Digestive System & Metabolism - Exam 3 Flashcards Preview

Anatomy and Physiology II > Digestive System & Metabolism - Exam 3 > Flashcards

Flashcards in Digestive System & Metabolism - Exam 3 Deck (129)
Loading flashcards...
1
Q

What are the main organs involved in digestion?

A

everything along the alimentary canal (gastrointestinal tract)

2
Q

What does the alimentary canal include?

A
mouth
pharynx
esophagus
stomach
small intestine
large intestine
rectum
3
Q

What is the alimentary canal made up of?

A

continuous muscular tube

4
Q

What are the accessory digestive organs?

A
teeth
tongue
gall bladder
salivary glands
liver
pancreas
5
Q

What is the role of the lips in digestion?

A

mechanical

help break down food

6
Q

What is the role of the teeth in digestion?

A

mechanical

chew food into smaller particles

7
Q

What is the role of the tongue in digestion?

A

mechanical

kneads food into smoother, smaller particles

8
Q

What is the role of the hard and soft palate in digestion?

A

mechanical
hard palate is used to knead food against
soft palate relates to gag reflex

9
Q

What is the role of the epithelium and salivary glands in digestion?

A

chemical

both secrete saliva and enzymes that both lubricate and help break down food into easily digested and absorbed pieces

10
Q

How is saliva produced?

A

controlled by the senses

smell, sight etc

11
Q

What starts the process of digestion?

A

senses

12
Q

What is the composition of saliva?

A
  • mainly water
  • electrolytes
  • digestive enzymes
  • proteins (musin)
  • protective substances
  • metabolic wastes
13
Q

What is the average output of saliva?

A

1-1.5 L per day

14
Q

What is another word for swallowing?

A

deglutition

15
Q

What is the purpose of the gag reflex?

A

to keep food from going into the wrong places

16
Q

What are the main digestive enzymes that digest the macromolecules?

A

protease
lipase
amylase
nuclease

17
Q

What is extrinsic control?

A

outside wall of digestive tract

18
Q

Where does extrinsic control stimuli come from?

A
  • info obtained by CNS

- emotion, special senses

19
Q

How could extrinsic control change saliva production and digestive activity?

A
  • sights and smells can increase saliva production

- senses are what begin digestive activities

20
Q

What is intrinsic control?

A

in wall of digestive tract

21
Q

Intrinsic controls are detected by which receptors?

A

nerve plexuses

hormone-producing cells

22
Q

What controls digestive activity?

A

intrinsic and extrinsic controls

23
Q

What does an increase in sympathetic nervous system stimulation do to saliva production and digestive activity?

A

inhibits saliva production and digestive acitivities

24
Q

What is the difference between segmentation and peristalsis?

A
  • segmentation is when nonadjacent alimentary canal organs contract and relax, breaking apart and moving food forwards and backwards
  • peristalsis is when adjacent segments of alimentary canal contract and relax to propel food forward
25
Q

What tissue drives segmentation and peristalsis

A

smooth muscle tissue

muscular mucosa

26
Q

What cells are responsible for the acidic environment of the stomach?

A

parietal cells

chief cells

27
Q

What do chief cells do?

A

release inactive pepsinogen

28
Q

What do parietal cells do?

A

release HCl

29
Q

Where are chief and parietal cells found?

A

gastric pits and glands of the stomach

30
Q

What happens when pepsinogen mixes with HCl?

A

it is converted to active pepsin

31
Q

What is pepsin?

A

a protease

32
Q

How do bile and pancreatic juices influence the chemical environment of the duodenum?

A

bile, pancreatic juices and chyme are mixed together through duodenum’s contractions to create a final spot for chemical break down to occur

33
Q

How do bile and pancreatic juices influence digestion?

A

bile emulsifies fats into smaller globules to increase surface area
pancreatic juices break down every type of macro

34
Q

What controls produce short and long reflexes?

A

intrinsic and extrinsic controls

35
Q

What causes a short reflex?

A

chemoreceptors, osmoreceptors, or mechanoreceptors go straight to the intrinsic nerve plexus (gut brain) rather than passing through the CNS

36
Q

What causes a long reflex?

A

External or internal stimuli passes through the CNS before being translated to the intrinsic nerve plexus

37
Q

What increases waves of peristalsis?

A

gastrocolic reflex

38
Q

What modifications are present in the digestive system that increase surface area?

A

villi in the small intestine dramatically increase surface area for absorption

39
Q

What other part of digestion increases surface area?

A

bile emulsifying fats

chewing of foods

40
Q

What is the path of absorption of lipids?

A
  • fatty acids and monoglycerides enter intestines via diffusion
  • fatty acids and monos are recombined to form tryglycerides and are mixed with other lipids and proteins to form chylomicrons
  • chylomicrons enter the lacteals of the villi and are transported to the systemic circulation via lymph in thoracic duct
  • short chain fatty acids are absorbed, move into capillary blood in villi by diffusion, and are transported to liver
41
Q

Where are long-chain fatty acids transported to?

