Digestive/Endocrine Flashcards Preview

Anatomy II > Digestive/Endocrine > Flashcards

Flashcards in Digestive/Endocrine Deck (68):
1

Liver Role in Digestion

Secretion of bile

2

Hepatic Triad

Hepatic Portal Vein
Bile Duct
Hepatic Artery

3

Hepatic Portal Vein

70% of blood that goes through the liver

4

Bile Duct

Collection of bile from all cells

5

Hepatic Artery

30% of blood that goes through the liver

6

Gallbladder

Stores bile produced in the liver and concentrates it

7

Pathway of Bile Secretion

1. Bile capillaries
2. Hepatic ducts create common hepatic duct
3. Cystic duct (gallbladder) and common hepatic duct make common bile duct
4. Common bile duct and pancreatic duct empty into duodenum

8

Components of Bile

1. Water and cholesterol
2. Bile salts (Na and K)
3. Bile pigments (bilirubin) from hemoglobin molecule

9

Acini

Dark clusters in the pancreas
Exocrine
99% of pancreas
Produce pancreatic juice

10

Islets of Langerhans

1% of gland
Pale staining cells
Produce hormones

11

Pancreatic Juice Components

Water, enzymes, and sodium bicarbonate

12

Digestive Enzymes of Pancreas

Pancreatic amylase
Pancreatic lipase
Ribonuclease
Deoxyribonuclease
Zymogens

13

Zymogens of Pancreas

Trypsinogen
Chymotrypsinogen
Procarboxypeptidase

14

Activation of Zymogens

Trypsinogen converted to trypsin by intestinal epithelium
Trypsin converts other two zymogens as well as digests dietary protein

15

Regulation of Pancreatic Secretions

Acetylcholine
Secretin
Cholecystokinin

16

Acetylcholine in Pancreas

Vagal origin
Stimulates acini to secrete enzymes during cephalic phase

17

Secretin in Pancreas

Acidity in intestine causes increased sodium bicarbonate release

18

Cholecystokinin in Pancreas

Fats and proteins cause increased digestive enzyme release, contraction of gallbladder, and relaxation of Sphincter of Oddi

19

Equations for Regulation of Pancreatic Secretions

HCl + NaHCO3 --> NaCl + H2CO3 --> NaCl + H2O + CO2

H2O goes into stomach, CO2 goes into the blood
Decreases acidity, lowers pH

20

Anatomy of Small Intestine

Duodenum
Jejunum
Ileum

21

Where does all absorption occur?

Small intestine

22

Histology of Small Intestine

1. Circular Folds (increase surface area, slow progress of chyme)
2. Gastric Pits (secrete chemicals)
3. Villi (contains arteriole, blood capillaries, venule, and lymphatic capillary)
4. Microvilli (contain enzymes that complete chemical digestion; contain brush border enzymes)

23

Functions of Microvilli

Absorption and digestion
Significant cell division within intestinal glands
Rupture and release digestive enzymes and proteins

24

Cells of Intestinal Glands

1. Microvilli
2. Goblet Cell
3. Enteroendocrine Cell
4. Paneth Cell

25

Enteroendocrine Cell

Secretes secretin, CCK, or gastric inhibitory peptide

26

Paneth Cell

Secretes lysozyme

27

Segmentation

Local mixing of chyme with intestinal juices

28

Digestion of Carbohydrates

1. Mouth: salivary amylase
2. Esophagus and Stomach: nothing
3. Duodenum: pancreatic amylase
4. Brush border enzymes (maltase, sucrase, and lactase) act on disaccharides to produce monosaccharides

29

Digestion of Proteins

1. Stomach: HCl denatures proteins and pepsin turns into peptides
2. Pancreas: trypsin and chymotrypsin take over
3. Carboxypeptidase: removes AA from carboxyl group
4. Aminopeptidase: removes AA from nitrogenous group
5. Dipeptidase: splits dipeptides in the middle and releases the last two free AA

30

Protein Absorption

Brush border enzymes produce amino acids that are absorbed into the intestinal epithelial cells and into the bloodstream

31

Digestion of Lipids

1. Mouth: lingual lipase
2. Small Intestine: emulsification by bile; pancreatic lipase splits into fatty acids and monoglycerides

32

Fat Digestion Sequence

Fat globule --> Monoglyceride --> Micelle

33

Absorption of Lipids

Fats are rebuilt and coated with protein to form chylomicrons in epithelial cells

34

Chylomicrons

Travel in lymphatic system to reach veins near the heart
Removed from the blood by liver and fat tissue

35

Digestion of Nucleic Acids

Pancreatic juice contains ribonuclease and deoxyribonuclease
Transported across intestinal epithelium

