Chapter24: Lecture Midterm II Flashcards

1
Q

Digestive system

A

consists of a group of organs that break down the food we eat into smaller moelcules that can be used by body cells

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

The digestive canal (gastrointestinal tube)

A

a continuous tube that extends through the thoracic and abdominal cavities from the esophagus to the anus through the thoracic and abdominopelvic cavities

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

Organs of the digestive canal include

A
  • esophagus
  • stomach
  • small intestine
  • large intestine
  • anal canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The accessory digestive organs include

A
  • mouth
  • teeth
  • tongue
  • salivary glands
  • pharynx
  • liver
  • gallbladder
  • and pancreas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What helps to breakdown food in the stomach

A

muscular contractions in the wall of the digestive canal physically breakdown the food by churning it and propelling the food along the canal from the esophagus to the anus

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

6 Basic functions of the digestive system

A
  1. ingestion
  2. secretion
  3. mixing and propulsion
  4. digestion
  5. absorption
  6. defecation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the secretion phase of the digestive system do

A

releases water, acid, buffers and enzymes into the lumen of the digestive canal

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

What does the mixing and propulsion stage of the digestive system do

A

churns, and moves food through the digestive canal

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

Each day, cells within the wall of the digestive canal and accessory digestive organs secrete a total of

A

7 litres of water, acid, buffers and enzymes into the lumen of the digestive canal

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

From the esophagus to the anal canal there are 4 layers of tissues from deep to superficial:

A
  • mucosa
  • submucosa
  • muscular layer
  • serosa/adventitia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The mucosa

A
  • inner lining of the digestive canal
  • composed of epithelium, lamina propria and muscularis mucosae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The epithelium layer of the mucosa in the mouth, pharynx, esophagus and anal canal is

A

non keratinized stratified squamous epithelium that serves a protective function

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

The stomach and intestines epithelium layer is

A

simple columnar epithelium; functions in secretion and absorption

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

the type of exocrine cells that secrete mucus and fluid into the lumen of the digestive canal

A

enteroendocrine cells

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

The lamina propria

A

is areolar connective tissue containing many blood and lymphatic vessels, which are routes by which nutrients absorbed into the digestive canal reach other tissues of the body

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

The lamina propria supports the

A

epithelium and binds to the muscularis mucosa

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

The lamina propria contains what cells

A

MALT
- prominent lymph nodules contain immune system cells that protect against disease

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

Muscularis mucosae

A

thin layer of smooth muscle fibers
- throws the mucous membrane of the stomach and small intestine into many small folds, which increase the surface area for digestion and absorption

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

Movement of the muscularis mucosae ensures that

A

all absorptive cells are fully exposed to the contents of the digestive canal

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

The submucosa

A

consists of areolar connective tissue that binds the mucosa to the muscularis
- contains many blood and lymphatic vessels that recieve absorbed food molecules
- contains glands and lymphatic tissue

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

The submucosa also contains an extensive network of

A

neurons known as the submucosal neural plexus

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

Muscular layer of the mouth, pharynx, superior and middle parts of the esophagus contains

A

skeletal muscle that produces voluntary swallowing
- skeletal muscle also forms the external anal sphincter which permits voluntary control of defecation

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

Throughout the rest of the digestive canal the muscular layer consists of

A

smooth muscle that is found in two sheets;
- inner sheet: circular fibers
- outer sheet: longitudinal fibers

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

Involuntary contractions of smooth muscle in the digestive tract…

A

help break down food, mix it with digestive secretions and propel it along the digestive canal

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

Those portions of the digestive canal that are suspended in the abdominal cavity have a superficial layer called the

A

serosa

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

Serosa

A

serous membrane composed of areolar connective tissue and simple squamous epithelium

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

The esophagus lacks…

A

serosa; instead, only a single layer of areolar connective tissue called the adventitia forms the superficial layer of this organ

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

The digestive canal is regulated by an intrinsic set of nerves called

A

enteric nervous system

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

The enteric nervous system is known as the

A

brain of the gut

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

The neurons of the ENS are arranged in two neural plexuses;

A
  • myenteric neural plexus
  • submucosal neural plexus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Myenteric neural plexus

