Brainscape's Knowledge GenomeTM

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


See full index

Phys 2 test 3 INTRANET > PHYStest3INTRANET > Flashcards

PHYStest3INTRANET Flashcards

1
Q

What is deglutition?

A

Swallowing.

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

Where is the Auerbach’s/myenteric plexus found at and what is it for?

A

In the muscularis externa and it is the enteric nervous system used for movement.

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

Where is the Meissner’s/submucous plexus at and what is it for?

A

In the Submucosa and it si the enteric nervous system used for secretion and blood flow.

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

GI smooth muscle fibers are electrically connected via what?

A

Gap junctions.

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

What is the purpose of the gap junctions in GI smooth muscle fibers?

A

allows ions to pass between muscles, allows muscle signals to move rapidly.

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

With GI smooth muscle what direction will the action potential travel?

A

In all directions.

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

How will most GI movement occur?

A

Rhythmically based on frequency of slow waves via pacemaker.

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

What is the pacemaker of GI smooth muscle?

A

Interstitial cells of Cajal.

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

Will the interstitial cells of Cajal have action potentials?

A

No, but they are slow undulating changes in resting membrane potential.

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

The Rhythmically based patterns for GI smooth muscle movement slow wave sets what?

A

A basic electrical rhythm (BER) for each gut segment.

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

Electrical slow waves only cause muscle contractions where?

A

In the stomach. Where action/spike potentials occur on top of slow wave= muscle contractions.

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

True action potentials occurring on top of slow waves is stimulated by what?

A

Depolarization from stretch, Parasympathetic NS, Ach, Other GI hormones.

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

The higher the slow wave potential is the more what?

A

Frequent the spike potentials can lead to tonic contractions.

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

GI spike potentials last much longer than most others due to what?

A

Calcium-sodium channels are slow to open and close.

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

What factors would lead to hyperpolarization of the spike potential?

A

Sympathetic stimulation, norepinephrine.

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

What are the nervous systems involved with controling the gut?

A
  1. Enteric/intrinsic nervous system. 2. Extrinsic nervous system: SNS and PNS.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Besides nervous control what is a controling mechanism of the gut?

A

Hormones.

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

What is the brain of the GI tract?

A

The enteric nervous system.

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

Can the enteric nervous system function on its own without SNS or PNS?

A

Yes, but it is greatly augmented by the SNS and PNS.

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

How many nerve plexi make up the enteric nervous system?

A

two.

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

How many neurons make up the enteric nervous system?

A

around 100 million.

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

What will the enteric nervous system control?

A

GI movements and secretions.

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

What will connect the enteric nervous system to the PNS and SNS?

A

Ganglia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The enteric nervous system ganglia receive information directly from where?

A

receptors in mucosa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Enteric nervous system ganglia send what where?

A

Send motor fibers directly to smooth muscles or glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Most of the GI function is reflexive involving what?

A

receptors in mucosa (mechano and chemo), and interneurons relay between ganglia of the 2 plexi.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where is the myenteric (auerbach’s) plexus found at in the muscluaris externa?

A

Between the muscle layers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Will the myenteric (auerbach’s) plexus be excitatory or inhibitory?

A

Both.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Submucosal (meissner’s) plexus primarily controls _____ activity.

A

Sensory.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What type of effect will the parasympathetic nervous system have on the GI tract?

A

Excitatory: increases motility and secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Parasympathetic preganglionics stimulate the GI tract via what?

A

Ach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Where are the parasympathetic postganglionic cell bodies that affect the GI tract found at?

A

in the enteric plexi.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The parasympathetic postganglionic stimulate the GI tract via what?

A

Ach or peptides like VIP or substance P.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the sympathetic nervous systems function with the GI tract?

A

Inhibitory: generally decreases motility and secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Where will the sympathetic nervous system arise from that works with the GI tract?

A

From cord segments T5-L2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How will the sympathetic preganglionics travel to the GI tract?

A

pass thru the sympathetic chain as splanchnic nerves and synapse in prevertebral ganglia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The sympathetic preganglionics work with the GI tract via what?

A

Ach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The sympathetic postganglionics work with the GI tract via what?

A

Adrenergic: norepinephron and small amounts of epinephrine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What will sympathetic activity do to smooth muscle in blood vessels?

A

Vasoconstriction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Sympathetic activity in sphincter muscles is usually what?

A

Excitatory.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

True or False most sympathetic and parasympathetic fibers synapse with the enteric nervous system rather than directly on muscle and glands?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What % of vagus fibers and sympathetic fibers are afferent?

A

Vagus-80%. Sympathetic-50%.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Why are visceral afferents needed?

A

For reflex activity in the GI tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What 3 levels are reflexes controlled or integrated at?

A
  1. Locally. 2. Prevertebral ganglia. 3. CNS.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Local reflexes in the GI tract involves what?

A

Secretion, peristalsis, mixing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Prevertebral reflexes of the GI tract involves what?

A

distance refelx for motility/ emptying of colon, ileum, and stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the enterogastric reflex?

A

signals from colon and small intestines back to stomach to inhibit stomach motility and stomach secretions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the colonoileal reflex?

A

Signals from colon back to ileum to inhibit emptying of ileum into colon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

CNS reflex to the GI tract travel how?

A

Transmit signals to brain stem or spinal cord and efferents via vagus or pelvic splanchnics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

CNS reflex to the GI tract is used for what?

A

Controlling stomach motor secretory activity, pain reflexes that inhibit the whole GI tract, and defecation reflex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

All blood from GI, pancreas, Spleen goes to the liver via what and leaves via what?

A

To liver via portal vein and leaves via hepatic veins to vena cava.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What will the liver do with non-fat, water-soluable nutrients?

A

Stores 1/2-3/4 of it for processing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Will Fat go to the liver?

A

No it bypasses the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How will fat bypass the liver?

A

Via intestinal lymphatic absorbtion to thoracic duct and general circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

GI hormones are released from what and into what?

A

From GI tract into portal circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the targets of GI hormones?

A

GI tract or elsewhere.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How many definitive GI hormones are there?

A

4 of them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Name the 4 GI hormones?

A
  1. Gastrin. 2. Cholecystokinin (CCK). 3. Secretin. 4. Gastric inhibitory peptide (GIP).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What will Gastrin do?

A

Stimulates gastric acid secretion and proliferation of gastric epithelium, decreased gastric emptying: peptides and amino acids in small intestine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What will Cholecystokinin or CCK do?

A

Stimulates secretion of pancreatic enzymes and contraction/emptying of gall bladder, decreased gastric emptying: fatty/amino acids in small intestine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What will Secretin do?

A

Stimulates secretion of water/bicarbonate from pancreas and bile ducts, decreases gastric emptying: acidic pH in small intestine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What will gastric inhibitory peptide (GIP) do?

A

inhibits gastric secretion/motility: increases release of insulin from beta cells in response to elevated blood glucose: presence of fat/glucose in small intestine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Other GI hormones that need to be mentioned are motilin and pancreatic polypeptide and what will they do?

A

Motilin- increases migrating motor complex to sweep undigested residual material through stomach/small intestine. Pancreatic polypeptide- A CCK antagonist. Suppresses pancreatic secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

When will motilin and pancreatic polypeptide be secreted?

A

Motilin- increased during fasting. Pancreatic polypeptide- decreased by somatostatin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What will enteroglucagon or glucagon-like peptide do?

A

enhances release of insulin decreases release of glucagon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What will glucagon do?

A

Lowers blood glucose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

When is glucagon secreted?

A

After ingestion of a meal containing carbohydrates or lipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Grehlin is a strong stimulant for what?

A

Appetite and feeding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What will Grehlin do with fat?

A

It suppresses fat utilization.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Grehlin is a potent stimulator of what?

A

Growth hormone secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

From where will Grehlin be secreted?

A

From cells in antrum of stomach prior to feeding, and cells in the pancreas, and in the arcuate nucleus of the hypothalamus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What is Prader-willi syndrome?

A

Plasma grehlin levels are very high in extreme obesity and uncontrollable appetite is present this might mean that obesity in this case might be due to other causes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Ghrelin is the counterpart of what hormone?

A

Leptin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Leptin is made where?

A

By adipose tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What will ghrelin produced in the arcuate nucleus of the hypothalamus do?

A

Stimulates the secretion of growth hormone from the anterior pituitary gland.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Those suffering from anorexia nervosa suffer from high levels of what?

A

Ghrelin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Ghrelin plays a role in what type of eating disorders?

A

Both anorexia and obesity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What will Ghrelin secretion be like in thinner people?

A

Increases during the time of day from midnight to dawn.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Secretion of ghrelin in thin people from midnight to dawn suggests what?

A

A flaw in the circadian system of obese individuals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Leptin plays a key role in regulating what?

A

Energy intake and energy expenditure, inculding appetite and metabolism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What is one of the most important adipose derived hormones?

A

Leptin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

How will increased levels of leptin be associated with appetite?

A

Suppression.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What will obese peoples leptin levels be like?

A

Abnormally high and this suggests that obese individuals may be leptin resistant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Short sleep duration may lead to obesity how?

A

through an increase of appetite via hormonal changes. Lack of sleep produces ghrelin which stimulates appetite and creates less leptin which amongst its many other effects suppresses appetite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

GI paracrines are secreted by what?

A

Endocrine cells in GI tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Where will GI paracrines act at?

A

They act locally on same tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What are the 2 GI paracrines that we need to know?

A

Somatostatin, and histamine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Majority of circulating somatostatin comes from where?

A

pancreas and GI.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What will somatostatins inhibit?

A

Inhibits secretion of GI hormones: gastrin, CCK, Secretin, GIP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What will somatostatins suppress?

A

Suppresses secretion of gastric acid and pepsin, decreased gastric emptying, reduces smooth muscle contractions and GI blood flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What is the overall effect of somatostatins?

A

Decreasing rate of nutrient absorption.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Where is the GI paracrine Histamine secreted from?

A

Enterochromaffin-like cell of stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What will the GI paracrine Hormone Histame do?

A

H2 receptors on parietal cells will bind histamine and increase H+ secretion in stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

GI neurocrines are peptides synthesized where?

A

In neurons of the GI tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

GI neurocrines are released when?

A

Action potentials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Where will GI neurocrines travel to act on target cells?

A

They travel across the synapse.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Give 2 examples of GI neurocrines?

A
  1. Vasoactive intestinal peptide (VIP). 2. Gasrin-releasing peptide.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What will VIP do?

A

induce smooth muscle relaxation, stimulate secretion of water into pancreatic juice and bile, inhibit gastric acid secretion/absorption from intestinal lumen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What will gastrin-releasing peptide do?

A

Increased gastrin secretions and this increases the HCL of the stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

Where will gastrin-releasing peptide be released at?

A

by postganglionic fibers of the vagus that innervate G cells of the stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

What are the 2 general types of contractions in the GI tract?

A
  1. Phasic. 2. Tonic.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

What are phasic contractions like?

A

Periodic contractions followed by relaxation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Where will phasic contractions be found at?

A

Esophagus, stomach, and small intestines.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What are phasic contractions used for?

A

for mixing and propulsion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

What are the phasic contraction frequency based on?

A

on BER (basic electrical rhythm) of region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

What are tonic contractions like?

A

constant contraction (tone) without relaxation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Where are tonic contractions located at?

A

upper stomach, lower esophagus, and some sphincters.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Tonic contractions last how long?

A

Minutes to hours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

What causes tonic contractions?

A

Not BER, but repetitve spike potentials, hormones, calcium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

What are the 2 types of movement in the GI tract?

A
  1. Propulsive. 2. Mixing.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

What is the main propulsive movement of the gut?

A

Peristalsis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

What type of musclular contractions are done for propulsion?

A

Ring-like.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

What stimulates ring-like contractions that produce propulsion in the GI tract?

A

distention, irritation, parasympathetic, hormones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

What enteric nervous system need to be functioning to have propulsion in the GI tract?

A

myenteric or auerbachs plexus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

What direction will peristalsis work in?

A

Both directions, but it dies out orally.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

What happens to material that is distal to the constriction rings in peristalsis?

A

It moves forward.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

As peristalsis moves contents of GI tract forward what happens to the muscle in the receiving segment?

A

It relaxes and longitudinal muscle contracts to expand its diameter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

What is the Law of the Gut?

A

combination of myenteric with relaxation of distal segment and movement from oral to anal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

Peristalsis can also cause mixing especially if what happens?

A

if food is propelled against a closed sphincter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

Can peristalsis occur in bile and gland ducts and ureters?

A

yes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

Absorption of food happens via contact with what?

A

Mucosa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

What are the 2 functions of the secretory glands in the GI tract?

A
  1. Digestion. 2. Lubrication/protection.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

Most GI secretions are formed in response to what?

A

Presence of food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

What is secreted for lubrication/protection?

A

Mucus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

What is secreted for digestion?

A

Enzymes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

Why are hormones secreted?

A

Regulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

What are secretory cells like of the GI tract that are in the epithelium region?

A

Single cells on the epithelium and pits/crypts that are invaginations of epithelium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

These single cell secretory cells in the on the epithelium secrete in response to what?

A

Local irritation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

Tubular glands of the GI tract are found where?

A

in stomach, and upper duodenum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

What will tubular glands secrete?

A

acid and pepsiongen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

What are the complex GI tract glands that are outside the GI tract?

A

salivary, pancreas, liver, gall bladder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

These complex glands of the GI tract are for what?

A

Digestion/emulsification of food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

What are the mechanical stiumi for secretion?

A

tactile, chemical, stretch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

How will para- and sympa- thetic nervous systems effect GI secretion?

A

Para-increase rate of secretion. Sympa- reduces rate of secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

What part of GI secretion will the hormones regulate?

A

Volume and character of secretions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Hormones of the GI tract are released from where and because of what?

A

from mucosa in response to food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

what is mucus (thick secretion) composed of?

A

Water, electrolytes, polysaccharides, protein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

Will mucus be the same at all parts of the GI tract?

A

No it varies between different parts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

What will mucus do to fecal particles?

A

Help them bind together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

Will mucus breakdown from enzymatic activity?

A

No it is resistant to breakdown by digestive enzymes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

What is the role of mucus in pH?

A

It is a buffering agent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

What do digestive enzymes need to be more effective at digestion?

A

Increased surface area provided by mastication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

What type of food really needs good mastication and why?

A

Raw fruits and vegetables to remove the cellulose surrounding the nutrients.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

The mouth prevents what from happening to the GI tract?

A

Excoration (Strip off or remove skin).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

Is chewing volunatry or involuntary?

A

Both.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

How much saliva is produced a day?

A

1-1.5 liters.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

What is the pH of saliva?

A

6-7.0.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

What 2 things will saliva contain?

A
  1. serous secretion-ptyalin. 2. Mucus secretions- mucin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

What are the 3 sets of salivary glands?

A
  1. Submandibular. 2. Parotid. 3. Sublingual.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

What are submandibular secretions like?

A

mixed serous and mucus. Amylase and mucus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

What are the partoid glands secretions like?

A

mostly serous. Salivary amylase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

What are the sublingual glands secretions like?

A

mixed serous and mucus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

Buccal glands secrete what?

A

Only mucus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

Saliva is a solvent for what?

A

molecules that stimulate taste buds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

Saliva initiates digestion of what via amylase?

A

Carbohydrates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

How is saliva an antibacterial agent?

A

Washes away and attacks pathogenic bacteria and food particles to decrease tooth decay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

Saliva functions to help reabsorbe what?

A

Na+ and Cl-.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

Saliva’s initial secretion by acinar cells is what?

A

Isotonic. (same salt content as blood).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

What will modify the composition of the isotonic saliva?

A

Ductal cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
160
Q

What will ductal cells do to saliva?

A

Na+ is reabsorbed, and K+ os actively secreted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
161
Q

Excess Na+ reabsorption caused ________ Cl- reabsorption.

A

Passive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
162
Q

In the formation of saliva what will actively be secreted and exchanged for Cl-?

A

Bicarbonate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
163
Q

Normaly water would follow bicarbonate in saliva formation, but ductal cells are not permeable to water so final saliva is like what?

A

Hypotonic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
164
Q

What will saliva be like during maximal salivation?

A

More closely resembles plasma.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
165
Q

How will para- and sympa- thetic nervous systems effect regulation of saliva?

A

They both increase, but mostly para- will increase the saliva.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
166
Q

Reflex for saliva production from para- and sympa comes from a reflex found in what nuclei?

A

Through superior and inferior salivatory nuclei in brainstem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
167
Q

Parasympathetic stimulation will be via what and to what to increase saliva?

A

Via Ach and to muscarinic receptors on acinar and ductal cells of saliva glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
168
Q

Parasympathetic stimulation of Ach to muscarinic receptors on acinar and ductal glands increases saliva how?

A

By increasing blood flow to glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
169
Q

What Spinal cord levels will sympathetic output to salivary glands come from?

A

T1-T3.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
170
Q

Sympathetic stimulation to saliva glands works via what and to what?

A

Norepinephrine wth beta receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
171
Q

Norephinephrine to beta receptors of saliva glands will do what?

A

Decreases blood flow and so there is less saliva.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
172
Q

What part of the brain regulates the food likes and dislikes?

A

appetite area of the brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
173
Q

Where is the appetite area of the brain at?

A

Located close to parasympathetic centers in anterior hypothalamus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
174
Q

The appetite area of the brain functions in response to what?

A

taste and smell areas of cerebral cortex and amygdala.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
175
Q

Reflex for saliva production originating in the stomach and proximal small intestine are due to what?

A

Irritating foods or nausea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
176
Q

How is the oral deglutition stage done?

A

Voluntaraly food is formed into a bolus and propelled backwards to pharynx by tongue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
177
Q

How is the pharyngeal and esophageal stages of deglutition done?

A

Involuntary and controlled by the swallowing center in the medulla.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
178
Q

The pharyngeal stage of deglutition is done via what nerves?

A

Trigeminal and glosso-pharyngeal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
179
Q

What are the mechanics of the first 2 parts of the pharyngeal stage of deglutition?

A

soft palate is pulled upward to prevent food from entering nasopharynx, and palatopharyngeal folds approximate allowing only small pieces to enter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
180
Q

What are the 3-5 parts of the pharyngeal stage deglutition?

A
  1. Vocal folds approximated and larynx pulled upward against epiglottis to keep food out of larynx and trachea. 4. Upward movement of larynex pulls and enlarges openings to esophagus and upper esophageal sphincter relaxes. 5. Contraction of pharynx via peristalsis moves food to esophagus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
181
Q

How long will the pharyngeal stage of deglutition last?

A

It is rapid lasting only 2-3 seconds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
182
Q

What happens to breathing during the pharyngeal stage of deglutition?

A

It is inhibited via swallowing center inhibition on respiration center.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
183
Q

What is the esophageal stage of deglutition like?

A

Involuntary via swallowing reflex and enteric nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
184
Q

What are the 2 phases of peristalsis exhibited by the esophagus during deglutition?

A

Primary and secondary waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
185
Q

What is the primary wave of esophagus deglutition?

A

Continuation of pharyngeal peristaltic waves, from pharynx to stomach in 8-10 seconds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
186
Q

How long will the primary wave phase last if aided by gravity?

A

5-8 seconds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
187
Q

What is the secondary wave phase of the esophagus deglutition like?

A

due to distention from food not moved by primary. The second wave continues until esophagus is clear.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
188
Q

The secondary wave phase happens via what reflex?

A

Pharyngeal reflex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
189
Q

Whatpathways will the pharyngeal reflex use?

A

vagus—> medulla—–> vagus and glossopharyngeal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
190
Q

The final stage of deglutition requires what?

A

Relaxation of stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
191
Q

Gastric relaxation happens via what?

A

Myenteric inhibitory neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
192
Q

Relaxation of entire stomach and proximal duodenum =?

A

Prepared to receive food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
193
Q

Where is the lower esophageal sphincter at?

A

The final 3 cm of the distal esophagus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
194
Q

What is the lower esohpageal sphincter normally like?

