U6 - Digestion system Flashcards

to shit

You may prefer our related Brainscape-certified flashcards:
1
Q

Difference between chemical and physical digestion?

A

physical - mechanical reduction and movement of the food molecules into absorbable units
chemical - organic polymers are broken down by hydrolytic enzymes

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

Proteins are broken down into absorbable components

A

short peptides ——> amino acids

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

Carbohydrates are broken down into absorbable components

A

disaccharide ——–> monosaccharides

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

Fats are broken down into absorbable components

A

glycerol + fatty acids

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

Nucleic acids are broken down into

A

nucleotides

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

Components of saliva

A

a. 99% water

b. also salivary amylase, an enzyme which
hydrolyses starch into maltose, and mucus

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

The process of swallowing

A
  1. tongue pushes food to the back of the
    mouth
  2. epiglottis contracts and folds down to close
    the opening to the trachea
  3. tongue pushes food further back into the
    pharynx, and food enters esophagus

4, epiglottis relaxes and opens the trachea

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

Describe peristalsis

A

rhythmic contraction of muscles

propelling food through the digestive tract

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

components of gastric juice

A

hydrochloric acid – produces a pH of about
2, breaks down food, kills most bacteria

pepsinogen – in acid becomes pepsin,
enzyme which hydrolyses protein into shorter
polypeptides

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

Sphincters at entrance at exit of stomach

A

cardiac sphincter – allows food in from
esophagus, closes to prevent acidic stomach
contents from moving back up

pyloric sphincter – opens and closes to
control movement of food into the
duodenum, first part of the small intestine

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

Functions of the liver

A
  1. production of bile – bile emulsifies fat by
    breaking it into smaller droplets, stored in
    the gall bladder until needed
  2. storage of nutrients – glycogen, fat-soluble
    vitamins, and minerals
  3. nutrient metabolism – metabolism of
    carbohydrates, proteins, and lipids
  4. detoxification of blood – drugs and toxins,
    such as alcohol, are filtered out of the blood
  5. production of blood protein – albumin
    maintains the tonicity of blood plasma
  6. removal of red blood cells – old or damaged
    RBC’s are filtered out and the haemoglobin
    in them is converted into bile pigments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why are liver and pancreas called accessory organs?

A

because they produce
digestive secretions but never touch the
food

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

How is bile involved in digestion of lipids

A

bile emulsifies fat by
breaking it into smaller droplets, stored in
the gall bladder until needed

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

Components of pancreatic juice

A

lipase – enzyme hydrolyses lipids into glycerol
and fatty acids

pancreatic amylase – enzyme hydrolyses starch
into maltose

trypsin – enzyme hydrolyses protein into shorter
polypeptides

nuclease – enzyme hydrolyses nucleic acids
(DNA and RNA) into nucleotides

sodium bicarbonate – base to neutralise the
acid from gastric juice, produces a pH around 8

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

Components of intestinal juice

A

maltase – enzyme hydrolyses maltose into
glucose

peptidase – enzyme hydrolyses short
polypeptides into amino acids

mucus – lubricates and protects the intestinal
wall

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

How is Small Intestine specialized for digestion and absorption?

A
  • secretes intestinal juice to finish chemical

digestion

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

three regions of small intestine?

A

duodenum – most chemical digestion
occurs here, receives secretions of liver
and pancreas

jejunum – longest region, most
absorption occurs here

ileum – finishes absorption

18
Q

What is a villus

A

lol

19
Q

What are microvilli

A
  • cells lining the villus are covered with many

tiny extensions

20
Q

how are monosaccharides and amino acids absorbed into the body?

A
  • these are actively transported into the cells
    lining the villus
  • they then pass by facilitated diffusion into the
    the tissue fluid, and from there diffuse into the
    villus capillaries that lead to the hepatic portal
    vein
21
Q

what happens to fatty acids and glycerol?

A

these diffuse into the cells of the villus, where
they are converted back into lipids

these are packaged into vesicles and
released via exocytosis

vesicles pass into the lacteal and are carried
through the lymphatic system to the liver

22
Q

Blood vessel that takes monosaccharide sugars and amino acids to the liver?

A

Hepatic Portal Vein

  • carries blood from the small intestine
    to the liver, where it is processed
  • portal vessels have the anatomy of a vein,
    even though they do not connect to the heart
23
Q

Large and small intestine size and length

A

Large - 1.5 m in length, but big diameter

Small - small in diameter, long in length

24
Q

Function of colon

A

the ileum of the small intestine connects to
the colon, the main part of the large intestine.
- prepares food for elimination

25
Q

Function of rectum

A
  • large intestine ends in a short, expandable
    region called the rectum
  • food that has passed through the entire
    digestive tract, now called feces, is stored
    here until it can be eliminated
26
Q

Function of appendix

A

Narrow pouch assets in maintenance of gut bacteria

27
Q

Order of organs and structures of digestive system

A

mouth-pharynx-esophagus-stomach-duodenum-ljejunum-ileum-colom-rectu-anus

28
Q

Hormone that comes from pancreas and maintains blood sugar levels?

A

in addition to digestive secretions, the
pancreas also secretes the hormone insulin

insulin is released when blood glucose levels
are high, usually after eating

insulin stimulates muscle and liver cells to
store glucose as glycogen

this causes glucose levels to decrease, an
example of negative feedback

29
Q

function of e/coli bacteria in colon?

A
  • colon is home to populations of anaerobic
    bacteria, bacteria that live without oxygen
  • the metabolism of these bacteria produces
    beneficial molecules, such as vitamins K and
    B7, as well as flatulence and the odour of
    feces
30
Q

Proteases (pepsin, trypsin)

A

Source = pepsin – stomach, trypsin - pancreas

Site of action = pepsin – stomach, trypsin –
small intestine

Optimum pH = pepsin – acidic (2), trypsin –
basic (8)

Function = protein + H2O → polypeptides

31
Q

Salivary amylase

A

Source = salivary glands

Site of action = mouth

Optimum pH = neutral (7)

Function = starch + H2O → maltose

32
Q

Lipase

A

Source = pancreas

Site of action = small intestine

Optimum pH = basic (8)

Function = lipids + H2O → glycerol + fatty acids

33
Q

Nuclease

A

Source = pancreas

Site of action = small intestine

Optimum pH = basic (8)

Function = nucleic acids + H2O → nucleotides

34
Q

Pancreatic amylase

A

Source = pancreas

Site of action = small intestine

Optimum pH = basic (8)

Function = starch + H2O → maltose

35
Q

Peptidase

A

Source = small intestine

Site of action = small intestine

Optimum pH = basic (8)

Function = polypeptides + H2O → amino acids

36
Q

Maltase

A

Source = small intestine

Site of action = small intestine

Optimum pH = basic (8)

Function = maltose + H2O → glucose + glucose

37
Q

steps of digestions

A

physical digestion: chewing, mixing, moving

chemical digestion: breaking down food
molecules into absorbable units

secretion: fluids, enzymes, hormones, bile,
mucus

absorption: through tract wall into blood or
lymph vessels

elimination: undigested material expelled

38
Q

pharynx

A
  • common passageway for air and food
    behind the mouth
  • contains the epiglottis, a muscular flap
    involved in swallowing
39
Q

esophagus

A

carries food to stomach

40
Q

trachea

A

air passage to lungs

41
Q

esophagus

A
  • long muscular tube connecting pharynx to
    stomach
  • lined by mucus secreting cells that lubricate
    the walls and assist the passage of food
42
Q

liver, pancreas placement

A

two other digestive organs are connected by
narrow ducts to the duodenum:

liver – above and beside the stomach

pancreas – between the stomach and the
intestine