A

located between the longitudinal and circular smooth muscle layers

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

Submucosal neural plexus

A

found within the submucosa

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

The ENS consists of

A

motor neurons, interneurons, and sensory neurons

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

because the motor neurons of the myenteric neural plexus supply the longitudinal and circular smooth muscle layers of the muscular layer

A

this neural plexus mostly controls digestive canal motility (movement), particularly the frequency and strength of contraction of the muscular layer

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

The motor neurons of the submucosal neural plexus supplies the

A

secretory cells of the mucosal epithelium, controlling the secretions of the organs of the digestive canal

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

The interneurons of the ENS interconnect

A

the neurons of myenteric and submucosal neural plexuses

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

The sensory neurons of the ENS supply the

A

mucosal epithelium and contain receptors that detect stimuli in the lumen of the digestive canal

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

The wall of the digestive canal contains two types of sensory receptors

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

What nerve supplies parasympathetic fibers to most parts of the digestive canal

A

the vagus nerve

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

The large intestine however, is supplied by

A

parasympathetic fibers from the sacral spinal cord

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

Parasympathetic preganglionic neurons of the vagus or pelvic splanchic nerves synapse withh

A

parasympathetic postganglionic neurons located in the myenteric and submucosal neural plexuses

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

Some of the parasympathetic posganglionic neurons synapse

A

directly with smooth muscle and glands within the wall of the digestive canal

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

In general, stimulation of the parasympathetic nerves that innervate the digestive canal causes an

A

increase in digestive canal secretion and motility by increasing the activity of ENS neurons

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

Sympathetic nerves that supply the digestive canal arise from

A

the thoracic and upper lumbar regions of the spinal cord
- make connections with the ENS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Sympathetic postganglionic neurons synapse with

A

neurons located in myenteric and submucosal neural plexus

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

In general the sympathetic nerves that supply the digestive canal

A

cause a decrease in digestive canal secretion and motility by inhibiting the neurons of the ENS

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

Emotions such as anger, fear and anxiety may

A

slow digestion because they stimulate sympathetic nerves that supply the digestive system

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

GI reflex pathways regulate

A

GI secretion and motility in response to stimuli within the GI tract

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

Peritoneum

A

largest serous membrane of the body;
- consists of a layer of simple squamous epithelium with an underlying supporting layer of areolar connective tissue

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

Parietal peritoneum

A

lines the wall of the abdominal cavity

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

Visceral peritoneum

A

covers some organs in the cavity and is their serosa

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

Peritoneal cavity

A

the slim space containing lubricating serous fluid between the parietal and visceral peritoneal cavity

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

Organs that are retroperitoneal

A

kidneys, ascending and descending colons of the large intestine, duodenum of the small intestine, and pancreas

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

Unlike the heart and lungs smooth surface, the peritoneum contains

A

large folds that weave between the viscera

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

The folds on the viscera contain

A

blood vessels, lymphatic vessels, and nerves that supply the abdominal organs

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

What are the 5 major peritoneal folds

A
  • greater omentum
  • falciform ligament
  • lesser omentum
  • mesentery
  • mesocolon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

The greater omentum

A
  • drapes over from transverse colon like a fatty apron
  • double sheet that folds back on itself (4 layers)
  • contains adipose tissue that contributes to beer belly
  • contains many lymph nodes that contain macrphages and antibody producing plasmocytes that help combat and contain infections of the digestive canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

The falciform ligament

A

attaches the liver to the anterior abdominal wall and diaphragm.
- The liver is the only digestive organ that is attached to the anterior abdominal wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

The lesser omentum

A

arises as an anterior fold in the serosa of the stomach and duodenum
- it connects the stomach and duodenum to the liver
- pathway for blood vessels entering the liver and contains the hepatic portal vein, common hepatic artery and bile duct, along with some lymph nodes

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

Mesentery

A
  • fan shaped fold of the peritoneum
  • binds the jejunum and ileum of the small intestine to the posterior abdominal wall
  • forms a double-layered structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Between the two layered folds of the mesentery, are the

A

blood and lymphatic vessels and lymph nodes

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

Mesocolon

A
  • two separate folds of peritoneum
  • bind the transverse colon and sigmoid colon of the large intestine to the posterior abdominal wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What carries blood and lymphatic vessels to the intestines

