The Digestive System
The breaking down of food molecules for use by body cells is known as
Digestion
The Digestive Process includes:
There are two types of digestions:
The physical break down of food material with instruments, in this case teeth, tongue, etc. is known as
Mechanical Digestion
The break down of food via enzymes, acids, carbohydrates (to simple sugars), lipids (to glycerol and fatty acids), proteins (into shorter AA sequences), etc... is known as
Chemical Digestion
G.I. Tract stands for
Gastro Intestinal Tract (Digestive Tract)
_____________ is a continuous tube, about 30 ft. long, which includes:
G.I. Tract
G.I. tract uses ______________________ as the supportive structure peripheral to the digestive tract.
Accessory Organs
As accessory organs for the G.I. Tract we find:
Histiology of the GI Tract includes
The innermost lining of the GI tract, a continuous mucous membrane from the mouth to the anus.
Mucosa or Mucous membrane
1) Mucosa's main function is to:
Which GI may perform one or the three of them depending the particular region.
Mucosa consists of three sublayers:
a- Lining Epithelial in the GI Tract is found in TWO types:
Stratified Squamous Epithelium works for mouth and esophagus to (function)
Simple Columnar Epithelium works from the esophagus to the anus for...
b- Lamina Propia is
c- Muscularis Mucosa is made of:
2) Submucosa is the layer below the ______________
It is made of ________________ which binds _________ and ____________ together. It is highly _____________.
3) Muscularis Externa is the layer below the __________.
Submucosa
4) Serosa is the ____________ layer, also called _______
_________________.
outer-most
Viscerous Peritoneum
GI Tract structures and accesory organs:
1) ________________ is formed by cheeks, hard and soft palates and tongue, stratified squamous epithelium
2) _________________ moves food over the teeth, comprised of skeletal muscle. Also involved in speech, and contains taste buds.
Tongue
3) ______________ are made of fleshy folds of skin surrounding the opening of the mouth
LIPS
4) _____________________ The non-keratinized pigmented border between the skin and the mouth, this pigmented area occupies the transition zone.
Vermilion
What zone does Vermilion transition?
It is the transition zone between Dry and Wet Skin
5) _________ __________ is the mucous membrane connecting the gingiva to the lip.
Labial Frenulum
6) ________________ is the space between the cheeks, and the teeth and gingiva
Vestibule
7) _________________ is a membranous fold of tissue on the underside of the tongue which attaches the tongue to the floor of the mouth.
Lingual Frenulum
8) ___________________ are projections (on the surface of the tongue in the GI Tract), and we find different types:
Papillae
Papillae "mushroom-like", which covers the tip of the tongue
Funjiform Papillae
Papillae Doughnut-like, form an inverted "V" on the posterior surface of the tongue.
Circumvallate Papillae
Papillae conical, covers anterior 2/3's of the tongue
Filiform Papillae
9) _________ _________ secrete saliva to keep membranes moist and to soften and dissolve food materials.
Saliva also contains salivary enzyme called _________.
The major Salivary Glands are:
This gland is located under and in front of the ears
Parotid Gland
This gland is located under the base of the tongue
Submandibular Gland
This gland is located under the tongue
Sublingual Gland
The secretions of the salivary glands are called ________.
Saliva
Salivary Amylase _______ _______ starches into simpler __________
10) This accessory structure of GI tract is involved in mechanical digestion to destroy food in mouth.
Teeth
Permanent and Deciduous Teeth are divided in 4 types:
Their main function is:
Dental formula
I2/2 : C1/1 : B2/2 : M3/3 = 16 teeth total of One Half of the Mouth
Oral Cavity involves different accessory organs like this one known as the "gums," this tissue surrounds the teeth, and its official name is ____________
Gingiva
The inflamation of gingivae is known as
Gingivitis
The exposed portion of the teeth is known as _________ ____________, and the ___________ __________ is the top portion covered with a hard white material called ____________.
