Digestion and Reproduction Vocabulary

Flashcards covering vocabulary from lecture notes on digestion and reproduction.

Renal compensation

Adjustment of pH by changing the rate of H+ secretion by the renal tubules.

Digestive System

Organ system that processes food, extracts nutrients, and eliminates residue in five stages: ingestion, digestion, absorption, compaction, and defecation.

Ingestion

Selective intake of food.

Digestion

Mechanical and chemical breakdown of food into a usable form.

Absorption

Uptake of nutrient molecules into the body’s tissues.

Compaction

Absorbing water and consolidating indigestible residue into feces.

Defecation

Elimination of feces.

Digestive Tract (Alimentary Canal)

Muscular tube extending from mouth to anus; includes mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

Accessory Organs of the Digestive System

Teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

Mucosa (Mucous Membrane)

Inner lining of the digestive tract, consisting of epithelium, lamina propria, and muscularis mucosae.

Lamina Propria

Loose connective tissue layer in the mucosa.

Muscularis Mucosae

Thin layer of smooth muscle in the mucosa.

Submucosa

Thicker layer of loose connective tissue containing blood vessels, lymphatics, and a nerve plexus.

Muscularis Externa

Two layers of muscle near the outer surface responsible for motility.

Serosa

Thin layer of areolar tissue topped by simple squamous mesothelium.

Adventitia

Fibrous connective tissue layer surrounding the pharynx, most of the esophagus, and the rectum.

Mouth

Also known as the oral or buccal cavity, involved in ingestion, taste, mastication, chemical digestion, swallowing, speech, and respiration.

Lingual Papillae

Bumps and projections on the tongue's surface, the site of most taste buds.

Pharynx

Muscular funnel connecting the oral cavity to the esophagus and the nasal cavity to the larynx.

Lower Esophageal Sphincter (LES)

Constriction that prevents stomach contents from regurgitating into the esophagus.

Intrinsic (Minor) Salivary Glands

Small glands dispersed amid oral tissues, secreting relatively thick saliva.

Extrinsic (Major) Salivary Glands

Three pairs of larger, discrete organs located outside of the oral mucosa.

Serous Cells Secretion

Watery fluid rich in enzymes and electrolytes.

Parotid Glands

Glands lying just beneath the skin anterior to the earlobes.

Submandibular Glands

Glands located halfway along the body of the mandible, medial to its margin.

Sublingual Glands

Glands in the floor of the mouth.

Saliva

Moistens and cleanses the mouth, inhibits bacterial growth, dissolves molecules, digests starch and fat, and makes swallowing easier.

Lysozyme

Enzyme that kills bacteria found in saliva.

Salivary Amylase

Enzyme that begins starch digestion in the mouth found in saliva.

Lingual Lipase

Enzyme that begins fat digestion in the mouth found in saliva.

3 types of teeth

Incisors
Canines
Premolars and Molars

Incisors

Anterior, chisel-like cutting teeth.

Canines

More pointed teeth used to puncture and shred food.

Premolars and Molars

Teeth with broad, lumpy surfaces adapted for crushing, shredding, and grinding.

Crown (Tooth)

Portion of the tooth above the gum attachment.

Root (Tooth)

Portion of the tooth below the gum, embedded in alveolar bone.

Dentin

Hard yellowish tissue that makes up most of the tooth.

Enamel

Tissue that covers dentin in the crown of the tooth.

Cement

Tissue that covers dentin in the root of the tooth.

Apical Foramen

Pore at the basal end of each root canal where nerves and vessels enter the tooth.

Swallowing (Deglutition)

Complex action involving over 22 muscles in the mouth, pharynx, and esophagus.

Swallowing Center

A pair of nuclei in the medulla oblongata that coordinates swallowing.

Peristalsis

Wave of involuntary contractions that propels food through the esophagus.

Cardiac Part (Stomach)

Small area within about 3 cm of the cardiac orifice in stomach.

Fundic Region (Fundus) (Stomach)

Dome superior to the esophageal attachment in stomach.

Body (Stomach)

Greatest part distal to the cardiac orifice in stomach.

Pyloric Part (Stomach)

Slightly narrower pouch at the inferior end of the stomach, subdivided into the antrum and pyloric canal.

Pylorus

Narrow passage into the duodenum.

Pyloric Sphincter

Ring of smooth muscle that regulates the passage of chyme into the duodenum.

