Digestion

Front 1

What are the functions of the Digestive System?

Back 1

Ingestion, Mechanical, Processing Absorption, Digestion, Excretion

Front 2

Describe the mesenteries?

Back 2

These are double layered peritoneal membrane, that are responsible for anchoring organs within the abdominopelvic cavity. Mesenteries also allows the passage of nerves, lymph and blood vessels

Front 3

Layers of Digestive Tract?

Back 3

Mucosa
Submucosa
Muscularis Externa
Serosa

Front 4

Describe the Mucosa?

Back 4

The mucosa is the inner most layer of the digestive tract. It includes to layers the epithelial layer and the lamina propria.

Front 5

Epithelial layer?

Back 5

Contains folds, and thus allows for maximum absorption along tract. May be stratified squamous as in the oral cavity, pharynx and oesophagus. Or may be simple columar as in the stomach, small intestines and most portions of the large intestine

Front 6

lamina Propria?

Back 6

Contains loose connective tissues, blood vessels, lymphatic vessels, smooth muscle cells, muscularis mucosae

Front 7

Describe the submucosa

Back 7

Lies below the mucosa. Contains dense connective tissue, lymphatic and blood vessels and submucosa plexus

Front 8

Muscularis externa

Back 8

Layer beneath submucosa, contains smooth muscles layers (longitudinal, oblique and circular). Responsible for movement along tract and muscle contract causes peristalsis as segmentation. Myenteric plexus lies between the circular and longitudinal layer.

Front 9

Serosa?

Back 9

Outermost layer. Not found in the oral cavity, pharynx, oesophagus or rectum. Has dense collagen fibers which attaches adjacted structures the digestive tract.

Front 10

Purpose of the Oral cavity?

Back 10

1) Analysis of material before swallowing
2) mechanical processing
3) First site of digestion for carbs
4)lubrication with mucous and saliva

Front 11

What are the various salivary glands and what do the produce?

Back 11

Parotid- salivary amylase (serous cells)
Sublingual- mucous cells
Submandibular- salivary amylase, buffers and mucins

Front 12

List six functions of saliva?

Back 12

1) Moistening food
2) Ease of swallowing
3) Digestion (carbs)
4) Moistens oral cavity
5) Aids in tasting
6) Helps maintain calcium phosphate matrix of teeth

Front 13

Four major components of saliva?

Back 13

Mucous
Lingual amylase
Lingual lipase
Alkaline electrolyte solution,
Minor- Thicyanates, lysozymes, antibodies

Front 14

Times saliva is produced

Back 14

1) When chewing gum
2) Smell or anticipation of food
3) Irritating stimuli in oesophagus, stomach and intestines
4) PNS stimulation

Front 15

What are the phases of swallowing?

Back 15

1) Oral phase
2) Pharyngeal
3) Oesophageal

Front 16

Describe the oral phase

Back 16

This is a voluntary phase. Hard palate compresses food and tongue pushes it to the oropharynx, while soft palate becomes elevated.

Front 17

The pharyngeal phase?

Back 17

-Bolus enter pharynx
-Bolus stimulates tactile receptors on uvula and palatal arches
-swallowing center of medulla oblongata recieves information
-Pharyngeal muscles stimulated to contract
-Larynx elevated
-Respiratory center are inhibited

Front 18

Esophageal phase

Back 18

-Bolus enter esophagus
-Peristalsis occurs, pushing bolus to stomach
-LES contracts
-Bolus enter stomach