bio 126 lec - digestive system

salivary glands, tongue, liver, gallbladder, pancreas

examples of accessory organs

mucosa > submucosa > muscularis > serosa

4 main layers of the alimentary tract from innermost to outermost are

lumen

hollow inside that makes contact with the food digested

stratified squamous epithelial cells

type of epithelial cells present in the mouth, pharynx, and upper portion of the esophagus

simple columnar epithelial cells

type of epithelial cells present in the stomach and small intestine

simple columnar epithelial cells

these epithelial cells are responsible for facilitating the absorption of nutrients, particularly in the small intestine

lamina propria

contain lymphatic tissues which can alert immune response incase a pathogen is present

muscularis mucosae

muscle that is found in the mucosa which increases surface area during digestion

epithelium, lamina propria, muscularis mucosae

structures present in the mucosa

submucosa

layer of GI tract where glands are located

submucosal plexus

networks of nerves and blood vessels which is in charge for the secretion of digestive juices

muscularis

in charge for the motility/movement of the digestive food throughout the GI tract; layer of the GI tract where different kinds of muscles are found

circular and longitudinal muscles

kinds of muscles found in the muscularis layer

myenteric plexus

found in the muscularis layer that is responsible for the peristaltic movement of the bowels

serosa

mainly made up of areolar connective tissue and epithelium

areolar connective tissue

type of tissue present in the serosa

adventitia

serosa is modified into what structure?

adventitia

is a network of collagen fibers that is the outermost layer of the wall of a blood vessel

peritoneum

a membranous sac that protects our abdominal organs; the lining of abdominal organs

parietal peritoneum

part of the membranous sac which is lining the abdominal tract

visceral peritoneum

part of the membranous sac which is lining the abdominal cortex

peritoneal cavity

in between the parietal and visceral peritoneum is

peritoneal fluid

fluid that lubricates the two peritoneal layers

intraperitoneal

refers to the structures surrounded by the peritoneum

retroperitoneal

refers to the structures outside the peritoneum

pancreas, kidney, duodenum

examples of retroperitoneal structures

in the mouth

ingestion only occurs where?

mouth

the digestive process starts with what structure

propulsion

movement of digested food in the GI tract

TRUE

T OR F: propulsion includes deglutition and peristalsis

deglutition

movement of the oropharynx

enzymes

chemical digestion is mostly due to the process of?

absorption

activity that mainly happens in the small intestine

mechanical digestion

activity that occurs in the mouth and the small intestine

inferior and superior labial frenulum

the lips are attached to the gums via what structures?

gingiva

also called as the gums

hard palate

bony structure that serve as a wall between the nasal cavity and the molar cavity

soft palate

poster to the hard palate which is made up of muscle and includes the uvula

lips

muscular, thin epithelium layer (gives it its pinkish color)

false

T or F: the tongue is NOT a muscular structure

ectoderm

the teeth originated from what germ layer?

baby teeth and permanent teeth

the two sets of dentition throughout life are

6 months

age when teeth first appear

20

total number of a complete set of baby teeth is

32

total number of a complete set of permanent teeth is

incisors > cuspid/canine > molars

order of appearance of baby teeth:

maxilla and mandible

for babies, the permanent teeth are first embedded where?

8, 4, 8

enumerate the total number of each tooth (arranged incisors, cuspids, and molars) present in a baby

8, 4, 8, 12

enumerate the total number of each tooth (arranged incisors, cuspids, premolars, and molars) present in an adult

incisors

teeth responsible for the initial bite

canines/cuspids

teeth responsible for piercing meat and food

premolars and molars

teeth responsible for chewing or mastication

3rd molar

the tooth referred to as the wisdom tooth

crown, neck, root

3 main parts of the tooth are

crown

part of the teeth that is not lined with the gums

neck

the region of the tooth that is at the gum line, between the root and the crown

root

part of the tooth that is below the gums; longest

enamel

coats the teeth and protects them from damage

cavities

caused by bacteria that eats the remaining sugars present in the teeth

dentin

 a layer of material that lies immediately underneath the enamel of the tooth

pulp cavity

contains blood vessels or nerves that connects to the root canal

periodontal ligament and cementum

keeps the teeth in place so it is stable in its socket

papilla

projections in the tongue

filiform

papilla that has no taste buds but can sense temperature, texture, and pain

fungiform, foliate, circumvallate

papillae that have taste buds

filiform

most abundant papilla

mouth

structure that helps in mastication and the forming of the bolus to be transported down the esophagus

parotid, sublingual, submandibular

3 salivary glands are

parotid salivary gland

salivary gland affected when we get mumps

saliva

helps keep oral cavity moist especially during mastication

true

T or F: even when we sleep we still produce saliva

6

total number of salivary glands in the mouth

mastication

the rhythmic, voluntary movement made possible by skeletal muscles

masseters and temporalis muscles

skeletal muscles responsible for mastication

brainstem

the mastication center in the brain

midbrain, pons, medulla

brainstem is composed of?

deglutition

is the upper movement of the larynx and pharynx that causes the epiglottis to go down

false (both voluntary and involuntary)

T or F: deglutition is only involuntary

buccal, pharyngeal-esophageal phase part 1, pharyngeal-esophageal phase part 2

3 phases of deglutition are:

buccal phase

voluntary phase of deglutition wherein food is still in the mouth

pharyngeal muscles

buccal phase contains what muscle that facilitates movement of bolus from the mouth towards the oropharynx?

pharyngeal-esophageal phase part 1

involuntary phase of deglutition that moves bolus from the oropharynx to the upper esophagus

pharyngeal-esophageal phase part 2

involuntary phase of deglutition that moves bolus further down the esophagus; where peristalsis starts

upper and lower esophageal sphincters

acts as a valve that opens and closes that permits passage of food to the esophagus

esophagus

connects the mouth or oral cavity to the stomach

relaxed

the sphincter is _____ when it allows the passage of food

contracted

the sphincter is _____ when it disables the passage of food

peristalsis

contracting and relaxing movement that allows food to move throughout the GI tract (lower esophagus downwards)

muscularis layer, circular, and longitudinal muscles

structures responsible for the continuous relaxing and contracting of food throughout the GI tract

circular muscle

muscle responsible for the pinching movement of the GI tract

longitudinal muscle

muscle that contracts ahead of the bolus; move the bolus throughout the GI tract

true

T or F: peristalsis is NOT reliant on gravity

unidirectional

peristalsis exhibits unidirectional or bidirectional movement?

oblique layer

structure in the muscularis layer that is only unique to the stomach

oblique layer

helps in the churning action happening in the stomach

lesser curvature

where lesser omentum is attached

greater curvature

where greater omentum is attached

pyloric sphincter

allows passage of food from stomach towards the duodenum

fist

the stomach is about the size of a?

rugae

folds of the stomach that are only prominent when the stomach is empty