Brainscape's Knowledge GenomeTM

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


See full index

Biology > Chapter 9 - Digestive System > Flashcards

Chapter 9 - Digestive System Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is digestion?

A

The breakdown of food into organic molecules:

Lipids into fatty acids and glycerol

Starch and carbs into monosaccharides

Proteins into amino acids

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

Mechanical digestion - what is it, and what ISNT it?

A

Physically breaking down large pieces of food - it is NOT chemical breakdown

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

Chemical digestion - what is it, and some examples

A

The enzymatic cleavage of chemical bonds

Ie, the peptide bonds of proteins, or the glycosidic bonds of starches

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

The order of what structures food travels through:

7

A 
Mouth
Pharynx 
Esophagus
Stomach
Small intestine
Large intestine
Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What additional structures help provide enzymes and lubrication to aid in digestion?
(4)

A

Salivary glands
Pancreas
Liver
Ball bladder

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

What is the enteric nervous system?

A

Millions of neurons that govern the GI system

These are present in the walls of the digestive tracts and trigger PERISTALSIS (rhythmic contractions of the gut to help move food along)

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

What controls the enteric nervous system?

A

It is largely autonomic, but it can function independently of the brain and spinal cord.

PARASYMPATHETIC: stimulates digestion, increased secretions, promotes peristalsis

SYMPATHETIC: inhibits the above activities

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

What is intracelullar digestion?

What is extracellular digestion?

A

Intracelullar: the oxidation of glucose and fatty acids for energy

Extracellular: obtaining nutrients from food in the lumen of the alimentary canal

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

What role do ADH (aka vasopressin) and ALDOSTERONE play in feeding behavior?

A

They trigger the sensation of thirst, encouraging the behavior of fluid consumption.

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

What substances trigger the feeling of HUNGER?

A

Glucagon (secreted by the pancreas)

Ghrelin (secreted by the stomach and pancreas)

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

What substances trigger SATIETY?

A

Leptin

Cholecystokinin (peptide hormone secreted by GI tract)

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

What 3 substances account for chemical digestion in the oral cavity?

A

Salivary amylase “ptyalin” (starch into smaller sugars such as maltose and dextrin)

Lipase (breaks down lipids)

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

What are the 3 portions of the pharynx?

A

Nasopharynx
Oropharynx
Laryngopharynx (above vocal cords)

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

What structures does the esophagus connect?

A

The pharynx and the stomach

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

Different muscle composition of the esophagus:

3

A

Top third: skeletal muscle
Middle third: mix
Bottom third: smooth muscle

Aka top: somatic/voluntary
Bottom: autonomic/involuntary control

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

Where does peristalsis start?

A

At the smooth muscle (lower third) of the esophagus

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

What is emesis?

A

VOMITING

the reverse of peristalsis

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

Where is swallowing initiated?

A

In the muscles of the oropharynx (upper esophageal sphincter)

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

What is the cardiac sphincter?

A

The lower esophageal sphincter

(Empties into the cardia of the stomach)

**weakness in this sphincter leads to gastroesophageal reflux disease (GERD) = “heartburn”

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

What are the THREE main sources of energy?

A

Protein
Carbohydrates
Fats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q 
Stomach as an organ
(Size?)
(What is it made of?)
(Where is it?)
(What substances does it use to digest food?)
A

Holds about 2 L’s
Made of muscle; thick mucosa
Upper left quadrant of the abdominal cavity, under the diaphragm
Uses hydrochloride acid and enzymes

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

Four main anatomical divisons of the stomach

A

Fundus - gastric glands
Body - gastric glands
Antrum - pyloric glands
Pylorus -pyloric glands

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

How does NSAIDs impact the stomach?

A

They MAY disrupt mucus production which leaves the mucosa unprotected and probe to irritation.

Gastritis, or gastric ulcers may result

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

How are gastric glands innervated?

What cell types do they have? (3)

A

Respond to signals from the vagus nerve (PARASYMPATHETIC nerve) which is activated by sight/smell/taste of food

Mucous cells
Chief cells
Parietal cells

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

What do mucous cells do?

A

bicarbonate-rich mucous that protects mucosa

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

What do chief cells and parietal cells do?

A

Chief cells make PEPSINOGEN (which is inactive - Pepsin is active)
And parietal cells make hydrochloric acid

These combine to make GASTRIC JUICE

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

What is special about PEPSIN?

A

An enzyme that breaks down proteins

It is activated by the ACIDIC environment - most active at a low pH
Other enzymes mostly active at physiological pH

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

What do the pyloric glands do?

A

They have G-cells that secrete GASTRIN

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

What is GASTRIN?

A

Peptide hormone

Induced parietal cells to secrete more HCl and stomach to contract and mix it’s contents.

30
Q

What is CHYME:

A

(Unlike chyle - lymphatic fluid)

Chyme is the contents of the stomach - an acidic, semi fluid mixture

31
Q

What 6 products does the stomach secrete?

A
  1. HCL
  2. PEPSINOGEN
  3. Mucus
  4. Bicarbonate
  5. Water
  6. Intrinsic factor
32
Q

What are brush-border enzymes?

A

Activated by the presence of chyme in the duodenum

Disaccharidases and peptidases
Break down dimers and trimers into absorbable monomers

33
Q

What other (3) things does the duodenum secrete?

A
  1. Enteropeptidase (activates other digestive enzymes)
  2. Secretin
  3. Cholecystokinin (CCK)
34
Q

Disaccharidases

A

Digest the sugar close to their name (or maltase digests maltose)

Lack of a particular disaccharidase means inability to break down that corresponding disaccharide

Undigested disaccharides have an osmotic effect (pull water into the stool - cause DIARRHEA)

*lactose intolerance leads to bloating, flatulence, diarrhea etc

35
Q

How do bacteria in the intestine hydro luxe disaccharides?

What is the byproduct?

A

Methane has as a byproduct

36
Q

Peptidases

A

Aminopeptidase (removes the n-terminal amino acid)

Dipepridase (cleave the peptide bond to make free amino acids)

Di and even tripeptides CAN be absorbed into the small intestine, unlike polysaccharides

37
Q

What is enteropeptidase?

A

Critical for the activation of TRYPSINOGEN into TRYPSIN
(Pancreatic protease)

Can also activate procarboxypeptidases A and B to their active forms

38
Q

What is SECRETIN?

A

Peptide hormone

Causes pancreatic enzymes to be released into the duodenum

Regulates pH by reducing HCl secretions

It’s an ENTEROGASTRONE: slows down motility in the digestive tract to allow time to things to be digested, ie fats

39
Q

What is CHOLECYSTOKININ?

A

Secreted in response to chyme entering the duodenum

Stimulated the release of bile and pancreatic juices

Promotes SATIETY in the brain

40
Q

What is bile made of?

3

A

Bike salts
Pigments (ie bilirubin)
Cholesterol

41
Q

What role does bile play?

A

Doesn’t chemically digest anything (it’s not an enzyme) but plays a role in mechanical digestion of FATS and ultimately help in the chemical digestion of lipids.

42
Q

Mechanism of bile:

A

Hydrophobic and hydrophilic ends - act as detergents

  1. Emulsify fats and cholesterol into micelles (increased surface area)
  2. Increased surf area helps pancreatic LIPASE act on the lipids (breaks Esther bonds)
43
Q

What are pancreatic juices composed of?

A

Several enzymes in a bicarbonate-rich alkaline solution.

Neutralizes acidic chyme - provides an ideal environment for the digestive enzymes (whose optimal pH are close to 8.5

44
Q

What (3) peptide hormones does the pancreas release?

A

Insulin
Glucagon
Somatostatin

45
Q

What is pancreatic lipase?

A

Breaks down fats into free fatty acids and glycerol

46
Q

What structure allows pancreatic juices to enter the duodenum?

A

Pancreatic duct which runs inside the pancreas

Empties into the MAJOR and MINOR DUODENAL PAPILLAE

(Minor is ABOVE the major)

47
Q

What do BILE DUCTS connect?

A

The liver with the gallbladder and the small intestine

48
Q

What is the HEPATIC PORTAL VEIN?

A

The liver receives ALL blood draining from the abdominal portion of the digestive tract through this vein

NUTRIENT-RICH blood

The liver processes the blood, then drains into the INFERIOR VENA CAVA

49
Q

How does the lives store nutrients?

A

Stores sugars as glycogen

Stores fats as triacylglycerols

Can also do the reverse: gluconeogenesis and mobilizing fats in lipoproteins

50
Q

Examples of things that the liver detoxifies:

A

Ammonia (byproduct of amino acid breakdown) into urea

Alcohol
Medications

51
Q

What is pancreatitis?

A

Inflammation of the pancreas

Results in pemature activation of pancreatic enzymes and autodigestion of the pancreatic tissue.

Outcomes of this are a lot of pain, potentially diabetes, and reduced digestion of proteins and fats.

52
Q

How does jaundice occur?

What is it?

(3 poss causes)

A

When the liver is not able to process bilirubin
(The liver conjugated the bilirubin - attached it to a protein - and then secreted into bile)

May be caused by:
Liver damage
Excessive red blood cell destruction
Blockage of bike duct

53
Q

Which PROTEINS does they we synthesize?

2

A

Albumin (maintains plasma oncotic pressure - carrier for many drugs and hormones)

Clotting factors (used during blood coagulation)

54
Q

What is CIRRHOSIS OF THE LIVER?

Causes of CIRRHOSIS OF THE LIVER
4

A

Scarring of the liver - scar tissue builds up and creates resistance in the portal vein - leads to portal hypertension.

Alcohol consumption
Hepatitis C
Autoimmune hepatitis
Fatty liver disease

55
Q

What are the results of CIRRHOSIS OF THE LIVER?

5

A
  • swollen veins in the digestive system (due to a backup of fluid in the backup system)
  • the swollen veins especially impact the ESOPHAGUS which may rupture (hematemesis)
  • bleeding disorders (bc of disruption of clotting factors)
  • increased ammonia in the blood (may affect mental functions)
  • hepatocellular carcinoma
56
Q

What does the gallbladder do?

Where is it located?

A

Stores and concentrates bile

Just below the liver (right upper quadrant)

57
Q

How does the gallbladder work?

What activates is?

A

Upon release of CCK (from the duodenum) gallbladder contracts and pushes bile into the biliary tree.

Bile duct merges with the pancreatic duct and together they empty into the duodenum.

58
Q

What are gall stones made of?

Meet do they happen here?

A

Cholesterol or bilirubin

They happen in he gallbladder because bile is concentrated here

59
Q

How are amino acids and simple sugars absorbed into the epithelium?

A

Secondary active transport

Facilitated diffusion

60
Q

What happens to large fatty acids (the can’t just go into the cell):

A
  1. Break down to move separately into the cell
  2. Chylomicrons (insoluble: made up of triglycerides and estherified cholesterol molecules)
  3. Chylomicrons enter the lymph via the lacteals
  4. Lacteals converge and enter the venous circulation via thoracic duct in the neck, and the lymph empties into the L subclavian vein.
61
Q

Which (4) vitamins are fat-soluble?

A

A
D
E
K

62
Q

What happens to fat-soluble vitamins?

A

Dissolve into chylomicrons and are absorbed into the body.

63
Q

What happens if the body cannot digest fats properly?

A

Body’s inability to digest fats can lead to problems with gallbladder, pancreas, small intestine.

May lead to deficiencies in fat-soluble vitamins

64
Q

What is the main role of the large intestine?

How does it physically compare to the small intestine?

A

Water absorption (although the small intestine actually absorbs more!)

Larger diameter but shorter length.

65
Q

3 main parts of the large intestine

A

Cecum
Colon
Rectum

66
Q

What does the cecum do?

A

A pocket that accepts fluid coming from the small intestine via the ILEOCECAL VALVE

This is the site of the APPENDIX

67
Q

What is the appendix?

A

Small finger-like projection (long tube)

Likely plays a role in warding off bacteria and repopulating the large intestine with flora after episodes if diarrhea.

Located in LOWER RIGHT quadrant

68
Q

What is the colon?

A 
Divided into sections;
   Ascending
   Transverse
   Descending
   Sigmoid

Absorbs water and salts (ie sodium chloride) from indigenes material left over from the small intestine.

Concentrates the remaining material into feces

69
Q

What does the rectum do?

A

Site of storage for feces

  • indigestible material
  • bacteria (ie, E Coli) - ABOUT 30%!
  • digestive secretions that aren’t re absorbed (bile, enzymes)
70
Q

What are he two sphincters of the anus?

A

Internal and external anal sphincters

Internal: autonomic
External: somatic

71
Q

Good bacteria in the gut

A

Mostly anaerobes, but some aerobic bacteria

Some bacteria in the guy produce vitamin K (needed for clotting factor)

Some produce Biotin (Vit B7) which is an important coenzyme in metabolic processes

Biology (11 decks)

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