Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Body_TP > Liver/Pancreas Histology > Flashcards

Liver/Pancreas Histology Flashcards

1
Q

liver

A

-largest organ in the abdoment and also a gland since it secretes proteins and hormones the body needs
-divided into a larger right lobe and a smaller left lobe by the falciform ligament
-each lobe is further divided into 2 sectors by the right hepatic vein and left hepatic vein —> sectors are then divided into a total of eight hepatic segments which each have redundant functions but their own blood supply and biliary drainage
-within the hepatic segments are hepatic lobules, which have hexagonal structures centered around a central vein, surrounded by portal triads at the periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

dual blood supply of liver

A

-hepatic artery brings in oxygen-rich blood from the heart (25% of blood supply)
-portal vein brings nutrient-rich but oxygen-poor blood from the GI tract (provides 75% of the blood supply)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

liver function

A

-detoxification- all blood leaving the stomach and intestines passes through the liver —> it removes toxins, byproducts, bacteria, and old RBCs
-bile production- a fluid critical for digestion of fats and absorption of fat-soluble vitamins in the small intestine
-storage- stors a significant amount of vitamins, minerals, and glycogen
-blood clotting regulation
-immune system support
-produces albumin, which controls osmotic pressure by keeping the fluids in the bloodstream from diffusing into the surrounding tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

liver lobule

A

-basic unit of the liver
-hexagonal shape with central vein at the center
-composed of hepatocytes arranged in plates
-portal triad located at each corner of the lobule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

portal triad

A

-hepatic artery- supplied oxygen-rich blood
-portal vein- carries nutrient-rich blood from the digestive organs
-bile duct- transports bile produced by hepatocytes
-blood flow direction- toward the central vein
-bile flow- toward the bile duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

histology of portal triad

A

-portal vein has larger, thinner wall
-hepatic artery a thicker and smaller diameter
-bile duct is lined with cuboidal epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

central vein

A

-located at the center of each hepatic lobule and lined by a single layer of endothelial cells
-receives oxygen and nutrient rich blood at the sinusoids from the portal vein and hepatic artery
-coalesces into the hepatic vein, which carries deoxygenated blood back to the inferior vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

central vein histology

A

-wide lumen
-nearby sinusoids where the blood enters the portal triad —> goes through sinusoids —> heads toward CV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

bile duct

A

-lined with simple cuboidal epithelium cells called cholangiocytes
-small bile ductules join together to form left and right hepatic ducts
-passes through the liver and collects bile as the liver produces it
-cholangiocytes modify bile composition and volume through secretion and absorption of water and electrolytes —> cells act as an access point for immune cells while acting as a barrier and help maintain homeostasis of the biliary system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

space of disse

A

-space between the sinusoidal endothelium and hepatocytes
-important for the transport of lymphatic fluid to lymphatic capillaries in the portal triad
-essential for uptake of macromolecules, bile salts, nutrients, and ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

hepatocytes

A

-main functional cells of the liver
-polygonal shaped, arranged in interconnecting plates
-bile canaliculi between adjacent cells
-help with endocrine and exocrine secretion, synthesis of proteins and lipids, metabolism, detoxification, and activation of immune cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

kupffer cells

A

-macrophages located in the walls of the hepatic sinusoids
-variable and irregular shape with oval or indented nuclei
-cell surface has microvilli and long, slender projections
-remove pathogens and debris through phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

stellate or ito cells

A

-mesenchymal cells located in the space of disse
-star-shaped, containing multiple lipid vacuoles
-vitamin A storage, liver development and regeneration, and response to hepatic injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

endocrine vs exocrine pancreatic functions

A

-endocrine- hormones —> bloodstream
-exocrine- digestive enzymes —> small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

alpha cells

A

-produce glucagon in response to low blood glucose, fasting response, and after exercise
-make up 20% of islet cells
-H&E: stain pink due to the glucagon granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

glucagon function

A

-glycogenolysis- stimulates the liver to convert glycogen to glucose
-gluconeogenesis- stimulates liver to uptake amino acids from blood to glucose
-lipolysis- form of gluconeogenesis, which stimulates the liver and adipose tissue to covert triglycerides to free fatty acids and glycerol
-glycerol is then converted to glucose in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

beta cells

A

-produce insulin from the food in the intestine
-food is in the intestine —> release of gastrointestinal hormones (glucose-dependent insulinotropic peptide) —> insulin production by beta cells
-secretion is stimulated by increased blood glucose
-make up 75% of islet cells
-H&E: stain blue due to insulin granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

insulin function

A

-decreases blood glucose by stimulating glycolysis (glucose —> ATP) then stimulating glycogenesis (glucose —> glycogen)
-inhibits glycogenolysis and gluconeogenesis
-promotes tryglyceride and protein synthesis
-as blood glucose goes down, the release is inhibited
-facilitates glucose uptake- especially in skeletal muscle and adipose tissue but RBCs, brain, liver, kidneys, and small intestine do not need it
-mechanism is largely unknown (activates tyrosine kinases —> move glucose transporter GLUT4 storage vesicles to plasma membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

delta cells

A

-produce somatostatin, which is also released by the hypothalamus, stomach, and intestines and is stimulated by increased glucose and ghrelin
-coordinates insulin and glucagon secretion to maintain glucose homeostasis
-4% of islet cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

somatostatin function

A

-inhibits release of glucagon and insulin
-activates somatostatin receptors on alpha and beta cells coupled to inhibitory G protein —> suppresses electrical stimulation —> no exocytosis of granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

pancreatic polypeptide cell

A

-gamma or F cells
-produce pancreatic polypeptide hormone —> produced after eating and in response to fasting
-secretion is stimulated by intestinal hormones cholecystokinin, secretin, and gastrin
-1% of islet cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

pancreatic polypeptide function

A

-regulates appetite to reduce hunger levels by sending signals to the brain through vagus nerve
-slows digestion by reducing the rate of gastric emptying, pancreatic exocrine secretion, and gallbladder contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

exocrine products of pancreas

A

-essential for breaking down food into constituent molecules for absorption
-produces pancreatic juice containing digestive enzymes, bicarbonate, and water
-products are released into the duodenum

24
Q

acinar cells secrete digestive enzymes

A

-amylase- breaks down starches (carbs) into simple sugars
-protease- breaks down proteins into amino acids Ex. trypsin, chymotrypsin, and carboxypeptidase
-lipases- break down fats into fatty acids and glycerol
-nucleases- break down nucleic acids (DNA and RNA) into nucleotides

25
Q

EM of acinar cell

A

-abundant ER for protein synthesis
-stores inactive enzymes in secretory vesicles called zymogen granules
-zymogen is an inactive enzyme precursor that releases via exocytosis when stimulated by CCK

26
Q

intercalated ducts secrete bicarbonate and water

A

-bicarbonates are secreted into the duodenum and neutralize HCl
-secretin hormone, which is released when the acidic chyme is in the duodenum, stimulates bicarbonate release

27
Q

histology of exocrine cells

A

-acinar cells have apical granules stained pink and pyramidal shape
-centroacinar cells are pale, low cuboidal cells and the first cells of the intercalated ducts

28
Q

histology of endocrine cells

A

-arranged in islets with dense fenestrated capillaries
-endocrine products are delivered to the systemic circulation via the portal system

29
Q

histology of pancreatic lobules

A

-formed by groups of acini and islets wrapped in a layer of connective tissue
-vasculature, nerves, and lymphatics run with the septa

30
Q

ductal cells (exocrine) and classification of ducts

A

-epithelial ductal cells- transition to columnar cells along path to main pancreatic duct
-intercalated ducts are the most proximal part
-intralobular ducts join the acini within a lobule
-interlobular ducts connect lobules

31
Q

secretion of centroacinar cells

A

-secretin hormone binds to secretin receptors on the acinar cells
-leads to GPCR signalling, which involves adenylate cyclase converting ATP to cAMP, a secondary messenger
-cAMP will stimulate the secretion of bicarbonate and water

32
Q

secretion of intercalated ducts

A

-lined with centroacinar cells
-stimulated by the secretion of the centroacinar cells and move the products along to the main pancreatic duct

33
Q

secretion of acinar cells

A

-CCK will directly and indirectly stimulate the release of digestive enzymes from the acinar cells
-directly by binding to CCK receptors on the acinar cells
-indirectly by stimulating the vagus nerve to release acetylcholine, which will stimulate the release of digestive enzymes by the acinar cells

34
Q

pancreas anatomy

A

-composed of a tail, body, neck, and head (nestled into the duodenum of the small intestine)
-main duct running through it with branches coming off

