Brainscape's Knowledge GenomeTM

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


See full index

A & P II > Digestive System > Flashcards

Digestive System Flashcards

1
Q

Main functions of the Digestive system

A

–Take in food (Ingestion)
–Break it down into nutrient molecules (Digestion)
–Absorb molecules into the bloodstream (Absorbtion)
–Rid body of any indigestible remains (Defecati

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

Organs of the digestive system fall into two groups:

A

Alimentary canal (gastrointestinal or GI tract or gut)

Accessory digestive organs

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

Gi tract

A
  • Continuous muscular tube that runs from the mouth to anus
  • Digests food: breaks down into smaller fragments
  • Absorbs fragments through lining into blood
  • Organs: mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Accessory digestive organs

A 
•Teeth
•Tongue
•Gallbladder
•Digestive glands: produce secretions that help break down foodstuffs
–Salivary glands
–Liver
–Pancreas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ingestion

A

Eating

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

Propulsion

A

Propulsion: movement of food through the
alimentary canal, which includes:
•Swallowing
Peristalsis

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

Peristalsis

A

major means of propulsion of food that involves alternating waves of contraction and relaxation

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

Mechanical breakdown

A

includes chewing,
mixing food with saliva, churning food in
stomach, and segmentation

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

Segmentation

A

local constriction of intestine that mixes food with digestive juices

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

Digestion

A

series of catabolic steps that involves enzymes that break down complex food molecules into chemical building blocks

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

Absorption

A

passage of digested fragments from lumen of GI tract into blood or lymph

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

Defecation

A

elimination of indigestible substances via anus in form of feces

  • Distension initiates spinal defecation reflex
  • Parasympathetic signals
  • Stimulate contraction of sigmoid colon and rectum
  • Relax internal anal sphincter
  • Conscious control allows relaxation of external anal sphincter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Appendix

A

Appendicitis: acute inflammation of appendix; usually results from a blockage by feces that traps infectious bacteria
•Venous drainage can be impaired, leading to ischemia and necrosis (tissue death)
•Ruptured appendix can cause peritonitis
•Symptoms: pain in umbilical region, moving to lower right abdominal quadrant
•loss of appetite, nausea, and vomiting are also seen
•Treatment: surgical removal (appendectomy)

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

Subdivisions of large intestine

A

Cecum: first part of large intestine
2. Appendix: masses of lymphoid tissue
•Part of MALT of immune system
•Bacterial storehouse capable of recolonizing gut when necessary
•Twisted shape of appendix makes it susceptible to blockages
Colon: has several regions, most which are
retroperitoneal (except for transverse and
sigmoid regions)
•Ascending colon: travels up right side of abdominal cavity to level of right kidney
•Transverse colon: travels across abdominal cavity

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

Modifications of small intestine for absorption

A
  • Circular folds
  • Villi
  • Microvilli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Circular folds

A

•Permanent folds (~1 cm deep) that force chyme to slowly spiral through lumen, allowing more time for nutrient absorptio

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

Villi

A

•Fingerlike projections of mucosa (~1 mm high) with a core that contains dense capillary bed and lymphatic capillary called a lacteal for absorption

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

Microvilli

A

•Cytoplasmic extensions of mucosal cell that give fuzzy appearance called the brush border that contains membrane-bound enzymes brush border enzymes, used for final carbohydrate and protein digestion

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

Small intestine

A

the major organ of digestion and absorption

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

Hepatopancreatic sphincter

A

controls entry of bile and pancreatic juice into duodenum

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

Digestive enzymes

A

Proteases (for proteins): secreted in inactive form to prevent self-digestion
•Amylase (for carbohydrates)
•Lipases (for lipids)
•Nucleases (for nucleic acids)

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

The pancreas

A

Location: mostly retroperitoneal, deep to greater curvature of stomach
•Head is encircled by duodenum; tail abuts spleen
•Exocrine function: produce pancreatic juice
•Ducts: secrete to duodenum via main pancreatic duct; smaller duct cells produce water and bicarbonate
•Endocrine function: secretion of insulin and glucagon by pancreatic islet cells

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

The gallbladder

A
  • Gallbladder is a thin-walled muscular sac on ventral surface of liver
  • Functions to store and concentrate bile by absorbing water and ions
  • Contains many honeycomb folds that allow it to expand as it fills
  • Muscular contractions release bile via cystic duct, which flows into bile duct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Hepatitis

A

•Usually viral infection, drug toxicity, wild mushroom poiso

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

Cirrhosis

A
  • Progressive, chronic inflammation from chronic hepatitis or alcoholism
  • Liver  fatty, fibrous  portal hypertension
26
Q

The liver / Bile

A

Yellow-green, alkaline solution containing:
•Bile salts: cholesterol derivatives that function in fat emulsification and absorption
•Bilirubin: pigment formed from heme
•Bacteria break down in intestine to stercobilin that gives brown color of feces
•Cholesterol, triglycerides, phospholipids, and electrolytes

27
Q

Gross anatomy of the liver

A

Hepatic artery and vein enter liver at porta hepatis
•Bile ducts
•Common hepatic duct leaves liver
•Cystic duct connects to gallbladder
•Bile duct formed by union of common hepatic and cystic ducts

28
Q

Liver

A

digestive function is production of bile

•Bile: fat emulsifier

29
Q

Gallbladder

A

chief function is storage of bile

30
Q

Pancreas

A

supplies most of enzymes needed to digest chyme, as well as bicarbonate to neutralize stomach acid

31
Q

Enteroendocrine cells

A

Secrete chemical messengers into lamina propria
•Act as paracrines
•Serotonin and histamine
•Hormones
•Somatostatin (also acts as paracrine) and gastrin

32
Q

Mucous neck cells

A

•Secrete thin, acidic mucus of unknown function

33
Q

Parietal cells

A

Secretions include:
•Hydrochloric acid (HCl)
•pH 1.5–3.5; denatures protein, activates pepsin, breaks down plant cell walls, and kills many bacteria
•Intrinsic factor
•Glycoprotein required for absorption of vitamin B12 in small intestine

34
Q

Chief cells

A

Secretions include:
•Pepsinogen: inactive enzyme that is activated to pepsin by HCl and by pepsin itself (a positive feedback mechanism)
•Lipases
•Digests ~15% of lipids

35
Q

Enteroendocrine cells

A

Secrete chemical messengers into lamina propria
•Act as paracrines
•Serotonin and histamine
•Hormones
•Somatostatin (also acts as paracrine) and gastrin

36
Q

Types of gland cells

A

Mucous neck cells
•Parietal cells
•Chief cells
•Enteroendocrine cells

37
Q

Greater omentum

A

drapes inferiorly from greater curvature over intestine, spleen, and transverse colon
•Blends with mesocolon, mesentery that anchors large intestine to abdominal wall
•Contains fat deposits and lymph nodes

38
Q

Stomach

A

is a temporary storage tank that starts chemical breakdown of protein digestion
•Converts bolus of food to paste-like chyme
•Empty stomach has ~50 ml volume but can expand to 4 L
•When empty, stomach mucosa forms many folds called rugae

39
Q

deglutition

A

Deglutition involves coordination of 22 muscle groups and two phases:
•Buccal phase: voluntary contraction of tongue
•Pharyngeal-esophageal phase: involuntary phase that primarily involves vagus nerve
•Controlled by swallowing center in medulla and lower pons

40
Q

Pharynx and esophagus

A

are conduits to pass food from mouth to stomach

41
Q

Flat muscular tube that runs from laryngopharynx to stomach
•Is collapsed when not involved in food propulsion
•Pierces diaphragm at esophageal hiatus
•Joins stomach at cardial orifice
•Gastroesophageal (cardiac) sphincter surrounds cardial orifice
•Keeps orifice closed when food is not being swallowed
•Mucus cells on both sides of sphincter help protect esophagus from acid

A

The esophagus

42
Q

The Pharynx

A

Food passes from mouth into oropharynx and then into laryngopharynx
•Allows passage of food, fluids, and air
•Stratified squamous epithelium lining with mucus-producing glands
•External muscle layers consists of two skeletal muscle layers
•Inner layer of muscles runs longitudinally
•Outer pharyngeal constrictors encircle wall of pharynx

43
Q

Dentin

A

bonelike material under enamel

44
Q

Cement

A

calcified connective tissue

–Covers root; attaches it to periodontal ligament

45
Q

Incisors

A

chisel shaped for cutting

46
Q

Canines

A

fanglike teeth that tear or pierce

47
Q

Premolars

A

bicuspids): broad crowns with rounded cusps used to grind or

48
Q

Molars

A

road crowns, rounded cusps: best grinders

•During chewing, upper and lower molars lock together, creating tremendous crushing force

49
Q

Tongue

A

Tongue

50
Q

saliva

A

Cleanses mouth
–Dissolves food chemicals for taste
–Moistens food; compacts into bolus
–Begins breakdown of starch with enzyme amylase

51
Q

Palate

A

forms the roof of the mouth and has two distinct part

52
Q

Hard palate:

A

tformed by palatine bones and palatine
processes of maxillae
-Mucosa is slightly corrugated to help create friction against tongue

53
Q 
where food is chewed and mixed with enzyme-containing saliva that begins process of digestion, and swallowing process is initiated
•Associated organs include:
–Mouth
–Tongue
–Salivary glands
–Teeth
A

Mouth

54
Q

Mesentery

A

double layer of peritoneum; layers are fused back to back
–Extends from body wall to digestive organs
–Provides routes for blood vessels, lymphatics, and nerves
–Holds organs in place and also stores fat

55
Q

Peritoneum

A

serous membranes of abdominal cavity that consists of:
–Visceral peritoneum: membrane on external surface of most digestive organs
–Parietal peritoneum: membrane that lines body wal

56
Q

Peritoneal cavity

A

Fluid-filled space between two peritoneums

–Fluid lubricates mobile organs

57
Q

Absorption of water

A

95% is absorbed in the small intestine by osmosis

•Most of rest is absorbed in large intestine

58
Q

Absorption

A

Absorption is process of moving substances from lumen of gut into body

59
Q

Protein digestion

A

Digestion begins in stomach when pepsinogen is converted to pepsin at pH 1.5–2.5
•Becomes inactive in high pH of duodenum

60
Q

Starch digestion

A

Pancreatic amylase breaks down starch or
glycogen that escaped salivary amylase into
oligosaccharides and disaccharides

A & P II (1 decks)

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