Lesson 4: Specialized Digestion and Illness

Question 1

what are the different types of digestive systems?

Answer 1

complete, complex, and simple Ex: humans have a complete digestion system; each animal species have unique adaptations to obtain and digest food

Question 2

what is an example of “unique adaptations” in animals that help them obtain and digest food?

Answer 2

mosquitos: have specializied mouth structure in order to obtain nutrients from sucking blood

Question 3

simple digestion, what is it?

Answer 3

there is only one opening that serves as both the mouth and the anus (food comes in one way and goes out the same way)- called a two way digestion

Question 4

what organisms have simple digestion?

Answer 4

simple organisms perform simple digestion: flatworms and jellyfish for instance

Question 5

what is the gastrovascular cavity? what happens in it?

Answer 5

a simple sac that is a part of simple digestion
- food is broken down chemically in the cavity; the cells that surround the cavity are responsible for absorbing the nutrients

Question 6

complex digestion, what is it?

Answer 6

more complex animals have complex digestive systems; food movement is in one direction

Question 7

what organisms have complex digestion- give an example

Answer 7

earthworms, for instance, have two openings; they have specialized regions that enable the breakdown and absorption of food

Question 8

what are accessory organs?

Answer 8

functions to support the digestive system, but are not considered a part of the digestive tract

Question 9

how do accessory organs support the digestive system?

Answer 9

they produce enzymes and secrete substances that are needed for digestion, absorption, and excretion
food does not pass through these organs!

Question 10

what are the main accessory organs?

Answer 10

• liver
• pancreas
• gallbladder

Question 11

why are the accessory organs placed in the way that they are? what purpose does it serve?

Answer 11

they are placed in specific locations because it helps them carry out their specific functions and tasks
- for instance, the liver is near the gallbladder as they work together to produce and store bile
- pancreas is under the stomach as it produces substances for stomach digestion purposes

Question 12

what is the pancreas? where is it found? what does it do? what are the types of hormones secreted?

Answer 12

a gland found between the stomach and the duodenum; it controls sugar levels (insulin) and enzymes that helps digestion
- amylase is secreted to digest starches (carbs)
- trypsin is secreted to digest proteins
- lipase is secreted to break down fats

Question 13

how does the pancreas aid with digestion? what is in the substance it produces?

Answer 13

produces a juice made up of water, sodium bicarbonate, and digestive enzymes- the sodium bicarbonate neutralizes the stomach’s acidity, so that the digestive enzymes can do their jobs

Question 14

how does the pancreas help maintain sugar levels when blood sugar is high?

Answer 14

pancreas releases insulin, which makes excess sugars move into cells where its used as energy or stored for later use; insulin also tells the liver to shut down sugar production

Question 15

how does the pancreas help maintain sugar levels when blood sugar is low?

Answer 15

pancreas release a hormone called glucagon, which tells the body’s cells and liver to release stored sugars back into the bloodstream

Question 16

so generally, what keeps our sugar levels balanced?

Answer 16

the pancreas use of insulin and glucagon

Question 17

if the pancreas gets weakened by something such as a disease, what could happen?

Answer 17

the organ’s ability to produce insulin may be reduced or extinguished, which can lead to diabetes

Question 18

what exactly happens with no insulin release?

Answer 18

sugar builds up in the blood, which hardens blood vessels- this can cause heart attacks, kidney failures, and strokes

Question 19

what happens if we don’t have our pancreas?

Answer 19

sugar levels go haywire and too much sugar would be in our blood

Question 20

what is the liver’s role in digestion?

Answer 20

to release bile that breaks down fats into smaller droplets called micelles in order to make them easier to digest
- the liver also filters any toxins found in the blood such as alcohol
- stores carbs as glycogens
- stores fat soluble vitamins
- liver can regenerate! doesn’t mean its invincible to harm though

Question 21

what happens when the liver detects a useless or harmful toxin in the blood?

Answer 21

it either converts it into a product that cannot hurt the body or it isolates it and whisks it away (by channeling it to the kidneys and intestine to be excreted)

Question 22

what is the main substance that the liver produces?

Answer 22

bile! its a bitter greenish liquid that is stored in the gallbladder and used to break down fats

Question 23

what is the gallbladder used for? what happens when fats enter the duodenum?

Answer 23

where bile is stored; when fats enter the duodenum, the gallbladder is stimulated to begin contracting, which pushes bile through the cystic duct and into the duodenum

Question 24

what is acid reflux? how does it occur? where is it located?

Answer 24

a digestive illness that is caused when the gastroesophageal sphincter does not fully close
- located between the esophagus and the stomach

Question 25

what does it mean if you constantly have heartburn/ acid reflux? how does it happen? what are some consequences of it?

Answer 25

GERD: gastroesophageal reflux disease
- the relaxed sphincter allows swallowed foods to reenter the esophagus and irritates it
- overtime you can develop esophagitus, and may lead to respiratory problems (asthma, etc)

Question 26

GERD symptoms

Answer 26

• heartburn
• nausea
• problems swallowing
• bad breath
• hoarseness
• sore throat
• regurgitation (food comes up throat)

Question 27

what are stomach ulcers? whats it caused by and how does it occur?

Answer 27

a digestive illness caused by a harmful bacteria called helicobacter pylori (H. pylori)
- occurs because the bacteria has the ability to adapt and survive in highly acidic conditions in the stomach; they can do this by secreting enzymes that neutralize the acidic content

Question 28

how is the stomach ULCER itself produced? (due to the bacteria)

Answer 28

the ulcers are produced when the bacteria burrows itself into the protective mucus layer in our stomach- this prevents the production of the mucus, which allows our stomach acids to make open sores on our stomach linings called ulcers

Question 29

what are the problems with having ulcers?

Answer 29

• they bleed and become very painful
• can become very dangerous as the H pylori bacteria may infect the entire body

Question 30

how can you get rid of these ulcers?

Answer 30

can be treated with antibiotics!

Question 31

what are endoscopies? whats it used for?

Answer 31

narrow tube with a light source, lens, and camera; used by putting it inside you and analyzing the GI tract
- also used to perform medical procedures and surgeries (gallbladder removal for instance)

Question 32

how is the tube of endoscopies inserted?

Answer 32

through the mouth, anus, or small incision (when incisions are made and inserted through them, its called an endoscopy)

Question 33

what is a colonoscopy?

Answer 33

inserted through the anus/rectum and into the colon

Question 34

why are endoscopies done?

Answer 34

when patients complain about symptoms of possible digestive illnesses

Question 35

how was the digestive tract previously analyzed? when was the endoscopy discovered and upgraded?

Answer 35

through surgical openings on patients- in 1895, endoscopy was discovered and in 1997, the upgraded capsule endoscopy was discovered