Brainscape's Knowledge GenomeTM

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


See full index

Human Bio 2021 > CH 6 The Digestive System > Flashcards

CH 6 The Digestive System Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is active transport?

A

The use of energy to move substances, usually ions, across a cell membrane

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

What is the alimentary canal?

A

The tube via which food passes through the body, consisting of the mouth, oesophagus, stomach and intestines

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

What is bile?

A

A secretion of the liver, stored in the gall bladder and released into the small intestine

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

What are bile salts?

A

Substances that breakdown fats into tiny droplets

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

What is a bolus?

A

A ball-like structure of food and saliva

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

What is a canine?

A

The pointed tooth between the incisors and premolars

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

What is chemical digestion?

A

The breakdown of food to small molecules by chemicals

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

What is chyme?

A

The semifluid mass of partially digested food that leaves the stomach

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

What is a circular muscle?

A

Smooth muscle with fibres arranged in a circle around an organ
eg. the stomach

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

What is coeliac disease?

A

An autoimmune disease due to the immune system reacting to gluten

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

What is colorectal cancer?

A

Cancer in the colon and rectum (bowel cancer)

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

What is constipation?

A

A condition in which defection is difficult, with faeces being hard and dry

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

What is deoxyribonuclease?

A

An enzyme in pancreatic juice that digests DNA

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

What is diarrhoea?

A

The frequent passing of watery faeces

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

What is digestion?

A

The mechanical breakdown of food to small molecules that can be absorbed

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

What is the digestive system?

A

The system that breaks down the food taken in the body ready for absorption into the body

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

What is elimination?

A

Removal of indigestible material, bacteria and bile pigments from the body

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

What does emulsify mean?

A

To mix two liquids that would not normally mix

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

What is faeces?

A

Material passed out of the rectum

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

What is the gastric gland?

A

The secretory unit of the stomach located in gastric pits, produces gastric juice

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

What is gastric juice?

A

The digestive juice secreted by the glands of the stomach

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

What is an incisor?

A

The narrow-edged tooth at the front of the mouth, use for cutting

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

What is ingestion?

A

The intake of food, liquids or drugs into the mouth

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

What is intestinal juice?

A

The digestive juice secreted by the glands of the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is lacteal?

A

A lymph capillary in the small intestine; absorbs fat from digested food

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

What is the large intestine?

A

The part of the intestine between the small intestine and the anus; it is made up of the caecum, colon and rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is a longitudinal muscle?

A

Smooth muscle with fibres arranged length wise along an organ

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

What is mastication?

A

The process of chewing; to grind or crush food with teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is mechanical digestion?

A

The mechanical breakdown of food into small particles

30
Q

What is microvilli?

A

Microscopic projections from the membranes of cells lining the small intestine; they increase the surface area for absorption

31
Q

What is a molar?

A

A grinding tooth at the back of the mouth

32
Q

What is mucosa?

A

A mucous membrane in particular the mucous membrane that forms the internal lining of the alimentary canal

33
Q

What is the oesophagus?

A

The tube that carries food from the throat to the stomach

34
Q

What is pancreatic amylase?

A

An enzyme in pancreatic juice that breaks down starch

35
Q

What is pancreatic juice?

A

The liquid secreted by the pancreas

36
Q

What is pancreatic lipase?

A

An enzyme in pancreatic juice that breaks down fats

37
Q

What is peristalsis?

A

Waves of muscular contraction that push food along the alimentary canal

38
Q

What is the pharynx?

A

The throat; the pharynx joins the mouth cavity to the oesophagus and larynx

39
Q

What is a premolar?

A

The teeth between the canine and molars

40
Q

What is the pyloric sphincter?

A

A ring of smooth muscle between the stomach and the duodenum

41
Q

What is ribonuclease?

A

An enzyme in pancreatic juice that digests RNA

42
Q

What is saliva?

A

A fluid secreted into the mouth by salivary glands to begin digestion of food

43
Q

What is the salivary gland?

A

Gland in the mouth that secretes saliva

44
Q

What is segmentation?

A

A process occurring in the small intestine which uses the contraction of circular muscles to push the chyme into segments, mixing it with digestive juices

45
Q

What is the small intestine?

A

The longest part of the alimentary canal; receives material from the stomach

46
Q

What is the stomach?

A

A muscular organ the receives food from the oesophagus and mixes it with acid and enzymes to form chyme

47
Q

What is trypsin?

A

An enzyme in pancreatic juice that breaks down protein

48
Q

What is villi?

A

Projections from the internal lining of the small intestine

49
Q

What do carbohydrates, proteins and fats breakdown to?

A

Carbohydrates- simple sugars
Proteins- amino acids
Fats- fatty acids and glycerol

50
Q

What processes does mechanical digestion do in the mouth, stomach and small intestine?

A

Mouth- the teeth cut, tear and grind the food
Stomach- churning action in the stomach breaks down the food further
Small intestine- gall bladder releases bile into the small intestine> bile salts act as emulsifying agents, breaking down fat into smaller droplets

51
Q

Explain the mouth:

A
  • Ingestion of food occurs at the mouth
  • the food is chewed (mastication)
  • chemical and mechanical digestion commences before the food is swallowed
    >Saliva (chemical)
  • mucous to lubricate
  • salivary amylase to commence the chemical digestion of starch into maltose
    >Teeth (mechanical)
  • 4 incisors for biting and cutting
  • 2 canines for tearing
  • 4 premolars for for crushing and grinding
  • 6 molars for crushing and grinding
52
Q

Explain the oesophagus:

A
  • a bolus from the mouth and the pharynx goes into the oesophagus
  • double muscle layer, contains circular and longitudinal muscle
  • then peristalsis occurs to move the bolus downwards assisted with mucous that lubricates the inner lining
53
Q

Explain the stomach:

A
  • mechanical digestion in the stomach is achieved by waves of contractions along the stomach wall
  • chemical digestion is achieved through the secretion of enzymes in the stomach
  • the stomach has a third muscle layer called the obliques muscle layer which allows the stomach to contract in a variety of waves to churn the food and mix it with the stomach juices until the food is converted to a thick mixture called chyme
  • the lining of the stomach (the mucosa) is specialised for the secretion of gastric juice by gastric glands
  • the acidic environment allows the enzyme pepsinogen to convert to pepsin (active form) and also breaks down DNA and RNA
  • alcohol and some drugs are absorbed in the stomach but not nutrients as there is a thick layer of mucous
54
Q

Explain gastric juice:

A
  • contains HCL, mucous and digestive enzymes
  • responsible for chemical digestion in the stomach
  • pH is approximately 2-3 due to the hydrochloric acid
55
Q

Explain the pyloric sphincter:

A
  • the lower end of the stomach there is a thickening of the circular muscle which results in a constriction
  • the constriction is to prevent the stomach contents moving through
56
Q

Explain the small intestine?

A
  • 6-7m in length
  • receives material from the pyloric sphincter
  • mechanical digestion continues through segmentation
  • contractions help break up the bolus and mix it with juices and bile
  • chemical digestion occurs under the influence of pancreatic juice, bile and intestinal juice
57
Q

What are the 3 regions of the small intestine?

A
  1. Duodenum- mostly chemical digestion occurs
  2. Jejunum- lining allows effective absorption of carbohydrates and proteins
  3. Ileum- vitamin B12, bile salts and any remaining products of digestion are absorbed
58
Q

What are the components of pancreatic juice?

