Digestive System Practicum Flashcards
What is ingestion
Selective intake of food
What is digestion
Mechanical and biochemical processes
What is the net result of digestion
A breakdown of food into a form usable by the body
What is adsorption
Uptake of nutrient molecules into the epithelial cells of the digestive tract and into blood or lymph
What is defecation
Elimination of undigested residue
A broad range of biochemical reactions occurring in the body
Metabolism
The buildup of small molecules into larger more complex molecules via enzymatic reactions
Anabolism
The breakdown of large complex molecules into smaller molecules via enzymatic reactions
Catabolism
the act/process of chewing + food is crushed and mixed with saliva to form bolus for swallowing
Mastication
Ball like mixture of food and saliva that forms in the mouth during the process of chewing
Bolus
The pulpy acidic fluid which passes from the stomach to the small intestine consisting of gastric juices and partly digested food (bolus enters stomach and leaves as ____)
Chyme
Involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward
Peristalsis
The GI Tract is known as what (2 terms)
Gastrointestinal Tract and Alimentary Tract
The GI Tract is composed of:
- Oral Cavity
- Pharynx
- Esophagus
- Stomach
- Large Intestine
- Small Intestine
Accessory Organs for GI Tract
- Teeth
- Tongue
- Salivary glands
- Liver
- Gall bladder
- Pancreas
Ingested food…
Needs to be broken down
Breaks down food by chewing; or churning of the stomach
Physical (mechanical) Digestion
Breaks down food by enzymes and acids
Chemical Digestion
What happens to digested food
It gets absorbed into the body thru absorption (when it is small enough to pass thru epithelial cells)
Things that don’t get absorbed get:
Eliminated
Behind the nasal cavity
Nasopharynx
Behind oral cavity
Oropharynx
Epiglottis to base of larynx
Laryngopharynx
2 layers to the Laryngopharynx:
Skeletal muscles: inner (longitudinal) and outer (circular constrictor which are wave-like contractions that propel food down esophagus)
Mouth chews food to create:
Bolus
Swallowing of bolus:
Deglutition
What takes bolus to stomach
Esophagus
Wave of muscle contraction to take bolus to stomach
Peristalsis
Material that leaves the stomach and enters the duodenum
Chyme
Esophagus is:
Highly muscularized for peristalsis
Gastric Gland is made up of what and do what:
branched tubules in inner lining of stomach and they secrete gastric juice including protective mucus
What is gastric juice and what is it composed of?
It is a digestive fluid formed within stomach lining with a key role of digesting proteins that is made of:
- water
- electrolytes
- hydrochloric acid
- enzymes
- intrinsic factor
- paracrine hormones
Hydrochloric Acid
- a strong acid secreted by parietal cells
- lowers stomach pH to 2
- converts pepsinogen into pepsin and breaks nutrients apart
kills bacteria from food
Pepsinogen
- secreted by chief cells
- converted into pepsin in presence of hydrochloric acid
- pepsin breaks tertiary and secondary proteins for easier digestion
Gastric Lipase
- another digestive enzyme made by chief cells
- helps break down short and medium chain fats
Amylase
- found in gastric juices but not made by the stomach
- enzyme comes from saliva and travels with bolus into stomach
- breaks down carbs but acidity stops it
- the mucus is secreted by neck cells and coats/protects the stomach lining from acidic environment
Intrinsic Factor
- secreted by parietal cells
- key for absorption of vitamin B-12
- essential for healthy nervous system and blood cell production
What is the disease that develops with age where little pouches form inside the lining of the colon and on rare occasions be bleed/develop an infection
Diverticulosis when infected called diverticulitis
What condition is a type of inflammatory bowel disease that causes the swelling of tissues in the digestive tract that can lead to abdominal pain, severe diarrhea, fatigue, and weight loss/malnutrition
Crohn’s disease
Teeth are either baby teeth or adult teeth, what are there scientific names?
Deciduous = baby
Permanent = adult
What is stimulated by food or pressure in mouth
Saliva
Saliva is made of ____ which moistens food and binds it into a ball called ____
mucin and bolus
Enzyme in saliva that breaks down starches into less complex sugars:
Salivary Amylase
Salivary Glands are made up of what parts:
- Parotid Gland
- Submandibular
- Sublingual
What is the largest gland in the body with how many lobes
Liver and 4
What is produced in the liver, what does it do, and where is it stored:
Bile and it emulsifies fats for better digestion, it is stored in the gallbladder and finally released when digestion occurs
Blockage of what duct causes bile to accumulate and cause what?
The common hepatic/bile duct and jaundice occurs
Jaundice can also indicate what?
Cirrhosis or hepatits
A system of veins that plays a crucial role in our body
Hepatic portal circulation
Definition and function of the Hepatic Portal Circulation
- consists of veins that transport blood from specific regions of the gastrointestinal tract (between esophagus and rectum) to liver
- includes venous drainage from supplementary organs like spleen and pancreas
- primary function is to supply liver with metabolites and ensure ingested substances are processed in liver before systemic circulation
- limits damage from ingested toxins
____ cells produce ____ granules which are inactive enzymes that are secreted and ____ in the _____
Acinar, Zymogen, activated, duodenum
Examples of Pancreatic Enzymes:
Proteases which digest proteins and peptides
- trypsin
- chymotrypsin
- carboxypeptidase
Other pancreatic enzymes:
- amylases: digest carbs
- lipases: digests lipids and fats
- nucleases: digest nucleic acids DNA and RNA