A

mesocolon

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

Together the mesentery and mesocolon

A

hold the intestines loosely in place, allowing movement as muscular contractions mix and move the luminal contents along the digestive canal

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

The mouth is formed by

A

lips, cheeks, hard and soft palates, oral cavity, teeth, salivary glands and tongue

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

What attaches the lip to its corresponding gum

A

labial frenulum

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

What helps keep food between the upper and lower teeth when chewing

A

contraction of buccinator muscles

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

Fauces

A

opening of the mouth to the pharynx

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

hard palate

A

anterior portion of roof of the mouth- formed by maxillae and palatine bones

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

soft palate

A

posterior portion of roof of mouth - arch shaped muscular partition between oropharynx and nasopharynx

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

Uvula

A

during swallowing, the soft palate and uvula are drawn superiorly, closing off the nasopharynx and preventing swallowed foods and liquids from entering the nasal cavity

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

Salivary glands

A

releases a secretion called saliva into the oral cavity; to keep the mouth and pharynx moist and clean

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

When food enters the mouth,

A

secretion of saliva increases, and it lubricates, dissolves, and begins chemical breakdown of food

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

The mucosa and submucosa of the mouth contain

A

about 800-1000 small salivary glands that open directly and indirectly via short ducts into the oral cavity
- these include: ; labial, buccal, and palatal glands and lingual

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

All small glands located in the mucosa and submucosa are called

A

minor slaivary glands

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

Three main pairs of salivary glands

A
  • parotid
  • submandibular
  • sublingual
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Parotid glands

A

located inferior and anterior to the ears, between the skin and the masseter muscle

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

Submandibular glands

A

are found on the floor of the oral cavity proper; they are medial and partly inferior to the mandible

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

The submandibular glands are lateral to the

A

lingual frenulum

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

Sublingual glands

A

beneath the tongue, and superior to the submandibular glands

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

What is saliva composed of

A

99% water and 0.5% other solutes
- solutes include ions: sodium, potassium, chloride, bicarbonate and phosphate

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

Some dissolved gasses and various organic substances are also present such as

A

urea, uric acid, mucus, immunoglobulin A, the bacteriolytic enzyme, lysozyme, and salivary amylase (digestive enzyme that acts on starch)

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

All salivary glands supply the same ingredients; T or F

A

False

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

The parotid glands secrete;

A

watery (serous) liquid containing salivary amylase

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

Submandibular glands secrete

A

salivary amylase mixed with mucus

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

The sublingual glands secrete

A

mostly mucus and small amount of salivary amylase

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

The water in saliva provides a medium for

A

dissolving foods so that they can be tasted by gustatory receptors so that digestive reactions can begin

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

what activates salivary amylase

A

chloride ions

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

salivation is controlled by

A

the autonomic nervous system

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

average salivary secreted daily

A

1000 -1500 mL

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

Parasympathetic promotes salivation whereas

A

sympathetic does not

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

Tongue

A

accessory digestive organ composed of skeletal muscle covered with mucus membrane

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

The tongue participates in

A

chewing, swallowing, and speeth

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

The upper and lateral surfaces of the tongue are covered with

A

papillae, some of which contain taste buds

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

The extrinsic muscles of the tongue

A

move it from side to side and in and out to maneuver food for chewing
- form the floor of the mouth and hold the tongue in position

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

intrinsic muscles of the tongue

A

originate and insert into the connective tissue within the tongue
- alter the size and shape of the tongue for speech and swallowing

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

Lingual papillae

A

projections of the lamina propria covered with stratified squamous epithelium
- contain gustatory epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

some lingual papillae lack taste buds but contain

A

receptors for touch and increase friction between tongue and food, making it easier for the tongue to move

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

Lingual glands

A

in the lamina propria of the tongue
- secreye mucus and watery fluid that contains lingual lipase, which acts on as much as 30% of dietary glycerides

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

Teeth

A

accessory digestive organs located in dental alveoli in mandible and maxillae

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

enamel

A

consists of calcium phosphate and calcium carbonate
- harder than bone

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

incisors:

A

closest to midline
- chisel shaped and adapted for cutting into food

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

canines:

A

have a pointed surface called a cusp
- used to tear or shred food

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

molars;