A

Pancreatic amylase- breaks down starch to maltose
Pancreatic protease- splits proteins into peptides
Pancreatic lipase- breaks down fats to fatty acids and glycerol
Deoxyribonuclease/Ribonuclease- enzymes that digest RNA and DNA

59
Q

Explain bile:

A
  • secreted into the duodenum through the common bile duct
  • contains bile salts that act like detergent and emulsifies fats into tiny droplets
  • mechanical digestion as it increases surface area
60
Q

Explain intestinal juice:

A
  • contains enzymes that complete the breakdown of proteins, carbohydrates and lipids
    >Peptidase- breaks down peptides into amino acids
    >Sucrase, lactase and maltase> breaks these down into glucose, fructose and galactose
    >Lipases- break down lipids into fatty acids and glycerol
61
Q

How is a large surface area required In the system?

A
  • small intestine is very long 6-7m
  • the mucosa (inner lining) has folds extending into the interior of the small intestine
  • the mucosa has small, finger like projections called villi that extend from the folded surface
  • the cells covering the outside of the villi have tiny microscopic projections from their external surface called microvilli
62
Q

Explain villi and their function:

A
  • the structure of villi is suited to its function of nutrient absorption
  • each villus is 1mm long and is covered with a layer of cells
  • in the villus is a lymph capillary called a lacteal which is surrounded by.a network of blood capillaries
63
Q

What happens to different nutrients in the small intestine?

A
  • fatty acids, glycerol and fat soluble vitamins goes into the lacteal
  • everything else gets absorbed into the blood
  • water and water soluble vitamins are absorbed by diffusion
64
Q

Explain the large intestine?

A
  • 1.5 m long
  • made up of the caecum, colon, rectum and anus
  • no villi or digestive juices are secreted but a large amount of mucous is
  • movement is slow taking 18-24 hours
  • water becomes absorbed so the contents get more solid
  • bacteria breaks down most of the remaining organic compounds
  • the semi solid material left makes up the faeces
65
Q

Describe what faeces is:

A
  • contains water, undigested food material, bacteria, bile pigments and the remains of cells that have broken from the internal lining of the alimentary canal
  • Passes through the rectum and anus to the exterior of the body
  • this is “defamation” which is best described as “elimination”
66
Q

Explain the effect of diet on the alimentary canal:

A
  • size and contents of a meal effect how fast it moves through the alimentary canal
    Size> the greater the size, the greater the stretch of the stomach which pushes material to the small intestine faster
    Contents>
  • high protein/fat content slows movement from the stomach to the small intestine
  • alcohol and caffeine stimulate the movement
67
Q

Explain constipation:

A
  • when the movement of the large intestine is reduced and the contents remain there for a long time
  • water is absorbed and faeces becomes drier and harder
68
Q

What are the causes of constipation?

A
  • caused by lack of roughage in the diet which contains cellulose (insoluble fibre and component of plant foods)
  • lack of exercise
  • emotional problems
69
Q

Explain diarrhoea:

A
  • frequent defecation of watery faeces
    -caused by the irritation of the small or large intestine
    >Irritation may be caused by
  • a bacteria
  • a virus
  • a parasite
  • cancer such as bowel cancer
  • coeliac disease
  • lactose intolerence
70
Q

What is the importance of soluble fibre in a diet?

A
  • linked to lower cholesterol levels in the blood, decreased risk of heart disease and cancer and beneficial effects on blood glucose levels
  • fats are trapped by soluble fibre preventing their absorption by the body
  • good sources of soluble fibres is fruit, vegetables, oat bran, barley and soy products
71
Q

Explain bowel cancer:

A
  • uncontrolled growth of cells in the wall of the large intestine
  • may be linked to diet, high alcohol consumption or smoking
  • a diet high in red and processed meat and low in fibre (fruit and veg) may increase the risk as well as being overweight
72
Q

Explain coeliac disease:

A
  • unable to tolerate a protein called gluten (found in wheat, rye and barley)
  • if it is ingested their immune system responds by damaging or destroying their villi therefore cannot absorb nutrients and person becomes malnourished
    >Symptoms vary but include:
  • muscle cramps
  • joint pain or tingling in legs
    >Treatment
  • having a gluten free diet
  • inherited and no cure

Human Bio 2021 (8 decks)

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