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).