A

have four cusps
- used to crush and grind food and prepare food for swallowing

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

When food is first swallowed, it passes from the mouth to the

A

pharynx

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

The pharynx is composed of

A

skeletal muscle and lined by mucus membrane

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

the pharynx is divided into 3 portions

A
  • nasopharynx
  • oropharynx
  • laryngopharynx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Nasopharynx

A

functions only in respiration

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

Swallowed foods passes from the mouth to

A

the oropharynx and laryngopharynx; muscular contractions of these areas help propel food to the esophagus and then into the stomach

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

The mucosa of the esophagus consists of

A

non-keratinized stratified squamous epithelium, lamina propria, and musuclaris mucosae

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

Near the stomach, the mucosa of the esophagus contains

A

mucus glands

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

At the ends of the esophagus, the muscular layer

A

becomes slightly more prominent and forms the upper esophageal sphincter and the lower esophageal sphincter

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

The superficial layer of the esophagus is known as the

A

adventitia

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

The adventitia attaches the esophagus to

A

surrounding structures

115
Q

The movement of food from the mouth into the stomach is achieved by the act of

A

deglutition

116
Q

Deglutition

A

facilitated by the secretion of saliva and mucus and involves the mouth, pharynx and esophagus

117
Q

Swallowing occurs in three stages

A
  1. voluntary stage
  2. pharyngeal stage
  3. esophageal stage
118
Q

Voluntary stage of swallowing;

A

bolus is forced to the back of the oral cavity and into the oropharynx by the movement of the tongue upward and backward against the palate

119
Q

Pharyngeal stage of swallowing;

A
  • The bolus stimulates receptors in the oropharynx, which send impulses to the deglutition center in the medulla
  • the returning impulses cause the soft palate and uvula to move upward and close off the nasopharynx
  • the bolus moves through the oropharynx and the laryngopharynx
120
Q

Esophageal stage of swallowing;

A
  • begins once the bolus enters the esophagus
  • peristalsis of the circular and longitudinal layers pushes the bolus onward
121
Q

Stomach

A

J shaped enlargement of the digestive canal directly inferior to the diaphragm of the abdomen

122
Q

The stomach connects the

A

esophagus to the duodenum

123
Q

Because we can eat faster than the intestines digest…

A

the stomach serves as a mixing chamber and a holding reservoir

124
Q

After food is ingested, the stomach

A

forces a small quantity of material into the duodenum

125
Q

In the stomach digestion of

A

starch and triglycerides continues, digestion of proteins begins
- certain substances are absorbed

126
Q

The semisolid bolus is converted to —- in the stomach

A

chyme

127
Q

When the stomach is empty, the mucosa lies in

A

large gastric folds (rugae)
- can be seen with unaided eye

128
Q

The pylorus of the stomach communicates with

A

the duodenum via a smooth muscle sphincter called pyloric sphincter

129
Q

convex portion of the stomach

A

greater curvature

130
Q

concave portion of the stomach

A

lesser curvature

131
Q

The surface of the mucosa of the stomach is a layer of

A

simple columnar epithelial cells called surface mucus cells

132
Q

In the stomach, the epithelial cells extend down into the lamina propria where they form columns of

A

secretory cells called gasric glands

133
Q

Several gastric glands open to the bottom of narrow channels called

A

gastric pits

134
Q

The gastric glands secrete three types of exocrine cells

A
  • mucous neck cells
  • chief cells
  • parietal cells
135
Q

Both surface mucous cells and —- —– —- secrete mucus

A

mucous neck cells

136
Q

Parietal cells produce

A

intrinsic factor (needed for absorption of vit b12) and hydrochloric acid

137
Q

The chief cells secrete

A

pepsinogen and gastric lipase

138
Q

The secretions of mucous neck, parietal and chief cells produce

A

gastric juice

139
Q

G cells of the stomach

A

secrete gastrin which stimulates parietal cells to secrete HCL and chief cells to secrete pepsinogen;
contracts with lower esophageal sphincter, increases motility of stomach. relaxes pyloric sphincter

140
Q

Pancreas

A

retroperitoneal gland that is thick and lies posterior to the greater curvature of the stomach

141
Q

The pancreas is connected to the

A

duodenum of the small intestine from the head portion

142
Q

Pancreatic juices are secreted by

A

exocrine cells into small ducts that ultimately unite to form two larger ducts
- pancreatic and accessory duct

