Brainscape's Knowledge GenomeTM

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


See full index

T1 Phys > 9 The Gastrointestinal System > Flashcards

9 The Gastrointestinal System Flashcards

1
Q

What’s the aka for the gastrointestinal tract?

A

aka alimentary canal

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

What are the accessory digestive organs?

A
  • teeth
  • tongue
  • salivary glands
  • liver
  • gallbladder
  • pancreas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are teh functions of the gastrointestinal system?

A
  1. ingestion
  2. secretion
  3. mixing and propulsion
  4. digestion
  5. absorption
  6. elimination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What’s medical terminology for:

  • chewing
  • swallowing
  • vomiting
  • taste
A
  • chewing: mastication
  • swallowing: deglutition
  • vomiting: emesis
  • taste: gustation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the three major salivary glands?

A
  • parotid: inferior and anterior to the ear, between the skin and the masseter
  • submandibular glands: floor of the mouth
  • sublingual glands: beneath the tongue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The wall of the GI tract from the lower esophagus to the anal canal has the same 4 layered arrangement:

A
  • mucosa
  • submucosa
  • muscularis
  • serosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What’s the mucosa of the GI tract made of?

A

a mucous membrane consisting of:

  • epithelium
    • apithelial cells
    • exocrine cells (secrete mucous, liguid)
    • enteroendocrine cells (secrete hormone)
  • lamina propria
    • CT (areolar)
    • blood and lymphatic vessels (for absorption)
    • mucosa-associated lymphatic tissue (MALT) (for immune function/protection)
  • muscularis mucosa
    • a smooth muscle layer that creates folds in the mucosa (in some places, folds upon folds upon folds to increase surface area)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What’s the submucosa of the GI tract?

A
  • a CT layer that binds the mucosa to the muscularis layer
  • contains many blood and lymphatic vessels (for nutrient transport)
  • contains neurons of the enteric nervous system for GI control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What’s the serosa of the GI tract?

A
  • serous membrane
  • outermost layer of teh organs in teh abdominal cavity
  • aka visceral peritoneum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the layers of peritoneum, what’s its purpose, and what’s between the layers?

A
  • visceral peritoneum (aka the serosa)
  • parietal peritoneum
  • purpose: contains large folds that bind organs to one another and to the walls of the abdominal cavity
    • some organs (kidneys, ascending and descending colons, duodenum, pancrease) are covered by teh peritoneum on their anterior side only - they are called retroperitoneal
  • between the two layers is the peritoneal cavity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How long does food mix in the stomach?

A

2-4 hours

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

The soupy mix of food in the stomach is called ___

A

chyme

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

How much absorption happens in the stomach?

A

little-no absorption (water, ions, some fats, medicatinos, alcohol)

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

Once food particles are small enough in the stomach, they pass through the ___ ___ into the small intestine

A

pyloric sphincter

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

The wall of the stomach has the same 4 layered arrangement as the rest of the GI tract with some additions:

A
  1. the mucosal layer has specialized cells that secrete:
    • mucous (mucous neck cells)
    • intrinsic factor and HCl (parietal cells)
    • secretions from mucous, parietal and chief cells (Gcells not included) are collectively called gastric juice
    • pepsinogen and gastric lipase (chief cells)
    • gastrin (a hormone secreted by G cells)
      • stimulates gastric juice production
      • strengthens LES contraction
      • increases stomach peristalsis
      • relaxes the pyoloric sphincter
    • secretions from mucous, parietal and chief cells (G cells not included) are collectively called gastric juice
  2. the muscularis has an additional (oblique) layer of smooth muscle to facilitate mixing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How long and wide is the small intestine?

A

~3m long and 2.5 cm diameter

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

What are the 3 regions of the small intestine?

A
  • duodenum
  • jejunum
  • ileum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The mucosal layer of the small intestine has villi, and each villus is covered in epithelium. The cells of the epithelium are:

A
  • absorptive cells (digestion/absorption)
    • absorptive cells have microvilli (brush border)
  • goblet cells (mucous)
  • Paneth cells (kill bacteria)
  • enteroendocrine cells (secrete hormones)

Each villus has an arteriole, a venule and a lacteal (e.g. lactase – lack of these results in some degree of lactose intolerance)

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

In the small intestine, absorbed nutrients pass into:

A
  • either:
    • the blood stream (carbohydrates, proteins, water, electrolytes, water-soluble vitamins) and go to the liver
    • the lymphatics (lipids) via a lacteal
      • generally speaking, fats get delivered to lymph, everything else to blood
  • remaining food passes through the iliocecal valve/sphincter into the large intestine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where is the Pancreas located and how does it function?

A
  • sits posterior to the stomach
  • has both endocrine and exocrine functions
  • exocrine function: secretes pancreatice juice (water, salts, sodium bicarbonate, enzymes) into the duodenal lumen
  • juices are secreted into the proximal duodenum via 2 main ducts:
    • a common duct formed by the pancreatic duct joining the common bile duct from the liver/gallbladder
    • accessory duct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the liver located?

A

sits inferior to the diaphragm in the right upserior region of the abdominal cavity

(has 2 lobes: larger right and smaller left)

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

Where does the liver receive blood from?

A
  • hepatic artery - oxygenated blood
  • hepatic portal vein - deoxygenated blood containing absorbed nutrients, medications, microbes and toxins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Blood flows past hepatocytes (liver cells). What do the hepatocytes do?

A
  • absorb oxygen, nutrients and toxins
  • release nutrients (needed by other cells)
  • hepatocytes also manufacture and secrete bile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the liver function: carboydrate metabolism

A
  • helps maintain blood sugar levels
  • low blood sugar - hepatocytes break down glycogen and release glucose into the blood
  • high blood sugar - hepatocytes remove glucose from the blood and store it (as glycogen and fats)
  • can convert some amino acids, lactic acid, and other sugars into glucose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the liver function: lipid metabolism

A

hepatocytes store fat, break it down (to make ATP), and make cholesterol

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

Describe the liver function: protein metabolism

A
  • makes amino acids available for energy
  • can convert amino acids into carbs or fats
  • synthesizes most plasma proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the liver function: drug and hormone processing

A

detoxifies/inactivates substances (drugs, alcohol, hormones)

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

How is the liver generally concerned with bilirubin, vitamins and minerals, and more specifically concerned with vit D?

A
  • biliruben elimination (when, due to liver disfunction, this accumulates, it leads to yellow pigmentation – like jaundice)
  • vitamin andmineral storage
  • vitamin D activation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where’s the gallbladder located, how is it shaped and what does it do?

A
  • pear-shaped organ sitting in the posterior surface ofhte liver
  • stores and concentrates bile (helps break down fats)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What’s bile, how is it made and what’s its function?

A
  • a yellow/brown/olive liquid
  • made by hepatocytes
  • collects into larger and larger vessels
  • function: emulsification (breakdown) of fats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

From where does food enter the large intestine?

A

from the small intestine (ileum) through the ileocecal valve/sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the 4 main regions of hte large intesting?

A
  • cecum
  • colon
  • rectum
  • anal canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the functions of the large intestine?

A
  • completion of absorption
  • vitamin K production
  • formation and elimination of feces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What’s the cecum and what’s attached to it?

A
  • small pouch attached to the ileocecal valve
  • contents move from the cecum into the colon
  • attached tothe cecum is the appendix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the portions/divisions of the colon?

A
  • ascending (to the hepatic flexure)
  • transverse (to the splenic flexure)
  • descending (to the left iliac crest)
  • sigmoid (to the rectum at ~S3)

flexure = bend

36
Q

How does food move through the colon?

A
  • as food accumulates in the ascending colon, haustra fill up/distend which stimulates smooth muscle contraction and food moves into the next haustra
  • regular peristalsis occurs, but more slowly than in the small intestine
  • with each meal, mass peristalsis moves feces from the transverse colon into the rectum
37
Q

What are the divisions of the GI tract?

A
  • upper GI: mouth, pharynx, esophagus, stomach, duodenum
    • reverse movement could be vomit
  • lower GI: most of the intestines and the anus
    • no reverse at this point, diarreah if there’s need to expel quickly
38
Q

What are the 3 overlapping phases in the process of digestion?

A
  • cephalic
  • gastric
  • intestinal
39
Q

What happens in the cephalic phase of digestion?

A
  • the thought, smell, sight, initial taste of food activates the NS
  • salivary and gastric glands are stimulated to prepare the mouth and stomach for digestion
40
Q

What happens in the gastric phase of digestion?

A
  • once food reaches the stomach:
    • stretch receptors are stimulated by the change in the stomach shape
    • chemo receptors are stimulated by the change in stomach pH
  • these changes:
    • increase peristalsis and gastric juice production
    • stimulate gastrin release (g cells release gastrin)
  • small amounts of chyme pass through the pyloric sphincter into the duodenum
  • food leaving the stomach decreases the volume of the stomach and removes some of the stimulus from stretch receptors
  • food leaving the stomach allows the stomach to become more acidic
  • decreasing stretch receptor stimulation and normalizing pH removes some of the stimulus for gastrin release (stops negative feedback loop; return to homeostasis)
41
Q

What happens in the intestinal phase of digestion?

A
  • chyme in the duodenum causes enteroendocrine cells to release hormones:
    • cholecystokinin (CCK)
    • secretin
  • these hormones:
    • stimulate the gallbladder to eject bile into the duodenum (CCK)
    • secretin decrease gastric juice production (CCK/secretin)
    • slows food coming through the pyloric valve (CCK/secretin)
    • increases pancreatic juice secretion (CCK/secretin)
42
Q

Describe the endocrine system:

A
  • a system of glands and cells that secrete hormones to regulate and integrate body systems
  • a control system
  • endocrine glands: organs that secreete substances into the blood in resopnse to stimuli
  • glands work slower than nerves (seconds to hours to days)
43
Q

What’s a general description for hormones and how they work?

A
  • chemical messengers (aka mediator molecules)
  • don’t actually participate in a response, they simply activate it
  • released into the interstitial fluid which then enters the bloodstream and via the circulation, have access to body cells
  • they are released in one part of the body to regulate activity in another
44
Q

What’s a general description of hormone receptors and how they work?

A
  • to function (deliver their ‘message’), hormones must bind to receptors on the cell membranes of target cells/organs
    • must have proper lock/key match
  • when the hormone binds to the receptor, it changes the shape of the receptor
  • changing the receptor’s shape activates pathways that modify cellular functions (i.e. the ‘message’ is delivered)
  • one hormone can regulate several different body functions
  • one body function can be regulated by several different hormones
45
Q

What’s upregulation/down regulation where hormones are concerned?

A
  • the increase/decrease in target cell receptors due to a lack/excess of circulating hormone
  • this increases/decreases sensitivity to the hormone
46
Q

What are the endocrine glands?

A
  • pituitary
  • thyroid
  • parathyroid
  • adrenal
  • pineal
47
Q

What are the ‘part time’ endocrine organs?

A
  • hypothalamus
  • thymus
  • ovaries/testes
  • pancreas
  • kidneys
  • stomach and small intestine
  • heart
  • adipose tissue
  • placenta
  • liver
  • skin
48
Q

The key overlap between the nervous and endocrine systems, these 2 regulate all aspects of growth, development, metabolism and homeostasis

A

hypothalamus and pituitary

49
Q

Describe the functions of the hypothalamus

A
  • the major integrating centre between the nervous and endocrine systems
  • receives input/information from many different structures
  • controls the ANS, regulates body temperature, thirst, hunger, some emotions
  • hormonally, it regulates the synthesis and release of anterior pituitary hormones
  • neurologically, it regulates the synthesis and release of posterior pituitary hormones
50
Q

What’s the aka, location and structure of the pituitary gland?

A
  • aka the hyphophysis
  • a small gland that sits in the sella turcica (turkish saddle) of the sphenoid bone
  • has 2 lobes:
    • anterior lobe (aka adenohypophysis)
    • posterior lobe (aka neurohypophysis)
51
Q

What are the hormones released by the anterior pituitary?

A
  • human growth hormone (hGH)
  • thyroid stimulating hormone (TSH)
  • adrenocorticotropic hormone (ACTH)
  • luteinizing hormone (LH)
  • follicle stimulating hormone (FSH)
  • prolactin (PRL)
  • melanocyte stimulating hormone (MSH)
52
Q

What are the general functions of Human Growth Hormone (hGH)?

A
  • stimulates tissue growth
  • promotes healing and tissue repair
  • increasses the use of lipids for energy
  • decreases cellular uptake of glucose/elevates blood glucose levels
  • hGH is released in bursts every few hours
53
Q

What are factors that will promote the release of hGH?

A
  • hypoglycemia
  • deep sleep (stages 3 and 4 or nREM)
  • increased SyNS (e.g. vigorous exercise)
  • other hormones (glucagon, cortisol, insulin, estrogens)
54
Q

What are factors that will inhibit the release of hGH?

A
  • hyperglycemia
  • REM sleep
  • obesity
  • low levels of thyroid hormones
  • high levels of hGH in the blood (negative loop)
55
Q

What’s adrenocorticotropic hormone?

A
  • stimulates the release of cortisol from teh adrenal glands
  • release increases with stress-related stimuli (e.g. injury, hypoglycemia), macrophage activity
56
Q

What’s Luteinizing Hormone (LH)?

A
  • females: triggers ovulation
  • males: stimulates testes to release testosterone
57
Q

What’s Follicle Stimulating Hormone (FSH)?

A
  • females: triggers ovarian follicle development
  • males: triggers sperm production in the testes
58
Q

What’s Prolactin (PRL)?

A
  • initiates and maintains milk production in the mammary glands
    • just production, not necessarily release or uptake
59
Q

What hormones can be released by the posterior pituitary?

A
  • oxytocin
  • antidiuretic hormone (ADH) (aka vasopressin)
60
Q

What’s Oxytocin?

A
  • during delivery, it anhances smooth muscle contraction of the uterus
  • post-partum, it stimulates milk ejection (release of – as opposed to production)
  • part of a positive feedback loop
61
Q

Describe Antidiuretic Hormone (ADH)

A
  • decreases urine production
  • causes arteriolar vasoconstriction
62
Q

What are some factors that will promote the release of ADH?

A
  • dehydration
  • pain/stress/anxiety/trauma
  • nicotine
  • some medications
63
Q

What are some factors that will inhibit the release of ADH?

A
  • increased blood volume
  • alcohol
64
Q

Where’s the thyroid gland, what does it produce, and what controls it?

A
  • inferior to the larynx
  • produces thyroid hormones and cacitonin
  • activity is controlled by the hypothalamus-pituitary
65
Q

What do Thyroid Hormones do?

A
  • increase basal metabolic rate (base metabolic level)
  • maintain body temperature
  • stimulate protein synthesis
  • increasse the use of glucose and lipids to generate ATP
  • mobilize lipids and anhance cholesterol excretion
  • enhance the actions of norepinephrine and epinephrine (= increased HR, increased heartt contractility, increased BP)
  • with hGH and insulin, body growth accelerates
66
Q

What does Calcitonin do?

A

decreases blood calcium levels by inhibiting osteoclast activity

67
Q

What’s epinephrine?

A

adrenaline

68
Q

Where is the Parathyroid Gland and what does it do?

A
  • located on the posterior aspect of the thyroid gland
  • secrete parathyroid hormone (PTH)
  • increase blood calcium, magnesium, and phosphate levels by increasing the number and activity of osteoclasts
  • also works on the kidneys to decrease their secretion of calcium and magnesium and to promote the formation of calcitriol (active form of vit D)
69
Q

Each Adrenal Gland has an Adrenal Cortex and Adrenal Medulla. What do each release?

A

Adrenal cortex releases:

  • aldosterone
  • cortisol
  • androgens

Adrenal medulla releases:

  • epinephrine (adrenaline)
  • norepinephrine (noradrenaline)
    • both are released during stress and exercise – they increase the SyNS response)

(cortex = bark (outside); medulla is inside)

70
Q

What does Aldosterone do?

A
  • regulates sodium and potassium levels
  • helps regulate blood pressure/volume
  • helps in the elimination of H+ (acid)
  • stimulates the kidneys to reabsorb sodium and water and stimulates arteriolar smooth muscle contraction
  • released in response to dehydration, sodium deficiency, hemorrhage
71
Q

What do Androgens do?

A
  • during puberty: stimulate axillary and pubic hair growth
  • males (after puberty): weak
  • femails (after puberty): function in libido and are converted to estrogens
72
Q

What does the Pineal Gland do?

A
  • secretes melatonin to regulate sleep cycles
  • increased secretion in darkness, decreased secretion in sunlight
73
Q

What does the Thymus do?

A

hormones promote the maturation of T cells

74
Q

What do Ovaries do?

A
  • secrete estrogens and progesterone which (along with FSH and LH) regulate the menstrual cycle, maintain pregnancy and prepare the mammary glands for lactation
  • they also initiate/maintain the 2o female sex charateristics
  • with the placenta, they secrete relaxin which increases tissue/joint compliance in preparation for delivery
75
Q

What do Testes do?

A

secrete testosterone which regulates sperm production and initiates/maintains the 2o male sex characteristics

76
Q

Where is the Pancreas located?

A

located in the curve of the duodenum

77
Q

Pancreatic islets (islets of Langerhans) are the endocrine cells which secrete:

A
  • glucagon
  • insulin
  • somatostatin
78
Q

What does Glucagon do?

A
  • increases blood glucose levels
  • stimulates hepatocytes to release glucose from their stores
  • triggered by hypoglycemia, exercise
79
Q

What does insulin do?

A
  • decreases blood glucose levels
  • it stimulates:
    • body cells to take up glucose from the blood
    • hepatocytes to uptake and store glucose (as glycogen)
    • hepatocytes to slow their release of glucose
  • triggered by hyperglycemia
  • also triggered by hGH, ACTH, PaNS, some amino acids, and the GI tract
80
Q

What does Somatostatin do?

A
  • inhibits glucagon and insulin release
  • may slow GI absorption
81
Q

What hormones can the kidneys release and what do those hormones do?

A
  • erythropoietin (EPO) stimulates RBC production
  • calcitriol (active form of vidD)
82
Q

What hormones can the stomach/intestine release?

A
  • gastrin
  • CCK
  • secretin
83
Q

What hormones can the heart release and what do those hormones do?

A

atrial naturetic peptide (ANP) decresase BP

84
Q

What hormone can adipose release and what does that hormone do?

A

leptin suppresses appetite

85
Q

What hormone can the placenta release and what does that hormone do?

A

human chorionic gonadotropin (hCG) helps maintain pregnancy

86
Q

What hormone can the liver/skin release and what does that hormone do?

A

calcitriol (active form of vitD) – starts in skin, continues in liver, ends in kidneys

T1 Phys (9 decks)

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