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Anatomy 2 Test 3 > Chapter 24 > Flashcards

Chapter 24 Flashcards

1
Q

Digestive system and homeostasis:

A
  • Breaks down food to be absorbed and used by body cells
  • absorbs water vitamins and minerals
  • eliminates waste from body
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2
Q

Basic processes of the digestive system:

A
  1. ingestion
  2. secretion - walls of GI tract
  3. motility - mixing and propulsion
  4. digestion - mechanical and chemical
  5. absorption - blood and lymph
  6. defecation - wastes
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3
Q

Organs of the GI tract:

A
  • mouth
  • pharynx
  • esophagus
  • stomach
  • small intestine
  • large intestine
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4
Q

Accessory digestive organs:

A
  • Teeth
  • Tongue
  • Salivary Glands
  • Liver
  • Gallbladder
  • Pancreas
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5
Q

What are the 4 basic layers of the GI tract?

A

Mucosa, submucosa, muscularis, serosa

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6
Q

What are the 3 layers of the MUCOSA that lines the GI tract?

A
  1. Epithelium
  2. Lamina Propria
  3. Muscularis mucosae
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7
Q

What parts of the mucosa in GI tract have epithelium, what kind, and what is it for?

A

Epithelium provides tight junctions to prevent leakage.

  • mouth pharynx esophagus anus -> stratified squamous epithelium provides protection
  • stomach, intestines -> simple columnar epithelium allows secretions and absorption
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8
Q

What is the Lamina Propria in mucosa of GI tract made of and what is it for?

A

Areolar connective tissue, blood, and lymphatic vessels

it is the majority of Mucosa- associated lymphatic tissue (MALT)

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9
Q

What is the musclaris mucosae of mucosa in the GI tract made of and what is it for?

A

THIN layer of smooth muscle

-mucosal fold which increase surface area for secretin and absorption

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10
Q

What is the SUBMUCOSA of the GI tracts made of and for?

A
  • Areolar connective tissue, blood vessels, and lymphatic vessels
  • it is a neural network - submucosal plexus
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11
Q

Where is the MUSCULARIS found and what is its purpose in the GI tracts?

A
  • Mouth, Pharynx, upper/middle esophagus->skeletal muscle for voluntary swallowing
  • External Sphincter-> skeletal muscle for voluntary defecation
  • Rest of GI tract- smooth muscle -> involuntary for breakdown and mixing, inner layer circular, outer layer longitudinal
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12
Q

What is the SEROSA made of and for?

A
  • Areolar connective tissue and simple squamous epithelium

- covering of GI tract in abdominopelvic activity

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13
Q

What types of nerves are there in the GI tract?

A

Enteric Nerves and Autonomic Nerves

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14
Q

What are enteric nerves?

A

“brain of the gut”

  • functions independently - “intrinsic”
  • myentric plexus
  • submucosal plexus
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15
Q

What is the Myentric Plexus in enteric nerves for and made of?

A
  • between longitudinal and circular muscle layers

- controls motility

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16
Q

What is the submucosal plexus for and where?

A
  • in submucosa
  • motor: organ secretions
  • sensory: stretch and chemoreceptors
  • detects what is in the food you swallow
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17
Q

Autonomic nerves in the GI tract?

A

“extrinsic” -> outside control

  • parasympathetic -> action on ENS(stimulates) > increased Gi motility and secretions
  • sympathetic -> action on ENS (inhibits) -> decreased Gi motility and secretions
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18
Q

What are the parts of the Mouth?

A

cheeks, tongue, hard/soft palates

  • Lips (or labia)
  • Hard palate (anterior)
  • Soft palate (posterior)
  • Uvula
  • Salivary Glands
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19
Q

What are the types of salivary glands?

A

Major salivary glands - parotid, submandibular, sublingual

small salivary glands- labial buccal palatal lingual

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20
Q

What mechanical digestion process does the MOUTH provide?

A

chewing, produces bolus

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21
Q

what chemical digestion does the mouth provide?

A

salivary amylase - breakdown of starch (only monosaccarhides can be absorbed - creates sugar)
lingual lipase - breakdown of trigyclerides - activated by stomach acid

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22
Q

what is bolus?

A

mushy ball of food you form in mouth before swallowing

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23
Q

what does saliva do?

