Digestive System Flashcards

1
Q

What does the digestive system include?

A

The digestive system includes the gastrointestinal (GI) tract and several accessory organs.

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

What organs are part of the GI tract?

A

The GI tract includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

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

How are glands that release substances into the GI tract classified?

A

Glands that release substances into the GI tract are classified as exocrine glands because the GI tract is continuous with the external environment.

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

What are the accessory organs that assist in the digestion of nutrients?

A

The pancreas, liver, and gallbladder produce and store secretions.

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

Digestion

A

the breaking down of ingested food (mechanical digestion vs. chemical digestion)

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

Absorption

A

the entry of nutrients into the cells lining the GI tract en route to the blood or lymph

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

Defecation

A

the elimination of wastes and indigestible substances

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

What are the four layers of tissue that surround the lumen of the GI tract from deep to superficial?

A

The four layers are mucosa, submucosa, muscularis, and serosa.

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

What are the primary functions of the gastrointestinal (GI) tract?

A

The primary functions are ingestion, digestion, absorption of nutrients, and elimination of waste products.

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

What is the innermost layer of the GI tract called?

A

The innermost layer is called the mucosa.

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

What does the epithelial tissue layer of the mucosa contain?

A

The epithelial tissue layer contains both endocrine glands, which secrete hormones into the blood, and exocrine glands, which secrete substances into the lumen of the tract.

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

What is the function of the smooth muscle layer in the mucosa?

A

The smooth muscle layer creates folds in the inner lining of the stomach and small intestine, increasing the surface area available for digestion and absorption of nutrients.

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

What does the connective tissue layer of the mucosa contain?

A

The connective tissue layer contains blood vessels and lymphatic vessels that collect absorbed nutrients.

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

What is located superficial to the mucosa in the GI tract?

A

The submucosa is located superficial to the mucosa.

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

What is the composition of the submucosa?

A

The submucosa contains connective tissue intermixed with blood vessels, lymphatic vessels, and a plexus of neurons that belong to the enteric nervous system.

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

What is the function of the neurons found in the submucosa?

A

Neurons in the submucosa coordinate various functions of the GI tract.

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

What is the role of the submucosa?

A

The submucosa is a mass of connective tissue that binds the mucosa to the muscularis. It also contains blood vessels and lymphatic vessels that transport nutrients away from the GI tract.

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

What is located superficial to the submucosa in the GI tract?

A

The muscularis is located superficial to the submucosa.

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

What types of muscles comprise the muscularis in different parts of the GI tract?

A

The muscularis contains skeletal muscle in the initial portion of the GI tract (such as the mouth, pharynx, and upper esophagus) and smooth muscle in the rest of the GI tract.

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

How is skeletal muscle innervated and controlled?

A

Skeletal muscle is innervated by the somatic nervous system and under voluntary control.

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

How is smooth muscle innervated and controlled?

A

Smooth muscle is innervated by the autonomic nervous system and under involuntary control.

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

What are the functions of the muscles in the muscularis?

A

The muscles in the muscularis assist in the mechanical digestion of food (motility) and the movement of food along the GI tract (peristalsis).

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

What is the most superficial layer that provides support to the GI tract?

A

The serosa is the most superficial layer supporting the GI tract.

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

What is the function of the serosa?