143
Q

The pancreatic duct

A

larger of the two ducts in the pancreas
- joins bile duct from liver and gallbladder

144
Q

The accessory duct

A

leads from the pancreas and empties into the duodenum superior to the hepatopancreatic ampulla

145
Q

Pancreatic acini

A

make up the exocrine portion

146
Q

Pancretic acini secrete

A

digestive enzymes called pancreatic juice

147
Q

Pancreatic islets

A

endocrine portion of pancreas
- secrete hormones

148
Q

Pancreatic juice

A
  • clear, colorless liquid consisting of mostly water, some salts, sodium bicarbonate and several enzymes
149
Q

What makes pancreatic juice alkaline

A

sodium bicarbonate and it buffers acidic gastric juice

150
Q

Sodium bicarb stops the action of

A

pepsin from the stomach and creates a proper pH for the action of digestive enzymes in the small intestine

151
Q

The enzymes in pancreatic juice include

A
  • pancreatic amylase, trypsin, chymotrypsin, carboxypeptidase, elastase, deozyribonuclease, pancreatic lipase
152
Q

Function of pancreatic amylase

A

digests starch

153
Q

Protein digesting peptides

A

trypsin, chymotripsin, carboxypeptidase, and elastase

154
Q

Function of pancreatic lipase

A

digests triglycerides

155
Q

Function of ribonuclease

A

digests ribonucleic acid

156
Q

Protein digesting enzymes of the pancreas are produced in an

A

inactive form because the enzymes do not digest the cells of the pancreas itself

157
Q

Liver

A

heaviest gland of the body,
- located inferior to the diaphragm to the right

158
Q

Gallbladder

A

pear shaped sac located in the depression of the posterior surface of the liver

159
Q

The liver is almost completely covered by

A

visceral peritoneum and completely covered by a dense irregular connective tissue layer

160
Q

The liver is comprised of

A

a large right lobe and a smaller left lobe

161
Q

The parts of the gallbladder include the broad

A

fundus which projects inferiorly beyond the inferior border of the liver; central portion and the neck

162
Q

The liver is composed of these components

A
  • hepatocytes
  • bile canaliculi
  • hepatic sinusoids
163
Q

Hepatocytes

A
  • major functional cells of the liver and performa a wide array of metabolic, secretory and endocrine functions
164
Q

Grooves in cell membranes between neighbouring hepatocytes provide

A

spaces for bile canaliculi into which hepatocytes secrete bile

165
Q

Bile

A

yellow, brownish, or olive green liquid secreted by hepatocytes, serves as both an excretory product and a digestive secretion

166
Q

Bile canaliculi

A

small ducts between hepatocytes that collect bile produced by the hepatocytes

167
Q

From bile canliculi, bile passes into

A

bile ductules, and then bile ducts

168
Q

The bile ducts in the liver merge and eventually form

A

the right and left hepatic ducts

169
Q

The right and left hepatic ducts unit and exit the liver as

A

common hepatic duct

170
Q

The common hepatic duct joins the cystic duct

A

from the gallbladder and forms the common bile duct

171
Q

From the common bile duct, bile enters the

A

duodenum of the small intestine to participate in digestion

172
Q

Hepatic sinusoids

A
  • highly permeable blood capillaries between rows of hepatocytes that receive oxygenated blood from branches of the hepatic artery, and nutrient rich deoxygenated blood from branches of the hepatic portal vein
173
Q

The hepatic portal vein brings venous blood from

A

digestive canal organs to the spleen and liver

174
Q

Hepatic sinusoids converge and deliver blood into a

A

central vein

175
Q

From central veins blood flows into

A

hepatic veins which flows towards the inferior vena cava

176
Q

In contrast to blood, which flows towards the central vein, bile

A

flows the opposite direction

177
Q

Stellate reticuloendothelial cells or hepatic macrophages

A

destroy worn out white and red blood cells, bacteria and other foreign matter in the venous blood draining from the digestive canal

178
Q

Portal triad

A

a bile duct, branch of the hepatic artery and a branch of the hepatic vein are referred to as portal triad

179
Q

The hepatocytes, bile duct system, and hepatic sinusoids can be organized into an anatomical and functional unit called