36

Absorption of Electrolytes

Enter epithelial cells by diffusion and secondary active transport

37

Absorption of Vitamins

Absorbed unchanged
Fat soluble travel in micelles
Water soluble absorbed by diffusion
B12 combines with intrinsic factor

38

Absorption of Water

Small intestine reabsorbs 8 L
Large intestine reabsorbs 0.8 L
0.2 L passed in fecal matter

39

Four Regions of Large Intestine

Cecum
Appendix
Rectum
Anal Canal

40

Histology of Large Intestine

Mucosa: smooth tube, simple columnar cells, goblet cells
Muscular layer: outer longitudinal muscle
Serosa: visceral peritoneum
Appendix: contains large amounts of lymphatic tissue

41

Intestinal Microbes

Digest cellulose, pectin, plant polysaccharides
Absorb digested material
Bacteria synthesize vitamins B and K

42

Anatomy of Anal Canal

3 cm in length
Longitudinal ridges separated by mucus secreting anal sinuses

43

Defecation

1. Feces stretch rectum and stimulate stretch receptors
2. Spinal reflex stimulates contraction of the rectum
3. Spinal reflex relaxes internal sphincter
4. Impulses from the brain keep external sphincter contracted

44

Endocrine System

Hormones released into the bloodstream travel throughout the body
Results may take hours, but last a long time

45

Nervous System

Certain parts release hormones into the blood
Rest releases neurotransmitters to excite or inhibit nerve, muscle, and gland cells
Results in milliseconds, brief duration of effects

46

Cell Communications

Gap Junctions
Neurotransmitters
Paracrine Hormones
Hormones

47

Paracrine Hormones

Secreted into tissue fluids to effect nearby cells

48

Similarities in Nervous and Endocrine Systems

Secrete norepinephrine, dopamine, and ADH
Systems regulate each other

49

Exocrine Glands

Secretes products into ducts which empty into body cavities or body surface
Extracellular effects
Sweat, oil, mucous, and digestive glands

50

Endocrine Glands

Secrete products into bloodstream
Intracellular effects
Pituitary, thyroid, parathyroid, adrenal, pineal

51

Anterior and Posterior Pituitary Glands

Posterior pituitary gland develops from hypothalamus
Anterior pituitary gland develops from the roof of the mouth

52

Hypothalamus

Master of the endocrine system

53

Anatomy of Pituitary Gland

Anterior lobe: adenohypophysis
Posterior lobe: neurohypophysis

54

Posterior Pituitary Gland

Releases oxytocin and ADH

55

Anterior Pituitary Gland

Releases follicle stimulating hormone, lutenizing hormone, thyroid stimulating hormone, ACTH, prolactin, and growth hormone

56

Tropic Hormones

Target other endocrine glands
1. Gonadotropins (FSH and LH)
2. Thyroid stimulating hormone
3. ACTH

57

Growth Hormone

Secreted by somatotropes of anterior pituitary
Promotes tissue growth by affecting mitosis
Indirectly stimulates liver to produce insulin growth factor

58

Actions of GH

Protein synthesis
Lipid metabolism
Carbohydrate metabolism
Electrolyte balance

59

Protein Synthesis of GH

Translates mRNA into proteins
Increases amino acids into the cell to support protein synthesis

60

Lipid Metabolism of GH

Supports energy needs
Protein-sparing effect

61

Carbohydrate Metabolism of GH

Glucose-sparing effect by mobilizing fatty acids, reducing dependence on glucose to avoid competition with the brain
Stimulates gluconeogenesis in the liver

62

Electrolyte Balance of GH

Na, K, Cl retention by kidneys
Increases calcium absorption by the small intestine

63

Thyroid Stimulating Hormone

Hypothalamus regulates thyrotroph cells
Thyrotropin releasing hormone (TRH)
Thyrotroph cells produce TSH
TSH stimulates synthesis and secretion of T3 (triiodothyronine) and T4 (thyroxine)

64

Follicle Stimulating Hormone

Gonadotrophin releasing hormone (GnRH)
Gonadotrophic cells release FSH

65

FSH Functions

Initiates formation of follicles within the ovary
Stimulates follicle cells to secrete estrogen
Stimulates sperm production in the testes

66

Lutenizing Hormone

Gonadotrophin releasing hormone (GnRH)
Gonadotrophic cells produce LH
In females, LH stimulates ovulation
In males, LH stimulates interstitial cells to secrete testosterone

67

Prolactin

Prolactin inhibiting hormone (PIH) prevents prolactin release
Lactotrophic cells produce prolactin
Suckling reduces levels of PIH and prolactin levels rise along with milk production

68

Adrenocorticotrophic Hormone

Regulates response to stress
Corticotrophic cells secrete ACTH and MSH
ACTH stimulates cells of adrenal cortex that produce glucocorticoids such as cortisol