A

The serosa contributes to the peritoneum, which holds and suspends portions of the GI tract within the abdominal cavity to prevent them from falling to the floor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the mesentery?
The mesentery is a portion of the peritoneum that suspends the small intestine.
26
What do the mesenteric arteries and veins supply?
The mesenteric arteries and veins collectively supply blood to the small and large intestines.
27
Organs of the GI Tract:
mouth, pharynx, esophagus, stomach, small intestine, large intestine
28
Gi tract is responsible for ...
Digestion and absorption of food.
29
What assists in the mechanical digestion of food within the oral cavity?
Both the teeth and tongue assist in the mechanical digestion of food.
30
What is the function of taste buds in the tongue?
Taste buds are sensory receptors that provide taste sensations and transmit signals to the brain via the facial nerve (CN VII) and glossopharyngeal nerve (CN IX).
31
What additional function does the tongue have related to digestion?
Once activated, the tongue secretes an enzyme that digests lipids in the stomach's acidic environment.
32
Which cranial nerves transmit sensory signals from taste buds to the brain?
The facial nerve (CN VII) and glossopharyngeal nerve (CN IX) transmit sensory signals from taste buds to the brain.
33
What is the function of the palate?
The palate separates the oral and nasal cavities.
34
What is the hard palate composed of?
The hard palate is composed of portions of the maxilla and palatine bones.
35
What is the soft palate composed of?
The soft palate is composed of skeletal muscle.
36
What is the function of the soft palate during swallowing?
During swallowing, the soft palate moves up to cover the posterior opening to the nasal cavity, preventing food from entering it.
37
What is the uvula, and what is its function?
The uvula is a muscular process hanging off the soft palate's posterior border. The soft palate and uvula are pulled superiorly to prevent food from entering the nasal cavity during swallowing.
38
What do salivary glands secrete into the oral cavity?
Salivary glands secrete saliva; a mixture of water, ions, and a digestive enzyme that digests carbohydrates.
39
What type of control are salivary glands under?
Salivary glands are under autonomic control.
40
What types of innervation do salivary glands receive?
Salivary glands receive sympathetic innervation from periarticular nerves and parasympathetic innervation from the facial nerve (CN VII) and glossopharyngeal nerve (CN IX).
41
What are the functions of saliva?
Saliva's functions include keeping the mucous membranes of the mouth, pharynx, and esophagus moist and assisting in the chemical digestion of carbohydrates.
42
What is the role of the facial nerve (CN VII) and glossopharyngeal nerve (CN IX) in innervating salivary glands?
The facial nerve (CN VII) and glossopharyngeal nerve (CN IX) provide unique sensory innervation related to taste and parasympathetic motor innervation to the salivary glands.
43
How is the pharynx divided into sections?
The pharynx is divided into three sections: the nasal pharynx, oral pharynx, and laryngeal pharynx.
44
What are the respiratory and digestive functions of the oropharynx and laryngopharynx?
The oropharynx and laryngopharynx serve as the common passageway for incoming and outgoing air and incoming food, giving them both respiratory and digestive functions.
45
What is the function of the epiglottis during swallowing?
The epiglottis moves down to cover the opening to the larynx, preventing food from entering the lower respiratory tract during the swallowing mechanism.
46
What role do muscular contractions play in the oropharynx and laryngopharynx?
Muscular contractions in these areas help propel food along and prevent it from entering the larynx, aided by the action of the epiglottis.
47
What is the location of the esophagus in the trachea?
The esophagus is posterior to the trachea, passing inferiorly through the neck and thoracic cavity.
48
What structures does the esophagus pass through to enter the abdominal cavity?
Along with the openings for the aorta and inferior vena cava, the diaphragm also has an opening for the esophagus, which allows the esophagus to pass into the abdominal cavity and empty its contents into the stomach.
49
What regulates the passage of food into and out of the esophagus?
Smooth muscle sphincters at either end of the esophagus regulate the passage of food into (upper esophageal sphincter) and out of (lower esophageal sphincter) the esophagus.
50
What is the function of the esophagus?
The esophagus is a muscular tube that serves as a passageway for food from the pharynx to the stomach.
51
Where is the stomach located in the abdominal cavity?
The stomach is located in the upper left quadrant of the abdominal cavity, just inferior to the diaphragm.
52
What are the primary functions of the stomach?
The primary functions of the stomach are to assist in the mechanical and chemical digestion of food and to store partially digested food before it enters the small intestine.
53
What regulates the passage of food from the stomach into the small intestine?
A smooth muscle sphincter called the pyloric sphincter regulates the passage of food from the stomach into the small intestine.
54
How does the folded nature of the mucosal layer of the stomach benefit digestion?
The folded nature of the mucosal layer increases the surface area available for chemical digestion.
55
What do the exocrine glands in the stomach secrete into the lumen?
The exocrine glands secrete gastric juice, which contains acid (HCl) and digestive enzymes that assist in the chemical digestion of food.
56
What is the role of endocrine gland cells in the stomach?
Endocrine gland cells secrete a hormone called gastrin, which stimulates gastric secretions and motility, further enhancing the digestive process.
57
How does the mucus secreted by some exocrine glands protect the stomach lining?
The mucus secreted by some exocrine glands has a basic pH and coats the mucosal lining, protecting it from the stomach's acidic environment.
58
What is peptic ulcer disease?
Peptic ulcer disease is a condition where the acid secreted in the stomach erodes the mucosa of the stomach or duodenum, causing pain and bleeding.
59
What are two common causes of peptic ulcer disease?