The constricted portion of the tooth where the crown and root meet is known as ___________
Neck
The portion of the tooth which is embedded in the alveolar portion of the maxillae or mandible is known as ________.
It is covered with a bone-like substance called _________.
_________ __________ anchor the root in the bony socket (alveolus) of the jaw.
This junction forms a fibrous joint called a _________
___________ is a protein-rich bonelike material, underlies the enamel cap and forms the bulk of the tooth.
_________ _________ is the unhardened central cavity of the tooth, contains arterial and venous capillaries and nerves.
Pulp Cavity
Remember that The grinding up of the food stuff by the teeth is called
Mechanical Digestion
_______ is a rounded mass of a substance, especially of chewed food at the moment of swallowing.
Bolus
11) _______________ is a muscular tube (A10 inches long) from the pharynx to the stomach.
12) ____________ is an enlarged section of the digestive tract which is formed of :
____________ The outside curvature of the stomach
Greater Curvature
___________ the inside curvature of the stomach
Lesser Curvature
____________ the large folds in the stomach that contain gastric pits with gastric glands
Rugea
The smooth lining is dotted with millions of Gastric ________, which are holes that lead into tubular gastric glands that produce the stomach secretion called ____________
Cells that line in the Gastric Pit are secretary gland cells, and are - Please tell what they do produce:
Secrete Mucus
secrete HCL (which activates Pepsin from Pepsinogens)
Secrete Gastrin (Hormone)
Chief Cells -
Produce Pepsinogen and Secrete Lipase.
The food that has been mixed with water and gastric juices, and has been in the GI Tract for more than 2-3 hours is calles
Chime
__________ is an:
Pepsin
____________ is an active enzyme that:
Gastric Lipase
________ curds milk so it will stay in an infants stomach longer
Rennin
_____________ promotes secretion of gastric juices and increases motility of the stomach until the pH reaches 2.0. This is made by _____________
_____________ decreases gastric secretions
_________________ inhibit stomach emtying
Cholecystokinin
13) ____________ is found in the duodenal loop formed as the duodenum leaves the stomach.
Pancreas
Pancreas contains exocrine and endocrine parts:
14) The second largest gland of the body.
Liver
Liver functional cells are called __________ cells, they form ___________
Liver is composed of seasame seed-sized structural and functional units called_____________.
Consists of radial cords of ________ cells arranged around a _________ ______, capillaries enlarge to form vessels called ____________ which are lined with __________ reticuloendothelial cells (phagocytes). This remove ________ as ____________ and worn-out _______ cells from the blood as it flows past.
BILE Pathway
2- These bile ducts join to form the _______________________________
3- The common hepatic duct and the ___________ duct (from __________) join to form the ________ _____________ Duct.
4- The common bile duct and the pancreatic duct join to form the _________________ __________ which empties into the duodenum via called __________ _________
Hepatic Blood supply
1- The ___________ artery delivers oxygenated blood from the aorta to the liver.
2- The ___________ ________ vein carries deoxygenated blood containing nutrients from the digestive tract.
3- The hepatic vein empties blood from the __________ to the IVC
Liver
4- Blood from the ___________________ vein and the _____________ artery enters into the sinusoids of the ______________ of the liver. This blood carries oxygen and nutrients to the ________ cells and ____________ _______________ cells also known as ___________ cells
In liver, nutrients are stored or used to make new materials, poisons are stored or detoxified, and the blood is returned to the system.
Each lobule drains into its ______________ vein .
Many central veins join to form the _________ vein which drains into the IVC
_______ is a salt produced b the hepatic cells, used to ____________ fats into smaller droplets to increase the surface area for __________ to act on fats by braking them down.
____________ and _________ sumarize the hormonal and neural mechanism that control Bile secretion. HOWEVER, the major stimulus for enhance Bile secretion, is ___________
Functions of the Liver are
15) _________________ is a pear-shaped sac which is used to store and concentrate bile salts.
Gallbladder
Gallbladder main function is to secrete __________ into the _____________ for fat _______________.
16) ___________ is 1" Diameter.