A

helps dissolve food for taste and contains enzymes

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24
Q

what is the composition of saliva?

A

99.5% water, .5% solutes

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25
Q

what activates salivary amylase?

A

Cl-

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26
Q

what is in saliva and what does are there functions?

A
  • Cl- activates salivary amylase
  • icarbonate/phosphate ions – buffers – pH 6.35 -.85
  • Salivary amylase – enzyme (starch)
  • Bacteriolytic enzyme – lysozyme
  • Immunoglobulin A –prevent microbe attachment
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27
Q

How much do you salivate daily and what is it controlled by?

A
  • 1000-1500 ml
  • controlled by autonomic nervous system
  • parasympathetic- > promotes salivation
  • sympathetic -> inhibits (stress)
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28
Q

What is the tongue made of and parts of the tongue?

A
  • skeletal muscle covered in mucous membrane
  • hyoid, temporal, and mandible bones
  • extrinsic muscles move tongue for chewing and swallowing
  • intrinsic alter shape and size of tongue for speech and swalling
  • lingual frenulum- limits posterior movement
  • lingual glands- secret mucous and lingual lipase (acts on triglycerides)
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29
Q

What are the parts of the teeth?

A
  • in alveolar processes of mandible and maxillae
  • Process covered by gingivae (gums)
  • Inside Process – periodontal ligament
  • Crown, Neck, Roots (1-3)
  • Inside – Dentin – calcified connective tissue (hard)
  • Crown covered by enamel (hardest body substance)
  • Cementum – Anchors dentin of root to ligament
  • Pulp Cavity, Pulp (Con. Tissue, Blood, Nerves, Lymph), Root canals
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30
Q

What is the pharynx and what is it made of and what does it do?

A
  • Funnel shaped tube from mouth to esophagus.
  • Skeletal muscle covered by mucous membrane.
  • Muscle contractions (oropharynx, laryngopharnx) help propel bolus from mouth to esophagus
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31
Q

What is the esophagus made of?

A

-Collapsible muscular tube from pharynx to stomach
(via esophageal hiatus – opening in the diaphragm)
- Mucosa: stratified squamous epithalium (abrasion)
near stomach contains mucous glands
- Submucosa: blood vessels and mucous glands
- Muscularis:
1st 1/3 = Skeletal muscle
2nd 1/3 = Skeletal and Smooth muscle
3rd 1/3 = Smooth muscle

Upper Esophageal - > UES regulates movement of bolus pharynx ->
esophagus
-Lower esophagageal-> LESregulates movement
of bolus esophagus -> stomach

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32
Q

What does the esophagus do?

A

moves bolus, secretes mucus, no digestive enzymes, no absorption

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33
Q

What is deglutition?

A

Deglutition is swallowing.

  • bolus is forced to back of oral cavity into oropharynx by tongue
  • involves mouth, pharynx, esophagus
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34
Q

What are the phases of deglutition and what occurs?

A
  1. Voluntary - swallowing
2. Involuntary phase
Bolus stimulates receptors in oropharnyx -> lowers pons
APs to deglutition center in medulla
APs from deglutition center
soft palate & uvula up (block nasopharynx) 
epiglottis closes larynx
bolus through oro & laryngopharynx 
UES relaxes - bolus into esophagus
  1. Esophageal Stage
    - Peristalsis: coordinated contraction/ relaxation of circulation longitudinal muscles - pushes bolus
    - squeeze bolus toward stomach
    - LES relaxes - bolus into stomach
    - mucus secreted by esophageal glands lubricate bolus and reduce friction
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35
Q

How long does it take food to get from mouth to stomach

A

4-8 seconds

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36
Q

What facilitates deglutition?

A

secretion of saliva and mucus

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37
Q

What does the stomach serve as?

A

Mixing chamber/ holding reservoir

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38
Q

What are the 4 main regions of the stomach and where?

A
  1. Cardia - surround superior opening
  2. Fundus - rounded superior portion
  3. Body - large central portion
  4. pyloris - antrum and canal (pyloric sphincter)
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39
Q

What are the 2 stomach curvatures and where?

A

Lesser - concave medial border

greater - convex lateral border

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40
Q

What are the three parts of the small intestine?