Two common causes are bacterial infection, specifically Helicobacter pylori (H. pylori), and chronic use of NSAIDs (nonsteroidal anti-inflammatory drugs) like aspirin and ibuprofen.
60
What is the long, highly-convoluted tube in the middle of the abdominal cavity that connects the stomach to the large intestine?
The small intestine
61
What is the primary site of both digestion (mechanical and chemical) and absorption of food along the GI tract?
The small intestine
62
What is the initial 10 to 15 inches of the small intestine connected to the stomach called?
The duodenum
63
What is the middle portion of the small intestine called?
The jejunum
64
What is the terminal portion of the small intestine connected to the large intestine called?
The ileum
65
What is the function of the highly folded mucosa of the small intestine?
Increases surface area for chemical digestion and absorption; contains gland cells
66
What do exocrine gland cells in the small intestine secrete?
Intestinal juice containing digestive enzymes
67
What do endocrine gland cells in the small intestine secrete?
Hormones that stimulate the release of bicarbonate (from pancreas) and digestive enzymes and bile (from pancreas and gallbladder respectively)
68
What does the release of bicarbonate from the pancreas do in the small intestine?
Neutralizes stomach acid entering the small intestine
69
What does the release of bile from the gallbladder do in the small intestine?
Assists in the chemical digestion of lipids
70
What is the function of the large intestine in the GI tract?
Performs additional digestion and absorption of certain materials and eliminates waste products
71
What role do bacteria in the large intestine play?
Assist in final stages of chemical digestion, produce gas (flatulence), and synthesize some vitamins
72
What are some conditions potentially linked to the bacteria in the large intestine?
Cardiovascular disease, diabetes mellitus, and neurological disorders
73
What are probiotic foods and supplements used for in relation to gut bacteria?
To affect the composition of gut bacteria and promote health
74
What are some other functions of the large intestine?
Absorption of water, ions, and some vitamins; elimination of digestive wastes and indigestible products
75
What is the tube that serves as a passageway for the by-products of digestion from the small intestine to the anus?
The large intestine
76
What is the initial portion of the large intestine called?
The cecum
77
Where is the cecum located in the abdominal cavity?
In the lower right quadrant
78
What is connected to the cecum?
The vermiform appendix
79
What is the function of the vermiform appendix?
Its function is not well understood
80
Name the sequence of parts through which the large intestine passes.
Ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal
81
What regulates the passage of digested material from the small intestine into the large intestine?
The ileocecal sphincter
82
What type of muscle makes up the internal anal sphincter?
Smooth muscle
83
What type of muscle makes up the external anal sphincter?
Skeletal muscle
84
Which sphincters regulate the passage of material out of the large intestine?
The anal sphincters, consisting of the smooth muscle internal anal sphincter and the skeletal muscle external anal sphincter.
85
Accessory digestive organs:
liver pancreas gallbladder
86
purpose of accessory organs:
Produce/store secretions that assist in the digestion of food (exocrine functions)
87
Where is the pancreas located in the abdominal cavity?
In the upper left quadrant, posterior to the stomach
88
What are the exocrine functions of the pancreas?
Secretion of digestive enzymes and bicarbonate into the lumen of the small intestine
89
What is pancreatic juice?
A secretion containing bicarbonate and digestive enzymes aiding in chemical digestion of food
90
How is pancreatic juice carried from the pancreas to the duodenum?
Through two small ducts
91
Where is the liver located in the abdominal cavity?
In the upper right quadrant, just inferior to the diaphragm
92
What is one of the direct digestive functions of the liver?
Production of bile
93
Where is bile produced and stored?
Produced by the liver and stored in the gallbladder
94
What stimulates the gallbladder to release bile?
A hormone secreted by the small intestine
95
Name some additional functions of the liver.
Metabolism of nutrients, storage of glycogen and vitamins, detoxification of blood, production of active vitamin D
96
What are the two blood vessels that supply blood to the liver?
Hepatic artery and hepatic portal vein
97
What does the hepatic artery carry to the liver?
Oxygenated blood
98
What does the hepatic portal vein carry to the liver?
Nutrient-rich deoxygenated blood from the GI tract
99
How is the blood drained from the liver back into systemic circulation?
Via the hepatic veins after filtration
100
What is one of the components of bile?
Bilirubin
101
When is bilirubin released?
When red blood cells are broken down
102
What conditions can lead to excess bilirubin accumulation in the blood?
Compromised liver function (e.g., hepatitis, cirrhosis) or blockage of bile release into the GI tract (e.g., gallstones)
103
What is the common visible symptom of excess bilirubin accumulation?
Yellowish tinge of the skin, mucous membranes, and eyes, known as "jaundice"
104
What are the intrinsic plexuses of nerves in the GI tract called?
Enteric Nervous System (ENS)
105
What type of sensory input does the ENS receive from the GI tract?
Chemoreceptors and stretch receptors
106
What type of signals does the ENS send to the glands and smooth muscle of the GI tract?
Motor signals
107
How is the ENS regulated extrinsically?
By neurons from the Autonomic Nervous System (ANS)
108
What effect does sympathetic stimulation have on GI activity?
Decreases GI activity
109
What effect does parasympathetic stimulation have on GI activity?
Increases GI activity
110
How does sensory input and motor output in the GI tract involve the central nervous system?
Through the autonomic nervous system
111
Where does sensory input and motor output occur in the enteric nervous system (ENS)?
Within plexuses of neurons entirely within the GI tract
112
What is unique about the regulation of GI function by the ENS?
It is entirely independent of the central nervous system