Module 2- Anatomy and Digestion Flashcards
what is cecum?
pouch that forms the first part of the large intestine
where is situated the ileocecal valve or sphincter?
it is situated at the junction of the ileum (last portion of your small intestine) and the colon (first portion of your large intestine)
what is a lumen?
the cavity or channel within the GI tract
what is an appendix?
a narrow, finger-shaped pouch that projects out from the colon. The usefulness or purpose of the appendix is debated.
what is appendicitis?
Appendicitis is when the appendix becomes inflamed and infected
true or false
the pharynx extends from the nasal cavity and mouth to the esophagus, whereas the larynx is the upper portion of the trachea (for breathing and voice)
true
what are the blood functions?
- delivers oxygen (from lungs) and nutrients to tissues
- removes carbon dioxide (at lungs) and wastes (at kidney) from tissues
what is lymph?
a clear or whitish fluid
It is the fluid that flows through the lymphatic system: a system composed of lymph vessels (channels) and intervening lymph nodes
lymph contains what?
WBC - White blood cells
What does lymph transport?
transports some fats and fat-soluble vitamins
explain the lymphatic system
no pump, circulates between cells. Collects into tiny vessels/channels . Enters central bloodstream via subclavian veins
how the blood circulates
1) blood leaves the right side of the heart by way of the pulmonary artery
2)Blood loses carbon dioxide and picks up oxygen in the lungs and returns to the left side of the heart by way of the pulmonary vein
3)Blood leaves the left side of the heart by way of the aorta, the main artery that launches blood on its
course through the body
4) Blood may leave the aorta to go to the upper body and head or Blood may leave the aorta to go to the lower body
5) Blood may go to the digestive tract and then the liver; or Blood may go to the pelvis, kidneys, and legs
6) Blood returns to the right side of the heart.
7) Lymph from most of the body’s organs, including the digestive system, enter the bloodstream near the heart.
what is the digestive system?
the organs and glands associated with the ingestion and digestion of food
what is digestion?
the body’s way of breaking down foods into nutrients in preparation for absorption
what is absorption?
the uptake of nutrients by cells of the small intestine for transport into either the blood or the lymph
Digestive juices are secreted by…
salivary glands, stomach, pancreas, liver and small intestine
what do digestive juices contain?
enzymes - break down nutrients
where does digestion begin?
mouth- saliva contain salivary amylase and lingual amylase that break down
what are the major subdivisions of the digestive tract
1) oral cavity, teeth, tongue
2) pharynx
3) esophagus
4) stomach
5) small intestine
6) large intestine
describe the oral cavity
mechanical processing, moistening, mixing with salivary secretions
describe the pharynx
muscular propulsion of materials into the esophagus
describe the esophagus
transport of materials to the stomach
describe the stomach
chemical breakdown of materials by acid and enzymes; mechanical processing through muscular contractions
describe the small intestine
enzymatic digestion and absorption of water, organic substrate, vitamins and ions
describe the large intestine
enzymatic digestion and absorption of water, organic substrates, vitamins and ions
what is peristalsis
series of involuntary wave-like muscle contractions which move food along the digestive tract
what are the 4 types of sphincter contractions
- upper esophageal sphincter
- lower esophageal sphincter (cardiac sphincter)
- pyloric sphincter
- ileocecal sphincter
where is the upper esophageal sphincter and what is his function?
top of esophagus
opens in response to swallowing
where is the lower esophageal sphincter and what is his function?
bottom of esophagus
prevent reflux of stomach content
where is the pyloric sphincter and what is his function?
bottom of the stomach.
Holds the chyme in the stomach for it to be mixed with gastric juice and liquefied. Prevents intestinal contents from backing up into the stomach
where is the ileocecal sphincter and what is his function?
end of the small intestine
allows emptying into the large intestine
what are the major functions of the stomach
- storage of ingested food for slow release
- mechanical breakdown to chyme
- gastrin (hormone) is secreted by cells of stomach
- production of intrinsic factor, a glycoprotein required for absorption of vit B12 in small intestine
what are the 2 systems that coordinate the digestive and hormonal processes?
endocrine system
nervous system
what protects stomach cells from acid and disease-causing bacteria?
a. hydrochloric acid
b. water
c. gastric glands
d. mucus
e. bile
d. mucus
what is the normal blood pH range?
