Digestion Lecture Flashcards
What is Digestion?
The process in which food substances are changed into forms that can be absorbed through cell membranes
What is Ingestion?
To take Food In
What is Mechanical Digestion?
Chewing, Peristalsis, Churning
What is Chemical Digestion?
Breaking down of food particles through a series of metabolic reactions
What is Propulsion?
Movement; Peristalsis
What is Absorption?
Passage of digested food from GI tract into bloodstream
What is Defecation?
Elimination of Waste
What is the Gastrointestinal Tract?
A tube that starts at the mouth and ends with the Anus
~28ft long
What are these?
Mouth Pharynx Esophagus Stomach Small Intestine Large Intestine
Alimentary Canal Organs
What Are These?
Salivary Glands
Liver
Gall Bladder
Pancreas
Accessory Glands
What are the layers of the Alimentary Canal Wall?
Mucosa ( Innermost )
Submucosa
Muscularis
Serosa ( Outer )
What are the 3 Layers of the Mucosa?
Mucus Epithelium ( Inner ) Lamina Propria ( Loose Connective Tissue ) Muscularis Mucosa ( Smooth Muscle )
What does the Epithelium Villi Do?
Increase the Surface Area
What Do Mucosa Glands do?
Secrete Mucus
Where is the Submucosa?
Beneath a the Mucosa
What is the Submucosa made of?
Loose Connective Tissue, Blood Vessels, Lymph Vessels, Nerves
What does the Submucosa do?
Nourish the Mucosa
Carry Nutrients Away
What is the Muscularis Made of?
Thick Layer of Smooth Muscle
What are the 2 Layers of the Muscularis?
a) Circular Layer: Around Submucosa
b) Longitudinal Layer: Around Circular Layer
Purpose of Muscularis?
Movement of Food Along the Tract
What are the Movements of the tube?
Mixing Movements
Peristalsis: Wave-Like Motions
What do Sphincter Muslces do?
Circular Muscles that Prevent Backflow
Gastroesophageal (cardiac ) Sphincter
Between esophagus and stomach
Pyloric Sphincter
Between Stomach and Small Intestine
Ileocecal Valve
Between the Small Intestine and Large Intestine
Internal Anal Sphincter
(smooth muscle) large intestine/outside
External Anal Sphincter
(Skeletal Muscle) Large Intestine/Outside
Name the 2 Parts of the Oral/Buccal Cavity?
a) Vestibule
b) Oral Cavity
What is the Vestibule?
Small outer region bounded by the lips and cheeks on the outside and the gums and teeth on the inside
What is the Oral Cavity?
Extends from behind the teeth and gums to the opening of the pharynx
What does the Oral Cavity/Buccal Cavity Do?
A) Ingestion
B) Mechanical Digestion
C) Prepares food for Chemical Digestion
What Kind of muscle is the Tongue Made of?
Skeletal
Where is the Tongue Connected
Connected to the floor of the mouth by frenulum
Function of the Tongue?
a) manipulate food
• chewing- mastication
• swallowing- deglutition
b) speech formation
What is the Palate?
Roof of the Mouth
Which Part of the palate is hard or soft?
Anterior: Hard
Posterior: Soft
A set of primary teeth consists of 20
teeth, whereas a set of secondary teeth
consists of 32 teeth. T/F
True
Pancreatic digestive secretions are
regulated by
cholecystokinin
Which layer of the alimentary canal is
responsible for the absorption of
nutrients?
Mucosa
The effects of sympathetic nerve impulses on the alimentary canal are___ and impulses are ___
inhibitory, or slow down inactivity; stimulative, or cause an increase in activity
The greater omentum is composed of
the peritoneal membrane
Heartburn is usually caused by the
effects of gastric juice on the?
Esophagus
A characteristic shared by all enzymes involved in protein digestion is that all are
secreted in an inactive form.
One of the major functions of the large intestines is to
reabsorb water from chyme
Which constituent of bile has a
digestive function?
Bile Salts
The liver functions to
A) destroy damaged red blood cells.
B) all of the above
C) form glucose from noncarbohydrates.
D) store vitamin D.
B
The hormone called secretin
functions to:
Stimulate the release of pancreatic
juice
Gastrin Functions
enhancing gastric mucosal growth, gastric motility, and secretion of hydrochloric acid (HCl) into the stomach.
The parietal cells of gastric glands
secrete
hydrochloric acid
Main Part of the Stomach
Body
The salivary enzyme amylase functions to digest
Carbohydrates
Teeth best adapted for biting off
relatively large pieces of food
Incisors
List them in order
mucosa, submucosa, muscularis,
and serosa.
The chamber of the mouth between the tongue and the palate is the vestibule.
t/f
False