A

lymphatic system

42
Q

Where are short and medium-chain fatty acids transported to?

A

cardiovascular system

blood circulation

43
Q

How do we get fat out of the small intestines?

A

lipoproteins (chylomicron, VLDL, LDL, HDL)

44
Q

What do chylomicrons do and where do they end up?

A

transport lipids from intestines to lymph

end in liver

45
Q

Where does VLDL start, what does it do, and where does it end?

A
  • liver after consuming saturated fats
  • deposits fats around body
  • circulation
46
Q

Where does LDL start, what does it do, and where does it end?

A
  • converted VLDL
  • deliver cholesterol to tissues
  • liver or arteries
47
Q

Where does HDL start, what does it do, and where does it end up?

A
  • liver after consuming unsaturated fats
  • artery scrubber
  • returns cholesterol to liver
48
Q

What is found in the large intestine that helps aid in digestion and produces vitamins?

A

gut bacteria aids in digestion and produces vitamin K

49
Q

In what portion of the GI tract does most absorption occur?

A

small intestines

50
Q

How does the GI tract protect itself from its own digestion in the stomach and small intestines?

A
  • bicarbonate ions neutralizes HCl in stomach

- pepsin and pepsinogen protect from self-digestion in small intestine

51
Q

How is ATP generated from glucose?

A

Glycolysis reaction breaks down 6C glucose to 2 molecules of 3C pyruvate. Pyruvate is then converted to acetyl-CoA in the transition reaction. Acetyl. CoA enters Krebs with oxaloacetate presence, producing coenzymes that carry electrons to the ETC to produce ATP.

52
Q

How are fatty acids broken down?

A

lingual lipase chemically breaks down large fat molecules, and bile later breaks down to micelles which later become chylomicrons

53
Q

Why do fats produce more ATP than any other macromolecule?

A

Fat contains long carbon chains, so they have a lot of carbon to be converted to acetyl-CoA. More acetyl CoA equals more ATP generation.

54
Q

In what form are simple carbs stored in the liver and skeletal muscle?

A

glycogen

55
Q

Connect Type I diabetes to ketoacidosis and ketone bodies in the blood

A

Type I diabetes is characterized by the body’s inability to produce its own insulin. When insulin is not present to process glucose for energy use, the body starts to burn fat for energy, which produces ketone bodies. The buildup of ketone bodies in the blood turns blood more acidic, causing DKA.

56
Q

Why are vegetarians advised to eat multiple types of vegetables to get the proper amount of protein in their diet?

A

Many vegetables are incomplete proteins, which means they lack 1 or more of the essential amino acids. Eating a wide range of vegetables in combination with each other will ensure that each vegetable acts as a complimentary protein, to ensure that you are receiving adequate amino acids

57
Q

Can glucose be converted to and stored as fat?

A

yes

58
Q

How is fat used in the body?

A

as phospholipids in cell membranes
as cushion and insulation
as a fuel source
sterols

59
Q

Why are minerals important in the diet?

A

aid in metabolism

60
Q

What is the muscular layer of the esophagus made up of?

A

smooth muscle

61
Q

What is the enteric nerve plexus?

A

gut brain

62
Q

What factors in the stomach create a barrier to protect against the harsh environment?

A

mucus (bicarbonate ions)
high turnover of cells
tight junctions

63
Q

How much gastric juice is produced daily?

A

3 Liters

64
Q

Control of gastric secretion occurs in how many phases?

A

3

65
Q

What are the 3 phases of gastric secretion control?

A
  • before (cephalic/reflex phase)
  • during (gastric phase)
  • after (intestinal phase)
66
Q

How does the intestinal phase control gastric secretions?

A

contents are released into duodenum which stimulates reduction of gastric juice production

67
Q

How are the rhythmic contractions of the stomach paced?

A

stimulus influences peristaltic waves because of the presence of autorhythmic cells

68
Q

When does the stomach empty?

A

within 4 hours after a meal

69
Q

The emptying of the stomach is largely dependent upon what?

A

ability to liquefy food and digestion in duodenum

70
Q

What part of the duodenum secretes bicarbonate-rich mucus?

A

duodenal glands

71
Q

What accessory organs also secrete into the duodenum?

A

gallbladder

pancreas

72
Q

What stimulates the duodenum?

A

stretch and change in chemical environment

73
Q

What is the role of the gallbladder?

A

storage site

74
Q

What produces bile?

A

gallbladder

75
Q

What are the characteristics of bile?

A
  • yellow-green, alkaline solution
  • contains bile salts, pigments, cholesterol, triglycerides, phospholipids, and electrolytes
  • main pigment is bilirubin
76
Q

What is the backbone of bile salts?

A

cholesterol

77
Q

What are gallstones?