A

Tonically constricted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
195
Q

What will cause the lower esophageal sphincter to relax?

A

Receptive relaxation with peristaltic waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
196
Q

Paralysis of the swallowing mechanism is due to damage to what crainial nerves?

A

V, VII, IX, X.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
197
Q

What diseases cause swallowing disorders?

A

Those that damage the swallowing center in the brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
198
Q

What happens during swallowing with a failure of the glottis to close?

A

Food passes into lungs instead of the esophagus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
199
Q

What happens to swallowing under anesthesia?

A

Vomit materials into pharynx then instead of swallowing simply sucked into trachea because refelx mechanism is blocked.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
200
Q

What is achalasia?

A

Lower esophageal sphincter fails to relax during swallowing so food fails to pass from esophagus to stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
201
Q

Achalasia is due to what?

A

Damage of myenteric plexus, secondary to chronic reflux.

202
Q

What is the treatment for Achalasia?

A

Stretching via balloon or antispasmotic drugs.

203
Q

What are the 2 esophageal sphincters?

A

upper and lower.

204
Q

The upper and lower esophageal sphincters are aka?

A

Upper- Criropharyngeal muscle. Lower- cardiac sphincter.

205
Q

What will the upper esophageal sphincter do?

A

Prevents air from entering the esophagus.

206
Q

What will the lower esophageal sphincter do?

A

Prevents reflux of stomach contents.

207
Q

When are both esophageal sphincters closed?

A

They are both closed except during swallowing.

208
Q

What is the esophageal secretions like?

A

Entirely mucus for lubrication.

209
Q

What kind of glands will the esophagus be lined with?

A

Simple mucous glands.

210
Q

The Proximal and distal portion of the esophagus have mucous glands to prevent what?

A

Excoriation from newly swallowed food and digestion by refluxed gastric juices.

211
Q

How long will it take food to pass through the esophagus?

A

about 10 seconds.

212
Q

What are the 2 types of esophageal peristalsis?

A

primary and secondary.

213
Q

How are the primary and secondary esophageal peristalsis initiated?

A

Primary- by swallowing. Secondary- initiated by digestion if primary wave does not move all food through.

214
Q

The gastroesophageal reflux disorder is aka?

A

Heartburn.

215
Q

What are the symptoms of the gastroesophageal reflux disorder?

A

Chronic cough, ENT complaints, asthma, hoarseness, anemia.

216
Q

What are the causes of gastroesophageal reflux disorder (GERD)?

A

inapproptiate relaxation of Lower esophageal sphincter.

217
Q

What complications can come with GERD?

A

Risk of barrett’s esophagus and cancer.

218
Q

What are the treatments of GERD?

A

Diet/lifestyle modifications, medications (H2 receptor blockers).

219
Q

What are the 3 functions of the stomach?

A
  1. Storage until processing can occur. 2. Mixing with gastric secretions to form chyme. 3. Controlled emptying of chyme.
220
Q

How will chyme be released from the stomach?

A

Slowly to facilitate proper digestion and absorption by small intestines.

221
Q

What are the 2 major parts of the stomach?

A

body and antrum.

222
Q

What will increasd food volume do to the stomach?

A

Stretching activates local myenteric plexus and increases stomach emptying.

223
Q

Gastrin will do what to the stomach?

A

Increases; secretion of gastric juices, motor activity, and opens the pyloric quicker.

224
Q

What reflex will decrease the stomach emptying?

A

Enterogastric reflex.

225
Q

The enterogastric reflex is from where?

A

Duodenum to stomach.

226
Q

How will the enterogastric reflex travel?

A

extrinsic nerves to prevertebral sympathetic ganglia then back to stomach. (vagus to brian and vagus to stomach).

227
Q

What will presence of fatty or acidic chyme in the stomach do?

A

Increase hormones. Mainly Cholecystokinine, also secretin and gastrin inhibiting peptide.

228
Q

What is the largest factor controlling gastric emptying?

A

Duodenum.

229
Q

How will the duodenum control gastric emptying?

A

It limits the amount of chyme to only what small intestines can process.

230
Q

The Enterogastric reflex is initated by what?

A

Distention of duodenum, irritation of duodenum, acidity of duodenal chyme, and breakdown products of protein and fat.

231
Q

Gastric secretions include what?

A

Mucus, HCL, Pepsinogen, intrinsic factor, gastrin, salts, water, and bicarbonate.

232
Q

What is the role of mucus in the stomach?

A

Protection from corrosion by HCL.

233
Q

What is HCl’s role in the stomach?

A

Acidification to optimal pH for enzymes to function.

234
Q

What is the role of pepsiongen in the stomach?

A

Precursor of enzyme for protein digestion.

235
Q

What will intrinsic factor’s role be in the stomach?

A

Absorption of vitamin B12 in colon.

236
Q

What will gastrin’s role be in the stomach?

A

Regulates H+ secretion.

237
Q

How much mucus will line the entire surface of the stomach?

A

Very viscous alkaline mucus will line the stomach nearly 1 cm thick.

238
Q

What type of cells will secrete mucus in the stomach?

A

Mucous neck cells.

239
Q

What type of cells secrete pepsinogen in the stomach (give both names)?

A

Peptic or chief cells.

240
Q

What type of cells secrete HCL and Intrinsic factor in the stomach (give both names)?

A

Parietal (oxyntic).

241
Q

What is the group of glands called that have cells that secrete HCL, Pepsinogenm intrinsic factor, and mucus?

A

Oxyntic or gastric glands.

242
Q

What are pyloric glands?

A

Glands that secrete gastrin, mucus and small amounts of pepsinogen.

243
Q

What are the different type of pyloric glands?

A

Mucous cells, few peptic cells and no parietal cells.

244
Q

What is achlorhydria?

A

Lack of stomach acid.

245
Q

What will a lack of stomach acid lead to?

A

A B12 deficiency.

246
Q

What will a B12 deficiency lead to?

A

Pernicious anemia due to Failure of RBC maturation.

247
Q

What is needed to convert pepsinogen to pepsin?

A

HCL.

248
Q

Parietal cells are closely associated with what?

A

Enterochromafin-like cells.

249
Q

Enterochromafin-like cells = what?

A

Histamine.

250
Q

HCL secretion is directly related what?

A

The amount of histamine.

251
Q

What are 3 primary stimuli for H+ secretion?

A
  1. Ach. 2. Histamine. 3. Gastrin.
252
Q

What are the 3 phases of HCL secretion and they make up what % of HCL secretion?

A
  1. Cephalic-30%. 2. Gastric- 60%. 3. Intestinal-10%.
253
Q

In general how will the cephalic phase of HCL secretion work?

A

Before a meal via Ach gastrin is released and this leads to H+ secretion.

254
Q

How will the gastric phase of HCL secretion work?

