Brainscape's Knowledge GenomeTM

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


See full index

Human physiology Spain > Chapter 9B > Flashcards

Chapter 9B Flashcards

1
Q

gastric phase (the end)

The pH of the stomach chyme in/decreases and the distension of
the stomach walls lessens because chyme
has passed into the small intestine,
suppressing secretion of gastric juice
(positive/negative feedback loop)

A

decreases, negative

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

HORMONAL REGULATION: gastric secre>on during the gastric phase is regulated by the
hormone X

A

gastrin

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

Gastrin is released from the X cells
of the gastric glands in response to:

  1. distension of the stomach by
    chyme
  2. partially/fully digested proteins in
    chyme
  3. low/high pH of chyme
  4. caffeine in gastric chyme
  5. acetylcholine released from
    parasympathetic/sympathetic neurons
  • Once released, gastrin enters the
    bloodstream and finally reaches its
    target organs in the digestive system
A

G cells
partially
high

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

Gastrin functions:

  1. stimulates gastric glands to
    secrete gastric juice
  2. strengthens the contraction of the
    X sphincter to
    prevent reflux of acid chyme into
    the esophagus
  3. promotes gastric emptying by
    increasing motiity of the stomach
    and relaxing the pyloric sphincter
A

lower esophageal

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

Gastrin secretion is inhibited when the
pH of gastric juice drops below/rises above 2.0 and
is stimulated when the pH decreases/rises.

A

drops below
rises

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

Intestinal phase:
* It begins once food enters the small intestine.
* In contrast to reflexes initiated during the cephalic and gastric phases, which
stimulate stomach secretory activity and motility, those occurring during the
intestinal phase have inhibitory effects that slow X

A

the exit of chyme from the
stomach. This prevents the duodenum from
being overloaded with more chyme
than it can handle.

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

These activities of the intestinal phase
of digestion are regulated by X and X mechanisms.

A

NEURAL
and HORMONAL

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

Distension of the duodenum by
the presence of chyme causes
the X reflex.

  • Stretch receptors in the
    duodenal wall send nerve
    impulses to the medulla
    oblongata, where they inhibit
    parasympathetic stimulation
    and stimulate the sympathetic
    nerves to the stomach.
  • As a result, ……..
A

enterogastric
gastric motility is inhibited and there is an
increase in the contraction of the pyloric sphincter, which decreases gastric emptying.

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

HORMONAL REGULATION: The intestinal phase of digestion is mediated by two
major hormones secreted by the small intestine:

  1. Cholecystokinin (CCK): is
    secreted by the CCK cells of
    intestinal glands in the small
    intestine in response to chyme
    containing X and X
  2. Secretin: is released from the S
    cells of the intestinal glands in
    the small intestine in response
    to X entering the
    duodenum .
A

amino acids from
partially digested proteins and
fatty acids from partially
digested triglycerides.

acidic chyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • Functions of CCK:
    1. produces hunger/satiety (acts on
    hypothalamus)
    2. slows/rapids gastric emptying by promoting
    contraction of the pyloric sphincter
    3. stimulates secretion of pancreatic
    juice (rich in digestive enzymes)
    4. promotes normal growth and
    maintenance of the pancreas
    5. contraction of the wall of the
    gallbladder (squeezes stored bile out)
    6. relaxation of hepatopancreatic
    ampulla sphincter (Oddi sphincter)
    allowing pancrea2c juice and bile to
    flow into the duodenum
    7. enhances the effects of secre2n
A

satiety
slows

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

Functions of secretin:

  1. stimulates the flow of
    X juice that is rich in
    bicarbonate (HCO3 −) ions to
    buffer the acidic chyme that
    enters the duodenum from the
    stomach
  2. inhibits secretion of X
    juice (slows production of acid
    in the stomach)
  3. promotes normal growth and
    maintenance of the pancreas
  4. enhances the effects of CCK
A

pancreatic
gastric

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

The opening from the ileum into the large intestine is guarded by a fold of mucous
membrane called the X (valve), which allows materials from the
small intestine to pass into the large intestine.

A

ileocecal sphincter

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

Structurally, the four
major regions of the
large intestine are:

Rectum
Cecum
Anal canal
Colon

put in right order

A
  1. Cecum
  2. Colon (ascending,
    transverse and
    descending)
  3. Rectum
  4. Anal canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The opening of the anal canal to the
exterior (anus), is guarded by:
* Internal anal sphincter of
smooth muscle (involuntary)
and
* External anal sphincter of
skeletal muscle (voluntary).
* These sphincters keep the anus
closed except during the elimination
of feces.

A

ok

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

Large intestine:

The epithelium contains mostly X cells (water absorption) and goblet cells
(secrete mucus that lubricates)

  • Both cells are located in long, straight, tubular intestinal glands (crypts of
    X) that extend the full thickness of the mucosa.
  • Solitary lympha>c nodules are also found.
  • Large intes>ne does not have circular folds or villi; however, microvilli are present on
    the absorp>ve cells.
A

absorptive
Lieberkühn

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

Muscularis consists of an external layer of longitudinal smooth muscle (teniae
coli) and an internal layer of circular smooth muscle.
* Tonic contractions of the bands gather the colon into a series of pouches
called X which give the colon a puckered appearance.
Small pouches of visceral peritoneum filled with fat and attached to teniae
coli are called omental (fatty) appendices

A

haustra

17
Q

The passage of chyme from the ileum into the cecum is regulated by X which is normally partially closed.
* After a meal, a gastroileal X intensifies peristalsis, opens the ileocecal valve
and forces chyme from the ileum (small intes<ne) into the cecum (large
intes<ne).
* It works with the gastrocolic reflex to s<mulate the urge to defecate
* The hormone gastrin also relaxes the sphincter.

A

ileocecal sphincter
reflex

18
Q

When substances pass the ileocecal sphincter, movements of the colon begin:

  1. Haustral churning: when walls contract, squeeze the contents into the next
    haustrum.
  2. Slow peristalsis also occurs.
  3. Mass peristalsis due to the X reflex: strong peristaltic wave that
    begins at about the middle of the transverse colon and quickly drives the
    contents of the colon into the rectum.
A

gastrocolic

19
Q

The X reflex involves
an increase in motility of the
colon in response to stretch in
the stomach and the
byproducts of digestion in the
small intestine.

  • This reflex is responsible for
    the urge to defecate following
    a meal.
A

gastrocolic

20
Q

Mucus and enzymes are secreted by the gland of the large intestine

true/false

A

false: no enzymes

21
Q

The final stage of diges(on occurs in the colon through the ac>vity of X that
inhabit the lumen: ferment any remaining carbohydrates and proteins

A

bacteria

22
Q

Large intes>ne also absorbs water (osmosis), ions (sodium and chloride), and some
bacterial products such us vitamins B and K

A

ok

23
Q

By the >me chyme has remained in the large intes>ne 3–10 hours, it has become solid
or semisolid because of water absorp>on and is now called X

A

feces

24
Q

Func>ons of the large intes>ne:

  1. Haustral churning, peristalsis, and mass peristalsis drive contents of colon into
    rectum.
  2. Bacteria in large intes>ne convert proteins to amino acids, break down amino
    acids, and produce some B vitamins and vitamin K.
  3. Absorp>on of some water, ions, and vitamins
  4. Forma>on of feces.
  5. Defeca>on (emptying rectum).
A

ok

25
Q

large intestine:

Mass peristaltic movements push fecal material into the rectum.

  • Distension s>mulates stretch receptors, which ini>ates a defeca(on reflex:
  • Receptors send sensory nerve impulses to the sacral spinal cord.
  • Motor impulses from the cord travel along parasympathe>c nerves back to the
    descending colon, sigmoid colon, rectum, and anus.
A

ok

26
Q
  • The resulting contraction of the
    longitudinal rectal muscles shortens
    the rectum, thereby increasing the
    pressure within it.
  • This pressure, along with voluntary
    contractions of the diaphragm and
    abdominal muscles, plus
    parasympathetic stimulation, opens
    the internal anal sphincter.
  • If the anus is voluntarily constricted,
    defecation can be postponed.
A

ok

Human physiology Spain (23 decks)

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