A

Duodenum, jejunum, ileum

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41
Q

Where is the stomach located?

A

Directly inferior to the diaphragm in the epigastric, umbilical, and left hypochrodriac regions of the abdomen

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42
Q

What is the digestion process in the stomach

A
  • forces small quantity of material into small intestine on intervals
  • digestion of starch continues
  • digestion of proteins and triglycerides begins
  • blous->liquid-> certain substances absorbed
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43
Q

What are the two parts of the pyloris?

A

pyloric antrum, pyloric canal

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44
Q

What is rugae?

A

large folds in the stomach that occur when stomach is empty

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45
Q

What are the layers of the stomach?

A

Mucosa - surface mucosa cells, lamina propria, muscular mucosae

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46
Q

what are the 3 types of exocrine glands in the stomach?

A
  1. mucous and mucous neck cells - secrete mucus
  2. parietal cells - Hcl & intrinsic factor ( intrinsic factor needed for absorption of B12)
  3. Chief cells - pepsinogen and gastric lipase

(secretions make up gastric juice)

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47
Q

Where are gastric pits located?

A

gastric glands

  • epithelial cells extend to lamina forming columns of gastric glands
  • glands open to channels called pits - > secretions from glands go in the pits and them into lumen of stomach
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48
Q

what is the type of entroendocrine cell in the stomach

A

G-cell

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49
Q

What are the 3 additional layers that lie deep to the mucosa in the stomach?

A
  1. Submucosa - areolar connective tissue
  2. muscularis - 3 layers of smooth muscle, outer longitudinal layer, middle circular layer, inner oblique layer
  3. serosa - simple squamous epithelial and areolar conn. tissue ; part of visceral peritoneum
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50
Q

where is the G-cell located?

A

pyloric antrum and secretes gastrin into bloodstream

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51
Q

Summarize the mechanical and chemical digestion in the stomach?

A

Food is mixed every 15-20 sec, becomes CHYME, funds primarily stores for 1 hr, salivary amylase still active, churning increases acidity, inactivates salivary amylase, activates lingual lipase, digest triglycerides into fatty acids and diglycerides, parietal cells secret HCl, activates pepsinogen, pepsin created, protein breakdown to amino acids, gastic lipase breaks short-chain triglycerides into fatty acids and monoglycerides

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52
Q

What do parietal cells do in the stomach?

A

kill microbes, denature proteins, stimulate hormone release to promote flow of bile and pancreatic juices

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53
Q

What is HCl secretion stimulated by in the stomach?

A

ACh, gastrin, and histamine (synergist)

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54
Q

How long before food is moved from stomach to duodenum and what spends the least amount of time in the stomach?

A

2-4 hours

carbs

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55
Q

Digestion requires secretions from:

A

pancreas, liver, and gallbladder

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56
Q

What is the pancreas what is it made of?

A

Retroperitineal gland
Made of small clusters of glandular epithelial cells.
12-15 cm long 2.5 cm thick

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57
Q

What are the three parts of the pancreas?

A

Head- expanded portion near curve of duodenum

Body & tail- superior and left head

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58
Q

Where are pancreatic juices secreted to

A

Small ducts that unite to form 2 big ducts the pancreatic and accessory ducts

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59
Q

Where is the pancreatic duct

A

Enters the duodenum as dilated common duct called hepatopancreatic ampulla

  • ampulla opens in elevation of duodenal mucosa known as major duodenal papilla
60
Q

What are the types of clusters in the pancreas?

A

99% are acini and constitute as the exocrine portion of organ
1% are pancreatic islets and form endocrine portion

61
Q

what do acini secrete

A

picture of fluids called pancreatic juices

62
Q

what do pancreatic islets secrete

A

glycagon, insulin, somatosin, pancreatic polypeptides

63
Q

Where do exocrine pancreatic juice secrete into

A

pancratic duct and duodenum via common duct (with bile) or accessory duct

64
Q

How much pancreatic juice do you form daily and what does it contain

A

1200-1500ml and water, salts, sodium bicarbonate, and enzymes

65
Q

what does sodium bicarbonate do

A

buffers acidic gastric juice pH 7.1-8.2

-stops action of pepsin in stomach creates proper pH

66
Q

what are the key enzymes in pancreatic juices and functions

A
  1. pancreatic amylase - starch digestion
  2. trypsin- protein digestion
  3. chymotrypsin- protein digestion
  4. carboxypeptidase- protein digestion
  5. elastase- protein digestion
  6. pancreatic lipase - triglyceride digestion
  7. ribonuclease and deoxyribonuclease- nucleic acid digestion
67
Q