A

After a meal vagus nerve stimulates gastrin and stomach distention and amino acid and small peptides also help with HCL secretion.

255
Q

How will the intestinal phase of HCL secretion work?

A

Receptors in small intestine and distention and amino acid triggers local neural reflex and gastrin.

256
Q

Once HCL is no longer needed what will inhibit the secretion of HCL?

A

Decreased pH is major control, but also somatostatin and gastric inhibitory peptide (GIP) will inhibit gastrin secretion.

257
Q

Lower pH inhibits secretion of what?

A

Gastrin and therefore HCL.

258
Q

What will bicarbonate do in the stomach and where is it released from?

A

Released from surface cells and it is trapped in the mucus to increase the pH to around 7.

259
Q

What will stimulate the secretion of mucus?

A

Ach from parasympathetic NS and eating food.

260
Q

What are the causes of gastritis?

A

Bacterial infection and ingested irritants.

261
Q

What will chronic gastritis lead to?

A

atrophy–> little to no secretion—> achlorhydria and pernicious anemia due to loss of HCL and Intrinsic factor.

262
Q

What are the most frequent sites for peptic ulcers?

A

Within centemeters of pylorus, along lesser curvature of stomach or distal esophagus.

263
Q

What is the Etiology (study of cause of disease) of peptic ulcers?

A

Imbalance between rate of secretion of HCL and pepsinogen vs. integrity of gastroduodenal mucosa.

264
Q

What type of bacteria will destroy mucosal barrier and increases gastric acid secretion?

A

Helicobacter pylori.

265
Q

What are other factors that lead to peptic ulcers?

A

Smoking, alcohol, asprin.

266
Q

What is a type of effective treatment of peptic ulcers?

A

Antibiotics and acid-suppressant drugs.

267
Q

How will acid-suppressant drugs work?

A

antihistamine—> reducing gastric acid secretion by 70-80%.

268
Q

The pancreas is made of compound glands similar to what glands?

A

Salivary glands.

269
Q

What 2 things will the pancreas secrete?

A

Digestive enzymes and sodium bicarbonate.

270
Q

The pancreas will secrete digestive enzymes and sodium bicarbonate from where?

A

Digestive enzymes from acini. Sodium bicarbonate from ductule/duct of acini.

271
Q

What is the purpose of sodium bicarbonate secreted from the pancreas?

A

TO Neutralize acidity of chyme.

272
Q

What will stimulate the secretions of the pancreas?

A

Chyme in upper small intestine and the characteristics of pancreatic secretions will be dependent on content of chyme.

273
Q

The pancreatic duct joins what?

A

Hepatic duct.

274
Q

Pancreatic secretions go through what sphincter?

A

Sphincter of oddi.

275
Q

What form will pancreatic enzymes be synthesized as?

A

Inactive form.

276
Q

Name the 3 digestive enzymes synthesized in the pancreas?

A

Trypsinogen, chymotrypsinogen and procarboxyypolypeptidase.

277
Q

What is the total amount of pancreatic secretions of enzymes per day?

A

1 liter.

278
Q

When will the proteolytic (inactive) pancreatic enzymes become active?

A

Not until the duodenum.

279
Q

What will keep trypsin from becoming active and where will this be secreted from?

A

Trypsin inhibitor and it is secreted the same cells that secrete trypsin.

280
Q

How will trypsin inhibitor effect other enzymes?

A

Trypsin activates other enzymes and so trypsin inhibitor prevents activation of all.

281
Q

What happens to pancreatic enzymes when the duct is blocked or damaged?

A

Secretions pool and trypsin inhibitor is overwhelmed and pancreatic enzymes are activated and it can digest the pancreas within hours.

282
Q

What will it be called when the pancreatic enzymes digest the pancreas?

A

Acute pancreatitis.

283
Q

What will Acetylcholine do to the pancreas?

A

Stimulates acini to secrete enzymes.

284
Q

What will cholecystokinin do to the pancreas?

A

Stimulates acini to secrete enzymes.

285
Q

What will secretin do to the pancreas?

A

Stimulates duct for more water and solution of sodium bicarbonate.

286
Q

Cholecystokinin is secreted by what and when?

A

By duodenum and jejunum when food enters the small intestine.

287
Q

Where will Ach come from that goes to the Pancreas?

A

From parasympathetic ns via vagus and cholinergic nerves in enteric NS.

288
Q

Secretin is secreted by what and when?

A

By duodenum and jejunum when food enters the small intestine.

289
Q

What does it mean that the pancreas stimuli potentiate each other?

A

That the total secretion is greater than the sum of the individual secretions.

290
Q

What are the pancreatic enzymes for digesting proteins?

A

Trypsin chymotrypsin and carboxypolypeptidase.

291
Q

How will trypsin and chymotrypsin digest proteins?

A

Digests them into peptides but doesn’t release indivual amino acids.

292
Q

How will carboxypolypeptidase digest proteins?

A

Splits some peptides into individual amino acids.

293
Q

What is the pancreatic enzyme for carbohydrate digestion?

A

Pancreatic amylase.

294
Q

How will pancreatic amylase work?

A

Hydrolizes starches, glycogen and other CHO into disaccharides and trisaccharides.

295
Q

What are the 3 pancreatic enzymes for fat digestion?

A
  1. Lipase. 2. Cholesterol esterase. 3. Phospholipase.
296
Q

How will lipase digest fat?

A

takes neutral fat into fatty acids and monoglycerides.

297
Q

How will Cholesterol esterase digest fat?

A

hydrolizes cholesterol esters.

298
Q

How will phospholipases digest fat?

A

Phospholipids into fatty acids.

299
Q

Bicarbonate and ions and water are mainly secreted by what part of the pancreas?

A

By epithelial cells of the ductules and ducts that lead from the acini.

300
Q

Bicarbonate concentration from pancreas is how much more concentrated that bicarbonate ions found in the plasma?

A

5 times.

301
Q

What is the purpose of pancreatic secretion of bicarbonate ions?

A

To neutralize HCL that is empted into duodenum from stomach.

302
Q

What are the 3 phases of pancreatic secretion?

A

The same as the stomach cephalic, gastric, and intestinal phases.

303
Q

What will the cephalic and gastric phase of pancreatic secretion be like?

A

Nervous system singals the secretion in the stomach also causes Vagal Ach release in the pancreas.

304
Q

What is the major phase of pancreatic secretion?

A

The intestinal phase.

305
Q

What is the intestinal phase of pancreatic secretion like?

A

After chyme enters the small intestines then pancreatic secretions become great due to secretin.

306
Q

What will secretin do?

A

Stimulates secretion of large amounts of bicarbonate ions.

307
Q

The inactive form of secretin is a prosecretin and it comes from where?

A

S cells of duodenum and jejunum.

308
Q

When will secretin be released?

A

When acidic chyme enters the duodenum from the stomach.

309
Q

How will secretn effect the digestive actvity in the duodenum?

A

It will decrease the digestive activity by gastric juices in duodenum.

310
Q

What are the 2 functions of secretin?

A
  1. Protective mechanism to prevent duodenal ulcers. 2. Provides appropriate pH (7-8) for pancreatic enzymes.
311
Q

What is the most common cause of pancreatitis?

A

Drinking excess alcohol.

312
Q

What is the second most common cause of pancreatitis?

A

blockage of the papilla of vater by a gallstone.

313
Q

Without pancreatic enzymes how will fat, carbohydrate and protein digestion be affected?

A

60% of fat and 1/3-1/2 of proteins and carbohydrates entering small intestines may be unabsorbed.

314
Q

How much bile is secreted by the liver a day?

A

600-1000 ml.

315
Q

Bile is made from what precursor?

A

Cholesterol from diet or synthesized.

316
Q

What is the composition of Bile?

A

Mostly bile salts, bilirubin, cholesterol, lecithin and electrolytes of plasma.

317
Q

What are the 2 important functions of bile?

A
  1. Fat digestion and absorption. 2. Excretion of waste from blood (bilirubin and excess excess cholesterol).
318
Q

How will bile help with fat digestion and absorption?

A

Emulsify large fat particles into smaller particles which can be attacked by lipase enzymes of pancreatic juices, and aid in absorption fo digested fat end products through intestinal mucosal membrane.

319
Q

Without bile salts what happens to ingested fats?

A

40% are lost in feces and we develop a metabolic deficit.

320
Q

Hepatocytes secrete bile into what?

A

Canalliculi.

321
Q

What is the initial and secondary stages of bile?

A

Initial- bile acids, and cholesterol. Secondary- sodium and bicarbonate.

322
Q

When will bile be secreted from liver cells?

A

Continually.

323
Q

What is the maximun volume of the gall bladder?

A

30-60 ml.

324
Q

How many hours of bile secretion can be stored in gall bladder?

A

12 hours because water, sodium, chloride and other electrolytes are continually absorbed through the gallbladder mucosa.

325
Q

What will the gall bladder do with bile?

A

Make it more concentrated.

326
Q

What will make the gall bladder empty?

A

Digestion in the small intestine will cause release of CCK which will cause emptying of the gall bladder.

327
Q

How will the gall bladder empty?

A

Rhythmic contractions and relaxation of sphincter of oddi.

328
Q

Besides CCK what will cause the gall bladder to empty?

A

Ach from the vagus and enteric nervous system.

329
Q

With significant quantities of fat present how long will it take for the gall bladder to empty?

A

about 1 hour.

330
Q

What happens to the bile salts that are secreted?

A

90% are reabsorbed into blood from small intestines.

331
Q

How many times can bile salts be reabsorbed before they are carried out in the feces?

A

17 times.

332
Q

How much cholesterol is removed from blood a day and secreted into bile?

A

1-2 grams.

333
Q

Cholesterol is insoluable in pure water so how will it become soluable?

A

Mixes with bile salt and lecithin and becomes soluable.

334
Q

What causes gall stones?

A

Cholesterol may precipitate in gall bladder.

335
Q

What type of movements will the small intestines have?

A

Mixing or segmentation contractions.

336
Q

Small intestine has segments that are like what and caused by what?

A

Sausage-like segments via basic electrical rhythms.

337
Q

Slow wave is not effective in the small intestines without what?

A

added stimulation from myenteric plexus.

338
Q

The small intestines chop chyme how many times per mintue?

A

2-3 times.

339
Q

Mixing or segmentation contractions can be propulsive but less than what?

A

Peristaltic waves.

340
Q

Propulsive movements = what?

A

Peristalsis.

341
Q

Chyme travels from pylorus through the entire small intestines to the ileocecal valve in how long?

A

3-5 hours.

342
Q

Spreading chyme along the small intestine walls helps with what?

A

digestion/absorption.

343
Q

What hormones will increase the movements of chyme in the small intestines?

A

Gastrin, CCK, insulin, motilin and serotonin.

344
Q

What hormones will decrease the movements of chyme in the small intestines?

A

Secretin and glucagon.

345
Q

What reflex will open the ileocecal valve and let chyme pass from small intestines and become feces in the large intestines?

A

The gastroileal reflex.

346
Q

What is peristaltic rush?

A

An intense irritation of Small intestine mucosa.

347
Q

Peristaltic rush creats what?

A

Powerful and rapid peristalsis.

348
Q

Peristaltic rush is mediated by what?

A

Relfexes in autonomic nervous system and brainstem and intrinsic stimulation of myenteric plexus.

349
Q

Peristaltic rush relieves the small intestine of what?

A

Irritating substances in chyme and excessive distention.

350
Q

Food in duodenum will increase secretion of CCK from what type of cells?

A

I cells in duodenum and upper jejunum.

351
Q

What will secretin of CCK in duodenum and upper jejunum do?

A

increases the secretion of more pancreatic digestive enzymes by acinar cells.

352
Q

When will 70-80% of pancreatic enzymes be secreted?

A

After a meal.

353
Q

What will increase the secretn of CCK from I cells in duodenum and upper jejunum?

A

Products of partial protein digestion and long-chain fatty acids in chyme coming from stomach.

354
Q

What do brunner’s glands in the duodenum secrete?

A

Mucus.

355
Q

Brunner’s glands in the duodenum secrete mucus in response to what?

A

Tactile, vagal stimulation and secretin

356
Q

What is the function of mucus in the duodenum?

A

Protection from acidic juices and neutralizing HCL.

357
Q

What will inhibit the secretion of mucus in the small intestines?

A

Sympathetic nervous system.

358
Q

What happens to duodenum with too much sympathetic stimulation?

A

Can leave the duodenum unprotected causing peptic ulcers.

359
Q

What cells make up the crypts and villi of the small intestines?

A

goblet cells and enterocytes.

360
Q

What will goblet cells secrete?

A

Mucus to lubricate and protect.

361
Q

What will enterocytes secrete?

A

water and electrolytes.

362
Q

Secretin is secreted by what and when?

A

1800 ml/day.

363
Q

What will the secretion of chloride and bicarbonate in the small intestines do?

A

Osmotic movement of water.

364
Q

The enzyme peptidase does what in the small intestine?

A

splits peptides into amino acids.

365
Q

What will these enzymes do in the small intestines sucrase, maltase, isomaltase and lactase?

A

Split disaccharides into monsaccharides.

366
Q

What will lipase do in the small intestine?

A

Split neural fat into glycerol and fatty acids.

367
Q

What is the life cycle of epithelial cells in the small intestines?

A

5 days.

368
Q

What does sprue mean?

A

Pathological malabsorption.

369
Q

What are the major foods on which the body lives on?

A

Carbs, fats, and proteins.

370
Q

Hydrolysis is done on all 3 types of major food to break them down, but how will hydrolysis differ between these 3 types of food?

A

Type of enzymes required for hydolysis.

371
Q

Almost all carbs are digested as what?

A

Monosaccharides.

372
Q

How will the body get monosaccharides?

A

Polysaccharides or disaccharides that are bound by condensation.

373
Q

What is fat?

A

Triglycerides.

374
Q

How will fats be digested?

A

The triglycerides are a combination of 3 fatty acids condensed with a single glycerol and they are digested as fatty acids.

375
Q

How will proteins be digested?

A

As amino acids.

376
Q

How will amino acids make proteins?

A

Amino acids bound by peptide linkages.

377
Q

What are the 3 major sources of carbs?

A

sucrose, lactose, starches.

378
Q

What is sucrose?

A

Disaccharide in cane sugar.

379
Q

What is lactose?

A

Disaccharide in milk.

380
Q

What are starches?

A

Large polysaccharides present in almost all nonanimal foods.

381
Q

Can cellulose be digested by humans?

A

No.

382
Q

What will chewing and saliva do to starch?

A

hydrolyzes it to disaccharide maltose and glucose molecules.

383
Q

What % of starches are hydrolyzed by the time food is swallowed?

A

5%.

384
Q

Starch digestion continues in proximal stomach up to when?

A

1 hour before mixing with secretions.

385
Q

Digestion of carbs is done in 15-30 minutes after chyme emptys stomach by what?

A

Pancreatic amylase.

386
Q

Carbs that are digested are converted into what?

A

Maltose and or other very small glucose polymers.

387
Q

What cells contain lactase, sucrase, maltase, and alpha-dextrinase and what will the enzymes do?

A

Enterocytes. They split the disaccharides lactaose, sucrose, maltose and small glucose polymers into monsaccharides.

388
Q

Monosaccharides are the final product of carbs and they are absorbed how?

A

They are water soluable and are absorbed into the portal blood.

389
Q

What will happen to lactose?

A

Split into galactose and glucose.

390
Q

What will happen to sucrose?

A

Spilts into fructose and glucose.

391
Q

What happens to maltose and small glucose polymers?

A

Split into glucose.

392
Q

What will make up more than 80% of final products of carbs?

A

Glucose.

393
Q

What % of carbs will be galactose and fructose for final products?

A

10%.

394
Q

What will digest proteins in the acidic stomach?

A

Pepsin.

395
Q

HCL when secreted by parietal cells has a pH of what?

A

0.8 when secreted.

396
Q

Once HCL mixes with other stomach contents what will the pH be?

A

2-3 when mixed.

397
Q

Why will it be important for the stomach pH to be between 2 and 3?

A

This is the pH for pepsin to function best.

398
Q

Pepsin will do what to proteins?

A

Digests collagen.

399
Q

Why will collagen need to be digested in proteins?

A

This allows other enzymes to penetrate meat and digest other meat proteins.

400
Q

Pepsin provides what % of total protein digestion?

A

10-20%.

401
Q

Pepsin converts protein into what?

A

Proteoses, peptones, and a few polypeptides.

402
Q

Where will most protein digestion occur at?

A

The duodenum and jejunum.

403
Q

Protein digestion happens in the duodenum and jejunum via what?

A

Pancreatic proteolytic enzymes.

404
Q

Trypsin and chymotrypsin are pancreatic proteolytic enzymes that do what?

A

Turn protein molecules into polypeptides.

405
Q

Carboxypolypeptidase is a proteolytic enzyme that does what?

A

Cleaves amino acids from polypeptides.

406
Q

What is the active form of proelastase and what will it do?

A

Elastase and it digests elastin fibers of meat.

407
Q

After pancreatic enzyme activity of proteins what remains?

A

Dipeptides and tripeptides.

408
Q

How will the dipeptides and tripeptides be digested?

A

Peptidases.

409
Q

What is the last stage of protein digestion?

A

Digestion of peptidases.

410
Q

What is the final 99% of proteins products absorbed?

A

Individual amino acids.

411
Q

What is the most abundant dietary fat?

A

Triglycerides.

412
Q

What are some other dietary forms of fat besides trigylcerides?

A

Phospholipids, cholesterol and cholesterol esters.

413
Q

What % of triglycerides are digested in the stomach by lipases?

A

less than 10%.

414
Q

Essentially all fat digestion occurs where?

A

In the small intestines.

415
Q

Most fat emulsifaction occurs where via what?

A

In duodenum via bile.

416
Q

What is the most important enzyme for digestion of triglycerides?

A

Pancreatic lipase.

417
Q

Is the lipase from enterocytes of the small intestine important in digestion of triglycerides?

A

It is not usually needed.

418
Q

When will lipase attack fat?

A

After emulsification.

419
Q

What will pancreatic lipases do to triglycerides?

A

Split into Free fatty acids and 2-monoglycerides.

420
Q

What will Bile salt do to the Free fatty acids and the monoglycerides?

A

Removes them.

421
Q

What will transport the monoglycerides and free fatty acids to the brush border to be absorbed into the blood?

A

Bile salts that form micelles.

422
Q

What is the total fluid absorbed in the GI each day by the intestines?

A

1.5 liters.

423
Q

How much fluid is secreted by the GI tract each day?

A

7 liters

424
Q

So total how much fluid will the GI tract absorbe each day?

A

8-9 liters.

425
Q

Of the 8-9 liters abosrbed each day how much happens in the small intestine?

A

7-7.5

426
Q

How much fluid that will be absorbed will pass through the ilieocecal valve into the colon?

A

1.5 liters.

427
Q

How effective is the stomach at absorbing things?

A

Bad.

428
Q

Why will the stomach be a poor absorber?

A

Lacks villus type of absorptive membrane and tight junctions between epithelial cells.

429
Q

What type of substances can be absorbed in the stomach?

A

Only a few highly lipid-soluable substanace like alcohol and some drugs like asprin.

430
Q

What is the absorptive surface of the small intestines?

A

Folds of kerckring.

431
Q

Folds of kerckring increase absorptive surface area of the small intestines how much?

A

3 times.

432
Q

What is on the surface of the small intestine epithelium to help increase surface area?

A

Micro villi.

433
Q

How much surface area will the micro villi increase of the small intestines?

A

10 times.

434
Q

What is on the micro villi and how much will it increase surface area?

A

Brush border and increases surface area another 20 times.

435
Q

How much total area for absorption will there be in the small intestines?

A

more than 250 square meters which is equal to the area of a tennis court surface.

436
Q

How much fat, amino acids, ions and water are absorbed through the intestines a day?

A

fat- less than 100 g. Amino acids- 50-100g. Ions- 50-100g. Water- 7-8 liters.