A

the hepatic acinus

180
Q

Hepatocytes in hepatic acinus are

A

arranged in three zones around the short axis with no sharp boundaries between them

181
Q

Cells in zone one of the hepatic acinus

A

closest to the branches of the portal triad and the first to receive incoming oxygen and nutrients and toxins from incoming blood

182
Q

Which cells are the first ones to take up glucose and store it as glycogen after a meal and break down glycogen during fasting

A

cells in zone one of a hepatic acinus

183
Q

Cells in zone three are

A

farthest from portal triad and are the last to show effects of bile obstruction or exposure to toxins

184
Q

The mucosa of the gallbladder consists of

A

simple columnar epithelium arranged in mucosal folds (rugae) resembling those of the stomach

185
Q

The wall of the gallbladder lacks a

A

submucosa

186
Q

The middle (muscular) layer of the gallbladder consists of

A

smooth muscle fibers which ejects the contents of the gallbladder into the cystic duct

187
Q

Function of the gallbladder

A

store and concentrate the bile produced by the liver until it is needed by the duodenum

188
Q

In the concentration process of the gallbladder

A

water and ions are absorbed by the gallbladder mucosa

189
Q

The liver receives blood from

A
  • the hepatic artery - obtains oxygenated blood
  • hepatic portal vein - receives deoxygenated blood containing newly absorbed nutrients, drugs, and possibly microbes and toxins from the digestive canal.
190
Q

Branches of both the hepatic artery and hepatic portal vein carry blood into

A

hepatic sinusoids, where oxygen, most of the nutrients, and certain toxic substances are taken up by hepatocytes

191
Q

Products manufactured by hepatocytes and nutrients needed by other cells are

A

secreted back into the blood, which then drains into the central vein and eventually passes into the hepatic vein

192
Q

Because blood passes from the digestive canal to the liver

A

the liver is often a site for metastasis of cancer that originates in the digestive canal

193
Q

pH of bille

A

7.6 - 8.6

194
Q

the principle pigment in bile is

A

billirubin

195
Q

Bile plays a role in

A

emuslification, the breakdown of large lipid globules into a suspension of small lipid globules

196
Q

As digestion and absorption continue in the small intestine

A

bile release increases

197
Q

The liver performs other functions in addition to bile production

A
  • carbohydrate metabolism
  • lipid metabolism
  • protein metabolism
  • processing of drugs and hormones
  • excretion of billirubin
  • synthesis of bile salts
  • storage: of glycogen
  • phagocytosis
  • activation of vitamin D
198
Q

Most digestion and absorption of nutrients occurs in the

A

small intestine

199
Q

The area for digestion and absorption is further increased by

A
  • circular folds
  • intestinal villi
  • microvilli
200
Q

Three regions of the small intestine

A

duodenum
jejunum
ileum

201
Q

Longest and shortest region of small intestine

A

short: duodenum
- long: lieum

202
Q

The small intestine joins the large intestine through a smooth muscle sphincter called

A

ileal orifice

203
Q

The epithelium of the mucosa for the small intestine consists of

A
  • absorptive cells
  • goblet cells
204
Q

Absorptive cells of the small intestine

A

contain enzymes that digest food and posess intestinal microvilli that absorb nutrients in small intestinal chuyme

205
Q

Goblet cells of the small intestine

A

secrete mucus

206
Q

Cells lining the crevices of the small intestine form

A

intestinal glands

207
Q

The intestinal glands of the small intestine also contain

A
  • paneth cells
  • enteroendocrine cells
208
Q

Paneth cells of the small intestine

A

secrete lysozyme, bactericidal enzyme and are capable of phagocytosis

209
Q

What cells have a role in regulating microbial population in the small intestine

A

paneth cells

210
Q

There are 3 types of enteroendocrine cells

A

S cells, CCK cells, and K cells, which secrete the hormones secretin, cholecystokinin, and glucose dependant insulinotropic peptide

211
Q

The lamina propria of the small intestine contains an abundance of

A

MALT

212
Q

The submucosa of the duodenum contains

A

duodenal glands

213
Q

Duodenal glands secrete

A

an alkaline mucus that helps neutralize gastric acid in the chyme

214
Q

Circular folds of the small intestine enhance

A

absorption by increasing the surface area and causing the chyme to spiral, rather than moving in a straight line

