4C - Body Systems Flashcards
The Digestive System
Process of Digestion, 1-4
Ingestion
Digestion (mechanical/physical or chemical)
Absorbtion
Excretion
How long does digestion take/ transit time
18-24 hours.
Bile emulsification
Bile emulsification is when bile (a digestive fluid) breaks down large fat molecules into smaller droplets. This helps enzymes digest the fats more easily. Think of it like mixing oil into tiny drops in water so it can spread out and get absorbed better.
Emulsification
is a process aided by bile, in which large
lipid molecules (globules) are separated into smaller lipid globules.
* This increases the surface area on which lipases can act to chemically digest fats.
How many salivary glands and ducts do we have?
6
What do salivary glands produce
salivary amylase (an enzyme)
how does salivary amylase break down simple sugars/ monosaccharides
hydrolysis
What does chewing and your tongue do to your food
a ball “bolus”
this passes thru the pharynx and directed to the esophagus
Pharnyx
part of throat behind mouth and nasal cavity above esophagus and larynx
The pharynx (throat) acts as a passageway for food to move from the mouth to the esophagus and for air to travel from the nose/mouth to the larynx and lungs.
Larnyx
hollow tube is the air passage for lungs, location of vocal chords
Epiglottis
The epiglottis is a small, flap-like structure in your throat that acts as a traffic director. When you swallow, it covers your windpipe to keep food and liquids from going into your lungs, and when you’re breathing, it stays open to let air pass through.
Peristalis
involuntary constriction of muscle to move food along tube-like
structures like the esophagus, intestines, or contractile motions of the stomach
Esophagus
The esophagus is a muscular tube that connects your throat (pharynx) to your stomach, using peristalsis to push food and drinks down for digestion.
Esophageal Sphincter
PREVENTS STOMACH CONTENTS FROM GOING BACK UP INTO THE ESOPHAGUS
The esophageal sphincter is a ring of muscle at the bottom of the esophagus that acts like a valve, opening to let food into the stomach and closing to prevent stomach acid from flowing back up.
Rugae
Rugae are the folds in the lining of your stomach that allow it to expand when you eat, and help mix food with digestive juices.
increase surface area
Stomach function
storage
some digestion of proteins by HCl (aq) and pepsin
churning / pushes food into small intestine
Pyloric Sphincter
CONTROLS TJE EXIT FROM STOMACH TO SMALL INTESTINE
The pyloric sphincter is a muscle valve located at the bottom of the stomach that controls the release of partially digested food (chyme) into the small intestine.
Pepsin
Pepsin is an enzyme in the stomach that helps break down proteins into smaller pieces, making it easier for your body to digest them.
What are gastric juices made up of?
secreted from glandular tissue
water, mucus, salts, and hydrochloric acids (stomach acids)
What is stomach acids involved in
Protein digestion by activating the enzyme pepsin
* Prevents infection by killing bacteria / microorganisms
* Absorption (water, alcohol), pH, ‘motility’, storage
Chyme
semi-solid stomach contents (partially digested
food, water, HCl(aq), and digestive enzymes).
what do Chief cells do
release pepsinogen (inactive enzyme) and
chymosin.
pepsinogen
Pepsinogen is an inactive precursor (or “zymogen”) of the enzyme pepsin. It is secreted by the stomach lining and is converted into active pepsin when it comes into contact with stomach acid, allowing it to break down proteins.
Parietal cells
secrete HCl(aq)
Mucous cells
secrete protective mucus (called mucin).
Important for the prevention of ulcers, protects the
mucosa (lining of stomach).
Gastrin
Gastrin is a peptide hormone that targets chief and parietal cells to regulate gastric product release, enhance mucosal growth, motility, and HCl secretion. It is stimulated by food in the stomach.