437
Q

Will the intestines be working close to their absorptive capacity usually?

A

No.

438
Q

What will the large intestines absorbe?

A

Water ions and very few nutrients.

439
Q

How will water and ions be transported through the intestinal membrane?

A

Entirely by diffusion via usual laws of osmosis.

440
Q

Intestines must absorb 25-30 g of sodium to prevent what?

A

Net loss of water.

441
Q

What will aldosterone do in the intestines?

A

Greatly enhances na+ absorption and water retention.

442
Q

Essentially all Carbs are absorbed as what?

A

Glucose 80% and some other monosaccharides.

443
Q

Glucose is transported across the intestinal membrane how?

A

Via sodium co-transport mechanism.

444
Q

What must be transported to have glucose absorbed?

A

Without Na+ transport virtually no glucose can be absorbed.

445
Q

How will galactose be absorbed?

A

Same mechanism as glucose.

446
Q

How will fructose be absorbed?

A

Via diffusion through intestineal epithelium, but not coupled with sodium transport.

447
Q

What is the rate of fructose absorption like?

A

1/2 that of glucose or galactose.

448
Q

After digestion how will most proteins be absorbed?

A

Dipeptides, tripeptides, and a few free amino acids.

449
Q

How will the dipeptides and tripeptides be transported across the intestinal membrane?

A

Via sodium co-transport mechanism like glucose.

450
Q

In the presence of ____ _____ 97% of fat is absorbed.

A

Bile micelles.

451
Q

IN absence of Bile micelles how much fat is absorbed?

A

40-50%.

452
Q

What is the purpose of the ileocecal valve?

A

To prevent backflow of feces.

453
Q

The ileocecal sphincter in ileum proximal to valve constricted and slows emptying of ileal contents into cecum until when?

A

Gastroileal reflex after a meal.

454
Q

What will delaying release of chyme into colon do?

A

Increases absorption of nutrients.

455
Q

What will increase and decrease the contraction of the ileocecal sphincter?

A

Increase- with distention or irritationof cecum. Decreased- with distention, irritation, chyme in ileum.

456
Q

Will the large intestines have cyrpts of leiberkuhn and villi?

A

Crypts of leiberkuhn yes, but no villi.

457
Q

What will large intestine cells secrete?

A

No enzymes, but lots of mucus.

458
Q

The proximal 1/2 of the colon is known as what?

A

absorbing colon.

459
Q

The distal 1/2 of the colon is known as what?

A

Storage colon.

460
Q

What is the difference between the epithelial cells of the large intestines and the small intestines?

A

Large has tight juncitons between epithelial cells.

461
Q

What is the purpose of tight junctions?

A

prevents backflow of ions for more complete absorption than small intestines.

462
Q

Mucosa of the large intestine secretes bicarbonate ions while simultaneously doing what?

A

absorbing an equal amount of chloride ions.

463
Q

When mucosa absorbes chloride ions what will this do?

A

Create an osmotic gradient which causes absorption of water.

464
Q

What is the maximun amount of fluid the large intestines can absore a day?

A

5-8 liters.

465
Q

What vitamins form in the large intestines?

A

K, B12, B1, B2.

466
Q

What is haustral mixing like and where is it done at?

A

Like segmentation but found in the large intestine.

467
Q

What will haustral mixing involve?

A

Contraction of circular muscle and taenia coli.

468
Q

What will haustral mixing cause?

A

Unstimulated parts to bulge—-> Haustrations.

469
Q

Haustral mixing digs deeply into fecal material and this does what?

A

Exposes it to colonic mucosa for absorption of fluid.

470
Q

What are the contractions like for haustral mixing?

A

Reach peak intensity then disappear and reoccur in 1-3 minutes in nearby regions as they slowly move towards the anus.

471
Q

A series of mass movement of the colon happens how many times a day?

A

1-3 times a day.

472
Q

When feces are forced into rectum they set off what?

A

Intrinsic reflex.

473
Q

What is the intrinsic reflex like?

A

Too weak to cause defecation and must be fortified by a second reflex.

474
Q

What are the 2 anal sphincters?

A

internal and external.

475
Q

Which anal sphincter is under voluntary control and controlled by what nerve?

A

External and controled by the pudendal nerve

476
Q

Most of the time the rectum is what?

A

Empty.

477
Q

Stretch signals for the defecation reflex synapse at what levels?

A

S-2,3,4

478
Q

The signals from S2-4 intensify what?

A

Peristaltic activity and relax the anal sphincter.

479
Q

If convenient defication is completed by what?

A

Voluntary relaxing the external anal sphincter.

480
Q

If defecation is delayed what happens?

A

The urge is temporarily reduced due to ability of rectum adaptation to distention.

481
Q

Feces is composed of what?

A

3/4 water and 1/4 solid matter.

482
Q

What is the solid matter of feces made of?

A

30% dead bacteria, 10-20% fat, 10-20% inorganic material, 2-3% protein, 30% undigested roughage from food and dried constituents of digestive jucies.

483
Q

Brown color of feces comes from what?

A

Stercobilin and urobilin.

484
Q

Stercobilin and urobilin are derivatives of what?

A

Bilirubin.

485
Q

What causes the odor of feces?

A

Product of bacterial action.

486
Q

What will large intestine irritation (bacterial infection= enteritis) lead to?

A

Secretion of extra large quantities of water and electrolytes in addition to mucosa and this is diarrhea.

487
Q

How much energy is liberated from carbs?

A

4C.

488
Q

How much energy is liberated from fat?

A

9C.

489
Q

How much energy is liberated from proteins?

A

4C.

490
Q

What is the average USA diet?

A

15%-Protein, 40%-fat, 45%- carbs.

491
Q

What is a non-western diet like?

A

Perdominantly CHO 80%.

492
Q

What is the daily requirement of Protein?

A

30-50g. Athletes 2.2 g/kg.

493
Q

What type of proein is more complete animal or vegetable/grain?

A

Animal.

494
Q

Nitrogen excretion equals what?

A

Protein metabolism.

495
Q

How will nitrogen be excreted?

A

90% in urine and 10% in feces.

496
Q

What will a negative nitrogen balance mean?

A

Daily stores of protein are decreasing due to consumption for energy.

497
Q

Respiratory quotient equals what?

A

FAT, CHO, PRO metabolism.

498
Q

What is the Co2 to O2 ratio for carb, fat, and protein metabolism?

A

Carbs 1:1, Fat 70:100, Pro 80:100

499
Q

What % of energy ingested reaches cells and where will the rest go?

A

27% the rest is converted to heat.

500
Q

What is the expenditure of energy in sedentary vs laborers?

A

Sedentary- 2000C/d laborere/athletes- 7000C/d

Phys 2 test 3 INTRANET (2 decks)

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