35
Q

exocrine pancreas

A

-acinar cells that release digestive enzymes
-ductal cells that release HCO3

36
Q

endocrine pancreas

A

-alpha cells that release glucagon
-beta cells that release insulin
-delta cells that release somatostatin

37
Q

pancreas + glucose metabolism

A

-produces digestive enzymes and hormones important for glucose and lipid metabolism
-high blood sugar —> pancreas releasing insulin —> helps glucose to enter cells and convert glucose to glycogen
-insulin lowers blood sugar levels

38
Q

diabetes overview

A

-chronic disruption of insulin signalling
-hyperglycemia- high blood glucose levels

39
Q

symptoms of diabetes

A

-excessive thirst or urination
-fatigue
-weight loss
-blurred vision

40
Q

untreated diabetes

A

-circulatory disorders
-renal failure
-blindness
-gangrene
-stroke
-heart attack

41
Q

type I diabetes

A

-autoimmune disease with unknown causes
-complete loss or inactivity of beta cells
-immune system attacks beta cells that produce insulin —> beta cells are destroyed and the pancreas can’t produce insulin —> high glucose levels in the blood

42
Q

type II diabetes

A

-metabolic disorder that can be caused by lifestyle factors and genetic predisposition
-decrease in insulin secretion
-tissues fail to respond to insulin- insulin binds to receptors —> signalling can’t activate GLUT4 transporter —> glucose can’t enter the cell —> high glucose levels in the blood (amyloid deposits)

43
Q

acute pancreatitis

A

-acute inflammation of the pancreas
-leading cause of GI-related hospitalizations in the US
-common causes include gallstones, alcohol use, and hypertriglyceridemia

44
Q

pathogenesis of acute pancreatitis

A

-premature activation of the enzyme trypsinogen to trypsin in acinar cells of the pancreas instead of the duodenum
-once activated, trypsin activates several pancreatic enzymes and leads to self digestion
-protein 1- serine protease inhibitor, kazal type 1 (SPINK1) and in pancreatitis, there is a mutation or absence of function of SPINK1
-protein 2- cystic fibrosis transmembrane conductance regulator (CFTR), an ATP-gated ion channel that mediates the passive diffusion of Cl and HCO3 —> in pancreatitis, you have a loss or disfunction of CFTR which leads to an abnormal secretion of digestive enzymes

45
Q

physiological condition of acute pancreatitis

A

increased intraductal pressure (gallstone) —> high intracellular Ca2+ level (alcohol use, hypertriglyceridemia)

46
Q

pancreatic ductal adenocarcinoma

A

-type of pancreatic cancer involving the organ’s exocrine cells (those releasing digestive enzymes)
-risk factors include chronic pancreatitis, diabetes, inherited DNA mutations, obesity, and smoking
-causes about 90% of all pancreas cancers
-3 lesion types: PanIn, IPMN, and MCN

47
Q

PanIN

A

-pancreatic intraepithelial neoplasia
-microscopic size (<5 mm)
-found in small intralobular ducts
-columnar or cuboidal cell type
-causes ~90% of PDAC cases
-commonly found in head of the pancreas

48
Q

IPMN

A

-intraductal papillary mucinous neoplasm
-characterized as growths of ductal epithelium
-columnar cell type
-macroscopic size (>= 1 cm)
-account for <10% of PDACs
-commonly found in the head and neck of the pancreas

49
Q

MCN

A

-mucinous cystic neoplasm
-does not involve pancreas ductal system
-characterized by ovarian-type stroma
-macroscopic size (avg. 10 cm)
-account for <3% of PDACs
-commonly found in the pancreas body and tail

50
Q

whipple procedure

A

surgeons remove the head of the pancreas, most or all of the duodenum, portion of bile duct, gallbladder with lymph nodes, and sometimes part of the stomach

51
Q

distal pancreatectomy

A

surgeons remove the body of the pancreas, tail of pancreas, and spleen

52
Q

total pancreatectomy

A

surgeons remove the entire pancreas, spleen, gallbladder, common bile duct, portion of the small intestine, and portion of the stomach

53
Q

external beam radiation therapy

A

machine directs radiation through skin to encounter tumors (neoadjuvant) or tumor sites (adjuvant)

54
Q

intensity-mediated radiation therapy

A

transmits targeted radiation to tumors by changing radiation beam strength via computer control

55
Q

stereotactic body radiation therapy

A

-provides targeted high doses of radiation in 5 treatments or fewer
-can treat tumors and neighboring tissue

56
Q
A

Human Body_TP (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions