Chapter 22 Digestive Flashcards Preview

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Flashcards in Chapter 22 Digestive Deck (66)
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1
Q

crushing, grinding, shearing to increase surface area and to mix with enzymes

A

mechanical processing

2
Q

chemical breakdown of food using digestive enzymes

A

digestion

3
Q

water, acids, enzymes, buffers, salts

A

secretions

4
Q

– inner lining of the GI tract with lots of mucus and some areolar CT.

The epithelium of theis varies from simple columnar to stratified squamous.

The lining of the GI tract is folded to increase surface area.

A

Mucosa

5
Q

Layers are present throughout the tube – some differences
-mucosa: innermost lining
-Epithelium, some connective tissue, mucosa production
-Epithelium: hollow tube so it lines it
-Mouth – stratified (many layers)
-Further down when absorbing nutrients is simple
-Mucous secretions: role in GI tract – lubrication and protection stomach from hydrochloric acid
-Alcohol thins mucous lining
Muscle: smooth muscle –
-surface area is key for absorbing things
-Submucosa: lots of connective tissue, blood supply and lots of vessels including lymphatic vessel, and nerves - parasympathetic
-Responsible for secretion: the sympathetic wi

A

organization of digestive tract

6
Q

composed of dense irregular CT

contains blood vessels and lymphatics

A

submucosa

7
Q

sensory nerves, parasympathetic, sympathetic

A

submucosal plexus

8
Q

smooth muscle arranged in two layers.

Circular and longitudinal layers of muscle.

Plays an important role in mechanical processing.

A

muscularis externa

9
Q

sympathetic, parasympathetic supply to the muscle.

control motility and movement

A

myenteric plexus

10
Q

help us move food through system – like squeezing toothpaste through almost empty tube

A

circular layer of digestive tract and muscularis externa

11
Q

shorten tubes and distance it needs to travel

A

longitudinal layer and muscularis externa

12
Q

visceral peritoneum

This is the general organization of the GI tract regardless of location.

outermost layer of stomach
keeps everything in place, especially blood supply *
forms sheets of CT to hold vasculature in place

A

serosa

13
Q

waves of muscular contraction to propel food through the GI tract.

In addition there are segmental and mixing contractions.

Smooth muscle = involuntar

A

peristalsis

14
Q

this system works mostly by reflexes called myenteric reflexes.

The presence of substance triggers mixing and secretion.

A

neural mechanisms

15
Q

digestive hormones affect digestion and movement

local mechanisms - pH

A

hormonal mechanisms

16
Q

Stratified squamous epithelium.

Tongue – contains glands that secrete mucins, lingual lipase.

A

oral cavity

17
Q

Opening in diaphragm

A

esophageal hiatus

18
Q

is voluntary but has a subconscious component.

A

deglutition

19
Q

the pushing of the bolus posteriorly and initiation of reflexes.
Chewing of food and pushing to back of mouth to swallow

A

buccal phase

20
Q

swallowing reflex. Pharyngeal muscles contract and elevate the larynx. This moves the epiglottis and soft palate.
After you made a decision to swallow, all the structures rise and the epiglottis covers trachea and soft palate closes nasal cavity

A

pharyngeal phase

21
Q

bolus is pushed to the stomach by peristalsis

moves food down to stomach

A

esophageal phase

22
Q

GI organs have a lining similar to visceral and parietal pericardium

A

visceral and parietal peritoneum

23
Q

consist of Areolar CT and provide a route for vasculature, lymphatics, as well as provide stability to the organs.

A

mesenteries

24
Q

Storage of food
Mechanical breakdown of food
Chemical breakdown of food
Production of intrinsic factor

A

stomach has 4 functions

25
Q

mucus producing glands

A

cardia of stomach

26
Q

gastric glands, acid, enzymes

A

body of stomach

27
Q

hormones and mucus of stomach

A

pyloris

28
Q

folds of stomach

A

rugae

29
Q

curved stop of stomach - rubs on diaphragm

A

fundus

30
Q

contain secretory cells. Lifespan in this environment is only about three days.

A

gastric pits of stomach

31
Q

HCl and intrinsic factor for B12 absorption

A

parietal cells of stomach

32
Q

HCl is not made in the cell. H+ and Cl- are pumped into the stomach where they combine. HCl has several functions.

Acidity kills most microorganisms
Acidity denature proteins
Acidity breaks down cell walls and CT
Converts pepsinogen to pepsin

A

stomach

33
Q

is a proteolytic enzyme.

Gastrin promotes mixing and secretion by the stomach.

A

pepsin of stomach

34
Q

protein digesting enzyme but when its secreted, its inactive

is converted by hydrochloric acid to pepsin (denatured)

A

pepsinogen

35
Q

importance in SI is lipid digestion
lipids are still too large to be absorbed in venous system even after breakdown.
one exception: fatty acids are too big to get into the vein so they need to get into lacteal (lympatic vessel) – goes to subclavian – from there blood goes to supior vena cava and to the heart

A

Lacteal

36
Q

where we have specialized cells for secretions – enteropeptidase, mucus, CCK, gastrin, secretin
gastrin: for secretion and motility
CCK: cholecystickinin – cells of small IN are responsible for contracting of gall bladder
secretin: stimulates pancreas

A

Intestinal Crypts

37
Q

10 inches long receives chyme from the stomach and continues digestion with secretions from the pancreas and liver.
digestion primarily occurs here

A

Doudenum - small intestine

38
Q

digestion is completed here and absorption of nutreitns begins

A

small intestine

39
Q

8 feet long nutrient absorption occurs here.
primarily absorption occurs
when you absorb things, you use every possible absorption methods possible (diffusion, etc.)

