BIOL 2302 Exam 4 Review Kasparian

The tube that runs through the entire body from mouth to anus is called the....

alimentary canal

What are the four functions of the digestive system?

Ingestion

Digestion

Absorption

Elimination

This layer of the alimentary canal is the most superficial lined with epithelium, a lamina propria and muscular layer.

mucosa

This layer consists of exocrine glands, blood vessels and nerve endings

submucosa

This layer consists of a circular and longitudinal layer of smooth muscle.

Muscularis externa

This layer consists of a layer continuous with the tissue that lines the body cavity that is the deepest layer of the alimentary canal.

Serosa

The anterior opening of the oral cavity is the....

mouth

Posterior opening to the oropharynx is called...

fauces

What tissue lines the oral cavity? What advantage does this tissue have that benefits the oral cavity?

non-keratinized stratified squamous epithelium; resists abrasion of food

Which functions of the digestive system occur at the oral cavity?

ingestion - take in of food

digestion - break down of starch by amylase enzyme in saliva

Which skeletal muscles are found at the lips and cheeks that assist in chewing and speech production?

Lips: orbicularis oris

Cheeks: Buccinators

The area bound by lips and cheeks externally and teeth and gums internally is called...

vestibule

The median fold that joints the internal aspect of each lip to gums is called....

labial frenulum

The part of the oral cavity underlain by the palatine bone and palatine process that assist in chewing is.....

hard palate

The mobile fold of skeletal muscle that closes off the nasopharynx during swallowing is called

soft palate

The soft palate projection that projects downward into oropharynx is called...

uvula

The organ in the oral cavity that grips and repositions food during chewing, mixes food with saliva, forms bolus, and initiates swallowing and forms speech sounds is called the....

tongue

These muscles alter the shape of the tongue to form sounds and more precise repositioning of food

intrinsic muscles

These muscles alter the tongues position in the oral cavity

extrinsic muscles

The structure under the tongue that secures tongue to the floor of the oral cavity is called...

lingual frenulum

The type of papillae that gives the tongue its roughness to provide friction is called....

filiform

The type of papillae that are scattered over the tongue and gives it a reddish hue are....

fungiform

This type of papillae forms a V-shaped row in the back of the tongue

Circumvallate

Which structure on the tongue divides the tongue between the 2/3 in the oral cavity and the remaining third in the oropharynx?

sulcus terminalis

What is the function of the salivary glands?

secretion of saliva

What are the four roles of saliva in digestion and maintaining the oral cavity?

1) cleansing mouth of bacteria

2) Moisten and dissolve food chemicals

3) aid in bolus formation

4) Amylase enzyme to break down starch

What are the three extrinsic salivary glands?

1) Parotid

2) Submandibular

3) Sublingual

Which extrinsic salivary gland is located anterior to the ear between master muscles that excretes saliva into the vestibule?

Parotid gland

Which extrinsic salivary gland lies in the medial aspect of mandibular body and excretes saliva at the base of lingual frenulum?

Submandibular gland

Which extrinsic salivary gland lies anterior to the submandibular gland under the tongue with 10-12 ducts that open to the floor of the mouth?

Sublingual gland

Salivary glands scattered throughout the oral mucosa that maintain the moist environment of the oral mucosa are....

intrinsic salivary glands

Saliva is made mostly of....

water (97-99%)

What are some other chemical properties of saliva?

-Hypo-osmotic

- slightly acidic

What electrolytes are found in saliva?

Sodium, Potassium, Chlorine, Phosphate, Bicarbonate

What proteins are found in saliva?

- mucin (eventually converted to mucus)

- lysozyme and defensins (immune proteins)

- IgA (Antibody found in mucus and saliva)

What metabolic wastes are surprisingly found in saliva?

Uric acid and urea

Extrinsic salivary glands respond what type of stimuli?

- ingested food (chemo and mechanoreceptors)

- thought of food (Psychological)

Which division of the nervous system stimulate the intrinsic salivary glands?

parasympathetic nervous system

Strong sympathetic stimulation causes which condition in the oral cavity?

dry mouth

- inhibition of salivation during sympathetic state

What calcified structures are responsible for carrying out the physical digestion of food particles through mastication?

teeth

Animals that have teeth of different shapes and serve different functions are known as....

heterodonts

Chisel shaped teeth that function in cutting and nipping at food are....

incisors

fanglike teeth that tear and pierce food are...

canines

The majority of teeth are crown shaped teeth that are best suited for grinding and crushing food are called...

premolar/molars

Primary (baby) teeth consists of how many teeth and at what age do they emerge?

- 20 teeth

- 6-24 months

Permanent teeth consists of how many teeth and at which age do they emerge?

-32 teeth

- 6 years - end of adolescence

What is the primary teeth dental formula?

2I, 1C, 2M x 4

What is the permanent teeth dental formula?

2I, 1C, 2PM, 3M x 4

What is the difference between the root and the crown?