7.35 to 7.45
what are the primary hormones on the GI tract?
gastrin
secretin
cholecystokinin
gastrin respond to what?
food in the stomach
secretin respond to what?
acidic chyme in the small intestine
cholecystokinin respond to what?
fat or protein in the small intestine
where is gastrin secreted from and it is stimulated from?
secreted -stomach wall
stimulated - stomach glands
where is secretin secreted from and it is stimulated from?
secreted - dudodenal wall
stimulated - pancreas
where is cholecystokinin secreted from and it is stimulated from?
secreted - intestinal wall
stimulated - gallbladder pancreas
what is the response of the gastrin hormone?
Hydrochloric acid secreted into the stomach to maintain an acidic pH
what is the response of the secretin hormone?
Bicarbonate-rich juices secreted into the small intestine to maintain a slightly alkaline pH
what is the response of the cholecystokinin hormone?
Bile is secreted into the duodenum to emulsify fats.
Bicarbonate- and enzyme-rich juices are secreted into the small intestine to maintain a slightly alkaline pH, digest fats and proteins, and slow GI tract motility
what are the primary functions of the liver?
- bile production and excretion
- process nutrients absorbed by small intestine. Metabolism of fats, proteins, and carbs
- enzyme activation
- storage of glycogen, vitamins, and minerals
- synthesis of plasma proteins, such as albumin, and clotting factors
- blood detoxification and purification
true or false
bile emulsifies lipids in the stomach
false
bile emulsifies lipids in the small intestine
where is bile stored?
in the gall bladder
when does bile production increase?
when fatty chyme enters the duodenum and stimulates the secretion of the gut hormone secretin
what is the function of pancreas exocrine and endocrine?
exocrine- digestive
endocrine - hormones
pancreatic juice is composed of
water, some salts, sodium bicarbonate, and several digestive enzymes
what is responsible for the slight alkalinity of pancreatic juice?
sodium bicarbonate
where are carbohydrates absorbed?
mouth, small intestine
where are proteins absorbed?
stomach, small intestine
where is fat absorbed?
small intestine
where is the majority of absorption done?
in the small intestine
what are villi, microvilli, crypts and goblet cells
villi: select and regulate nutrients absorbed
microvilli: enzyme and “pumps”. Allow nutrient to pass through to the body
crypts: secretion of intestinal juices
goblet cells: mucus secretion
what is simple diffusion and give an example of nutrients that are absorbed by simple diffusion?
simple diffusion is when nutrients cross into the intestinal cells freely. EX: water
what is facilitated diffusion and give an example of nutrients that are absorbed by facilitated diffusion?
Facilitated diffusion is when the nutrients need a specific carrier to transport them from one side of the cell to the other. ex: water soluble vitamin
what is active diffusion and give an example of nutrients that are absorbed by active diffusion?
Active diffusion occurs when nutrients move against a concentration gradient. Ex: amino acids and glucose
what is the hepatic portal system and what it does to our body?
Portal system is a system of blood vessels - begins and end in capillaries
They carry nutrients from digestion to the liver to store and metabolize
what are the classical functions of the large intestine?
- reabsorption of water and electrolytes
- compaction of intestinal contents into feces
- storage of fecal material prior to defecation
- home of the microbiota
what is the role of the microbiome
autoimmune disease, obesity, psychological conditions.
Ferment certain indigestible fibers
break down and help recycle parts of bile
what is the difference between probiotics and prebiotics
prebiotics : food components, such as fibers, that are not digested and are used as food for gut bacteria to promote their growth and activity
probiotics: living organisms in food that are beneficial to gut health, ex: yogurt
true or false questions:
1) most fibers transits through the digestive system without being digested and absorbed
2) the transit time, so the time that occurs from the mouth to the colon is approximately 12h
3) when a person is chocking the food goes to the esophagus
4) ulcer - the stomach has bacterial infection and it can lead to bleeding or perforation
- true
- false, it is 24h
- false, the food goes to the trachea and it blocks the air
- true
