Digestive Lab: Identifying Alimentary Canal Organs

where does food enter from

the oral cavity / the mouth

what is included in the oral cavity?

gums, teeth, tongue, & openins of the ducts of the salivary glands

what is the function of the lips (labia)?

protect the anterior opening called the oral orifice

what is the hard palate?

anterior portion of the palate; palatine processes of the maxillae & horizontal plates of the palatine bones underlie it

what is the soft palate

posterior portion of the palate; fibromuscular structure that is unsupported by bone

what is the uvula?

a fingerlike projection of the soft palate

extends inferiorly from its posterior margin

what is the tongue?

the floor of the oral cavity; largely supported by mylohyoid muscle & attatches to the hyoid bone, mandible, styloid processes, & pharynx

where are palatine tonsils

on each side of the mouth @ its posterior ends; lie in a concave area bounded anteriorly & posteriorly by membranes (palatoglossal arch & palatopharyngeal arch)

what are palatine tonsils

masses of lymphoid tissue

where are the lingual tonsil

covers the base of the toungue, posterior to the oral cavity priper

why are tonsils important

are a part of the body’s defense system

what is tonsillitis?

when the palatine tonsils become inflamed & enlarged, partially blocking the entrance to the pharynx posteriorly & making swallowing difficult & painful

what are the three divisions of the pharynx?

nasopharynx, oropharynx, & laryngopharynx

where is each subdivision located?

nasopharynx - behind the nasal cavity

oropharynx - behind the oral cavity, extending from the soft palate to the epiglottis

laryngopharynx - behind the larynx, extending from the epiglottis to the base of the larynx

what does the esophagus do?

a food passageway that conducts food to the stomach in a wavelike peristaltic motion

(has no digestive or absorptive function, it just moves the food)

what is a mesentary

a general term that refers to a double layer of peritoneum (a sheet of two serous membranes fused together) that extends from the digestive organs to the body wall

what are the two mesenteries?

greater omentum & lesser omentum

lesser omentum

extends from the liver to the lesser curvature of the stomach

greater omentum

extends from the greater curvature of the stomach, reflects downward, & covers most of the abdominal organs in an apronlike fashion.

what do gastric glands do?

secrete hydrochloric acid (HCl) & hydrolytic enzymes

what layer are gastric glands found in?

mucosa

what is the function of the stomach?

temporary storage region for food

site for mechaniclal & chemical breakdown of food

where does most digestive activity occur?

the pyloric part of the stomach

what the hell is chyme?!

food after it’s processed in the stomach becomes a creamy mass

what is the general function of the oral cavity, teeth, & tongue? is it a major subdivision or accessory organ?

• mechanical processing

• moistening

• mixing with salivary secretions

major subdivision of the digestive tract

what is the general function of the pharynx? is it a major subdivision or accessory organ?

• muscular propulsion of materials into the esophagus

major subdivision of the digestive tract

what is the general function of the esophagus? is it a major subdivision or accessory organ?

• chemical breakdown of materials by acid & enzymes; mechanical processing through muscular contractions

major subdivision of the digestive tract

what is the general function of the small intestine? is it a major subdivision or accessory organ?

• enzymatic digestion & absorption of water, organic substrates, vitamins, & ions

major subdivision of the digestive tract

what is the general function of the large intestine? is it a major subdivision or accessory organ?

• dehydration & compaction of indigestible materials in preparation for elimination

major subdivision of the digestive tract

what is the general function of salivary glands? is it a major subdivision or accessory organ?

• secretion of lubricating fluid containing enzymes that break down carbohydrates

accessory organ of the digestive system

what is the general function of the liver? is it a major subdivision or accessory organ?

• secretion of bile (important for lipid digestion)

• storage of nutrients

• many other vital functions

accessory organ of the digestive system

what is the general function of the gallbladder?

• storage & concentration of bile

accessory organ of the digestive system

what is the general function of the pancreas?

• exocrine cells secrete buffers & digestive enzymes

• endocrine cells secrete hormones

accessory organ of the digestive system

what happens by the time chyme reaches the large intestine

all nutrients have already been absorbed

what are the main functions of the large intestine

1. consolidate & propel unusable fecal matter towards an*s

2. absorb water

3. absorption of vitamins such as B & K which are produced by gut bacteria

identify the parts of the colon

ascending colon, descending colon, *FINISH THIS LATER