic juice
Secretin (not a mispelling!) -> bicarbonate-rich pancreatic juice
Vagal nerve -> minor pancreatic juice release

42. Name different divisions of small intestine.
Stomach -> Duodenum -> Jejunum -> Ileum -> Cecum

43. Define plicae, villi and microvilli.
Plicae- a fold or ridge of tissue
Villi- finger-like projections increasing surface area
Microvilli- same as villi just smaller

44. List the cells found in the epithelium of the mucosa in small intestine. Describe
the stimuli which trigger and release of intestinal juice from intestinal glands.
Sorry, not going to cover this- ha! Not covered much in notes and a lot of this is covered in other questions anyways I believe.

45. Describe how chyme is digested in the small intestine.
Chyme is release to the small intestines in a hypertonic solution. This solution needs a variety of enzymes, bicarbonate, and bile to break it down. A constant mixing due to peristalsis and segmentation ensure the chyme and chemicals interact.

46. Describe the neural control of mobility of the small intestine. Explain the roles of
gastroileal reflex and gastrin.
Neurons in the intestines coordinate with the brain to move things along. Nerves controlled by acetylcholine can also stimulate these muscles that move chyme along.
As chyme travels along the small intestine these muscle reflexes become stronger, which is known as the gastroileal reflex. The chemical gastrin further increases the strength of this muscle reflex.
A strong reflex is needed to push the chyme into the large intestines.