Crown - located above the gingiva

Root - embedded in the jawbone

The brittle material composed of calcium salts and hydroxyapatite crystals surrounding the tooth is called...

enamel

The calcified connective tissue that connects the enamel to the periodontal ligament is....

cementum

The connective tissue that anchors the tooth in the alveolus of the jaw and form the gomphosis fibrous going between tooth and mandible is called...

periodontal ligament

The bonelike material found deep to the enamel that forms the structural base of the tooth is called...

dentin

The connective tissue, blood vessels and nerves found at the center of the tooth in a cavity is called...

pulp

gradual demineralization of enamel and dentin by bacterial injection is called...

dental caries (cavities)

The film of sugar, bacterial and other debris that adheres to enamel is called...

Plaque

What causes caries?

acid produced by bacteria in plaque that dissolves the calcium salts in the enamel

Why are caries dangerous to teeth?

Salivary enzymes can break down the organic matter found deeper in the tooth

What substance forms when plaque calcifies?

tartar

When tartar forms, it creases space between gingiva and teeth which can lead to what disease?

gingivitis

Which dental disease results from autoimmune response to attack bacteria around teeth that create caries of their own?

peridontitis

What tissue lines the pharynx?

Statified squamous epithelium with increased concentration of mucus glands

Is the muscle of the pharynx smooth or skeletal?

skeletal

What muscular tube extends from the laryngopharynx to the stomach?

esophagus

How does the esophagus fold when food is absent?

longitudinal

What are the two phases of deglutition?

1) Buccal Phase

2) Pharyngeal-esophageal phase

What phase is characterized by the bolus forced into the oropharynx?

buccal phase

What phase is characterized by the beginning of peristalsis to move food through the esophagus and the trachea and nasopharynx are sealed off?

Pharyngeal-esophageal phase

What parts of the brain control the Pharyngeal-esophageal phase?

Medulla and lower pons

What organ is the main contributor for chemical breakdown of proteins where food is converted to chyme?

Stomach

The superior part of the stomach connected to the esophagus is known as the....

cardiac region

The dome-shaped region of the stomach just beneath the diaphragm is called the....

fundus

The mid portion of the stomach is called the....

body

The region where the duodenum and the stomach come together is called the...

pylorus

Flow from the stomach to the duodenum is controlled by the.....

pyloric sphincter

The convex extent on the lateral surface of the stomach is known as the...

greater curvature

The concave extent on the medial surface of the stomach is known as....

lesser curvature

The part of the stomach that runs from the liver to the lesser curvature is called the....

lesser omentum

The part of the stomach that drapes inferiorly from the greater curvature to the small intestine is called the....

greater momentum

Which nervous system innervates the stomach?

autonomic nervous system, or enteric nervous system

How is the muscularis of the stomach different from the rest of the alimentary canal?

it has an additional oblique layer for greater breakdown of food

Goblet cells of the stomach secrete what substance that lines the stomach?

bicarbonate mucus

The mucus surface of the stomach traps a bicarbonate rich fluid along the stomach wall for what reason?

to act as a buffer to the extreme acidic gastric juices produced by gastric pits of the stomach

The gastric glands that secrete gastric juice, mucus and gastrin are contained in...

gastric pits

What are three mechanisms the stomach utilizes to protect itself from acidic gastric juices?

1) Bicarbonate mucus coat

2) tight junctions in the epithelium

3) HCl impermeability

Gastric glands are located in which regions of the stomach?

Fundus and body

Mucous neck cells secrete....

acid mucus

Parietal cells secrete...

HCl

Chief cells secrete...

pepsinogen

Enteroendocrine cells secrete....

everything else (gastrin, histamine, endorphin, serotonin, Cholecystokinin, and somatostatin)

Pepsinogen is converted to its activated form Pepsin by what mechanism?

initially the presence of HCl in the stomach then by positive feedback when pepsin is finally present in low concentration

What phase of gastric regulation occurs prior to food ingestion?

Cephalic phase

What are the excitatory stimuli of the cephalic phase?

- sight or thought of food

- taste/smell receptors

What are the inhibitory stimuli of the cephalic phase?

- depression or loss of appetite

- decreased stimulation of the parasympathetic division due to sympathetic take over

What phase of gastric regulation begins when food enters the cardiac region of the stomach?

Gastric phase

What phase of gastric regulation occurs when partially digested food enters the duodenum

Intestinal phase

What are the excitatory stimuli of the gastric phase?

1) Stomach distension

2) activation of stretch receptors

3) activation fo chemoreceptors by peptides, caffeine and rising pH

4) release of gastrin from Enteroendocrine cells to the blood

What are the inhibitory stimuli of the gastric phase?

1) pH < 2

2) Limbic System take over due to emotionally upset that overrides the parasympathetic system

What is the excitatory stimuli of the intestinal phase?

1) low pH

What are the inhibitory stimuli of the intestinal phase?

1) distension of the duodenum

2) presence of fatty, acidic or hypertonic chyme

3) presence of irritants