Gastric Rugae

Longitudinal wrinkles formed as the stomach empties.

Gastric Pits

Depressions in the gastric mucosa lined with columnar epithelium.

Cardiac and Pyloric Glands

Glands mainly secreting mucus found in the stomach.

Gastric Glands

Glands producing acid and enzymes in the stomach.

Mucous Cells (Stomach)

Cells secreting mucus, predominate in the cardiac and pyloric glands in stomach.

Regenerative (Stem) Cells (Stomach)

Stem cells producing new cells in the base of the pit and neck of the gland.

Parietal Cells (Stomach)

Cells secreting hydrochloric acid, intrinsic factor, and ghrelin in the stomach.

Chief Cells (Stomach)

Enzymes secreting gastric lipase and pepsinogen in the stomach.

Enteroendocrine Cells (Stomach)

Cells secreting hormones and paracrine messengers in the stomach.

Zymogens

Inactive proteins secreted as digestive enzymes that are converted to active enzymes.

Hydrochloric Acid (in Pepsin Activation)

Enzyme that activates pepsin.

Autocatalytic Effect (of Pepsin)

Effect where pepsin converts pepsinogen into more pepsin.

Intrinsic Factor

Glycoprotein essential for the absorption of vitamin B12 by the small intestine.

Gut-Brain Peptides

Peptides produced in both the digestive tract and the central nervous system.

Carbonic Anhydrase (CAH)

Enzyme which catalyzes the first step in the reaction for HCL production.

Cephalic Phase (Gastric Activity)

Stage where the stomach responds to the sight, smell, taste, or thought of food.

Gastric Phase (Gastric Activity)

Phase where swallowed food activates gastric secretion and motility.

Intestinal Phase (Gastric Activity)

Phase that begins when chyme starts arriving in the duodenum.

Liver

Gland that secretes bile, which contributes to digestion.

Hepatic Lobules

Cylinders filling the interior of the liver.

Hepatocytes

Cuboidal cells radiating from the central vein of the liver.

Hepatic Sinusoids

Blood-filled channels between plates of hepatocytes.

Stellate Macrophages

Phagocytic cells removing bacteria and debris from the blood in the liver.

Bile Canaliculi

Narrow channels between hepatocytes where bile is secreted.

Gallbladder

Pear-shaped sac storing and concentrating bile.

Bilirubin

Principal bile pigment derived from the decomposition of hemoglobin.

Urobilinogen

Colorless product metabolized from bilirubin by bacteria.

Stercobilin

From this, feces get their brown color.

Bile Acids (Bile Salts)

Steroids synthesized from cholesterol, aiding in fat digestion.

Pancreas

Flattened, spongy gland pressed between the body wall and the greater curvature of the stomach.

Pancreatic Islets

Endocrine part of the pancreas.

Pancreatic Exocrine Tissue

Exocrine tissue secreting pancreatic juice.

Enteropeptidase

Enzyme that activated trypsin from trypsinogen.

Duodenum

Part of the small intestine that receives the stomach contents, pancreatic juice, and bile.

Jejunum

Where most digestion and nutrient absorption occur in the small intestine.

Ileum

Region of the small intestine with prominent lymphoid nodules.

Ileocecal Junction

Junction where the ileum joins the cecum of the large intestine.

Villi, Microvilli, Plicae Circulares

Three structures used to increase the absorptive surface area of the small intestine.

Villi

Cells covered with two kinds of epithelial cells: columnar enterocytes and mucus-secreting goblet cells.

Brush Border Enzymes

Enzymes that carry out some of the final stages of chemical digestion.

Plicae circulares

Circular or spiral ridges of the mucosa and submucosa that increases surface area and slows moment of chyme

Salivary Amylase

Breaks starch down into shorter segments (oligosaccharides).

Proteases (Peptidases)

Enzymes that digest proteins.

Lipases

Enzyme that helps in the digestion of fats.

Emulsifies

Breaks the fat up into small droplets dispersed through the watery chyme.

Cecum (Large Intestine)

Blind pouch in the lower right abdominal quadrant.

Colon

Region between the ileocecal junction and rectum.

Ascending, Transverse, and Descending Colons

Parts of the colon that form a squarish, three-sided frame around the small intestine

Sigmoid Colon

S-shaped portion of the large intestine in the pelvic cavity.

Anal Canal

Final 3 cm of the large intestine.

Anal Columns

Longitudinal ridges in the anal canal.