215
Q

Intestinal villi

A

finger like projections of the mucosa
- increase the surface area

216
Q

Nutrients absorbed by the epithelial cells covering the intestinal villus pass through

A

the wall of blood capillary or a lymphatic capillary to enter the blood plasma or lymph plasma

217
Q

Microvilli in the small intestine

A

projections of the apical membrane of the absorptive cells

218
Q

the microvillus border contains several enxymes that

A

have digestive functions

219
Q

The enzymatic digestion occurs at the

A

surface of absorptive cells that line the intestinal villi (microvillus border)

220
Q

Two types of movements by the small intestine

A

segmentations and a type of persistalsis called migrating motility complexes

221
Q

Segmentations

A

localized, mixing contractions that occur in portions of the intestine distended by a large volume of chyme

222
Q

Segmentations mix

A

chyme and digestive juices and bring particles of food into contact with the mucosa for absorption; they do not push the intestinal contents along the digestive canal

223
Q

Segmentation starts with contractions of

A

circular smooth muscle

224
Q

After most of a meal has been absorbed which lessens the distention of the wall of the small intestine,

A

segmentation stops and peristalsis begins

225
Q

Migrating motility complex begins

A

in the lower portion of the stomach and pushes chyme forward along a short stretch of small intestine before dying out

226
Q

Acidic pH in the stomach destroys

A

salivary amylase

227
Q

The small intestine digests

A

carbohydrates
proteins
lipids
nucleic acids

228
Q

Salivary amylase digests —- into

A

starches (polysaccharides) into:
- maltose
- maltoriose
- a- dextrins

229
Q

Pancreatic amylase digests — into —– in the small intestine

A

starches (polysaccharides) into:
- maltose
- maltriose
- a - dextrins

230
Q

Trypsin digests —- into ——

A

proteins into peptides in the small intestine

231
Q

Chymotrypsin digests —- into —–

A

proteins into peptides

232
Q

Elastase digests —- into —-

A

proteins into peptides

233
Q

Carboxypeptidase digests —- into —–

A

amino acid at carboxyl end of peptides into amino acids and peptides

234
Q

Pancreatic lipase digests —- into —–

A

triglycerides that have been emulsified by bile salts into fatty acids and monoglycerides

235
Q

Ribinuclease digests —- into

A

ribonucleic acid into nucleotides

236
Q

Deoxyribonuclease digests — into

A

deoxyribonucleic acid into nucleotides

237
Q

a-dextrinase at the small intestine digests a-dextrins to produce

A

glucose

238
Q

Maltase at the small intestine digests maltose to produce

A

glucose

239
Q

Sucrase in the small intestine digests sucrose to produce

A

glucose and fructose

240
Q

Lactase in the small intestine digests lactose to produce

A

glucose and galactose

241
Q

Enterokinase in the small intestine digests trypsinogen into

A

trypsin

242
Q

Gastric banding

A

procedure which places an inflatable band around cardia o stomach to make the person feel full after eating only a small amount of food

243
Q

Sleeve gasterectomy

A

stomach is removed to leave only a banana shaped section
- decrease in size causes person to feel full faster

244
Q

Gastric bypass

A

stomach is made smaller

245
Q

Large intestine

A

portion of the digestive canal extending from the ileum of the small intestine tot he anus and divided structurally into cecum, colon, rectum and anal canal

246
Q

The mucus membrane of the anal canal is arranged in longitdinal folds called

A

anal columns

247
Q

external anal sphincter is

A

skeletal muscle, therefore voluntary

248
Q

The epithelium of the large intestine contains mostly of

A

absorptive and goblet cells

249
Q

The absorption cells of the large intestine function primarily in

A

water absorption

250
Q

the goblet cells of the large intestine

A

secrete mucus and lubricates the passage of colonic contents

251
Q

The longitudinal muscles of the large intestine are

A

thickened and form three bands called teniae coli

252
Q

Tonic contractions of the teniae coli gather the colon into

A

pouches called haustra

253
Q

Immediately after a meal the gastoileal reflex intensifies

A

peristalsis in the ileum and forces chyme into the cecum

254
Q

Haustral churning

A

haustra remain relaxed and become distended while they fill up.
- when the distention reaches a certain point, the walls contracy and squeeze the cotents into the next hausrum

