DIgestive Flashcards
Process by which food substances are changed into forms that can be absorbed through cell membranes.
Digestion
Nutrients within the GI tract are not inside the body until they are?
Absorbed from the intestines
To take food in
Ingestion
Chewing, Peristalsis, Churning
Mechanincal Digestion
Breaks down food particles through a series of metabolic reactions
Chemical Digestion
Movement-peristalsis
Propulsion
Passage of digested food from Gi tract into bloodstream
Absorption
Elimination of indigestible wastes
Defecation
Allimentary canal is also known as?
GI tract
What is the GI tract called? Where does it start and end?
Muscular tube, mouth and anus
What does the allimentary canal pass through?
Body’s ventral cavity
How long is the GI tract?
Around 28 ft
What does the Allimentary canal run through?
The entire tract
Name the four layers of the alimentary canal wall.
- Mucosa(inner)
- Submucosa
- Muscularis
- Sercsa(outer)
Innermost layer, surrounds lumen of tract
Mucosal
3 layers of the Mucosal
- Mucus epithelium
- Lamina Propria
- Muscualris Mucosae
Histology of Mucosal
Epithelium, Simple Columnar
What do glands of mucosal do?
Secrete mucus
Function of Mucosal layer
a. Protects again disease
b. Secretes mucus and enzymes
c. Absorption of end products of digestion(Mucus)
Beneath the mucosal layer
Submucosal layer
Histology of Submucosal?
Loose CT, glands, blood vessels, lymph vessels, nerves
Function of submucosal
Nourishes mucosa, carries absorbed nutrients away
This layer of smooth muscle between submucosal and serosa
Muscularis Layer
Two layers of Muscularis
A. Circular Layer- around submucosa, controls diameter of passage way
B. Longitudinal Layer- Around circular layer, allows length of passageway to change
Function of Muscularis layer
Movement of food along the tract
Outermost layer
Serosal Layer
Histology of Serosal
tough, fibrous connective tissue
Functions of serosal layer
Lubrication, and free movement of canal on abdominal cavity
What are the movements of the tube?
Mixing and propelling nutrients
Wave-like contractions
Peristalsis
Circular muscle which prevents backflow
Sphincter muscles
(cardiac) sphincter, betweeen esophagus and stomach
Gastroesophageal Sphincter
Between the stomach and the small intestine
Pyloric Sphincter
Small intestine and large intestine
Ileocecal valve
Large intestine-Smooth muscle
Internal anal sphincter
Large Intestine-Skeletal muscle
External anal sphincter
Small outer region bounded by the lips and cheeks on the outside and gums and teeth on the inside
Vestibule
Extends from behind the teeth and gums to the opening of the pharynx
Oral Cavity
Function of Mouth and oral cavity and buccal cavity
Ingestion, Mechanical Digestion, Food preparation
What do the lateral walls of the mouth form?
Cheek
What do the cheeks consist of
- skin
- fat
- muscles
- Inner most lining
Surrounds the mouth opening
Lips
What do the lips consist of?
Skeletal muscles, Sensory receptors, and skin
What are the lips covered by?
Thin layer of skin
Vascularity of the lips?
Highly vascular
Shallow vertical groove above upper lip
Philtrum
Location of tongue
Floor of oral cavity
What is the tongue connected to the floor of the mouth by?
lingual Frenulum
What is the body of the tongue made up of?
Skeletal muscle
What does the tongue contain?
Papillae
Functions of the tongue
Mastication and deglutition
chewing
Mastication
swallowing
Deglutition
Where is the palate located?
Rood of oral cavity
Where is the hard palate?
Anterior portion
Where is the soft palate?
Posterior portion
Flap of tongue that keeps food from entering the nasal passageways.
Uvula
First set of teeth to develop
Primary teeth
what months do they develop during(primary)?
6-24 months
Amount of primary teeth
20
They are also know as(primaries)?
Decidous, baby
Secondary teeth are formed when?
6-12 years
Amount of secondary
32
How many incisors?(front)
8-breaks into small pieces
How many cuspids?(canine)
4-Grasping/tearing
How many bicuspids?(premolars)
8-Grinding
How many molars?
12-Grinding
Exposed part above the gum line
Crown
Below the gum, fits in the alveolar process
Root
Covering of crown-Hardest substance in the body
Enamel
Living tissue beneath the enamel, bulk of tooth
Dentin
Narrow part surrounded by gums
Neck
What do salivary glands secrete?
Saliva
What are the functions of saliva?
Lubrication, cleans mouth and teeth, binds food particles, and begins chemical digestion.
What kind of secretion are serous?
Watery, fluid
What do serous secretions contain?
Amylase, digests carbohydrates
What are mucous secretions?
Thick, cloudy, fluid
Lies over the masseter, in front and below ears
Parotid glands
Largest salivary gland
Parotid gland
Parotid gland has what type of secretion?
Water, serous fluid
Parotid has what type of enzyme?
Amylase
What does Parotid glands drain through?
Stenson ducts
Location of submandibular glands
Floor of mouth
Size of submandibular glands
Walnut, below angle of lower jaw
Submandibular secretion?
Mixed glands, mainly serous fluid
Location of sublingual glands
Floor of mouth, below tongue
Smallest salivary gland
Sublingual
Secretion of Sublingual
Mucous
Where does sublingual drain?
Beneath the tongue
The pharynx is also know as the?
Throat
Tube length of pharynx
around 5 in
Behind nasal cavity
Nasopharynx, air only
Behind oral cavity
Oropharynx, food only
Behind larynx
Laryngopharynx, food only
collapsible tube
Esophagus
How long is esophagus?
around 10 to 22 inches
function of esophagus
Passageway for food, connects mouth to stomach
Opening in the diaphragm
Esophageal hiatus
movement of food
Peristalsis
J-shaped pouch
Stomach