A

crystals formed from an imbalanced chemistry, which are then surrounded by cholesterol

78
Q

What is the result of gallstones?

A

trapping of material which could result in Jaundice and impairment of digestion of fats

79
Q

What is the role of the pancreas?

A

secretes pancreatic juice

80
Q

What is found in pancreatic juice?

A

bicarbonate ions

digestive enzymes

81
Q

What are released in an inactive form and become active in the duodenum?

A

proteases

82
Q

The release of bile is stimulated by what?

A

bile salts

Cholecystokinin (CCK)

83
Q

CCK is released by what cells in response to what?

A

released by intestinal cells in response to high fat content of chyme

84
Q

CCK also stimulates the release of what type of juice?

A

pancreatic juice

85
Q

Pancreatic juices are released from what type of cells?

A

enteroendocrine

86
Q

How does sympathetic stimulation alter digestive activity?

A

inhibits digestive activities

87
Q

How does parasympathetic stimulation alter digestive activities?

A

enhances secretion and motility

88
Q

What makes up the abdominal (peritoneal) cavity?

A
  • serous membrane
  • peritoneal cavity (parietal and visceral)
  • mesentery
89
Q

What is peritonitis and what is it caused by?

A

inflammation of peritoneum

bacterial or fungal infection

90
Q

What are the modifications of the small intestine that increases absorption?

A
  • muscular layers force chyme to spiral through lumen, slowing its movement and increasing absorption
  • villi increase surface area
91
Q

Compare and contrast water-soluble and fat soluble vitamins

A

water-soluble are soluble in water and are excreted in excess
fat-soluble are soluble in fats and are stored

92
Q

Where are electrolytes absorbed?

A
  • most absorbed throughout small intestine

- iron and calcium absorbed in duodenum

93
Q

Where is most of the water absorbed?

A

small intestine, 95%

94
Q

Why can water move freely back and forth across the intestinal mucosa by osmosis?

A

moving solutes across makes water follow

95
Q

What are common disorders of the digestive system?

A

constipation/diarrhea

appendicitis

96
Q

What is Celiac’s disease?

A

an autoimmune disorder that destroys villi, making digestion and absorption difficult

97
Q

What happens due to Celiac disease?

A

surface area decreases

nutrient deficiencies

98
Q

What is Crohn’s disease?

A

inflammatory condition

immune system treats foods/bacteria/other beneficial substances as foreign

99
Q

What causes Crohns?

A

cause not well-understood, but is due to abnormal reaction of immune system

100
Q

What happens because of Crohns?

A

build up of white blood cells, inflammation, and ulcerations

101
Q

How is Crohns treated?

A

removal of infected parts, which decreases surface area and decreases digestion and absorption

102
Q

What is metabolism?

A

sum of all reactions taking place

103
Q

What is anabolic?

A

growth

like steroids

104
Q

What is catabolic?

A

breakdown

like fasting

105
Q

What does your heart prefer?

A

fatty acids

106
Q

Which type of lipoproteins matter more when considering heart disease, heart attack etc.?

A

LDL

107
Q

What can the heart take up and lose for energy?

A

lactate

108
Q

What is a simple carbohydrate?

A

glucose

109
Q

What is a complex carbohydrate?

A

glycogen

110
Q

What are carbohydrates used for?

A

energy

111
Q

Carbohydrates are stored as what?

A

glycogen or fat

112
Q

What is glycogenesis?

A

formation of glycogen

113
Q

What is glycogenolysis?

A

liver

glycogen breakdown

114
Q

What hormones are involved in metabolism?

A

insulin

glucagon

115
Q

What does insulin do?

A

stimulates uptake (removal from blood) and use of glucose inside the cell

116
Q

What does glucagon do?

A

breakdown into glucose to enter circulation

117
Q

Where does each phase of metabolism take place?

A

Glycolysis - cytosol
Transition Reaction - between cytosol and mitochondria
Krebs - mitochondria
ETC - mitochondria

118
Q

What are the major forms of lipids?

A

triglycerides

cholesterol

119
Q

What are the characteristics of saturated fat?

A

saturated by hydrogen

linear carbon chain makes it solid at room temperature

120
Q

What are the characteristics of unsaturated fat?

A

not saturated by hydrogen

makes kink in chain that allows it to be liquid at room temperature

121
Q

What is cholesterol used for?

A

sex hormones

membranes

122
Q

Lipogenesis vs. Lipolysis

A

formation vs. breakdown

123
Q

What are proteins composed of?

A

amino acids

124
Q

The metabolism of proteins makes what?

A

ammonia
ammonia is toxic
urea

125
Q

Vitamins act as what in metabolism?

A

coenzymes

126
Q

K and B vitamins are produced by what?

A

bacteria

127
Q

What are the water-soluble vitamins?

A

B and C

128
Q

What are the fat-soluble vitamins?

A

A, D, E, & K

129
Q

Minerals act as what in metabolism?

A

cofactors