Protein digesting enzymes are produced in what form

A

inactive

68
Q

What activates trypsinogen in small intestine

A

enterokinase

69
Q

what activated/converts to trypsin

A

trypsinogen

70
Q

what does trypsin activate

A

chymotrsinogen, procarboxypeptidase, proelastase -> produce chymotrpsin, carboxypeptidase, and elastase

71
Q

what do pancreatic acinar cells secrete

A

protein called trypsin inhibitor which combines with any trypsin formed in the pancreas accidentally

72
Q

What divides the two lobes and which lobe is larger

A

falciform ligament - which is fold of mesentery

and right lobe is larger

73
Q

What is the gall bladder and what does it do

A

pear-shaped sac inferior to liver

- stores and concentrates bile produced in liver until needed in the small intestine

74
Q

how much does the liver weigh

A

3 lbs or 1.4 kg

75
Q

what is the liver covered by

A

visceral peritoneum and dense irregular connective tissue that is deep to peritoneum

76
Q

What de hepatocytes do what are they

A

they are major functional cell

they form hepatic laminas which are highly branches and irregular structures

77
Q

what do hepatic portal veins do

A

bring venous blood from the gastrointestinal organ and spleen into liver

78
Q

what do hepatic sinusoids do and what are they

A

they are highly permeable capillaries
they converge and deliver blood into central vein which transfers to hepatic veins which then drains into the inferior vena cava

79
Q

What is the path of bile

A

bile goes into bile canaliculi then to bile ductules then to bile ducts then to the right and left hepatic ducts and to the common duct

80
Q

what two ducts join to form the common bile duct

A

hepatic and cystic

81
Q

what is the difference between hepatic artery and the hepatic portal vein

A

the art is oxygenated and the vein is deoxygenated

82
Q

what is the path of the hepatic artery and portal vein

A

hepatic artery or hepatic portal vein -> to sinusoids(substances taken up by hepatocytes) -> central vein - > hepatic vein - > interior vena cava - > right atrium

83
Q

what are the two sources that blood is supplied to the liver

A

hepatic artery and hepatic portal vein

84
Q

what is the portal triad

A

vein, artery, and bile duct

85
Q

What is partially excretory product and partially degestive secretion

A

bile

86
Q

what do small lipid globules do

A

present large surface area that allows pancreatic lipase to more rapidly accomplish digestion of triglycerides

87
Q

what do bile salts do

A

aid in absorption of lipids

88
Q

as ____ and absorption continue in small intestine bile release _____

A

digestion

increase

89
Q

what is the role and composition of bile

A

800-1000 ml/ day pH 7.6-8.6
-yellow/brown/olive-green liquid
contains water, salt, cholesterol, lecithin, pigments and ions.
pigment comes from RBCs, bilirubin -> stercobili (brown color of poop)
emulsification

90
Q

what is emulsifcation

A

breakdown of large lipid globules into a suspension of small lipid globules

91
Q

what are the 9 functions of the liver

A
  1. carb metabolism-maintain blood glucose -low glycogen to glucose/ high glucose to glycogen
  2. lipid metab. -hepatocytes store tryglicerides, breakdown fatty acids for ATP, synthesize lipoproteins and cholesterol
    (3) Protein Metabolism
    - Deaminate amino acids for ATP production. Convert toxic ammonis produced to urea
    - Hepatocytes synthesize most plasma proteins
    (4) Processing of Drugs and Hormones
    - Detoxification (alcohol), excretion of drugs, alter or excrete steroid hormones.
    (5) Excretion of Bilirubin - absorbed by liver excreted in bile
    (6) Synthesis of Bile Salts - emulsification
    (7) Storage
    - Glycogen, Vitamins (A, B12, D, E, K)
    (8) Phagocytosis- kupffer
    (9) Activation of Vitamin D-skin liver and kidney participate in synthesizing active form
92
Q

where does most digestion and absorption occur

A

small intestine

93
Q

what has large surface area circular folds, villi, and microvilli

A

small intestine

94
Q

how long is the small intestine

A

10ft living, 21 dead

structure adapts for function

95
Q

what are the major parts of the small intestine

A 
stomach pyloric sphincter
duodenum-25 cm
jejunum -100cm
ileum - 200 cm 
ileocecal sphincter of Large intestine
96
Q

What are the 4 basic layers of the small intestine that are in the GI tract

A

mucosa
submucosa
muscularis
serosa

97
Q

What does the epithelial layer of the small intestine contain

A

i. absorptive cells
ii. goblet cells (mucus)
- -intestinal glands: i & ii. and iii. paneth cells (lysozyme) and iv. enterendocrine cells

98
Q

what are the three types of enter endocrine cells

A
  1. S cells - secretin
  2. CCK cells - cholecytoskinin (CCK)
  3. K cells - glucose dependent insulinotropic peptide (GIP)
99
Q

What is the Lamina propria of the small intestine made of and contain

A

areolar connective tissue

  • MALT
  • secondary lymphatic nodules (peyer’s patches) ->present in ileum
100
Q

What cells secrete lysozyme (bacterialdalenzyme), and are capable of phagocytosis

A

PANETH CELLS

101
Q

What type of noodles are numerous in the distal ileum

A

solitary lymphatic nodules

102
Q

what does the muscular mucose of the small intestine mucose consists of

A

smooth muscle

103
Q

What do the submucosa in S.I. do

A

secrete alkaline mucus

helps neutralize gastric juices

104
Q

what do circular folds in SI do

A

folds of mucosa and submucosa
increase surface area
encourage chyme to spiral

105
Q

what do villi in SI do

A

fingerlike projections on folds
increase surface area
contain lacteals (lypmhatic. cap.)

106
Q

what do microvilli do

A

projections off apical membrane of absorptive cells

form fuzzy line called brush border

107
Q

what are the brush border enzymes in the microvilli

A

(i) α-dextrinase, maltase, sucrase, lactase –(carbohydrate-digestion)
(ii) aminopeptidase, dipeptidase –(protein-digestion)
(iii) nucleosidases, phoshphatases –(nucleotide-digestion)

108
Q

together pancreatic juices and intestinal juices provide a ____ ____ that aid _____ of substances from chyme in small intestine

A

liquid medium

absorption

109
Q

what synthesizes the brush border enzymes and insert into plasma membrane of microvilli

A

absorptive cells

-some enzymatic digestion occurs here

110
Q

what are the two types of mechanical digestion movement in the S.I.

A

segmentations (occurs rapid in duodenum)

peristalsis called migrating motility complex MMC

111
Q

what is segmentations movement

A

localize, mixing contractions. occurs in chyme distends portions of SI. circular muscle contrations. ->segments ->chyme sloshing back and further
good for absorption
approx 12 per min in duodenum
8 per min in ileum

112
Q

what is peristalsis MMC

A

from lower stomach to end of SI singlow slow wave down length of SI pushes chyme a short distances APPROX 1 MMC every 90-120 min
chyme stays in SI for approx 3-5 hours

113
Q

how does the small intestine absorb monosaccharides

A
  1. glucose and galactose ->secondary active transport with NA+->facilitated diffusion ->blood cap of villus
  2. fructose -> facilitated diff. ->facilitated diff. -> blood cap of villus
114
Q

how are amino acids, dipeptides, and tripeptides absorbed in small intestine

A
  1. Amino acids- active transport or secondary active transport -> diffusion -> blood cap of villus
  2. dipeptides and tripeptides ->secondary A.T. w/ NA+ -> diffusion->blood cap of villus
115
Q

how are lipids absorbed in SI

A
  1. short chain fatty acid-> simple diff.->diff.->blood cap

2. long chain and monoglycerides->simple diff. ->triglyceride ->lacteal of villus

116
Q

What percent of absorption occurs in SI and LI and stomach

A

90 in SI

10 LI and stomach

117
Q

all carbs are absorbed as

A

monosaccharides

118
Q

amount of saliva produced, and ingestion of liquids ingested and secreted

A

1 liter

2.3 liters

119
Q

how much gastric juice and bile ingested and secreted

A

2 liters

1 liter

120
Q

how much pancreatic juice and intestinal juice infested and secreted

A

2 liters

1 liter

121
Q

small intestine and large intestine amounts absorbed

A

8.3 liters

.9 liters

122
Q

total ingested and secreted

A

9.3 liters

123
Q

total absorbed

A

9.2 liters

124
Q

excreted in feces

A

.1 liter

125
Q

Function of LI

A

completion of absorption
production of certain vitamins
formation/expulsion of feces

126
Q

the ileum connects to the ___ and is how long?

A

anus

1.5m long 6.5 cm in diameter

127
Q

What is the large intestine attached to

A

posterior abdominal wall by its mescaline; double layer of peritoneum

128
Q

what are the four major regions of the large intestine

A

cecum
colon
rectum
anal canal

129
Q

material from SI passes to the LI through the

A

ileocecal sphincter

130
Q

what is the vermiform appendix possibly for

A

immune activity

131
Q

the ascending and descending colon are _____

the transverse and sigmoid colon are

A

retroperitineal

not retroperitoneal

132
Q

the internal and external sphincter are made of

A

smooth and skeletal

133
Q

the LI is the ____ portion of the GI tract

A

terminal

134
Q

inferior to the ileocecral sphincter is the _____

appendix is also attached to this

A

cecum

135
Q

epithelium of LI has

A

absorptive cells - mainly water
and goblet cells- secrete mucus
arranged into intestinal glands (or crypts of lieberkuhn)

136
Q

muscularis of LI

A

circular and longitudinal muscle
some thick portions of longitudinal muscle forming bands(teenier coli)
-tonic contractions of bands -> gather colon into series of pouches called haustra

137
Q

Mechanical digestion of LI

A

ileosphincter regulates chyme entry into cecum ( gastrin relaxes the sphincter)

  • valve remains partially closed so passageway to chyme into cecum occurs slowly
  • accumulation in cecum and ascending colon
    • > haustral churning
    • > peristalsis - slower rate then GI
    • > mass peristalsis - drives content of color into rectum
138
Q

how often does mass peristalsis occur

A

3-4 times a day or immediately after a meal

139
Q

chemical digestion

A

digestion via bacterial activity

  • > fermentation of carbohydrates, release hydrogen, CO2 and methane
  • > proteins->amino acids
  • > amino acids->indole, skittle, hydrogen sulfide, fatty acids
  • > produce some band K vitamins
140
Q

absorption and feces fermentation

A

chyme in large intenstine 3-10 hours

feces semi-solid due to water reabsorption (90% water reabsorbed in SI)

141
Q

Defecation reflex is

A
  • mass peristalsis pushes fecal material into the rectum
  • rectal wall dissension stimulates stretch receptors
  • sensory APs to sacral spine cord
  • parasympathetic motor output to descending/sigmoid colon rectum and anus
  • ensuing contractions shorten rectum->increased pressure in rectum
  • pressure, contractions of diaphragm/ abdominal muscles ->opening of anal sphincters->defecation
142
Q

if defecation doesn’t occur where does it get backed up

A

sigmoid colon

143
Q

What are the three phases of digestion

A

cephalic, gastric, intestinal

144
Q

what is the cephalic phase of digestion

A
  • Prepares mouth and stomach for digestion.
  • Smell, sight, thought, taste of food activates neuralcenters in cortex, hypothalamus and brainstem.
  • Stimulates saliva, gastric juice secretion.
145
Q

what is the gastric phase of digestion

A
  • Begins when food is in stomach
  • Distention and pH stimulate peristaltic waves and HCl secretion (negative feedback {see figure})
  • Distension / high pH -> Gastrin secretion.
  • Gastrin stimulates HCl secretion, enhances LES contraction, enhances stomach motility, relaxes pyloric sphincter.
146
Q

what is the intestinal phase

A
  • Slow stomach emptying, to prevent duodenum overload.
  • Duodenum distension ->enterogastric reflex ->decreased stomach motility and pyloric sphincter contraction.
  • CCK & Secretin stimulate the secretion of pancreatic juices
  • Secretin also inhibits gastric juice secretion.

Anatomy 2 Test 3 (4 decks)

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