3 regions of the small intestine
duodenum
jejunum
ileum
Which structures in the lining of the small intestine increase surface area
villi and microvilli
lacteals
lymphatic vessels of the small intestine that absorb digested fats
INSIDE VILLI
tube within the villis
Which structures in the lining of the small intestine are involved with absorbtion
blood vessels and lymph/lacteals
main functions of the small intestine
The small intestine’s primary roles are chemical and physical digestion (e.g., enzyme breakdown, emulsification of lipids), absorption of nutrients into the bloodstream or lymph, and moving materials to the large intestine.
Chemical digestion
Chemical digestion involves breaking down food using enzymes and acids, turning large molecules into smaller ones (e.g., breaking proteins into amino acids).
mechanical/physical digestion
is the physical breakdown of food through actions like chewing or churning in the stomach, making food easier to digest chemically.
contractions, peristalsis, bile emulsification
where is Saliva secreted/produced and whats its function?
mouth
-contributes to starch digestion via salivary amylase.
-lubricates the isnside of the mouth to assist in swallowing
where is Mucus secreted/produced and whats its function?
The mouth, stomach, small and large intestine
-protects the cells lining from acids in the innermost portion of the digestive tract
-lubricatees food as it travels thru the digestive system
where are Enzymes secreted/produced and whats its function?
The mouth, stomach, small and large intestine
-promote digestion of food masses into particles small enough for absorption into the bloodstream
where is Bile secreted/produced and whats its function?
liver (stored in gall bladder)
-suspends fat in water, using bile salts, cholesterol and lechitin to acid digestion of fate in small intestine
-DIGEST FATS
where is Bicarbonate secreted/produced and whats its function?
Pancreas and small intestine
-neutralizes stomach acid when it reaches the small intestine
where are hormones secreted/produced and whats their function?
stomach, smalll intestine, and pancreas
-stimulate production and /or release of acid, enzymes bile and bicarbonate.
-help to regulate peristalsis
where is acids secreted/produced and whats its function?
Stomach
-Promotes digestion of proteins
Duodenum
-First 25-30cm (0.30m) of the small intestine
-where majority of chemical digestion takes place.
-important for nutrient absorbtion
Jejunum
-second part of the small intestine (2.5m)
-responsible for absorption
-contains villi (folds) and secretory glands
-involved in the continued breakdown and absorbtion
ileum
-third section of the small intestine (4m)
-reponsible for absorption
-has fewer villi that are still involved in absorption
-moves materials not absorbed into the large intestine
The large intestine sections
Ascending
transverse
decending
sigmouid
rectum
role of the large intestine (colon)
-absorb water
-form stool
what does the liver do?
produce bile
what is bile made of
bile pigments and salts
what does the gall bladder do?
-recieves and stores bile from the liver via the hepatic duct
-then releases bile into the duodenum via the common bile duct, where bile helps digest fats/lipids
does bile digest lipids
NO
What are the fuctions of the pancreas?
Secrete pancreatic fluid into the duedenum
which organ has bost exocrine (digestive) and endocrine (hormonal) functions?
THE PANCREAS!!!!!!!!!
what is pancreatic fluid and what does it do
contains digestive enzymes and bicarbonate that neutalizes the acidic chyme coming from the stomach and enters the SI
CCK (Cholecystokinin)
a hormone that triggers the release of bile from the gall bladder into the small intestine
this is stimulated by the presence of lipids (fatty chyme coming in from the stomach) in the duodenum
secreted in small intestine
PH of the mouth
8
ph of the stomach
2
ph of the small intestine
8
what is secretin
a hormone that is triggered by low pH chyme entering the small intestine. it is produced/secreted by specialized cells in the duodenum.
LOWERS PH OF CHYME
Gastrin
tells the stomach to make more stomach acid. stimulated by food entering the stomach
how are amino acids transported into cells?
active transport because they are charged and cant be brought in passively.
how are monosaccharides brought into cell?
active transport
bcus they are charged
how are glycerol and fatty acids come into cell?
passive transport cus the have no charge and is non-polar just like the membrane which is made up of lipids anyway so it just glides thru.
where are fatty acids and glycerols sent before the bloodstream
lymph vessel
what absorbs vitamins
the large intestine
