Bio - 7.1, 7.2, 7.3, 7.4, 7.5 Flashcards
1
Q
importance of food
A
- for growth
- source of energy
- for replacement of worn and damaged tissues
2
Q
balanced diet
A
- contains the right amount of carbohydrates, protein and fats in a single serving
3
Q
digestive system - process
A
mouth => esophagus => stomach => duodenum => ileum => colon => rectum => anus
4
Q
main stages of digestion
A
- ingestion
- digestion
- absorption
- assimilation
- egestion
5
Q
ingestion
A
taking of substances into the body
6
Q
digestion
A
breakdown of food
7
Q
absorption
A
the movement of nutrient from the intestines into the blood
8
Q
assimilation
A
uptake and use of nutrients by cells
9
Q
egestion
A
the removal of undigested food from the body as feces
10
Q
physical digestion
A
- breakdown of food into smaller pieces
- no chemical change to food molecules
- increases surface area (quicker chemical digestion)
eg. chewing, bile
11
Q
chemical digestion
A
- breakdown of large insoluble molecules into small soluble molecules
- produces molecules absorbed
eg. enzymes
12
Q
mouth
A
- saliva = breaks down starch, moistens food
- teeth = cut food into smaller pieces
13
Q
esophagus
A
- moves food to the stomach
14
Q
stomach
A
- mixes food with enzymes and acids
- pH 1-2
- contains HCl acid to kill microorganisms
15
Q
duodenum
A
- first part of small intestine
- receives bile and enzymes
- neutralizes and absorption
- villi and microvilli
16
Q
ileum
A
- final part of the small intestine
- absorption of remaining nutrients
- villi and microvilli for absorption (longer than duodenum for maximised ROR)
17
Q
small intestine
A
- absorb nutrients and water into blood stream
- duodenum & ileum
18
Q
large intestine
A
- absorb water & recycle it
19
Q
rectum
A
- stores feces
20
Q
anus
A
- exit for feces
21
Q
liver
A
- filters blood
- produces bile to break down fats
22
Q
gall bladder
A
- stores bile
23
Q
pancreas
A
- make enzymes to break down foods
24
Q
crown - teeth
A
- enamel
- dentine
25
root - teeth
- gum
- pulp cavity
- fibers
- jaw bone
- blood supply to the tooth
26
enamel
- very hard covering
- contains calcium
27
dentine
- layer containing living cells
- not as hard as enamel
28
gums
- recedes with age
29
pulp cavity
- contains blood vessels and nerves
30
fibers
- help to hold tooth in the jaw bone
31
tooth decay - process
particles of foods get trapped in cracks of teeth => bacteria feeds on the sugar form acids => dissolves hole in enamel and dentine => nerves affected => tooth pain => infection can spread quick => can form abscess at the root of the tooth
32
dental decay
- bacteria + saliva = formed plaque
- plaque can harden and become tartar
33
gum disease
- plaque can cause infections
- gums will swell and bleed
- bacteria may infect the root = loose teeth
34
4 different teeth
1. incisors
2. canines
3. premolars
4. molars
35
incisors
- cut food into smaller bits
36
canine
- used to pierce and tear food
37
premolar
- used to crush food
38
molar
- used to grind and crush food
39
alimentary canal
- long continuous tube where food physically travels
- starts from mouth ends at anus
- doesn't include accessory organs (liver, pancreas, gallbladder)
40
peristalsis movement - meaning
- wave-like muscle contraction
- occurs in the walls of the alimentary canal
41
bile
- alkaline substance
- produced by liver
- stored in gallbladder
- emulsifies fats in small intestines
42
emulsification
- process of breaking down large fat droplets into smaller droplets to increase surface area
- critical for fat digestion
43
assimilation in LIVER
1. nutrients are absorbed through the villi
2. blood capillaries merges to form the Hepatic Portal Vein
3. transports glucose & amino acid to the liver
4. liver converts excess glucose into glycogen and stores it in the gall bladder
44
villus - features (3)
- thin epithelium
- lacteal
- blood capillary
45
thin epithelium
- one cell thick (increase diffusion)
46
lacteal
- absorbs fatty acids and glycerol
47
blood capillary
- absorb glucose and amino acids
48
intestinal villi
- increase surface area for small intestine
- contain absorptive and goblet cells and lamina propria
49
microvilli
- has a brush border
- further increase the surface area
- contains enzyme
50
absorptive cells
- absorbing nutrients
51
goblet cells
- produce mucus
- protect and lubricate the lining of the intestine
52
lamina propria
- a layer beneath the epithelium
- contains blood vessels and lymphatic vessels
- transport absorb nutrient to the rest of the body
