Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Human Physiology > Digestive System > Flashcards

Digestive System Flashcards

1
Q

Alimentary canal (GI tract):

A

mouth, pharynx, esophagus, stomach, small intestine, large intestine.

Breaks down food to simple molecules. Absorbed into the
bloodstream

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

Accessory digestive organs:

A

teeth, tongue, gallbladder, salivary glands, liver, and pancreas.

Produce a variety of secretions which help the Alimentary canal do its work.

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

Digestion process

A
  • Ingestion: Eating
  • Propulsion: Swallowing and peristalsis
  • Mechanical digestion: Chewing, tongue mixing, stomach churning, segmentation in intestine.
  • Chemical digestion: Enzymatic catabolic steps producing simple molecules from complex molecules.
  • Absorption: Small intestine
  • Defecation: Pooping
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Mechanoreceptors

A

respond to stretch

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

Chemoreceptors

A

respond to osmolarity, pH, presence of digestive substrates and end-products.

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

Mesentery

A

double layered peritoneum which connects many digestive organs to the body wall. Mesentery provides
route for blood and lymph vessels, fat deposits, anchoring organs

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

retroperitoneal organs

A

most of pancreas, parts of large intestine

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

blood supply

A

arteries: celiac trunk > spleen, liver, stomach
Veins: hepatic portal system > nutrient rich from spleen and intestines to liver

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

Alimentary canal: MUCOSA

A

Epithelial cell layer lining complete digestive system.
Specialized for
(1) secretion of mucus, digestive enzymes, and hormones.
(2) Absorption of the end products of digestion into the blood.
(3) protection against infectious diseases.

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

mucosa epithelial

A

columnar layer with mucus
secreting goblet cells. Sits on basement membrane.

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

mucosa lamina propria

A

connective tissue underlaying
epithelial cells. Capillaries supply nutrients to epithelial layer and to transport absorbed nutrients to liver. Contains lymphatic tissues.

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

Muscularis mucosae:

A

Thin smooth muscles layer causing small local movements.

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

Alimentary Submucosa

A

Underlies mucosa. Contains blood and lymph vessels, lymphoid follicles, nerve fibers. Rich in elastin.

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

Alimentary Muscularis Externa:

A

Inner circular and outer
longitudinal layer of smooth muscle. Responsible to
segmentation (mixing) and peristalsis (moving).

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

Alimentary Serosa:

A

Protective outmost layer of intraperitoneal organs. Visceral peritoneal. Adventitia is connective tissue attaching esophagus and retroperitoneal organs to body.

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

The Mouth: (oral cavity, buccal cavity)

A

Walls lined with stratified squamous epithelium
Opens to oropharynx

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

Hard palate

A

underlain by palatine bones and is used during chewing when tongue forces food against palate. Has raised ridges helping in food control.

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

Soft palate

A

formed by skeletal muscle. Uvula seals nasal cavity during swallowing.

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

Tongue

A
  • Filiform papillae contain keratin and increase roughness of
    tongue. Smallest and most numerous papillae.
  • Fungiform papillae are scattered around surface of tongue.
  • Circumvallate papillae are found at back of tongue.
  • Fungiform and circumvallate papillae contain taste buds.
  • Sulcus terminalis demarcates front 2/3 and
    back 1/3 of tongue.
  • Circumvallate papillae just anterior to sulcus
    terminalis. Lingual tonsils just posterior of
    sulcus terminalis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

salivary glands

A

Average saliva output is 1 to 1.5 liters/day.

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

Tooth structure:

A

Dentin (hard) which surrounds the pulp cavity. crown is exposed
USAG-1 3rd set of teeth??

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

The Pharynx:

A

Only oropharynx and laryngopharynx involved with GI tract. Lined by stratified squamous epithelial cells and mucus. Pharyngeal constrictor muscles encircle the pharynx and help propel food down to esophagus.

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

Esophagus:

A

Muscular tube about 25 cm (10 inches) long. Expandable.
Penetrates diaphragm at esophageal hiatus. Joins to stomach at cardiac orifice which is surrounded by gastroesophageal sphincter.

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

The Stomach:

A

A temporary storage tank where chemical breakdown of
proteins begins. Food is converted to easily absorbed chyme. The stomach is 15 to 25 cm (6-10 inches) depending on how full it is. When empty, has volume of ~50 mls. When full, has volume of up to 4 liters (80X larger). Expandability is due to rugae (folds of stomach wall).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Regions of stomach
Cardiac region, fundus, body, pyloric region (pyloric antrum, canal, sphincter), greater curvature, lesser curvature.
26
stomach mods
1.) Muscularis externa has extra muscle layer (oblique layer) enabling the stomach to churn and mix food. 2.) The lining of the stomach has several interesting features. * Epithelial lining is rich in mucus secreting goblet cells. Mucus lining traps bicarbonate ions to protect stomach walls. Lots of tight junctions between epithelial cells. * Gastric pits are located under epithelial lining and contain cells specialized in secreting proteins necessary for digestion.
27
mucous neck cells secrete
mucus
28
parietal cells secrete
HCl and Intrinsic factor. HCl cause low stomach pH = activate digestive enz. Intrinsic = B12 absorption
29
chief cells secrete
pepsinogen > activated by low pH (HCl) > form pepsin. Forward feedback.
30
enteroendocrine cells (G cells) secrete:
local hormones including gastrin, histamine, endorphins, serotonin, cholecystokinin, somatostatin. These hormones have several roles in digestion.
31
Reg Gastric Secretion: CEPHALIC PHASE
smell, taste, sight, thought of food stim thru Vagus Nerve btwn stomach and brain
32
Reg Gastric Secretion: GASTRIC PHASE
distension/stretch, partial dig proteins/peptides, and high acidity stim GASTRIN > secretion of HCl. Inhibited by low pH.
33
Reg Gastric Secretion: INTESTINAL PHASE
Partially digested food just arriving within the duodenum stimulates release of intestinal gastrin which increases gastric secretions. "fun time digesting chyme" As duodenum fills with chyme, it stretches, and inhibitory phase (enterogastric reflex) causes pyloric sphincter to close. Additionally, enterogastric reflex causes release of hormones
34
Intestinal hormones
§ SECRETIN increases release of pancreatic digestive enzymes. § CHOLECYSTOKININ (CCK) causes bile release from gallbladder. § GASTRIC INHIBITORY PEPTIDE temporarily inhibits opening of pyloric sphincter.
35
small intestine: DUODENUM
after stomach sphincter mostly retroperitoneal receive bile from gallbladder and liver via bile duct and receives pancreatic juice after sphincter of oddi/ampulla of vater
36
small intestine: JEJUNUM
Second part of small intestine. Connects duodenum to ileum. About 8 feet long.
37
small intestine: ILEUM
Third part of small intestine. Connects jejunum to large intestine via ileocecal valve. About 12 feet long.
38
small intestine features
SA max by circular folds, villi, microvilli. Absorbed nutrients into blood enzymes on epithelial surface not in juice Lysozyme is secreted by Paneth cells in crypts. Intestinal juice is secreted in response to stretch and acidic chyme. 12L/day. contain the epithelial stem cells. Paneth protect. Peyers patches located in submucosal layer Duodenal glands (Brunner’s glands) found within duodenum secrete bicarbonate-rich mucus to protect intestine from acidic chyme.
39
liver functions
detox metabolism immune system produce cholesterol store micronutrients blood sugar balance produce bile protein synth
40
Hepatic portal system
drains blood from intestines, stomach, and spleen and transport it to the liver where the nutrient rich blood is processed before return to general circulation.
41
portal triad
portal vein hepatic artery bile duct
42
filter excess debris from the blood in liver
sinusoidal capillaries cont Kupffer cells (phagocytes)
43
The Pancreas:
Produces pancreatic juice containing many digestive enzymes. Dumps into small intestine through pancreatic duct.
44
Pancreas islet secretes
insulin and glucagon
45
pancreatic juice contains...
bicarbonate (enzymes) amylase (starch) lipases (fat) nucleases (nucleic acid)
46
Pancreatic juice release is regulated by
GI tract hormones secretin and cholecystokinin (CCK) during intestinal phase of gastric digestion.
47
how long does digestion in small intestine take?
3-6 hrs
48
Most of substances required for chemical digestion (bile salts, digestive enzymes, bicarbonate ions) are provided by:
liver and pancreas.
49
Peristalsis in intestine occurs
after most nutrients are absorbed. Peristalsis moves unabsorbed material, dead cells, bacteria out of small intestine through the iliocecal sphincter.
50
large intestine
Major function is water absorption from indigestible material and elimination of partially dehydrated feces. lined by simple columnar 12-24hrs
51
Dental Cavities:
bacterial cell called streptococcus mutans. T hick capsule allows S. mutans to adhere to teeth and cause plaque. Acidic secretions progressively weaken enamel. * growing evidence links poor oral health to atherosclerosis.
52
Barrett Esophagus:
Metaplasia and cancer of the esophagus associated with gastric reflux (heartburn). Long term inflammation leads to cancer.
53
Stomach stress ulcers
caused by alcoholism, high doses of corticosteroids, and other anti inflammatory drugs.
54
Peptic stomach ulcers are caused by
Helicobacter pylori. H. pylori grows in the bicarbonate rich mucus of the stomach and neutralizes it. This allows HCl and digestive enzymes to degrade the stomach wall.
55
Stomach cancer:
Nitrites commonly used to preserve food. However, during digestion, nitrites convert to nitrous acid > mutagen that can cause cancer. Deamination strips away NH2 groups from A and C bases. This changes their chemistry so they base-pair wrong> mistakes in DNA… the ultimate cause of all cancer.
56
Inflammatory Bowel Diseases:
Crohn’s disease and Ulcerative colitis. Unknown cause. Typically thought to be autoimmune diseases. Long term effects of IBD include severe diarrhea, bleeding, intestinal paralysis, and colon cancer. typically treated with various immunosuppressive drugs and anti-inflammatory drugs. Possibly treated with parasitic worms?
57
Colorectal cancer:
Second leading cancer related death. coloscopy removes polyps
58
Cirrhosis of the liver
fibrosis that separates into nodules of hepatic tissue. can't function. causes: alcoholism, hepatitis B and C, cystic fibrosis, fatty liver, and obesity.
59
diabetes
Type 1: inability of beta-cells in the pancreas to release insulin. Type 2: inability of cells to express insulin receptor high glucose = excessive water in urine > kidney problems ketoacidosis
60
alimentary canal (GI tract) layers
1. mucosa = epithelial, LP, MM (secrete, absorb, protect) 2. Submucosa = blood, lymph, nerve (ELASTIN) 3. muscularis externa = segment (mix) and peristalsis (move) 4. Serosa = protective, visceral peritoneal

Human Physiology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions