Chapter 3 Flashcards
What is appetite?
The psychological desire to consume specific food
Aroused by environmental causes
What is hunger?
The psychological drive for food.
It is non specific
What us anorexia?
A loss of appetite
The physiologicL need for food yet no appetite
What dose the hypothalamus do?
Triggers feelings of hunger or satiation (fullness)
It gets messages from the nerves and hormones
What are hormones?
Chemical messengers secreted in to the blood stream by endocrine glands to help regulate body functions.
What are pancreatic hormones?
Insulin—> lowers blood sugar
Glucagon —> raises blood sugar and makes you feel full
What foods have higher satiety levels?
Proteins—> the highest
High-fat diets
Bulky meals
Solid foods
What has the lowest satiety level?
Carbs.
What 3 process do food undergo?
Digestion—> mechanical and chemical
Absorption—> happens in the intestinal walls
Elimination—> waste excreted that we do not consume
What are sphincters?
Muscles that control the passage of food material from one GIT organ to the next.
What is the cephalic phase of digestion?
The fist step… Thought
Hunger releases our digestive juices
Cephalic= head= starts in the head
What is the second step of digestion?
Chewing/ saliva
What are enzymes and what do they do?
They are complex chemicals that induce chemical changes in other substances to
speed up bodily process
What is salivary alamase and what dose it do?
It is an enzyme
It breaks down starches
What is a bolus?
The mass of chewed mistimed food in the mouth.
What dose the epiglottis do?
It covers the opening to the trachea.
Prevents food from going in to the lungs.
What is peristalsis?
The muscular contractions that move food through the GI tract.
What dose pH stand for and what dose it measure?
Potential of hydrogen
A measure of a compounds acidity or alkalinity.
What is gastrin and what dose it do?
A hormone that is secreted by the cells lining the stomach.
They produce gastric juice
What are parietal cells?
They secret HCL and intrinsic factor.
What dose gastric juice contain?
Hydrochloride acid (HCL)
Pepsin
Gastric lipase
Intrinsic factor
What dose Hydrochloric acid do (HCL)?
Denatures proteins and activates pepsin.
What is pepsin?
An enzyme to digest protein
What dose gastric lipase do?
An enzyme to digest fat
What dose intrinsic factor do?
Proton to absorb vitamin B12
What is chyme?
Liquid product of mechanical digestion in the stomach.
What dose mucus do?
Layer that protects the stomach lining from acid in the gastric juices.
What dose bicarbonate do?
Neutralizes the acid on the stomach.
What are the three sections of the small intestine?
- Duodenum
- Jejunum
- Ileum
What connects the small intestine to the large intestine?
Ileoceal valve (sphincter)
Where dose most digestion take place?
The small intestine.
What is the colon?
The large intestine.
What are pro-biotics?
Bacteria that assist with the final digestion.
What do enzymes do?
Speed up digestion.
How do hormones assist in digestion?
They bind to the receptor cell membrane and activate a second messenger system withing the cell.
Where is secretin made?
The small intestine.
What are accessory organs to digestion?
The gallbladder
Pancreas
Liver
What dose emulsify mean?
To make smaller
What dose the gallbladder do?
Stores bile which is produced by the liver
What dose bile do?
Emulsifies the lipids
What dose the pancreas do?
Manufactures holds and secrets digestive enzymes
Insulin and glucagon are produced by the pancreas
Bicarbonate is secreted to neutralize chyme
What dose the liver do?
One of the most important organs
Syntheses chemicals for digestion
Receives the products for digestion via the portal vein
What dose enterocytes mean?
Intestinal cells
They are absorptive cells in the vili
What are vili?
Folds in the lining that allow the GI tract to absorb more nutrient
(Look like the pushed up carpet)
What is lacteals?
Small lymph vessel
What are the four types of absorption in the small intestine?
Passive diffusion
Facilitated diffusion
Active transport
Endocytosis
What is passive diffusion?
When nutrients pass through the enterocytes and into the blood stream with out the help of a carrier.
What is facilitated diffusion?
Requires a carrier protein
What is active transport?
Requires energy and a protein carrier to transport nutrients.
What is endocytosis? (Pianocytosis)
Active transport by which small amounts of intestinal contents is engulfed in to the cell membrane
Pinocytosis- pinocalada- cells drinking
What do lacteals do?
Pick up most lipids and fat soluble vitamins
What are lymph nodes?
Clusters of immune cells that filter microbes and other harmful agents.
What is haustra?
Unique to the colon
Segments in the colon that contract sluggishly to move contents.
What is enteric nervous system (ENS)?
In the gut wall
