Animal Nutrition and Human Digestion Flashcards
(119 cards)
1
Q
What do animals need to live?
A
food, oxygen, water
2
Q
How to animals make energy?
A
using food and oxygen
3
Q
How to animals build bodies?
A
using food for raw material (amino acids, sugars, fats, nucleotides) and ATP for energy synthesis.
4
Q
What are the 4 ways animals get their food?
A
fliter feeding, living in the food, fluid feeding, and bulk feeding
5
Q
What are the 3 animal diets?
A
heribivores, carnivoes, omnivores
6
Q
What is an herbivore?
A
an animals that eats mainly plants
7
Q
What are examples of herbivores?
A
gorillas, cows, rabbits, snails
8
Q
Whst is a carnivore?
A
an animal that eats only other animals
9
Q
What are examples of carnivores?
A
sharks, hawks, spiders, snakes
10
Q
What are omnivores?
A
animals that eat both animals and plants
11
Q
What are examples of omnivores?
A
cockroaches, bears, racoons, humans
12
Q
What are the 4 main steps in getting and using food?
A
- Injest
- Digest
- absorb
- Eliminate
13
Q
What is injesting?
A
taking in food
14
Q
What are the two steps within digestion?
A
mecahnical digestion and chemical digestion
15
Q
What is mechanical digestion?
A
breaking up food into smaller pieces?
16
Q
What is chemical digestion?
A
breaking down food into molecules small enough to be absorbed into cells. Involves enzymes
17
Q
What is absorption in digestion?
A
absorb nutrients accross cell membranes. Involves diffusion and active transport
18
Q
What is elimination in digestion?
A
when undigested material passes out by body
19
Q
What is the function of the mouth?
A
mechanical digestion using teeth and chemical digestion using saliva
20
Q
What are the components of saliva?
A
amylase enzyme, mucus, buffers, and antibacterial chemicals
21
Q
What is an amylase enzyme?
A
and enzyme that digests starch
22
Q
What does the mucus in saliva do?
A
- protect soft lining for the digestive system and it lubricates food for easier swallowing
23
Q
What do the buffers in saliva do?
A
they neutralize acid to prevent tooth decay
24
Q
What do the anti-baterial chemicals in saliva do?
A
they kill bacteria that enter the mouth with food
25
What are the 4 types of teeth?
Canine, Molars, Premolard, and Incisors
26
What is the purpose of canine teeth?
tearing
27
What is the purpose of molars?
grinding
28
What is the purpose of premolars?
tearing and grinding
29
What is the purpose of incisors?
cutting
30
What does the uvula do?
It secretes a large amount of saliva and prevents food from coming up once swallowed.
31
What are the 3 kinds of salivary glands?
- sublingual gland
- parotid gland
- submandibular gland
32
What is the tongue covered by?
papillae
33
What are papillae/?
Thy are small projections. Most of them house taste buds
34
What are taste buds?
receptors that send messages to the brain
35
What is a food bolus
It is a lump of chewed food that goes on into the next part of the digestive tract
36
What is a pharynx?
The part of the digestive system and connects the oral cavity to the esophagus. It is a shared passageway with respiratory system.
37
What is the epiglottis?
a flap of cartilage that closes the trachea when swallowing. It makes food go down the esophagus and prevents food from entering the respiratory system.
38
What is the trachea?
The windpipe
39
What is the esophagus made of and what does it do?
It is two layers of muscle circular and longitudinal. It moves food from the pharynx to the stomach.
40
peristalsis definition
involuntary muscle contractions which forms waves that move the food bolus along the digestive tract. It prevents the backward flow of food
41
What is the inside of the esophagus lubricated with?
mucous membranes
42
What do the circular muscles do?
They contract and narrow the passage behind the bolus and push it forward
43
What do the longitudinal muscles do?
the contract ahead of the bolus, causing the tube to shorten and slide the bolus
44
What are the two types of muscles in the esophagus?
circular muscles and longitudinal muscles
45
What is the upper esophageal sphincter (UES)?
skeletal muscles triggered by a swallowing reflex and the top of the tube. prevents against reflux of food and food from entering the respiratory system and air into the digestive tract.
46
What is the lower esophageal sphincter (LES) also known as?
the cardiac sphinter
47
Where the LES?
end of the rube leasing to the stomach
48
What does the lower esophageal sphincter do?
it prevents stomach contents from going back into esophagus and manages acid reflux. It is under autonomic control
49
What is reflux?
somach contents in reverse flow. Acid from the stomach enters the lower esophagus.
50
When does reflux often occur?
because the LES doesn't close properly
51
GERD stands for...
Gastroesophageal reflux disease
52
What happens if GERD occurs frequently?
it can damage the esophagus
53
What are treatments for acid reflux?
- lifestyle and dietary changes
- use antacids to neutralize acid in the stomach and esophagus
- use medications to reduce the amount of acid secreted into the stomach
- surgery to tighten esophageal sphincter (only in serious cases)
54
What is vomiting?
expulsion of stomach contents through esophagus and mouth. It is a protective mechanism for removing toxin or foreign substances from the body
55
vomitus
liquid contents being expelled
56
What is the mecahnism of vomiting?
1. relaxation of the LES
2. contraction in small intestine and stomach to move contents into the esophagus
3. contraction of diaphragm and abdominal walls squeeze stomach
4. results in expulsion of contents up the esophagus and out through the mouth
5. epiglottis closes entrance to trachea as breathing stops
57
What does the stomach do?
- disinfects food
- food storage
- digests proteins
58
How does the stomach disinfect food?
It contains hydrochloric acid with a pH of 2 that kills bacteria
59
How much food can the stomach fit?
1.5L
60
What enzyme digests protein?
pepsin enzyme
61
If the stomach is made out of protein, what stops the stomach from digesting itself?
mucus secreted by stomach cells protects stomach lining
62
Which muscles control the amount of food that enters and exit the stomach?
- lower esophageal sphincter (enter)
- pyloric sphincter (exit)
63
What is the shape of the stomach?
J shape
64
What kind of muscles are in the stomach?
smooth muscles
65
What are the 3 types of smooth muscles in the stomach?
oblique, circular, longitudinal
66
What folds in the stomach lining to provide elasticity allowing the stomach to expand when the bolus enters it?
rugae
67
Hw many tissue layers are in the stomach?
4
68
What are the 4 tissue layers in the stoach IN ORDER?
mucos, submucosa, muscularis, serosa
69
What is the mucosa layer in the stomach?
it is the innermost layer that is extensively folded. It secretes gastric juice.
70
What is the submucosa layer in the stomach?
layer of connective tissue contains nerves and blood vessels
71
What is the muscularis layer in the stomach
smooth muscle
72
What does the serosa layer in the stomach do?
it holds the stomach in place
73
What is the mechanical digestion in the stomach?
Nerve endings detect stretching of the stomach lining that occurs when food enters which causes a release of signals to cause an increase in muscular contractions which mixes food with gastric juice
74
What are the 3 gastric juice components?
Hydrochloric acid, inactive enzyme pepsinogen, and mucus
75
What does the hydrochloric acid (HCl) do?
- destroys microbes
- deactivates amylase
- chemically breaks down food
- it has a pH of approximately 2
76
What happens to the inactive enzyme popsinogen?
It gets activated by the low pH and turned into pepsin. It breaks down protein into amino acids
77
What does the mucus in gastric juice do?
It protects the stomach from the low pH
78
What is released into the blood stream to be transported to gastric cells in the stomach?
gastrin
79
What does gastrin do?
it stimulates the release of gastric juice by gastric glands.
80
What does gastric juice do?
it contributes to chemical digestion of food
81
What is chyme?
When the food bolus forms a half liquid - half solid of partially digested food and gastric juice
82
What is an ulcer?
an open sore on the stomach with damage to all layers of the stomach that causes bleeding and pain. It happens when acid burns through the stomach lining in an area that doesn't have enough mucus
83
What are ulcers caused by?
bacterial infection of stomach like H. pylori
84
How are ulcers cured?
antibiotics
85
What does the pyloric sphincter do?
it controls the amount of chyme released into the small intestine. It releases 1 chyme at a time
86
How does the pyloric sphincter release chyme and why?
It releases the chyme slow and steady in small proteins of time. It prevents overloading the small intestine and allows time for digestion
87
What are the functions of the small intestine?
- digestion (in the 1st section)
- absorption (in the 2nd and 3rd section)
88
What kind of digestiong occurs in the small intestine?
The digestion of carbohydrates, proteins and lipids.
89
What enzyme digests the carbohydrates?
amylase from the pancreas
90
what enzyme digests the proteins?
trypsin & chrymotrypsin from pancreas
91
what component of the stomach digests the lipids
bile from liver and lipase enzyme from pancreas
92
What is the absorption that occurs in the small intestine?
nutrients move into body cells by diffusion and active transport
93
What are the dimensions of the small intestine?
7m long
2.5 cm in diameter
94
What is the small intestine lined with?
longitudinal and circular muscles
95
What moves food along the small intestine?
peristalsis
96
What is peristalsis?
the involuntary contraction and relaxation of longitudinal and circular muscles throughout the digestive tract
97
What are villi and microvilli? What is their purpose?
They absorb things in the small intestine. They are finger-like projections that increase surface area for absorption
98
By how much does a villus increase surface area?
10x
99
What are villus lined with?
epithelial cells
100
What is the structure of the epithelial cells on villi?
They are assymetrical, with one side having a projection called a microvilli.
101
What are microvilli and what do they do?
they are a very thin membrance that increase surface area 500x
102
How do the villi absorb nutrients?
Each villus contains a small blood vessel (capillaries). All nutrients EXCEPT FATS are absorbed directly into the bloodstream.
103
How are fats absorbed?
they are transported by lactela into the lymphatic system, then the bloodstream
104
What is passive transport?
the transport of nutrients not requiring energy
105
How does passive transport work?
It follows the concentration gradient -> goes from high to low concentration, using diffusion, facilated diffusion, and osmosis(water)
105
What is active tranport?
the transport of nutrients that requires energy
106
How does Active transport work?
It requires a transport protein that goes against the concentration gradient being, from low to high
107
How many parts does the small intestine have?
- duodenum
- jejunum
- ileum
108
What happens in the duodenum?
digestion
109
What happens in the jejunum?
digestion and absorption
110
What happens in the Ileum?
absorption
111
What is the duodenum?
The first and shortest section of small intestine.
112
What is the function duodenum?
digestion and acid control
113
how does the duodenum perform acid control
the HCI in the chyme coverts inactive prosecretin in epithelial cell to active secretin. The secretin stimulates the pancreas to secrete bicarbonate (basic pH) into duodenum raising pH from 2.5 to 9. By doing this is neutralizes the acidic chyme to protect the walls of the small intestine.
114
What is secretin?
a hormone that stimulates the pancreas to secrete bicarbonate
114
How long is the jejunum?
roughly 2.5 m long
115
What is the length and width of the ileum?
1.5 m in length and 7.6 cm in diameter
116
What happens inside the ileum?
It is where the majority of absorption occurs, it then empties into the large intestine
117
What does the pancreas look like and where is it situated?
It is a long flat gland situated across the upper abdomen behind the stomach and spleen