Absorb nutrients

A

jejnum

40
Q

11 feet long
absorption continues
continues to absorb but by the time food gets here, the nutrients are gone – so now ileum starts removing water from it

largest and are done absorbing nutrients at this time – it pulls out water

A

ileum

41
Q

presence of food stretches the walls of the stomach activating the ENS which stimulates secretion and mixing.

A

gastric phase

42
Q

phases of digestion

A
  1. Cephalic
  2. Gastric
    3 Intestinal
43
Q

chyme begins to enter the small intestine. This relaxes some of the distension which will slow the stomach.

A

intestinal phase

44
Q

same as CCK but also stimulates the pancreas to produce bicarbonate.

A

secretin

45
Q

cholecystokinin inhibits secretion from the stomach and slows mixing.

A

CCK

46
Q

CNS stimulation

head so sight, smell and taste of food
not a lot of secretion or intense digestion activity

A

Cephalic phase

47
Q

presence of food stretches the walls of the stomach activating the ENS which stimulates secretion and mixing.
lasts as long as 4 hours

once food has entered, it stretches wall and stimulates secretions
more powerful – confirms presence of food in GI tract

A

gastric phase

48
Q

The stomach is a strictly a digestive organ. No nutrients are absorbed because of the thick mucus barrier and lack of transport mechanisms. Two exceptions are:
Alcohol – alcohol is lipid soluble and penetrates cell membranes easily.
Aspirin is lipid soluble as well and interferes with the properties of mucus therefore exposing epithelium to HCl.

A

Digestion and absorption in stomach

49
Q

responsible for mixing and secretion in the stomach

A

function of gastrin

50
Q

secrete bicarbonate

we need bicarbonate from pancreas to neutralize HCL coming in from stomach

A

function of secretin

51
Q

contraction of gall bladder and promotes enzyme secretion from pancreas

A

CCK

52
Q

2 hormones in pancreas

A

secretin tells pancreas we need bicarbonate and CCK tells we need enzymes

53
Q

liquidly things, turns pepsinogen to pepsin and helps break apart cell walls from plant base materials that we consume

A

HCL

54
Q

When ileum pushes contents into Ileum sphytner
relax to allow products from SI to enter LI and not go backwards
stuff in LI is considered waste/feces

A

Ileosecal valve

55
Q

ALL NUTRIENTS WE ABSORB GO TO LIVER FIRST AND OUR LIVER DECIDES WHAT TO DO WITH IT*****8
ONE EXEPTION TO THIS: LIPIDS ARE TOO LARGE TO GET INTO VENOUS CAPILLARIES SO FATTY ACIDS GO THROUGH LYMPATIC DRAINAGE – GOES THROUGH LACTYL

A

ok

56
Q

Taenia coli: 3 small bands of smooth muscle is located here and it runs length of LI and it coils up
Haustra: individual segments we see in LI

A

first part of LI: Cecum

57
Q

Reabsorption of water and some vitamins

Production of Vitamin K by bacteria

Production of biotin by bacteria

Production of vitamin B5 by bacteria

A

physiology of Large Intestine

58
Q

made up of mostly water and mucus to lubricate things in order to swallow it – also has electrolytes, antibodies and enzymes like amylase (carbohydrate digesting enzymes – helps taste sweet things easily)
purpose: lubricate, dissolve compounds for taste, and digestion of carbohydrates
So when we ingest food, carbohydrate production begins in mouth and then salivary amylase is denatured by HCL (because saliva is basic and HCL is acidic)

A

Saliva

59
Q

Largest organ and most versatile. Found in the right upper quadrant.

Four lobes

A

Liver

60
Q

When all nutrients come in they come in through the corners of the lobules and then slowly goes towards central veins – reason why: all the cells (hepatocytes – liver cells) take nutrients and do what is needed and carry out those function and the blood that gets passed that and goes to central veins go into circulation

A

central vein of liver

61
Q

fixed macrophages – WBC capable of phagocytosis that reside in liver so any debris that come in or any RBC that need recycled, you have some ability to engulf those through phagocytosis

A

kupffer cells

62
Q

Liver takes parts of RBC and makes bile – once its made by liver you have an organ that stores it

stimulated by CCK and contracts it

A

gall gladder

63
Q

Right and left hepatic ducts merge to become the common hepatic duct.

The cystic duct extends from the gall bladder.

The cystic duct merges with the common hepatic duct to form the common bile duct.

Common bile duct merges with the pancreatic duct and enters the small intestine.

A

bile duct system

64
Q

Cyctic duct, common hepatic and common bile
Common bile duct: goes behind stomach/pancreas and enters duadum

Can we digest lipids without gall bladder? YES – problem, the bile wont have a space to store lots of it

A

know these

65
Q

Antigen presentation by Kupffer cells

Synthesis of plasma proteins

Removal of circulating hormones

Removal or storage of toxins

Production of bile for emulsification of lipids

A

physiology of liver

66
Q

retroperitoneal organ that lies posterior to the stomach.

It is connected to the duodenum through ducts

The pancreatic duct merges with the common bile duct and enters the duodenum through the papilla.

A

pancreas