255
Q

Mass peristalsis in the large intestine

A

a strong persistaltic wave that begins at about the middle of the transverse colon and quickly drives the contents of the colon into rectum

256
Q

Because food in the stomach initiates the gastrocolic reflex in the colon

A

mass peristalsis usually takes place about 3-4 times a day

257
Q

The gases contribute to

A

flatus in the cp;pm

258
Q

Feces contain

A

water, inorganic salts, sloughed off epithelial cells, bacteria, products of bacterial decomposition, unabsorbed digested materials, and indigestible parts of food

259
Q

The large intestine absorbs

A

ions, sodium, chloride, and some vitamins

260
Q

Defecation reflex

A

mass peristaltic movements push fecal matter into the sigmoid colon of the rectum; the distention stimulates the stretch receptors

261
Q

In response to stretching of the rectal wall

A

the receptors send sensory nerve impulses to the sacral spinal cord.
- motor impulses from the cord travel along parasympathetic nerves

262
Q

Three phases of digestion

A
  • cephalic phase
  • gastric phase
  • intestinal phase
263
Q

When longitudinal rectal muscles contract

A

the internal anal sphincter opens

264
Q

cephalic phase

A

Prepares the mouth and stomach for the food that is about to be eaten
- salivary glands secrete saliva
- vagus nerve stimulates gastric glands to secrete gastric juice

265
Q

Gastric phase

A

In the gastric phase; neural and hormonal mechanisms begin to promote gastric secretion and motility

266
Q

Neural regulation of Gastric phase

A

When the stomach alls are distended, the pH increases because proteins have entered the stomach

267
Q

Hormonal regulation of Gastric phase

A

Gastrin released from the G cells of the gastric glands in response to several stimuli; stretching of stomach by chyme, high pH of chyme

268
Q

Gastrin stimulates gastric glands to

A

secrete large amounts of gastric juice

269
Q

Intestinal phase; NEURAL REGULATION

A

distention of the duodenum by the presence of chyme causes the enterogastric reflex;
- inhibit parasympathetic and stimulate sympathetic nerves

270
Q

Intestinal phase: hormonal regulation

A

CCK stimulates the secretion of pancreatic juice that is rich in digestive enxymes; also causes contraction of gallbladder which squeezes out bile

271
Q

Stimulus for gastrin

A

distension of stomach, partially digested proteins, caffeine in stomach and high pH of stomach chyme
- G cells located in mucosa of stomach

272
Q

Major effects of gastrin

A

promotes secretion of gastric juice, increases gastric motility and promotes growth of gastric mucosa

273
Q

Stimulus for Secretin

A
  • acidic chyme that enters small intestine
  • S cells in the mucosa of the duodenum
274
Q

Major effects of secretin

A

stimulates secretion of pancreatic juice and bile that are rich in bicarbonate ions (HCO3-)

275
Q

Stimulus for cholecystokinin

A
  • partially digested proteins, triglycerides, and fatty acids that enter the small intestine and stimulate secretion of CCK by entroendocrine cells
276
Q

Major effects of CCK (cholecystokinin)

A

stimulates secretion of pancreatic juice rich in digestive enzymes, causes ejection of bile from the gallbladder and opening of the hepatopancreatic ampulla which induces satiety

277
Q

Aging results in

A
  • decreased secretory mechanisms and motility
  • loss of strength and tone of digestive muscular tissue
  • changes in neurosecretory feedback
  • diminished response to pain and internal sensations
278
Q

Dental caries/tooth decay

A

gradual demineralizaton of the enamel and dentin

279
Q

Periodontal disease

A

inflammation of gums, alvolar bone, periodontium and cement
- inflammation of bleeding of gums

280
Q

Peptic ulcers

A

ulcers in digestive canal which can cause bleeding and eventually anemia

281
Q

Divertciular disease

A

saclike outpouchings of the wall of the colon
- characterized by pain, constipation, frequency of defecation, nausea, vomiting, and low grade fever

282
Q

Colorectal cancer

A

polyps dorm
- intake of alcohol, and diets high in animal fat and protein are associated with the risk of colorectal cancer

283
Q

Hepatitis

A

inflammation of the liver that can be caused by viruses, drugs, chemicals and alcohol