Mouth, Esophagus, Stomach Vocabulary Flores

Alimentary canal

Tube through which food passes in the digestive system. Starts at the mouth and ends at the anus

Ingestion

Taking in a substance through the mouth

Propulsion

Action of pushing forward

Mechanical digestion

Physically breaking food up into smaller pieces

Chemical digestion

Breaking food up into smaller pieces through the use of enzymes and other digestive juices

Absorption

uptake of a substance by a tissue (like the uptake of nutrients by the small intestine)

Defecation

to void excrement from the intestines through the anus

Cephalic phase

thinking about, smelling, or seeing food which has not entered the alimentary canal; when food is in the mouth

Gastric phase

Period in digestion when food is in the stomach

Intestinal phase

Period in digestion when food is in the small intestine

Mucosa

most superficial layer of the 4 layers of the alimentary canal

Epithelium (mucous membrane)

Most superficial of the 3 layers of the mucosa.

Lamina propria

middle layer of mucosa; made of connective tissue, contains blood vessels & lymph vessels

Muscularis mucosa

deepest layer of mucosa; thin muscular layer

Submucosa

made of dense connective tissue, blood vessels, and lymph vessels; contains glands that release digestive secretions & submucosal plexus

Muscularis

made of 2 layers of muscle, the circular and longitudinal layers; innervated my myenteric plexus

Serosa

Deepest layer; made of areolar connective tissue and epithelium; called the adventitia in the esophagus

Mouth

oral (buccal) cavity

Lips

labia; highly vascularized, thin layer of keratin

Superior & inferior labial frenulum

connect lips to gums

Hard palate

Anterior region of the roof of the mouth; separates mouth and nasal cavity; rigid shelf to push food against w/tongue

Soft palate

made of skeletal muscle; manipulated when we yawn, swallow, sing; moves up w/uvula to keep food out of nasal cavity when we swallow

Bolus

Ball of food, saliva, and mucus that is swallowed

Tongue

Strong muscle; helps mechanically and chemically digest food; involved in taste and touch reception as well; positions bolus for swallowing

Papillae

extensions of lamina propria on surface of tongue; contain taste buds or touch receptors

Lingual glands

produce lingual lipase

Lingual lipase

Helps digest fats; activated in stomach

Lingual frenulum

attacks tongue to floor of mouth

Ankyloglossia

Tongue tied; lingual frenulum is short or malformed

Saliva

95.5% water, 4.5% mucus, ions, enzymes, waste; moistens food & begins chemical digestion of carbs

Salivary amylase

enzyme in saliva that begins chemical digestion of carbohydrates; deactivated by acid in stomach when it is swallowed

Lysozyme

antibacterial enzyme in saliva

Parotid glands

salivary glands between masseter & ear; makes watery saliva w/salivary amylase & little to no mucus

Submandibular glands

salivary glands below the jaw; produce saliva w/more mucus than parotid glands do & makes salivary amylase

Sublingual glands

salivary glands below the tongue; produce saliva w/lots of mucus and very little salivary amylase

Deciduous teeth

Teeth that fall out; 20 of them

Permanent teeth

32; 8 incisors, 4 cuspids (canines), 8 premolars, 12 molars (3rd pair are wisdom teeth)

Gingivae (gums)

soft tissue surrounding teeth sockets & necks of teeth

Crown

Part of tooth above the gumline

Root

Part of tooth below the gumline

Pulp cavity

found in crown & root, contains nerves and blood vessels

Dentin

bone-like tissue covering pulp cavity

Cementum

harder bone-like layer covering dentin below the gumline; connects tooth to jaw bone

Enamel

outer layer covering dentin in the crown; hardest substance in the body

Pharynx (throat)

receives food and air from mouth; receives air from nasal cavity

Nasopharynx

involved in breathing only; opening from nasal cavity into back of oral cavity

Oropharynx

Part of pharynx at posterior end of the oral cavity; involved in breathing & swallowing

Laryngopharynx

Most inferior portion of pharynx; involved in breathing & swallowing

Esophagus

Muscular, 10 inch tube that passes through the mediastinum and connects pharynx to stomach

Esophageal hiatus

Opening in diaphragm through which esophagus enters the abdominal cavity

Upper esophageal sphincter

ring of muscle at superior end of esophagus - relaxes to allow food to enter esophagus

Peristalsis

Wavelike contractions of muscle that push bolus toward stomach

Lower esophageal sphincter (cardiac sphincter, gastroesophageal sphincter)

opens to allow food into stomach; when it doesn't close completely the stomach contents reflux = heartburn

Deglutition

Swallowing; 3 phases (voluntary/oral, pharyngeal, esophageal)

Voluntary phase (of deglutition)

tongue pushes bolus to back of oral cavity

Pharyngeal phase (of deglutition)

uvula and soft palate move up to close off nasopharynx; laryngeal muscles close opening into respiratory system; pharyngeal muscles constrict & push food into oropharynx & laryngopharynx; Upper esophageal sphincter relaxes

Medulla oblongata

swallowing center of brainstem

Esophageal phase

peristalsis begins; distention of esophagus near stomach opens cardiac sphincter; food enters stomach

Stomach

J-shaped sac; chemically digests proteins and fats (mainly proteins); mechanically digests all food; Stores food we eat until small intestine is ready to digest it; absorbs alcohol, water, and aspirin

Chyme

Acidic, soupy mixture of partially digested food and digestive juices in the stomach

Cardia

Point where esophagus connects to the stomach

Fundus

Inferior to diaphragm and superior and to the left of the cardia; contains cells that produce Ghrelin

Ghrelin

Hormone that targets the hypothalamus and triggers feeling of hunger

Body

Main part of stomach

Pylorus

Funnel shaped portion of the stomach; connects the stomach to the duodenum

Pyloric antrum

wide end of the pylorus connects to the body of the stomach

Pyloric canal

narrow end of pylorus that connects pylorus to duodenum

Pyloric sphincter

ring of muscle that controls gastric emptying

Greater curvature

convex lateral surface of the stomach

Lesser curvature

concave medial surface of the stomach

Oblique layer

Extra inner layer of muscle in the stomach that allows for more churning of food

Gastric pits

Pits of epithelial lining that open up into gastric glands

Gastric glands

contain cells that secrete digestive juices, enzymes, and hormones

Chief cells

cells in the gastric glands that secrete pepsinogen and gastric lipase

Parietal cells

Secrete HCl and intrinsic factor

G cells

Secrete gastrin

Mucus cells

Secrete mucus

pepsinogen

inactive form of enzyme pepsin; activated into pepsin when it comes into contact with Hal

pepsin

protein digesting enzyme

gastric lipase

helps digest fats

intrinsic factor

stimulates the small intestine to absorb vitamin B12

gastrin

hormone that stimulates gastric glands to secrete and promotes emptying of stomach; produced when we see, smell, or taste food

Mucosal barrier

physical barrier that protects mucosa of stomach from protein digesting enzymes & HCl; also contains bicarbonate ions to neutralize stomach acid