Digestive function

Mechanical digestion is what

food breakdown by physical forces

examples of mechanical digestion

mixing food in the mouth by the tongue, churning food in stomach, segmentation in the small intestine

purpose of mechanical digestion

prepares food for further degradation by enzymes

what is chemical digestion

enzymes breakdown food molecules into their building blocks

carbohydrates are broke into simple sugars by which enzymes

amylase, lactase, fructase

proteins are broken to amino acids by proteases such as

trypsin

fats are broken to fatty acids and glycerol alcohols by

lipases

Organs of the alimentary canal

mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

accessory organs of the digestive system

salivary glands, teeth, pancreas, liver, gallbladder

salivary gland purpose

secretion of lubricating fluid containing enzymes that break down carbohydrates

pharynx purpose

pharyngeal muscles propel materials into the esophagus

esophagus porpuse

transport of materials to the stomach

stomach purpose

chemical breakdown of materials via acid and enzymes and mechanical breakdown through muscular contractions

pancreas purpose

exocrine cells secrete buffers and enzymes, endocrine cells secrete hormones

small intestine function

enzymatic digestion and absorption of nutrients, breaks down food wiht checmical and mechanical

oral cavity purpose, teeth tongue

mechanical processing moistening, mixing with salivary secretions.

Liver function

secretions of bile(lipid digestion), storage of nutrients

gallbladder function

storage and concentration of bile

large intestine function

water absorption, and compacting of indigestible material for elimination.

Mucosa layer of alimentary canals, consists of?

innermost moist membrane, made of surface epithelium, CT, smooth muscle layer

submucosa layer of alimentary canal

beneath mucosa, CT with blood vessles nerves and lymphatics.

Muscularis externa layer of alimentary canal

circular and outer longitudinal layer of smooth muscle

serosa layer of alimentary canal

outermost layer of wall containing fluid producing cells.

visceral peritoneum of serosa layer of alimentary canal

innermost layer that wraps the canal organs.

parietal peritoneum of the serosa layer of alimentary canal

Outer layer of wall that lines the abdominopelvic cavity.

Smooth muscle movement rhythem caused by what

pacemaker cells

peristalsis is

waves that move a bolus

segmentation is

churns and fragments a bolus

Lips of the oral cavity

protects the anterior opening

uvula function of oral cavity

fleshy projection of the soft palate, for speech and directs food.

hard palate of oral cavity

forms the anterior roof

soft palate of oral cavity

soft palate forms the posterior roof.

What salivary glands empty secretions into mouth.

parotid, submandibular, sublingual glands

what is saliva made of and purpose

mucus and serous fluid, contains amylase, helps form a bolus

first phase of deglutition or swallowing

The upper esophageal sphincter is contracted, the toungue presses against the hard palate forcing the food into the oropharynx.

second phase of deglutition or swallowing

vulva and larynx rise to prevent food from entering the respiratory passagways, upper esophegeal spchinter relaxes, tongue blocks off the mouth.

Third phase of deglutition or swallowing

pharynx constrictor muscles contract, forces food into th eesophagus, the upper esophageal sphincter contracts after food enters.

esophagus located

runs from pharynx to stomach through the diaphragm

purpose of esophagus

conducts food by peristalsis, only food passageway

pharynx and esophagus activites

no chemical digestion, serve as passageway to the stomach.