Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Human Physiology > lecture 4: digestive system > Flashcards

lecture 4: digestive system Flashcards

1
Q

name the 2 paths involved in the digestive system (common names)

A

path food takes
accessory organs

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

name the 6 essential activities of digestion

A

ingestion
propulsion
mechanical breakdown
digestion (chemical, enzymes needed)
absorption
defecation

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

name the 2 groups of organs of digestive system

A

alimentary canal organs
accessory glands

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

describe alimentary canal organs (digestive track)

A

food passes through
mouth –> pharynx –> esophagus –> stomach –> small intestine –> large intestine –> anus

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

describe accessory glands

A

secretes digestive juices into the canal to aid digestion
salivary glands, liver, gallbladder, pancreas

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

what type of epithelium is mouth pharynx and esophagus lines with

A

stratified squamous

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

why do we choke

A

food gets into airway - talking while eating or chewing too fast

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

name the important sections of oral cavity

A

soft palate - muscle and connective tissue
hard palate - bone
tongue - skeletal muscles
epiglottis - elastic cartilage

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

name steps of the mouth digestion

A

entry point of food (ingestion)
food is chewed (mechanical)
saliva is secreted by salivary glands (chemical, mechanical)
tongue

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

describe food being chewed

A

teeth of varying shapes cut, smash and grind food so its easy to swallow
increases surface area of food - so enzymes can work more efficiently

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

describe purpose of saliva

A

lubricates foods for swallowing (contains mucin)
neutralizes acid in mouth (since its basic)
antibacterial agents kill bacteria
contains salivary amylase

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

describe function of tongue

A

tastes food (papillae)
pushes food around while chewing
helps form bolus and push it into pharynx while swallowing

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

describe pharynx

A

connects mouth and nasal cavity to trachea and esophagus
epiglottis - covers airway when swallowing
oro + laryngo + naso pharynx = call it all the pharynx

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

what is swallowing and is it voluntary

A

propulsion
starts off as voluntary then becomes involuntary

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

what happens when bolus enters the pharynx

A

esophageal sphincter relaxes (opens)
larynx moves up and epiglottis moves down to cover glottis (opening to larynx)

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

how does bolus move through esophagus

A

PERISTALSISSSS

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

describe esophagus + digestive activities

A

conducts food from pharynx to stomach ~ 25cm long
propulsion via peristalsis

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

name the 2 sphincter of esophagus

A

esophageal - pharynx/esophagus
gastroesophageal - esophagus/stomach

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

what is a sphincter

A

circular ring of muscle that acts like a valve (opens and closes)

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

what is peristalsis

A

alternating contraction and relaxation of smooth muscle lining the digestive track
propels food towards anus (one direction)

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

is peristalsis voluntary?

A

NOPEee
involuntary

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

what happens during emesis (vomiting)

A

Involuntary
reverse peristalsis

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

name parts of walls of digestive track

A

mucosa
submucosa
muscularis externa
serosa (adventitia)

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

describe mucosa (walls of digestive track)

A

surface epithelium (simple columnar or stratified squamous)
lamina propria (areolar connective tissue)
thin layer of smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
describe submucosa (walls of digestive track)
areolar connective tissue containing glands, nerve endings, blood vessels and lymphatic vessels
26
describe muscularis externa (walls of digestive track)
circular smooth muscle (inner) longitudinal smooth muscle layer (outer) PERISTALSIs
27
describe serosa (walls of digestive track)
fibrous connective tissue serous membrane (simple squamous)
28
what is strange about muscularis externa of stomach
extra internal layer called oblique layer - for churning
29
describe structure of stomach
located in upper abdominal cavity below diaphragm muscularis externa = longitudinal layer, circular layer and oblique layer
30
name steps of the stomach digestion
stores food churning (mechanical) digestion (chemical) empties chyme into duodenum (small intestine)
31
describe storing of food (stomach digestion)
rugae (accordion folds in mucosa) and very elastic wall allows stretching accommodates up to 2L
32
describe churning (stomach digestion)
oblique layer of smooth muscle pummels food and mixes with gastric juices --> produces chyme
33
describe digestion (stomach digestion)
hydrolysis of protein begins enzyme pepsin
34
describe the emptying of chyme into duodenum (small intestine (stomach digestion)
pyloric sphincter separates stomach and duodenum (propulsion) allows 3mL to enter small intestine at a time ~ 2-6 hrs to empty (slow digestion)
35
where is gastric juice found
stomach secreted by gastric pit epithelium
36
what does stomach epithelium produce
alkaline mucus to protect the stomach lining
37
how often is stomach epithelium replaced
every 3 days
38
describe gastric juice
acidity kills bacteria, denatures proteins, breaks down cell walls activates pepsin
39
name the 3 types of cells in gastric pits
parietal chief enteroendocrine
40
why is pepsin secreted in an inactive form (pepsinogen)
not to breakdown proteins in chief cells (pepsin is not specific, so it can attack all proteins) pepsinogen is secreted from chief cells into stomach then HCl mixes with it and produced pepsin (activated enzyme)
41
describe parietal cells
secretes HCl
42
describe chief cells
secretes pepsinogen in the presence of HCl pepsinogen is activated to pepsin
43
describe enteroendocrine cells
secrete hormones
44
name 4 hormones secreted by enteroendocrine cells
serotonin histamine somatostatin gastrin
45
describe hormone serotonin (digestive track)
stimulates muscle contractions excitatory
46
describe hormone histamine (digestive track)
stimulates release of HCl (sometimes why stomach hurts during allergic reaction) excitatory
47
describe hormone somatostatin (digestive track)
inhibitory
48
describe gastrin (digestive track)
stimulatory, excitatory ex: HCl secretion
49
name 3 parts of small intestine and functions
duodenum - digestion jejunum - absorption ileum - absorption
50
describe small intestine
3 parts longest section ~ 6 meters long length = maximizes surface area for absorption
51
what happens in duodenum
acidic chyme mixes with secretions from other organs
52
name and briefly describe 3 organs (secretions) that chyme mixes with in duodenum
pancreas - enzymes and alkaline solution liver and gallbladder - bile intestinal epithelium- brushborder enzymes
53
what is the purpose of the many structures of the small intestine
maximize surface area (250m^2) for absorption
54
name the 3 structural modifications of small intestine
circular folds villi microvilli
55
describe circular folds of small intestine
folding of mucosa and submucosa - like little hills
56
describe villi of small intestine
finger like projections of mucosa (on tops of hills) blood capillaries for absorption lymphatic vessels
57
describe microvilli of small intestine
projections of plasma membrane and epithelial cells looks like brush
58
does ALL absorption occur in small intestine?
NOOO some in stomach for things like alcohol, aspirin, drugs, water, vitamins (faster absorption)
59
what is segmentation
occurs in small intestine squeezing at top and bottom helps mix and breakdown food
60
what digestive activities occur in small intestine
propulsion (whole digestive system) mechanical breakdown (segmentation and bile) digestion (chemical) absorption
61
which digestive activities do not occur in small intestine
ingestion and defecation
62
what does liver do
produces bile metabolism detoxification
63
what does pancreas do
produced hydrolytic enzymes (for carbs, fats, proteins and nucleic acids) produced alkaline solution, rich in bicarbonate - neutralizes acidic chyme
64
what are bile salts
amphipathic and act as detergent or emulsifier to break up fat into small pieces (more access for lipases)
65
what does gallbladder do
stores excess bile
66
what two things are secreted into duodenum and from where
bile - liver/gallbladder alkaline solution - pancreas
67
what does bile do
makes fat soluble in water (breaks down) attaches to fat and gives it a hydrophilic side helps enzymes work
68
is bile mechanically or chemically digesting fats?
mechanically facilitates chemical breakdown BUT it isn’t chemical breakdown - just takes fats that are stuck together and beaks them up
69
what does bile contain
bile salts and pigments - byproducts of destruction of red blood cells in liver dark green or yellowish brown pigments are eliminated with feces
70
what is the hepatic portal vein
carries nutrient rich blood from capillaries of villi (all blood from intestines passes by liver before going to heart)
71
why does blood have to pass by the liver before going to the heart
stores vitamins and minerals detoxifies converts glucose into glycogen regulates amino acid levels converts ammonia to urea
72
describe large intestine
connected to small intestine at a T junction (includes cecum and illeocecum) ileocecal valve (sphincter) controls movement from small to large intestine shaped like a U 1.5 m long
73
what does large intestine do
reabsorbs water to form solid feces slow peristalsis (propulsion) 7L secreted and almost all reabsorbed
74
what do bacteria in the colon produce
gases and some vitamins (vit k, B vits, folic acid)
75
where are feces stored (explain process)
rectum until eliminated via anus internal sphincter - involuntary external sphincter - voluntary
76
what is feces
undigested food stuff (ex cellulose) bacteria
77
what causes diarrhea or constipation
diarrhea - moves fast through large intestine, not enough water reabsorbed constipation - moves slow through large intestine, too much water reabsorbed has to do with muscle contractions - frequency affects how long it is in small intestine
78
where does digestion of carbs start and where does it go ? explain areas
mouth continues in small intestine (duodenum)
79
name the enzymes involved in digestion of carbs
salivary amylase pancreatic amylases brush border enzymes
80
describe pancreatic amylase (digestion of carbs)
hydrolyzed to oligosaccharides and disaccharides
81
describe brush border enzymes (digestion of carbs)
hydrolyses to monomers disaccharides finalizes digestion of carbs
82
describe digestion of proteins (where)
starts in stomach continues into small intestine - duodenum
83
name enzymes used to digest proteins
pepsin (stomach) pancreatic enzymes brush border enzymes
84
describe pancreatic enzymes (digestion of proteins)
polypeptides to small polypeptides trypsin chymotrypsin carboxypeptidase secreted in inactive forms
85
describe brushborder enzymes (digestion of proteins)
small polypeptides to amino acids and some dipeptides/tripeptides dipeptidase aminopeptidase carboxypeptidase
86
where does digestion of fats start
small intestine
87
name enzymes that help digestion of fat
pancreatic lipases bile
88
describe pancreatic lipases (digestion of fats)
breaks down fat into glycerol, fatty acids and monoglycerides
89
describe bile (digestion of fat)
emulsifies fat increases surface area exposed to lipases
90
where does digestion of nucleic acids start
small intestine (duodenum)
91
name enzymes that help digest nucleic aids
pancreatic nucleases brush border enzymes
92
describe pancreatic nucleases and brush border enzymes (digestion of nucleic acids)
breaks down polynucleotide into sugars, bases and phosphates
93
describe absorption of carbs and proteins
from intestinal lumen --> crosses intestinal epithelium --> crosses interstitial fluid --> crosses epithelium of capillaries
94
how are carbs and proteins (nutrients) separated from blood
2 layers of cells
95
describe absorption of fats (name steps)
from intestinal lumen --> crosses intestinal epithelium --> crosses interstitial fluid --> crosses epithelium of lacteals
96
what are lacteals
lymphatic capillary
97
describe crossing intestinal epithelium (absorption of fats)
inside epithelial cell they (re)form triglycerides --> chylomicrons
98
describe crossing epithelium of lacteals (absorption of fats)
lacteals converge into larger vessels of lymphatic system eventually drain into large veins
99
what are chylomicrons
triglycerides packaged with phospholipids (balls on outside - hydrophilic head), cholesterol and proteins make fat soluble in water - environment of circulatory system
100
name the hormones that regulate digestion
gastrin secretin cholecystokinin (cck)
101
describe gastrin (regulates digestion, from where and what)
from stomach wall released in response to food stimulates secretion of gastric juices low stomach pH inhibits release of gastrin
102
describe secretin (regulates digestion, from where and what)
from duodenum wall releases in response to acidic chyme stimulates release of bicarbonate from pancreas
103
describe cck (regulates digestion, from where and what)
from duodenum wall released in response to presence of amino acids/fatty acids stimulates release of bile from gallbladder and release of pancreatic enzymes
104
why does it take longer to digest a fatty meal
fatty chyme in duodenum --> stimulates release of secretin and cck in high levels THIS inhibits peristalsis of stomach and the secretion of gastric juices
105
what is the mesentery
mesocolon = mesentery fold of tissue that attaches organs in abdominal cavity to body wall blood vessels, nerves, and lymphatic vessels branch through mesentery to supply organs

Human Physiology (17 decks)

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